A BEEF SLAUGHTER OPERATION
INTRODUCTION

The video tape was analyzed to determine the potential for upper extremity cumulative trauma disorders (UECTDs), ower 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
  2. 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.

  3. Consultant Assistance
  4. 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.

  5. Medical Management Program
  6. 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.

  7. Training programs
  8. 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

The principal problems identified on the submitted video documentation consisted of lack of adjustability, inappropriate orientation of the employee in relation to the task, highly repetitive motions, and inappropriate tool design. The use of frequent overtime exacerbates the hazard of these stressors.

Employees must perform frequent torso flexions often with the arms extended in front of the body to remove hides, trim half carcasses, and when deboning. Flexing the torso even when there is little or no load in the hand stresses the low back since the entire weight of the upper body must be supported. This type of action is consistent with the development of low back pain and injury such as strain and herniation. Employees should be reoriented to lower positions in relation to the work performed, such that they can perform their task while maintaining the torso in an ergonomically neutral posture. Tasks should be able to be performed while flexing the torso no more than about 6 to 10 degrees from vertical. Catwalks should be staged such that employees are positioned at lower heights where the work can be performed without the need to flex the torso. Where employees stand on the floor to perform tasks the overhead conveyors should be staged such that the meat is elevated to a height where ergonomically neutral positions can be maintained. Trimming and deboning tasks performed on a horizontal surface should incorporate adjustability such that all employees can work without flexing the torso. Where the work surface can not be height adjusted the station should be designed for the tallest employee and platforms should be provided to elevate shorter employees.

Employees use repeated, extended and elevated reaches to perform skinning operations, access meat from conveyors, to perform boning operations on meat still hanging from elevated chain conveyors, to drop heads, to trim half carcasses, to place severed hooves on removal racks, and to wash hooves which have been skinned and cleaned. The use of frequent reaches is consistent with the development of acute and chronic shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, tears and UECTDs such as bursitis, tendinitis, and rotator cuff injuries. Reach distances should be limited horizontally to no more than 16 to 17 inches and vertically to between shoulder and waist height. All tasks should be performed with the elbows in close to the torso. Employees should be elevated or the work lowered to reduce elevated reaches. Conveyor belts and cutting tables should be reduced in size, where ever possible, to reduce forward reaches. Cutting tables and fixtures which hold hooves for skinning should be adjustable such that employees can properly orient themselves, in relation to the work, for safe operation. As was mentioned previously, staging the catwalks and the chain conveyor should allow the meat to be brought to the employee in ergonomically desirable orientations.

The straight in-line design of the hand tools used at this facility, such as the blade and whizzard knives require repeated exertion of finger force usually with the wrist in a deviated posture. The slick handle material requires exertion of additional finger force to maintain adequate control of the tool. Repeatedly exerting finger force or exerting finger force for a prolonged period of time, especially when the wrist is deviated is consistent with the development of UECTDs such as tendinitis, tenosynovitis, stenosing tenosynovitis, muscle strain, and carpal tunnel syndrome. Factors which increase the necessary finger force increase the risk injury. Knives should be provided which can be used with the hand in an ergonomically neutral posture. Provide blade type knives or air knives with a bent handle which can be operated with the hand in an ergonomically neutral posture. Since one knife design will not be appropriate for all cutting tasks the line should be subdivided into tasks which can be performed with specialty knives specifically designed for that task. The use of specialty knives will facilitate maintaining neutral wrist postures. Some employees are performing cuts at highly repetitive rates. Repetitions in excess of 1500 to 2000 per hour have been shown to cause tendon and sheath swelling. Generally, repetitions should be kept below 1500 per hour especially for employees who show symptoms of repetitive motion injuries. 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. Work-rest schedules should be developed and enforced. Generally, a minimum of a 15 minute rest break at least every two hours is required.

