A BEEF SLAUGHTER OPERATION
INTRODUCTION

The video tape was analyzed to determine the potential for upper extremity cumulative trauma disorders (UECTDs), lower extremity cumulative trauma disorders (LECTDs), and low back problems. Cumulative trauma disorders and low back problems are serious conditions. While there is frequently no external sign of a disorder (as with cuts, contusions, etc.) these conditions are painful and can significantly affect both the occupational and non-occupational life of the person exposed. In addition, since they are cumulative disorders, if the task characteristics remain unchanged, the cumulative deterioration of the affected body part will frequently continue until irreversible damage is done. During the video tape analysis it was noted that the forces, repetitions, postures, and lifting tasks filmed had the potential to cause UECTDs and low back pain.

High finger or grip forces, frequent repetition with short rest periods, awkward body posture (flexed and extended wrist, elbow above mid-torso, etc.), and fatigue are factors which are associated with the development of UECTDs. These factors can cause irritation of the tendons, tendon sheathes, and nerves in the arms and hands. When these factors exist simultaneously the hazard is significantly increased. In addition, tendon and nerve irritations can be caused by direct contact of the upper extremities with tools and hard surfaces. Musculoskeletal problems at the shoulder may also result from the excessive shoulder moments generated when loads are lifted or held away from the body.

The development of low back problems is often associated with the magnitude and duration of spinal compressive loads, and frequent repetition of the manual material handling activity. Spinal compressive forces result from the load or force in the hands and the distance that the load is held away from the body. In addition, the potential for low back problems increases substantially when there is torso twisting during the lifting or load movement. Constrained postures during lifts, the handling of bulky loads, and poor contact between the hands and the loads also increases the hazard potential for low back problems. Frequent repetition with short rest, awkward body posture (flexed and extended wrists, elbow above mid-torso, twisted trunk, etc.) and fatigue are all factors which have been associated with the development of cumulative trauma disorders.

Specific hazards observed in the operations are listed along with recommended corrective actions whenever possible. In addition some of the hazards and controls are covered under general abatement strategies.

This report should not be considered a full ergonomic evaluation of the operations observed nor were all hazardous operations necessarily addressed. A full ergonomic evaluation should include the services of a properly trained ergonomist since proper intervention requires a variety of approaches and must be implemented over a period of time. This report discusses only engineering and work practice controls which can be implemented to reduce the potential for musculoskeletal disorders in the operations which were reviewed. These are not the only possible solutions and any solution has to be implemented and evaluated to prove its effectiveness. Employee participation and involvement is necessary to properly design engineering controls to minimize the hazards of UECTD and low back pain.

Not all recommended controls need necessarily be implemented for each employee in the operations evaluated. It is understood that often more than one operator uses these work stations and often operators have alternate jobs which may also contribute to the problems. The appearance of injuries and illness are often dependent on the anthropometry of the employee, the training received by the employee, and the employee's work practices including their rate of work. The recommendations are not all inclusive and a more in-depth study may be required to determine safe operating parameters for particular employees. Other factors which should be included for any program to be effective include employee training and participation in planning, ergonomic abatement committees, supervisor training, hazard analysis, administrative controls, and medical monitoring.

GENERAL ABATEMENT STRATEGIES


A multifaceted abatement program is necessary to properly control hazards leading to cumulative trauma disorders and to properly protect employees. Some elements of an ergonomic abatement program are summarized below.

  1. Engineering and Administrative Controls

    Cumulative trauma disorder hazards can be controlled through proper engineering design of the job, work station, and equipment so the work can be performed independent of specific worker characteristics and techniques. This requires the job be made to fit the worker and not make the worker fit the job.

    Engineering controls attempt to reduce extreme postures, excessive forces and repetitive motions. To be effective, employee input is necessary since improperly designed work stations and controls will not be used if employees believe they interfere with their work. Also, after installation, the effectiveness of the controls must be evaluated and modified if necessary to insure their effectiveness.

    Administrative controls can include but are not limited to: training of new employees in safe work techniques including lifting, working with minimum strain on the body, and minimizing the application of forces with the fingers; job rotation and job enhancement; adequate mandatory rest breaks; implementation of an exercise program.

  2. Consultant Assistance

    A properly trained ergonomic consultant should be used to assist in training employees and implementing the recommendations made. The consultant should review OSHA recommendations, perform a systematic evaluation with regard to existing and new work practices and work station design for all plant operations to determine cumulative trauma hazards, recommend engineering and administrative controls to reduce or eliminate ergonomic stressors, assist in implementing the recommendation, evaluate the effectiveness of the controls implemented, and make new recommendations if necessary.

  3. Medical Management Program

    A medical management program is necessary to monitor employees and prevent early symptoms from progressing to injuries. This program should include: determining the extent of injuries and illnesses; determining if injuries and illnesses are caused or aggravated by work; educating all employees and supervisors on early signs of injuries and disorders and encourage early reporting; instituting a formal documented tracking and surveillance program to monitor injury trends in the plant; providing adequate treatment of ergonomic related cases (including not reassigning employees to a job until it has been modified to minimize the hazards that resulted in the injury); and allowing adequate time off for recovery after surgery or other aggressive intervention.

    Preventive measures that should be instituted include early physical evaluation of employees with musculoskeletal symptoms; allowing adequate time off after a cumulative trauma disorder is diagnosed; and providing access to trained medical personnel for development and implementation of conservative treatment measures upon detection of cumulative trauma disorder symptoms.

  4. Training programs

    A training program is necessary to alert employees on the hazards of cumulative trauma disorders and controls and work practices that can be used to minimize the hazards. This includes designing and implementing a written training program for managers, supervisors, engineers, union representatives, health professionals and employees on the nature, range, and causes and means of prevention of ergonomic related disorders. The training program for new and reassigned workers should allow demonstrations of safe and effective methods of performing their job; familiarize employees with applicable safety procedures and equipment; allow the new or reassigned employee to work with a skilled employee and/or provide on the job training for specific jobs; and allow new or reassigned employees to condition their muscle/tendon groups prior to working at full capacity rate which has been determined to be safe and will not cause adverse effects.

    Workers should be instructed in the basics of body biomechanics, and work practices to minimize the ergonomic hazards associated with their jobs. This should include, but not be limited to, the items noted below:

    Avoid postures where:
    • the elbow is above mid-torso
    • the hand is above the shoulder
    • the arms must reach behind the torso
    Avoid wrist postures where there is:
    • inward or outward rotation with bent wrist
    • excessive palmer flexion or extension
    • ulnar or radial deviation
    • pinching or high finger forces with above postures
    Avoid mechanical stress concentrations on elbows, base of palm and backs of fingers.

    General lifting guidelines include:
    • keep the load close to the body
    • use the most comfortable posture
    • lift slowly and evenly (don't jerk)
    • do not twist the back
    • securely grip the load
    • use a lifting aid or get help
    The following are recommendations that can be utilized throughout the plant.

GENERAL RECOMMENDATIONS

In conclusion, many of the hazards observed throughout this plant can be divided into the categories of stressful postures or motions, unsafe rates of work or repetition, and contact stresses on various body parts which are all consistent with the development of musculoskeletal disorders.

Employees in the deboning area work at frequencies which are high enough to cause musculoskeletal injuries. Frequencies in these areas were measured at over 3000 hand strokes per hour. This is a level which has been shown to produce tendon injury unless measures are taken to provide adequate rest for affected body parts. Many tasks which are performed repeatedly need established work-rest schedules to ensure that over used and fatigued muscles are allowed sufficient rest periods for recuperation. One technique to accomplish this is through job rotation. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created which allows for as much variation as possible in the distribution and frequency of musculoskeletal activity. A second technique is to establish defined work-rest schedules which ensure adequate periods of recuperation time. These should be strictly enforced. This is especially important in areas where piece work is performed. The natural tendency is to over work when piece rate incentives are in effect, often ignoring early warning signs such as soreness and pain. Generally, a minimum of a 15 minute rest break at least every two hours is required.

Many of the hazards observed on the video tape involve employees working with their bodies in awkward postures. It appears that the lack of adjustable work stations is the principal cause for this hazard. Employees who have to bend excessively at the waist, reach up above shoulder height, reach excessively away from their bodies, or perform tasks at elevated work surfaces all assume additional job stress due to misalignment between the body and the workstation. Work stations should have considerable adjustability such that employees can change the height, depth, or angle to ensure work is performed in ergonomically neutral postures. The head should be vertical and should not tilt forward more than about 15 degrees. Arms should hang normally at the side of the body and should not reach forward farther than 16 to 18 inches and hands should be maintained, vertically, between the waist and mid-chest level. Tasks should never require employees to reach behind the coronal plane of the body (the plane which is parallel to the shoulders). The torso should not bend more than 6 to 10 degrees from vertical and when seated the back should maintain the normal standing lordosis (slight curvature of the spine towards the stomach). When seated the buttocks and feet should be firmly supported and the option to change from seated to standing postures is desirable. Work stations which allow frequent and simple adjustment will reduce the chance of injuries since employees can custom fit the work surface to their particular body needs.

All employees need training in ergonomic principles so they can perform their jobs and utilize their tools and work stations in a safe manner. Training allows employees to recognize the early warning signs of a problem and to take action to prevent an injury where significant time may be lost due to surgery or incapacitation. Trained employees can also make a significant contribution in creating practical low cost solutions to ergonomic problems. They have extensive knowledge of the work situation and job performance requirements. When this is combined with an understanding of the basic principles for safe operation, remediation of the problem can often be attained. One such solution will more than repay the cost of initial training. Supervisors should be extensively trained and made to understand that safety and ergonomics problems are real and every bit as important to the bottom line as production considerations. Trained supervisors can also help recognize problems in their early stage and can act as a stimulant to reinforce proper, safe work techniques. No program will succeed unless management thoroughly understands its principals and openly supports its existence.

Several different knives should be supplied to the employees depending on the type of operation they perform. The knives in current use are very good for tasks which use a stabbing type of motion but for those tasks which require a slicing motion this design forces the employees to deviate the wrist. Wrist deviation with application of finger force, such as is used in cutting tasks, is consistent with the development of tendinitis and carpal tunnel syndrome. Slicing tasks should be performed with a knife designed such that employees can maintain a neutral wrist posture during performance of the task. Special "L" shaped, ergonomically designed knives are available with several styles of blades which will permit the performance of the task while still maintaining power grip hand postures during cutting tasks. These knives should be provided for any employee who has a considerable amount of time spent with the hand in a deviated wrist posture. For many of the tasks a knife which is sharpened on both the front and back could reduce the number of arm actions which are necessary since cuts could be made on both the forward and return part of the stroke.

Tasks which alternate between slicing and stabbing motions may need to be broken down into separate motion oriented types of tasks with an assembly line type of configuration. One employee performs all the stabbing type cuts and then passes the work on to another employee who performs the slicing type cuts. Each employee should be issued a knife appropriate to their particular type of cutting task.

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles. Supply sit/stand stools to employees so they can adjust the positions which they work to minimize the amount of loading on any one muscle group. Provide foot rests 4 to 6 inches above the floor which allows employees to rest one leg while standing. Foot rests are believed to alleviate back stress as well as minimize foot fatigue.

There is a persistent problem throughout the plant with unloading of the barrels and tubs which are used to transport meat and hides. The use of these devises forces employee to repeatedly flex (bend over) at the waist to access materials in the transport devises. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent reaches present a hazard as they tend to force the torso to flex forward, move the load away from the body center, and because they create a weak position in terms of arm strength. Frequent reaches and torso flexions are consistent with the development of shoulder irritation and low back injuries. A change should be made in the transportation devices such that employees can access the materials without bending over. Generally, torso flexions should be limited to 6 to 10 degrees from vertical and reaches should be limited to 16 to 17 inches. A device should be provided which will lift and tilt the tubs and barrels to keep access at desirable heights and reach distances if the current barrels and tubs are to continue in use. Providing a transportation devise with a movable floor that raises as materials are withdrawn from the device would also remediate the problem.

The trimming tools used on the "bone shining" and "hide removal" areas are pneumatic powered and have slick metal handles. Pneumatically driven tools generate vibrations which can desensitize the hands which increases the need for additional grip force to control the tool. Metal handles have a poor coefficient of friction which also increases the grip force necessary for adequate control. In addition, pneumatic tools can also blow cool air onto the hands creating additional desensitization. Factors which increase the grip force requirements while the wrist is in a deviated posture are consistent with the development of hand pain and UECTDs such as carpal tunnel syndrome. Pneumatic tools should be provided with vibration dampening material which will also increase the coefficient of friction thus ecreasing the grip force required to control the tool. Exhaust air should be diverted such that it does not blow across the hands.

All employees work in a cold environment. Cold reduces the tactile response of the hands and requires the use of additional finger force to perform a given task. Strategies which are often used to negate the effects of the cold such as gloves also reduce the tactile response of the hands and require the use of additional finger force to achieve the same feeling of control when handling tools required for task performance. Increasing the amount of finger force used especially when deviated wrist postures are used is consistent with the development of UECTDs such as carpal tunnel syndrome. Because of this cause and effect scenario which is precipitated by working in cold environments it critical that the hand be kept in a neutral posture and that force and frequency be kept as low as possible.

Along the same line as the concerns mentioned above, all employees depicted on the video tape are wearing, what appears to be large rubber gloves during the operation. Gloves which fit poorly and/or are made of materials with a low coefficient of friction require more force production by the fingers and hands to overcome decreases in friction and tactile sensitivity. Increases in the force required for a task will significantly increase the chance of UECTDs of the hand and wrist such as carpal tunnel syndrome. Gloves should be made of a material which increases the coefficient of friction between the hand and the load surface, fit properly and to the fullest extent possible do not decrease tactile sensitivity. Because of the inherent restrictiveness and loss of feel, created by even the best gloves, it is important that force and frequency requirements of a task be maintained at an absolute minimum.

The specific task analysis of the video documentation collected at beef slaughter operation follows. Each task was studied to determine the ergonomic effects of several different factors. These factors are:
  • Frequency of the action of work cycle.
  • Awkward postures required to perform the task.
  • Forceful exertions required by the task.
  • Workplace conditions that may affect the hazard presented by a task.
  • Tools or Clothing used on the job which may affect the hazard presented by the task.
In some tasks all factors may be addressed and in others some factors may not be applicable. If a factor is not addressed in a particular task it was deemed to pose no problem in that particular task or it was not possible to make a determination from the submitted footage. In tasks where a hazard could be addressed under two factor areas it will only be listed in the factor deemed to be most relevant.

TASK # 1 Tape time- 00:00:00

TONGUE ROOM - This area is primarily concerned with the processing of beef tongue. There are several tasks performed here. 1) Hanging tongue to be further processed involves removing tongue from a tub and hanging it vertically on racks. 2) Skinning tongue is performed when the tongue is moved across a device similar to a planer which removes the rough outer coating, thus exposing the inner meat section. 3) Heat sealing tongue involves placing tongue in a bag and laying it on a device which then has a lid placed on it. While the lid is down the bags are heat sealed shut. Excess material is trimmed from the bag by an employee using a knife. 4) Placing sealed tongue in a steamer and then removing sealed and steamed bags of tongue from an ice bath. All tasks are performed while standing on cement floors.