CSHO data indicates that the work shift is routinely at least 10 hours long. This is a very stressful policy which will exacerbate any harmful effects present in a particular task. Studies have shown that the productivity of employees is greatly reduced beyond eight hours. When forced to work beyond their most productive hours employees will slow down unless this is not possible due to machine pacing. To keep up with the machine pacing employees are forced to over exert and are placed under a stress condition. This can lead to conditions which accentuate the harmful effects of activities. Preventing injury, especially in repetitive motion situations, is dependant on obtaining sufficient rest for the affected body part. Extending the work day reduces the amount of time available for rest and recuperation. Maintaining a consistent schedule of long work days will generally enhance the harmful effects of stressors present in the workplace making the affected employee more susceptible to injury.

Employees must forcefully grasp the meat hooks and knives for prolonged periods of time. The knife hand can relax at times when meat is brought to the table but the hook hand is in almost constant use since it is used to retrieve meat, secure meat during cutting, and to place finished pieces into their respective areas. Exerting force for prolonged periods of time can stress, stretch, and strain the finger tendons and activation muscles of the forearm. When the tendons are over exerted and not given adequate recuperation time they can get frayed, stretched, scarred, and inflamed which can lead to injuries such as tendinitis, stenosing tenosynovitis, or stenosing tenosynovitis crepitans (trigger finger). The amount of time employees spend with knives and hooks in their hand should be limited by rotation, and rest. The work day for tasks which require highly repetitive motions or which require prolonged periods of force exertion should be limited to no more than 8 hours a day with only occasional extended day shifts. Provide mechanical devices where ever possible to pull the meat thus eliminating the need to pull the hook with manual hand force.

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. Where possible supply sit/stand stools or foot rests 4 to 6 inches above the floor so employees can adjust the positions in which they work to minimize the amount of loading on any one muscle group.

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.

The specific task analysis of the video documentation collected at this beef slaughter operation follows. Each task was studied to determine the ergonomic effects of several different factors. These factors are:


  • Frequency of the action or 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

KILL FLOOR; CUTTING FRONT FEET - Employees cut the front hooves from a carcass as it passes in front of them on a hanging chain conveyor. The hooves after being severed are placed in a basket which is connected to a separate chain conveyor. This basket then removes the hooves to another area where they are processed. Employees must stand for the duration of the task.

Awkward Postures:

Known Hazard

Employees perform repeated elevated and extended reaches to place severed hooves into baskets located on a chain conveyor. Frequent reaches present a hazard as extending the arm creates a weak position in terms of arm strength. Fully extending the arm 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 acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears. In addition to acute muscle and tendon fatigue and failure there can be chronic tendon wear and tear, inflammation, and thickening from repeated use which is consistent with the development of UECTDs such as bursitis, tendinitis, and rotator cuff injuries.

Known Control


  1. Reduce the distance and elevation employees must reach to perform tasks. Reposition employees to different areas such that they can place the hooves into the basket while maintaining ergonomically neutral postures. There appears to be an area of the chain which can be accessed while employees maintain neutral posture but it is down the line from the area where the depicted employee is stationed. Increasing the distance of chain which is in a lower position to increase safe access should reduce the hazard to all employees down the line. Generally, reaches should be limited to no more than 16 to 17 inches, the hands should stay below shoulder level, and the elbows should be kept in close to the torso.


TASK # 2 Tape time- 00:01:34

KILL FLOOR; HIND LEG (FEET AND WHIZZER) - Employees at this station begin the skinning process. The hide, of the leg which is not attached to the overhead conveyor, is sliced with a traditional in-line knife and is pulled away from the carcass. The carcass then proceeds down the conveyor line where employees cut of the hoof using a hock cutter (giant scissors) and use an in-line whizzard knife to further remove the hide from the carcass. This same employee attaches a new hook to the leg which has previously been skinned which allows the other leg to hang free, permitting employees to remove the hide and cut the hock. Employees stand for the duration of the task.