Frequency:

Actual frequency calculations were not determined but compliance officer data suggests that on an average day the plant would process up to 750 head of cattle which should provide about 750 tongues per day. This would require a production rate of about 95 tongues processed per hour.

Known Hazard

There are frequent torso flexions, lifts above shoulder height, wrist deviations with finger force, and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There appears to be sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity. Higher force tasks such as hanging tongue and skinning tongue should be rotated with the lower force tasks such as heat sealing.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees hanging tongues perform repeated reaches above shoulder height. Reaching and handling loads above shoulder height places repeated loading on the muscles of the shoulder and upper arms which is consistent with the development of muscle fatigue, pain, and injury. In addition, repeatedly lifting the arms can create wear and tear, and thickening of the tendons and bursa located in the shoulder which is consistent with the development of UECTDs tendinitis, bursitis, inflammation and swelling, and potentially frozen shoulder syndrome.

Known Control


  1. Instruct employees to only load to those areas of the rack which can be accessed while the hands are below shoulder height.
  2. Provide an adjustable rack which can have the upper racks lowered for loading and unloading and then raised during the non-handling portions of the task.
Known Hazard

Employees hanging tongues use repeated deep torso flexions to obtain tongues from supply barrels. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the upper body. Muscle force must be increased to maintain control of the load as the torso is flexed, thus increasing the compressive force generated on the spine of the low back. Frequent reaches present a hazard as they tend to force the torso to flex forward, move the load away from the body center, and because they create a weak position in terms of arm strength. Frequent reaches and torso flexions are consistent with the development of shoulder irritation and low back injuries. Holding a load while flexing the torso significantly increases low back stress and increasing the distance the load is held from the body directly increases the hazard of low back injury.

Known Control


  1. Provide employees with a tub dumper such that the tub may be elevated and tilted to a point where it can be unloaded without using deep torso flexions.
  2. Have the tub dumped onto a table where employees can access the materials to be hung without flexing the torso more than 6 to 10 degrees from vertical.
Known Hazard

Tongue skinners perform the task with deviated wrists while exerting finger force to guide the tongue across the blade. Exertion of finger force while the wrist is in a deviated posture is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Educate the employee on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position.
  2. Provide the employees with gloves which have a high coefficient of friction surface. Gloves which have a low coefficient of friction surface require more finger force to adequately control the object worked on which increases the hazard of the task.
  3. Tilt the work surface such that the operation can be performed while minimizing the deviation of the wrist.
  4. Devise work-rest and rotation schedules such that employees have adequate periods of rest for recuperation of affected muscles.
Workplace Conditions:

Known Hazard

Employees performing cutting operations after the tongue has been skinned must operate with their arms abducted away from their bodies. This is caused by using a work surface which is too high for the employee. Repeated or prolonged abduction of the elbows creates stress on the musculoskeletal system of the shoulder, upper arm, and upper back. This situation slows muscle recovery, limits duration of activity, and makes the muscle, tendon, ligament system more susceptible to injury. This is consistent with the development of UECTDs such as tendinitis and musculoskeletal strains, sprains, fatigue and pain. In addition, this can lead to wear and tear, and thickening of the unsheathed tendons and bursa of the shoulder which is consistent with the possible development of frozen shoulder syndrome and rotator cuff injuries.

Known Control


  1. Provide employees with an adjustable work surface such that they can always work at the ergonomically correct height. Generally, the work height should be about 1 to 2 inches below elbow height when the arms are hanging straight down to side of the employee.
  2. Provide platforms for employees to elevate them in relation to the work surface such that they can work at ergonomically desirable heights.
Known Hazard

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins.

Known Control


  1. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles.
  2. Provide foot rests 4 to 6 inches above the floor allowing employees to rest one leg while standing. Foot rests are believed to alleviate back stress as well as minimize foot fatigue.
TASK # 2 Tape time- 00:04:29 & 00:06:24 & 00:09:30 & 00:10:00 & 00:13:59 & 01:08:10

BONING ROOMS - Deboning of meat and trimming of meat all appear to present similar hazards to employees. For this reason several deboning and trimming operations will be considered together. All operations involve cutting meat from the bone or slicing large meat sections into smaller commercial pieces. All operators remove large chunks of meat from a conveyor belt which runs in front of them and place it onto a work table, also located in front of the employee. The meat is handled almost exclusively by a meat hook which is in the employees non dominant hand. The meat is cut by a knife which is located in the employee's dominant hand. Various cuts are made and the scrap is usually placed on the upper conveyor with the meat pieces placed back on the original conveyor. Employees stand during this operation and are often paid base pay plus an incentive for piece work.

Frequency:

Actual frequency calculations were determined for some tasks and in addition compliance officer data suggests that on an average day the plant processes up to 750 head of cattle. Frequencies of operation were calculated at tape times 01:02:23 and 01:04:34. These frequency calculations show that the employees are performing in excess of 3000 cuts per hour.

Known Hazard

There are frequent wrist deviations with finger force, throwing of materials to elevated areas, torso flexions, contact trauma and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There appears to be sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required. Employees who show symptoms may have to slow down or be required to take more frequent rest breaks. The calculated repetitions of cutting actions are above 3000 per hour. Repetitions in excess of 1500 to 2000 repetitions per hour have been shown to cause tendon and tendon sheath swelling. Generally, repetitions should be kept below 1500 per hour especially for employees who show symptoms of repetitive motion injuries.
Awkward Postures:

Known Hazard

Employees employ a jerky throwing motion when using the hook to throw meat items onto the conveyor system. These motions often incorporate deviation of the wrist and inward or outward rotation of the forearm.

The use of these throwing motions when combined with awkward hand and arm postures are consistent with the development of UECTDs such as tennis elbow (tendinitis) or golfers elbow (medial epicondylitis).

Known Control


  1. Redesign the system so employees can discard unwanted items while minimizing the amount of required throwing actions. Lowering the upper conveyor or replacing it with a lower conveyor such that employees could push the items through a hole and have it fall to the conveyor would reduce the hazard of this operation. Replace throwing actions with pushing actions.
  2. Provide a cart under each cutting area where scraps could be placed using a sliding and dropping motion. Good meat items could be pushed to the present conveyor system.
Known Hazard

Employees performing work tasks at the workstation depicted at Tape time 00:04:29 use frequent reaches and torso flexions with the arms extended in front of the body to grasp and lift large slabs of beef from the conveyor belt to the work area. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent reaches present a hazard as they tend to force the torso to flex forward, move the load away from the body center, and because they create a weak position in terms of arm strength. Frequent reaches and torso flexions are consistent with the development of shoulder irritation and low back injuries. Holding a load while flexing the torso significantly increases low back stress and increasing the distance the load is held from the body directly increases the hazard of low back injury.

Known Control


  1. Educate the employee on the basics of body biomechanics, the importance of flexing the torso no more than 6 to 10 degrees from vertical, and maintaining the arms in close to the torso.
  2. Provide a slide area for employees such that they can slide the meat from the conveyor to the cutting area without reaching and lifting to perform the transfer.
  3. Remove this station from the production process such that employees are not subjected to the stressors. This station appears to have been added on and was not originally designed into the production process.
Known Hazard

Employees performing rib cleaning operations and slicing operations have considerable deviation of the wrist while exerting finger force. The use of deviated wrist postures while exerting finger force is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Develop a type of production line process where cuts that require a stabbing motion are performed in one area and cuts that require a slicing motion are performed in another. This is already happening to some extent as slicing and trimming operations appear to be performed separate from most of the deboning operations. The deboning process should be analyzed to determine if it could be further broken down into a section where a specialty knife can be designed to alleviate wrist deviation.
  2. Educate the employee on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position.
  3. Develop a knife which has cutting edges on both the sides. This would enable employees to perform rib trimming operations while minimizing the amount of wrist deviation.
Workplace Conditions:

Known Hazard

The lack of adjustability in the current work station forces many employees to assume awkward and potentially hazardous work postures. Many of the shorter employees have abducted elbows from working on a surface which is too high and some tall employees have considerable torso flexion when bending over to perform work tasks. These postures can lead to shoulder, upper arm, and low back pain and injury.

Known Control


  1. Provide fully adjustable work stations such that employees can adjust the height of the work area to minimize the hazard associated with working while assuming stressful body postures. Generally, the work height table height should be at about one inch below elbow height as employees stand with their arms hanging straight down to their sides.
  2. Raise the overall height of the system to accommodate taller employees and provide platforms to raise shorter employees to more desirable work levels.
Known Hazard

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins.

Known Control


  1. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles.
  2. Provide foot rests 4 to 6 inches above the floor allowing employees to rest one leg while standing. Foot rests are believed to alleviate back stress as well as minimize foot fatigue.
Tools and Clothing:

Known Hazard

Many employees are using a straight in-line type or knife to perform cutting operations. The use of in-line knives for certain cutting tasks requires deviation of the wrist and in addition, knives with handles made of a slick surface require additional finger force to maintain control. These are both factors in the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. If possible divide the tasks into sections which can be performed using knives specifically designed for the task. Tools should have a handle which is cylindrical or oval with a diameter of 1.25 to 1.75 inches. These tools should have a non-slip handle of rubber or plastic and can have flutes or ridges to increase torque application. The in-line knife is appropriate for tasks which use a stabbing motion where the wrist can be maintained in power posture. Slicing actions should be performed using an "L" shaped ergonomic designed knife. These allow employees to perform the cuts while maintaining the wrist in a more ergonomically neutral posture.
Known Hazard

There appears to be a contact trauma to the inside of employees fingers from use of the meat hook. Forceful contact by the hook to the small muscles and nerves located on the inside of the fingers is consistent with the development of pain, blood restriction, and damage to the affected entities.

Known Control


  1. Redesign the current hook such that the pressure and force is spread out over the entire handle and is not repeatedly exerted over the area contacted by the fingers. Use a design similar to a brass knuckle where employees slip their hands through a handle such that the pressure is on palm and the outside of the finger instead of the inside of the fingers.
  2. Pad the metal hook where it passes next to the fingers to widen the contact area such that the pressure is spread out over a wider area.
TASK # 3 Tape time- 00:10:57 & 00:12:06 & 01:13:00

BONE SHINERS - Employees use a whizzard pneumatic loop knife to trim meat scraps from bones which have had the major pieces of meat removed by the de-boning employees. Employees remove the bones from a conveyor which runs directly in front of them, place them on a work shelf located between them and the conveyor, and then use the tool to remove small pieces of meat that have been left behind from previous processes. Cleaned bones are thrown onto the conveyor to be taken to the next work area and meat scraps are pushed from the shelf to a bin for further processing in another area. Employees stand throughout the entire operation. (* note * I believe the pneumatic tool that these employees are using is called a "whizzard knife" and it will be referred to as such throughout this analysis)

Frequency:

The rate was not calculated from the video segment submitted for analysis as it appears that the task is essentially self paced. Employees are able to stack materials to the side during peak times and work on them during slack periods.

Known Hazard

There are frequent wrist deviations while exerting finger force and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There are sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees use deviated wrist postures while exerting finger force when operating the whizzard knives used for cutting meat scraps from the bone. The use of deviated wrist postures while exerting finger force is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Educate the employee on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position.
  2. Develop a whizzard knife which has the required bend incorporated into the handle instead of forcing the employee to deviate the wrist during work operations.
Workplace Conditions:

Known Hazard

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins.

Known Control


  1. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles.
  2. Supply sit/stand stools to employees so they can adjust the positions which they work to minimize the amount of loading on any one muscle group.
  3. Provide foot rests 4 to 6 inches above the floor allowing employees to rest one leg while standing. Foot rests are believed to alleviate back stress as well as minimize foot fatigue.
Tools and Clothing:

Known Hazard

The trimming tool is pneumatically powered and equipped with an in-line metal handle. Pneumatically driven tools generate vibrations which can desensitize the hands thus increasing the grip force required to control the tool. In-line metal handles force the use of deviated wrist postures and in addition have a poor coefficient of friction which increases the grip force necessary. Pneumatic tools can also blow cool air onto the hands causing further desensitization. High grip force requirements with wrist deviations are consistent with the development of hand pain and UECTD's such as carpal tunnel syndrome.

Known Control


  1. Provide vibration dampening material for the tool handle that will also increase the coefficient of friction thus decreasing the grip force required to control the tool.
  2. Ensure that exhaust air does not blow across the hands.
  3. Redesign the tool such that deviation of the wrist, which is required by the task, can be replaced by a bend in the tool handle.
TASK # 4 Tape time- 00:11:45 & 00:13:29

DROP FRONT QUARTER - Employees generally make two cuts through the rib cage to separate the front quarter from the hind quarter. Employees make the first cut and let the carcass proceed until it is positioned over the conveyor at which time the second cut is made which drops the front quarter onto the conveyor. It appears that the employee stands during the entire operation.

Awkward Postures:

Known Hazard

Employees use extended reaches over the head to access the carcass to make the needed cuts. The use of extended overhead reaches is consistent with the development of UECTDs such as muscle strain and tears, bursitis, tendinitis, and possibly frozen shoulder syndrome.

Known Control


  1. Lower the line which brings the carcass to the employee. Lowering the carcass by a foot would bring it into a better proximity for employees to perform the cuts and would still allow it to slide and drop onto the conveyor.
  2. Create a platform for employees to stand on which will raise them to a height where they can perform the task without lifting their arms above shoulder height. Generally, tasks should be performed at heights no higher than about shoulder height.
TASK # 5 Tape time- 00:15:38

DRY ICE PACKING - Employees pack boxes of meat with dry ice by removing dry ice from a tub and transporting it with a hand scoop. Employees stand for the entire time of the task.

Awkward Postures:

Known Hazard

Employees perform frequent reaches and torso flexions with the arms extended in front of the body to load and lift scoops of dry ice. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent reaches present a hazard as they tend to force the torso to flex forward, move the load away from the body center, and because they create a weak position in terms of arm strength. Frequent reaches and torso flexions are consistent with the development of shoulder irritation and low back injuries. Holding a load while flexing the torso significantly increases low back stress and increasing the distance the load is held from the body directly increases the hazard of low back injury.

Known Control


  1. Provide a tub dumper, adjustable bottom tubs, or other device which will keep the supply of dry ice at a level where employee can access the material without flexing the torso.
TASK # 6 Tape time- 00:25:40 & 00:27:40 & 00:30:19

KILL FLOOR - Three tasks (Lipper, Skinning preparation, and Bung dropper) were evaluated in the general area of the kill floor. A single cow is herded into the kill shoot where it is killed by being shot in the head with a pneumatic gun. After the cow falls it has a chain attached to one leg and it is lifted by a hoist and moved down the line where it's throat is cut. The Lipper appears to cut the upper lip from the cow after it has had its throat cut. The carcass then proceeds farther down the line where the Skinning prep. employee slices along the leg, begins to remove the hide from the non hanging leg, and uses a snip to cut off the hoof. Farther down the line the bung dropper cuts the anus away from the rest of the carcass and another employee places a band around it to prevent the contents of the stomach or bowel from leaking out. All employees stand during this operation.