Awkward Postures:

Known Hazard

Employees perform frequent torso flexions with the arms extended in front of the body to perform cuts and to remove hide from low lying areas of the carcass. Even when there is no load or only a light load lifted flexing the torso creates a hidden lifting task with the weight of the entire upper body requiring support. Increasing the flexion of the torso increases the compressive forces on the low back as muscle force must continually be increased to counteract the downward force created by the load lifted and the weight of the upper body. Compressive forces generated on the spine of the low back are increased as muscle force is increased, since the spine is the focal point for the antagonistic forces created by contraction of the back muscles and the downward pull of the load. Frequent torso flexions are consistent with the development of low back injuries such as muscle strain and disk herniation. 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. Lower employees such that they can perform their task while maintaining the torso in an ergonomically neutral posture. Tasks should be able to be performed while flexing the torso no more than about 6 to 10 degrees from vertical.
  2. Create stages of the catwalk where employees work on areas of the carcass at appropriate heights. The catwalk should not be the same elevation for all employees unless the height of the chain conveyor is adjusted to elevate or lower the carcass at various stages of the operation.
  3. Educate the employee on the basics of body biomechanics and the importance of maintaining the back in an ergonomically neutral position.
Known Hazard

The straight in-line design of the blade knife and air knife used by the employees cutting and removing the hide requires repeated exertion of finger force usually with the wrist in a deviated posture. The knives in-line design and slick handle material requires deviation of the wrist and exertion of additional finger force to maintain adequate control of the tool. Deviating the wrist bends the tendon and sheath over the bony and ligamentous elements of the wrist. When the tendon unit is pulled taut by exerting finger force there can be contact trauma which can abrade, fray, and irritate the tendon and/or its sheath creating inflammation, swelling, and hinderance to movement. Repeatedly exerting finger force or exerting finger force for a prolonged period of time, especially when the wrist is deviated is consistent with the development of UECTDs such as tendinitis, tenosynovitis, stenosing tenosynovitis, muscle strain, and carpal tunnel syndrome. Factors which increase the necessary finger force increase the risk injury.

Known Control


  1. Educate employees on the basics of body biomechanics and the importance of maintaining the wrist in an ergonomically neutral position. The wrist should remain straight at all times with little bending to either side or up and down.
  2. Provide a knife for the task which can be used with the hand in an ergonomically neutral posture.
  3. Experiment with an operating procedure which allows employees to skin the entire top of the leg with the hand in a power grip. This is a posture with the blade positioned downward when held with the hand in an orientation where the thumb is at the end of the handle.
  4. Provide an air knife with a bent handle which can be operated with the hand in an ergonomically neutral posture.
TASK # 3 Tape time- 00:04:28

HIDE REMOVAL WITH AIR KNIFE - Employees use a whizzard air knife to separate the hide from the carcass. Employees are positioned on cat walks and the carcass passes by their position while hanging from a chain conveyor. The hide is removed from the sides of the carcass from about the hind legs to the chest cavity. Employees stand for the duration of the task.

Frequency:

The rate as determined by compliance officer supplied information is about 1000 head of cattle processed per day.

Known Hazard

There are frequent extended reaches, exertions of finger force with the wrist in a deviated posture, 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 associated with this task 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

The straight in-line design of the air knife used by the employees removing hides requires repeated exertion of finger force usually with the wrist in a deviated posture. The slick handle material requires exertion of additional finger force to maintain adequate control of the tool. Deviating the wrist bends the tendon and sheath over the bony and ligamentous elements of the wrist. When the tendon unit is pulled taut by exerting finger force there can be contact trauma which can abrade, fray, and irritate the tendon and/or its sheath creating inflammation, swelling, and hinderance to movement. Repeatedly exerting finger force or exerting finger force for a prolonged period of time, especially when the wrist is deviated is consistent with the development of UECTDs such as tendinitis, tenosynovitis, stenosing tenosynovitis, muscle strain, 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. The wrist should remain straight at all times with little bending to either side or up and down.
  2. Provide an air knife with a bent handle or an adjustable head which can be operated with the hand in an ergonomically neutral posture.
Known Hazard

Employees use repeated, extended and elevated reaches to perform skinning operations. Frequent reaches present a hazard as extending the arm creates a weak position in terms of arm strength. Fully extending the arm 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 acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears. In addition to acute muscle and tendon fatigue and failure there can be chronic tendon wear and tear, inflammation, and thickening from repeated use which is consistent with the development of UECTDs such as bursitis, tendinitis, and rotator cuff injuries.