Frequency:

Actual frequency calculations were not determined but, compliance officer data suggests that on an average day the plant would process up to 750 head of cattle.

Known Hazard

There are frequent torso flexions, wrist deviations, and the job entails long periods of standing and bent torso postures. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There are sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees repeatedly exert finger force, with the wrist in a deviated posture, to perform cuts when dropping the bung. The use of deviated wrist postures while applying finger force is consistent with the development UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Educate employees on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position.
  2. Rotate employees through this position such that no single employee is exposed to the hazard for a prolonged period of time. A shift with no more than 2 hours of bung dropping in the morning and 2 hours in the afternoon could serve as a starting place. If pain or injury occurs with this time frame the time spent on this task may need to be reduced.
Known Hazard

Lippers and Skinning prep. employees repeatedly assume postures where they deeply flex the torso with the hands extended in front of the body. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent reaches present a hazard as they tend to force the torso to flex forward, move the load away from the body center, and because they create a weak position in terms of arm strength. Frequent reaches and torso flexions are consistent with the development of shoulder irritation and low back injuries. Holding a load while flexing the torso significantly increases low back stress and increasing the distance the load is held from the body directly increases the hazard of low back injury.

Known Control


  1. Educate employees on the basics of body biomechanics and the importance of limiting the number and severity of torso flexions. Generally, torso flexions should be limited to 6 to 10 degrees from vertical.
  2. Raise the entire line about 2 feet. This will allow both the lipper and the skinning prep. employees to perform their tasks while limiting the amount of torso flexion.
  3. Lower the platform which Skinning prep. employees work from. This task presents the greatest hazard since employees often must statically maintain the torso flexion posture for extended periods of time. Any combination of redesign techniques which will allow the performance of this task while maintaining proper torso postures should be undertaken. This work area presents a significant risk to the low back.
  4. Provide a stool for the lipper to work from. An employee who is in a seated position will not be required to repeatedly flex the torso.
TASK # 7 Tape time- 00:32:50

SKINNING THE PIZZLE - A long cylindrical piece of meat is hung from a hook on the wall. Several cuts are made at the top of the hanging meat and an outer skin is removed. Other unwanted meat items at the lower end of the hanging unit are cut off and discarded.

Awkward Postures:

Known Hazard

Employees hanging cylindrical meat perform repeated reaches above shoulder height and perform much of the skinning actions above shoulder height. Reaching and performing tasks above shoulder height places repeated loading on the muscles of the shoulder and upper arms which is consistent with the development of muscle fatigue, pain, and injury. In addition repeatedly lifting the arms can created wear and tear, and thickening of the tendons and bursa located in the shoulder which is consistent with the development of UECTDs tendinitis, bursitis, inflammation and swelling and potentially frozen shoulder syndrome.

Known Control


  1. Modify the work stations such that the task can be performed without the employee reaching over head height. This task should have a station designed for it which is horizontal or inclined. This would permit performance of the task without repeated reaching above head height. Generally, reaches should be limited to no higher than shoulder height.
Tools and Clothing:

Known Hazard

Employees are wearing, what appears to be smooth rubber, gloves during the operation. Gloves which fit poorly and/or are made of materials with a low coefficient of friction require more force production by the fingers and hands to overcome decreases in friction and tactile sensitivity. Increases in the force required for a task will significantly increase the chance of UECTDs of the hand and wrist such as carpal tunnel syndrome.

Known Control


  1. Make sure gloves fit properly and do not decrease tactile sensitivity. Gloves should be made of a material which increases the coefficient of friction between the hand and the load surface. This will reduce the hand and finger force required to perform a particular repetitive task. A glove with a sand paper or raspy surface should be provided to pizzle skinners such that they can grasp the outer skin and pull it while utilizing a minimum of force.
TASK # 8 Tape time- 00:38:00

HOOVES - Employees prepare and clean hooves for further processing. Employees burn the hair off the hoof by sticking it through a hole in a stack which encloses an open flame. After the hair is burned off the hoof it is washed and any remaining hair is scraped off using a knife. Employees stand throughout the entire operation.

Frequency:

Actual frequency calculations were not determined but compliance officer data suggests that on an average day the plant would process up to 750 head of cattle which should provide about 3000 hooves per day. This would require a production rate of about 380 hooves processed per hour.

Known Hazard

There are frequent lifts above shoulder height, wrist deviations with finger force, and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There appears to be sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal stressors.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees use deviated wrist postures with finger force to hold the knife during scraping operations and when using the non-knife hand to secure the hoof for scraping operations. The use of deviated wrist postures while exerting finger force is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Educate the employee on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position.
  2. Experiment with other techniques such as a grinder wheel with a wire brush which may be used to remove the hair but would not require the use of deviated wrist postures.
  3. Provide the employees with a bent handle knife which will allow them to perform the task while maintaining an ergonomically neutral wrist.
  4. Develop a clamp or jig which can be used to secure and hold the hoof during the scraping part of the task.
Known Hazard

Employees who burn the hair off the hooves work for extended periods of time with their hands above shoulder height. Handling loads above shoulder height places repeated static loading on the muscles of the shoulder and upper arms which restricts blood flow, slows recovery, and is consistent with the development of muscle fatigue, pain, and injury. In addition repeatedly lifting the arms can create wear and tear, and thickening of the tendons and bursa located in the shoulder which is consistent with the development of UECTDs such as tendinitis, bursitis, inflammation and swelling and potentially frozen shoulder syndrome.

Known Control


  1. Elevate employees such that they can place the hooves into the burner to be fired without lifting the hands above shoulder height.
Workplace Conditions:

Known Hazard

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins.

Known Control


  1. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles.
  2. Supply sit/stand stools to employees so they can adjust the positions which they work to minimize the amount of loading on any one muscle group.
  3. Provide foot rests 4 to 6 inches above the floor allowing employees to rest one leg while standing. Foot rests are believed to alleviate back stress as well as minimize foot fatigue.
TASK # 9 Tape time- 00:39:14

HEADS - Heads are placed on a hook conveyor and employees perform various operations on them to remove meat from the skull. Employees cut out the tongue, load machines which split the lower jaw away from the rest of the head, and trim any residual meat away from the skull. Employees stand during the entire process.

Frequency:

Actual frequency calculations were not determined for the entire head operations but frequencies were calculated for the jaw splitting section of the task. This rate was about 2 heads processed per minute. Compliance officer data suggests that on an average day this plant would process up to 750 head of cattle which should provide about 750 cattle heads per day. This would require a production rate of about 95 heads processed per hour or about 1.6 heads processed per minute.

Known Hazard

There are frequent torso flexions, lifts above shoulder height, wrist deviations with finger force, elbow abductions and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There appears to be sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity. Higher force tasks such as unloading heads from the conveyor should be rotated with the lower force tasks such as cutting out tongues and trimming head meat.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees abduct their elbows away from the body and pry with considerable force to break the tendons of the jaw prior to loading the head onto the jaw splitter. Abduction of the elbows creates stress on the musculoskeletal system of the shoulder, upper arm, and upper back all of which is intensified by the exertion of significant force during the task. Forceful static loading of the muscles slows muscle recovery, limits duration of activity, and makes the muscle, tendon, ligament system more susceptible to injury. This is consistent with the development of UECTDs such as tendinitis and musculoskeletal strains, sprains, fatigue and pain. In addition, this can lead to wear and tear, and thickening of the unsheathed tendons and bursa of the shoulder which is consistent with the possible development of frozen shoulder syndrome and rotator cuff injuries.

Known Control


  1. Redesign the jaw splitter such that the head can be loaded directly onto it without the need to loosen the lower jaw by breaking the supporting tendons.
  2. Use a knife or chisel to cut the tendons of the jaw instead of prying them apart. This would allow employees to keep the elbows in close to the torso during the operation.
  3. Develop a frequent work rotation and rest schedule for this task so there is ample time for muscle recovery.
  4. Raise the employee in relation to the work surface such that the prying motions can be performed with the elbows lowered and in close to the body. Generally, the work surface should be 1 to 2 inches below the elbow with the arms hanging at the employees side.
Forceful Exertions:

Known Hazard

A lifting analysis was performed on work tasks pictured on the submitted video documentation. The lifts were calculated as per the NIOSH lifting guidelines for "Continuous High Frequency Lifting, Variable Tasks". The lifts were divided into two basic tiers which seemed to pose the greatest hazard. These were lifts performed from the hook conveyor to the work surface (conveyor), and those performed from the work surface to the jaw puller (jaw). The data used in the calculation is as follows and was determined from the submitted video tape and accompanying compliance data:


EMPLOYEE AND TAPE TIME OF SEQUENCE TIER H V D F max F
Employee in blue shirt, back belt, hard hat; 00:40:53 conveyor 15" 48" <10" 15 3
jaw 20" 34" 18" 15 3
composite 17.5" 41" 14" 15 5


H = Horizontal distance load is held from body V = Vertical distance at the point of origin D = Travel distance from origin to destination F = Repetitions per minute Fmax = Constant given as per certain situations

The following formula was used to do the calculations. The formula is taken from the "NIOSH Work Practices Guide for Manual Lifting":

AL (lbs) = 90*(6/H)*(1-(0.01(|V-30|))*(0.7+3/D)*(1-F/Fmax)

The Action Limits (ALs) and Maximum Permissible Limits (MPLs) calculated using the NIOSH Work Practices Guide are as listed in the following table. The current load being lifted as determined by information supplied by the compliance officer is about 25 to 30 pounds.


TASK COMP. LIFTS IN POUNDS
#1; 00:40:53 AL 16.4
MPL 49.1


The AL and MPL values calculated are based on current ideal weight limit guidelines of 90 pounds and on ideal lifting conditions which include the following:

  1. Smooth lifts.
  2. Two handed symmetric lifts in the sagittal plane with no twisting.
  3. Moderate width (30 inches or less).
  4. Unrestricted lifting postures.
  5. Good couplings (handles, shoes, floor surface).
  6. Favorable ambient conditions.
  7. Maximum allowable weight of 90 pounds.
Since the average load lifted is above the AL for the composite lift analysis and the lifts do not conform to ideal circumstances it should be considered hazardous. Continued lifting, of items in this weight range, is consistent with the development of low back injury.

Known Control


  1. Educate employees on the basics of body biomechanics and the importance of maintaining the body in an ergonomically neutral position. Generally, the torso should not be bent forward more than 6 to 10 degrees from vertical and reaches should not exceed 16 to 17 inches.

    Anything that will reduce the H,V, or D distances will reduce the chance of injury.
  2. Administrative controls should be implemented whenever the AL is exceeded. According to the "NIOSH Lifting Guide", these should include worker selection criteria and placement strategies, and improved worker training in safe lifting techniques. Training requires that the individual have personal knowledge of: The risk of injury in the job due to lifting in a careless or unskilled fashion; Lifting methods by which one can reduce unnecessary stress; His or her physical capacities to perform required lifts.
  3. Relocate the conveyor or the work table such that the head can be dropped onto the work table from the conveyor, thus alleviating the need to lift and carry the heads.
  4. Redesign the jaw puller such that the head can be slid across the work surface and placed onto the machine without the employee lifting it for placement.
Workplace Conditions:

Known Hazard

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins.

Known Control


  1. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles.
  2. Provide foot rests 4 to 6 inches above the floor allowing employees to rest one leg while standing. Foot rests are believed to alleviate back stress as well as minimize foot fatigue.
TASK # 10 Tape time- 00:44:30

EVISCERATION - Employees cut the viscera from the carcasses as they progress down a hanging conveyor line. Employees stand on a moving conveyor as they remove the viscera. When the viscera is removed it drops onto the conveyor and is taken to another area while the carcass is taken away for further processing. Employees slowly walk throughout the entire process.

Awkward Postures:

Known Hazard

Employees use frequent reaches and torso flexions when removing lungs and other viscera located toward the front of the carcass. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent torso flexions are consistent with the development of low back injuries.

Known Control


  1. Rotate the two employees frequently between removing viscera from the back of the carcass and removing viscera from the front. Since removing the viscera from the back of the carcass involves little torso flexion performing this duty should provide time for rest and recuperation of stressed back muscles. Rotations should be performed at least every two hours.
  2. Develop and provide a longer handled knife for employees removing viscera from the front of the carcass to use, such that they can make the necessary cuts and remove the necessary parts without the need for frequent torso flexions.
  3. Angle the height of the conveyor such that one employee can be stationed at the upper area to make the cuts on the hind section and the other employee can be positioned at a lower level where the necessary cuts can be made to the front section without performing repeated torso flexions.
Known Hazard

Employees perform many cuts with the wrist in a deviated posture and with the exertion of finger force when cutting connections which hold the viscera to the inside of the body cavity. The use of deviated wrist postures in conjunction with application of finger force is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Provide employees with an ergonomic knife which has a design such that the cutting task can be performed with the employee's hand in an ergonomically neutral position. Any bend needed for the task should be incorporated into the tool instead of the employees bending their wrist.
TASK # 11 Tape time- 00:45:09

HEAD CLEANING - Employees remove heads from the carcass and hang them inside a small three sided washing booth. Employees wash the heads with a jet of water from a hose and nozzle after which the employee lifts the head and moves it to another area for further processing. Employees stand during the entire work cycle.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately one head processed every 0.65 minutes.

Known Hazard

There are frequent torso flexions, repeated lifts, and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There are sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees use frequent torso flexions with the arms extended in front of the body to grasp and lift heads during the cleaning process. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent torso flexions are consistent with the development of low back injuries. Holding a load while flexing the torso significantly increases low back stress and increasing the distance the load is held from the body directly increases the hazard of low back injury.