Known Control


  1. Reduce the distance employees must reach to perform skinning tasks. Generally, reaches should be limited to no more than 16 to 17 inches vertically and horizontally should be limited between shoulder and waist height. All tasks should be able to be performed with the elbows in close to the torso.
  2. Elevate or lower employees such that they can perform their task while maintaining the torso in an ergonomically neutral posture.
  3. Create stages of the catwalk where employees work on areas of the carcass at appropriate heights. The catwalk should not be the same elevation for all employees unless the height of the chain conveyor is adjusted to elevate or lower the carcass at various stages of the operation.
TASK # 4 Tape time- 00:06:36

HEAD DROPPER - Employees use a traditional straight in-line knife to trim the connecting tissues of the ears and to cut the connective tissues in the neck which secures the head to the carcass. this procedure allows the head to drop to the point where it is connected to the carcass only by the wind pipe. Employees stand for the duration of the task.

Workplace Conditions:

Known Hazard

The head dropping employee is standing too low in relation to the carcass. This forces the use of elevated hand postures which requires the elbow to abduct and the wrist to deviate. Prolonged abduction of the elbow creates stress on the musculoskeletal system of the shoulder, upper arm, and upper back which reduces nutrient flow to the area. Reduced nutrient flow slows muscle recovery, limits duration of activity, and makes the muscle, tendon, ligament system more susceptible to acute injury. This is consistent with the development of UECTDs such as musculoskeletal strains, sprains, fatigue and pain. In addition, repeatedly abducting the arm, even while lifting little weight, can lead to chronic wear and tear, and thickening of the unsheathed tendons and bursa of the shoulder which is consistent with the possible development of tendinitis, bursitis, frozen shoulder syndrome and rotator cuff injuries. Deviating the wrist bends the tendon unit over the bony and ligamentous elements of the wrist. When the tendon unit is pulled taut by exerting finger force there can be contact trauma which can abrade, fray, and irritate the tendon and/or its sheath creating inflammation, swelling, and hinderance to movement. Repeatedly exerting finger force or exerting finger force for a prolonged period of time, especially when the wrist is deviated is consistent with the development of UECTDs such as tendinitis, tenosynovitis, stenosing tenosynovitis, muscle strain, and carpal tunnel syndrome.

Known Control


  1. Employees should be elevated to the point where they can perform the elements of the task with the elbows in close to the side and the wrists in an ergonomically neutral posture. The employee depicted on the submitted video documentation appears to need to be elevated approximately 12 inches to lessen the stress of the task.
TASK # 5 Tape time- 00:09:01

HEAD TRIMMING - Employees perform various trimming operations on the head after it has been removed from the carcass. These trimming tasks as depicted seem to require little force, consist of a wide variety of motions, and are generally performed in an ergonomically neutral posture. This job appears to present minimal hazard to the employees, other than the fact that employees must stand for the duration of the task.

TASK # 6 Tape time- 00:09:46

FOOT ROOM - Employees remove hooves from a conveyor line located behind their bodies as they face the work area. They hang the hooves on a hook and trim the hide away. After the hide has been trimmed the hoof is washed and placed back on the conveyor for further processing. Employees use a straight in-line knife to perform the trimming operation and stand for the duration of the task.

Workplace Conditions:

Known Hazard

The current workstation has a fixed hang bar which forces or has the potential to force many employees to perform stressful actions. Fixed height bars require that tall employees flex the torso to perform the task and short employees must reach up necessitating deviation of the wrist or abduction of the elbow away while performing the cutting task. Flexing the torso can lead to low back injuries, deviating the wrist while performing repetitive cutting tasks can cause hand injuries such as tendinitis and carpal tunnel syndrome, and abducting the elbow can stress the shoulder causing bursitis or muscle strain. Additionally the bar is mounted to far away from the wash area which forces employees to repeatedly reach to wash their equipment and the skinned hooves. Reaching to distant locations stresses the shoulder and can lead to acute injuries such as strain and sprain and chronic injuries such as bursitis, tendinitis, and rotator cuff problems. Finally, employees must repeatedly reach past the pointed end of the hook used for hanging the hoof. This appears to create a significant hazard for puncture and stab injuries to the chest and arm.