Known Control


  1. Incorporate adjustability into the work station such that the employee can perform the task without using repeated torso flexions. The work station should incorporate a lift such that the employee can hang the head at about waist height, raise it to about shoulder height for washing, and then lower it to about waist height for removal and transport to another area.
  2. Modify the work process such that employees wash the head on the head processing line. This line is already at about shoulder height which would reduce the torso flexion hazard and would also reduce the amount of lifting required by the task.
Forceful Exertions:

Known Hazard

A lifting analysis was performed on work tasks pictured on the submitted video documentation. The lifts were calculated as per the NIOSH lifting guidelines for "Continuous High Frequency Lifting, Variable Tasks". The lifts were divided into two basic tiers which seemed to pose thegreatest hazard. These were lifts performed from the carcass line to the washing station and those performed during the washing to lift the head for access (low) and those performed from the washing station to the head processing line (mid). The data used in the calculation is as follows and was determined from the submitted video tape and accompanying compliance data:


LIFT #; EMPLOYEE; TAPE TIME OF SEQUENCE TIER H V D F max F
#1; HEAD WASHER; 00:45:09 LOW 15" 24" 12" 15 3
MID 15" 36 12" 15 2
COMP. 15" 28" 12" 15 5


H = Horizontal distance load is held from body V = Vertical distance at the point of origin D = Travel distance from origin to destination F = Repetitions per minute Fmax = Constant given as per certain situations

The following formula was used to do the calculations. The formula is taken from the "NIOSH Work Practices Guide for Manual Lifting":

AL (lbs) = 90*(6/H)*(1-(0.01(|V-30|))*(0.7+3/D)*(1-F/Fmax)

The Action Limits (ALs) and Maximum Permissible Limits (MPLs) calculated using the NIOSH Work Practices Guide are as listed in the following table. The current load being lifted as determined by CSHO submitted information is approximately 25 to 30 pounds


LIFT #; TAPE TIME COMP. LIFTS IN POUNDS
#1; 00:45:09 AL 22
MPL 63


The AL and MPL values calculated are based on current ideal weight limit guidelines of 90 pounds and on ideal lifting conditions which include the following:

  1. Smooth lifts.
  2. Two handed symmetric lifts in the sagittal plane with no twisting.
  3. Moderate width (30 inches or less).
  4. Unrestricted lifting postures.
  5. Good couplings (handles, shoes, floor surface).
  6. Favorable ambient conditions.
  7. Maximum allowable weight of 90 pounds.
Since the average load lifted is above the AL for the composite lift analysis, all loads have the potential to exceed the AL, and the lifts do not conform to ideal circumstances it should be considered hazardous. Continued lifting, of items in this weight range, is consistent with the development of low back injury.

Known Control


  1. Educate employees on the basics of body biomechanics and the importance of maintaining the body in an ergonomically neutral position. Generally speaking the torso should not be bent forward more than 6 to 10 degrees from vertical and reaches should not exceed 16 to 17 inches.
  2. Anything that will reduce the H,V, or D distances will reduce the chance of injury. Reduction of the weight of each individual package is also a solution to this problem.
  3. Administrative controls should be implemented whenever the AL is exceeded. According to the "NIOSH Lifting Guide", these should include worker selection criteria and placement strategies, and improved worker training in safe lifting techniques. Training requires that the individual have personal knowledge of: The risk of injury in the job due to lifting in a careless or unskilled fashion; Lifting methods by which one can reduce unnecessary stress; His or her physical capacities to perform required lifts.
  4. Redesign the operation such that employees wash the heads on the head processing line. This line is already at about shoulder height which would reduce the torso flexion hazard and would also reduce the number of lifts required by 1 to 2 for each head processed.
  5. Provide an articulated arm to lift the heads from the cow to the conveyor. The use of an articulated arm would allow for hosing down the head without transfer from one area to another. A system like this would completely eliminate the need to lift the heads during the process.
Workplace Conditions:

Known Hazard

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins.

Known Control


  1. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles.
Tools and Clothing:

Known Hazard

The water spray nozzle used for this operation appears to be quite heavy and presents a stress to the employees right hand and arm since in the current configuration employees must use the left hand to reorient the head for cleaning. Repeated lifting of heavy items is consistent with the development of UECTDs such as muscle fatigue and strain, and tendon injuries such as inflammation and impairment of function.

Known Control


  1. Provide a counter balance for the device such that the weight is supported mechanically allowing the operator to use the nozzle without supporting it's weight.
TASK # 12 Tape time- 00:46:00

HIDE REMOVAL - Employees stand on a pneumatically adjustable platform which is used to pull the hide from the carcass. The hide is attached to the platform which as it is lowered, pulls the hide off. Employees are positioned at either side of the carcass and use power shears to cut and trim any areas where the hide begins to stick. Employees stand during the entire operation.

Tools and Clothing:

Known Hazard

The shears used by the employees require them to use a deviated wrist posture with finger force to perform the necessary actions. In addition, the trimming tool is pneumatically powered and equipped with a metal handle. Pneumatically driven tools generate vibrations which can desensitize the hands which increases the grip force required to control the tool. Metal handles have a poor coefficient of friction which also increases the grip force necessary. Pneumatic tools can also blow cool air onto the hands causing further desensitization. High grip force requirements with wrist deviations are consistent with the development of hand pain and UECTD's such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Provide vibration dampening materials for the tool handle that will also increase the coefficient of friction thus decreasing the grip force required to control the tool.
  2. Ensure that exhaust air does not blow across the hands.
  3. Redesign the tool handle so necessary bends are incorporated such that deviated wrist postures can be eliminated. The tool handle should be bent such that employees can maintain an ergonomically neutral wrist.
TASK # 13 Tape time- 00:46:40

KIDNEY FAT REMOVAL - Employees use a knife to cut the fat from the kidneys. They take a kidney from a pile located in front of them, trim the fat off using an in-line knife, and place the trimmed kidney in a pile for further processing.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately 7 kidneys de-fatted per minute.

Known Hazard

There are frequent wrist deviations and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There are sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees use cutting techniques with require severe deviation of the wrist while exerting finger force to control the knife. Using deviated wrist postures while exerting finger force is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Educate the employee on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position. It appears that this task could be performed utilizing a neutral wrist posture if the employee had proper training and understood some basic ergonomic principals.
  2. Provide employees with knives which will allow them to perform the tasks while keeping the wrist in an ergonomically neutral posture.
TASK # 14 Tape time- 00:47:10 & 00:48:55

BOXING/PACKING - Employees transfer meat items from large tubs or barrels and pack them into boxes which are then shipped for retail sale. Boxes are placed on scales and loaded by hand until there is the required amount of material in them. Once filled the boxes are closed and pushed to a conveyor which moves then to another area for shipment. Employees stand for the duration of the task.

Frequency:

The video segment was too short to determine a frequency for the operation.

Known Hazard

There are frequent torso flexions and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There are sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees perform frequent reaches and torso flexions with the arms extended in front of the body to grasp and lift meat items from tubs and barrels for packing into shipping boxes. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent reaches present a hazard as they tend to force the torso to flex forward, and move the load away from the body center. Holding a load while flexing the torso significantly increases low back stress and increasing the distance the load is held from the body directly increases the hazard of low back injury.

Known Control


  1. Provide the employee with a tub or barrel dumper which will lift and tilt the tub or barrel such that the employee does not have to flex the torso to access the meat items. Generally, torso flexion should be limited to 6 to 10 degrees.
  2. Use a tub or barrel dumper to dump meat on a table from which employees can pack the boxes. Tables should be at a height which is about 1 to 2 inches below the elbow when the arm is hanging at the side. Packing from a table should reduce the torso flexions to an absolute minimum.
Known Hazard

Employees packing boxes perform repeated reaches above shoulder height to access additional boxes for packing. Reaching and handling loads above shoulder height places repeated loading on the muscles of the shoulder and upper arms which is consistent with the development of muscle fatigue, pain, and injury. In addition repeatedly lifting the arms can created wear and tear, and thickening of the tendons and bursa located in the shoulder which is consistent with the development of UECTDs such as tendinitis, bursitis, inflammation and swelling and potentially frozen shoulder syndrome.

Known Control


  1. Do not stack boxes so high that the employee is forced to reach above head height to access them. Generally, reaches should only be performed between about mid-thigh to about eye height.
TASK # 15 Tape time- 00:56:24

BOXING/PACKING - Employees transfer hides from large tubs into large vats where the hides are tanned. During the transfer process they are trimmed and defatted before they are placed into the vats. Employees stand for the duration of the task.

Frequency:

The frequency of operation as depicted on the submitted video segment appears to be about 2 hides trimmed and cleaned every minute.

Known Hazard

There are frequent torso flexions, wrist deviations, and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There are sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.
  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees perform frequent reaches and torso flexions with the arms extended in front of the body to grasp and lift hides from large tubs up to cutting tables. Flexing the torso while lifting creates significant compressive forces on the low back as the muscles attempt to counteract the downward force created by the load lifted and the weight of the upper body. Muscle force must be increased to maintain control of the load as torso flexion is increased thus increasing the compressive force generated on the spine of the low back. Frequent reaches present a hazard as they tend to force the torso to flex forward, and move the load away from the body center. Holding a load while flexing the torso significantly increases low back stress and increasing the distance the load is held from the body directly increases the hazard of low back injury.

Known Control


  1. Provide employees with a tub dumper which will lift and tilt the tub such that employees do not have to flex the torso to access the meat items. Generally, torso flexion should be limited to 6 to 10 degrees.
Known Hazard

Employees use repeated deviated wrist postures with finger force when trimming hides. Repeated finger activations while the wrist is in a deviated posture is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Educate the employee on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position.
  2. Develop a bent handle knife such that the employee can perform the task while maintaining the hand in a neutral wrist posture.
Forceful Exertions

Known Hazard

A lifting analysis was performed on work tasks pictured on the submitted video documentation. The lifts were calculated as per the NIOSH lifting guidelines. The data used in the calculation is given in the following table and was determined from the submitted video tape and accompanying compliance data:


Lift number; Tape time; and description of lift H V D F max F
#1; 00:57:00; LIFTING HIDE FROM TUB TO CUTTING TABLE. 18" 10" 26" 15 5


H = Horizontal distance load is held from body V = Vertical distance at the point of origin D = Travel distance from origin to destination F = Repetitions per minute Fmax = Constant given as per certain situations

The following formula was used to do the calculations. The formula is taken from the "NIOSH Work Practices Guide for Manual Lifting":

AL (lbs) = 90*(6/H)*(1-(0.01(|V-30|))*(0.7+3/D)*(1-F/Fmax)

The Action Limits (ALs) and Maximum Permissible Limits (MPLs) calculated using the NIOSH Work Practices Guide are as listed in the following table. The current load being lifted as determined by compliance officer supplied information is about 80 pounds. It is very difficult to determine the exact weight lifted since the hide is pulled out of the tub and the entire weight is not supported by the employee. A conservative estimate would be that at least 75% of the hide weight is supported by the employees during the lift. This would establish a lift weight of about 60 pounds.


Lift number; Tape time AL MPL
#1; 00:57:00 18.4 55.2


The AL and MPL values calculated are based on the current ideal weight limit guidelines of 90 pounds and on ideal lifting conditions which include the following:

  1. Smooth lifts.
  2. Two handed symmetric lifts in the sagittal plane with no twisting.
  3. Moderate width (30 inches or less).
  4. Unrestricted lifting postures.
  5. Good couplings (handles, shoes, floor surface).
  6. Favorable ambient conditions.
  7. Maximum allowable weight of 90 pounds.
Since the approximated load lifted is above the MPL and the lifts do not conform to ideal lifting conditions they should be considered hazardous. Continued lifting, of items in this weight range, is consistent with the development of low back injury.

Known Control


  1. Educate employees on the basics of body biomechanics and the importance of maintaining the body in an ergonomically neutral position. Generally, the torso should not be bent forward more than 6 to 10 degrees from vertical and reaches should not exceed 16 to 17 inches.
  2. Anything that will reduce the H,V, or D distances will reduce the chance of injury.
  3. Use two employees whenever possible. The use of two employees when using proper lifting techniques will generally reduce the hazard of any lift.
  4. Provide the employees with a tub dumper which will lift and tilt the tub such that employees can access materials while maintaining ergonomically neutral postures as listed in the previous control statements.
  5. Develop a lift system that will hook onto hides and lift and lower them out of the tubs. An articulated arm equipped with a vacuum lift could move the hides from the tub and deposit them on the trimming table.
TASK # 16 Tape time- 00:59:04

CRYOPAC - Employees work on the side of a conveyor line adjusting materials as they pass in front of them. Employees stand for the entire process.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately 12 items worked on each minute. Known Hazard

There are frequent extended reaches, contact trauma to the forearms and the job entails long periods of standing. It is difficult to determine the absolute number of repetitions, or period of time that a posture can be maintained or an activity performed, which will cause an injury. But the risk of injury is definitely increased as static posture times or repetitions of a movement are increased. There are sufficient frequencies of stressors to cause musculoskeletal injuries unless adequate engineering and administrative controls are implemented. Many of the engineering controls will be addressed in the following sections. Some administrative controls are mentioned below.

Known Control


  1. Jobs should be classified as to the nature and extent of exertion and a rotation schedule should be created that allows for as much variation as possible in the distribution and frequency of musculoskeletal activity.

  2. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.
Awkward Postures:

Known Hazard

Employees use frequent extended reaches in front of the body at or above shoulder level to perform the necessary operations on each piece of material as it passes in front of them. Frequent reaches present a hazard as they tend to force the torso to flex forward and move the load away from the body center. This creates compressive loads on the spine as the weight of the upper body, arm, and the load in the hand must all be supported. The muscles of the arm are at risk as extending the arm creates a weak position in terms of arm strength. The muscles in the arm are fully extended which is consistent with fatigue rates which are approximately 2 to 3 times faster than when the arm is bent and kept in close to the body. Frequent reaches are consistent with the development of shoulder musculoskeletal fatigue and tendon wear, tear, inflammation, and thickening. The repeated use of these motions are consistent with the development of UECTDs such as tendinitis, bursitis, rotator cuff injuries, muscle fatigue and pain, and possibly frozen shoulder syndrome. Excessive forward reaching can flex the torso forward which increases low back stress and increases the hazard of low back injury.

Known Control


  1. Instruct the employee to let the material come to her instead of reaching forward to grab materials at distant locations.
  2. Redesign the workstation such that employees do not have to reach up and out to perform their tasks. This could include raising the employee, lowering the conveyor, or repositioning the employee to a lower area of the conveyor. Generally, work tasks should be performed at a height which is about 1 inch below shoulder height when the arms are hanging straight down to the side of the body.
Workplace Conditions:

Known Hazard

Employees have extended periods of standing which creates static loading on the muscles of the back and legs. This is consistent with the development of musculoskeletal injury and generalized fatigue. In addition this can lead to venous pooling of blood in the legs which is consistent with increased fluid pressure in the legs and the development of varicose veins.

Known Control


  1. Where employees are required to stand for long periods of time provide anti-fatigue mats and/or shoes with well cushioned insteps and insoles.
  2. Supply sit/stand stools to employees so they can adjust the positions which they work to minimize the amount of loading on any one muscle group.
  3. Provide foot rests 4 to 6 inches above the floor allowing employees to rest one leg while standing. Foot rests are believed to alleviate back stress as well as minimize foot fatigue.
Known Hazard

The conveyor surface edges are square at positions where employees rest their forearms or wrists. Resting of forearms or wrists on these sharp surfaces is consistent with the development of tendinitis, nerve injuries (numbness and tingling of the fingers) and restriction of blood flow.

Known Control


  1. Round off or pad the edges of the work surface where the employees forearms or wrists might come in contact with the work surface.