Known Control


  1. Reorient the hanging hook to be as close to the wash unit as possible. Employees should be able to access the wash while maintaining ergonomically neutral body postures. Generally, reaches should be limited to no more than 16 to 17 inches.
  2. Provide adjustable platforms for employees to stand on or provide adjustability in the hook which holds the leg during trimming operations. The hook should be positioned such that the task can be performed with the hands between the shoulder and waist height and the elbows kept in close to torso. The torso should not be flexed more than about 6 to 10 degrees during task performance.
  3. Educate employees on the basics of body biomechanics and the importance of maintaining the body in ergonomically neutral positions. When providing adjustable equipment it is important to provide adequate training in its safe usage such that employees understand how and why adjustments should be performed.
TASK # 7 Tape time- 00:10:53

TRIMMING ½ CARCASS - Two employees perform this task. One is stationed on the floor and other works from an elevated cat walk. Each employee trims from areas that are appropriate for the work platform on which they are stationed. Both employees trim non-meat items from the ½ carcass as it passes before their station. Both use straight handled in-line knives to perform the trimming operations and stand for the duration of the task.

Awkward Postures:

Known Hazard

The straight in-line knives all require repeated exertions with finger force while the wrist is in a deviated posture. The in-line design of the knives forces the wrist to deviate and the slick handle material require the use of additional finger force to maintain adequate control of the tool. Deviating the wrist bends the tendon unit over the bony and ligamentous elements of the wrist. When the tendon unit is pulled taut by exerting finger force there can be contact trauma which can abrade, fray, and irritate the tendon and/or its sheath creating inflammation, swelling, and hinderance to movement. Repeatedly exerting finger force or exerting finger force for a prolonged period of time, especially when the wrist is deviated is consistent with the development of UECTDs such as tendinitis, tenosynovitis, stenosing tenosynovitis, muscle strain, and carpal tunnel syndrome.

Known Control


  1. Provide and encourage the use of knives with bent handles. It appears that the use of a knife with a handle bend of about 45 degrees would greatly reduce the deviation of the wrist.
  2. Reposition the task such that it can be performed with the hand in an ergonomically neutral posture. Ergonomically neutral postures maintain the wrist in a straight alignment with the arm and limits bending at the wrist in any direction. It appears that elevating the employees to the point where they are working with their hand at about waist level would reduce wrist deviations.
Workplace Conditions:

Known Hazard

Both employee must perform repeated elevated reaches to access areas to be trimmed and employees trimming from the cat walk often must perform repeated deep torso flexions to access lower areas of the carcass. Both of these problems arise from a lack of adjustability in the work station. Repeated elevated reaches stress the shoulder causing UECTDs such as musculoskeletal strain and sprain, bursitis, tendinitis, and rotator cuff injuries. Repeatedly flexing the torso, even when there is little weight supported in the hand is a stressor which can lead to low back injuries.

Known Control


  1. Employees should be provided with fully adjustable work stations which allow them to perform their particular trim operations while maintaining ergonomically neutral postures. Generally, the hand should be maintained below shoulder height and the torso should not be flexed more than 6 to 10 degrees.
  2. Educate employees on the basics of body biomechanics and the importance of maintaining the body in ergonomically neutral positions. When providing adjustable equipment it is important to provide adequate training in its safe usage such that employees understand how and why adjustments should be performed.
TASK # 8 Tape time- 00:12:49

BONERS - Employees retrieve bone-in meat items from a conveyor and remove the bone from the meat by slicing it with an in-line traditional knife. It appears that the meat is replaced to the original conveyor and the bone is thrown up to a different elevated conveyor. Employees stand for the duration of the task.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately 35 to 45 cuts performed each minute.

Known Hazard

There are frequent wrist deviations while exerting finger force, extended reaches, prolonged grasping of hooks, forceful exertions in an upward direction, 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 associated with this task 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.
  3. Employees are performing cuts at about 2400 repetitions per hour. Repetitions in excess of 1500 to 2000 repetitions per hour have been shown to cause tendon and sheath swelling. Generally, repetitions should be kept below 1500 per hour especially for employees who show symptoms of repetitive motion injuries. Employees who show symptoms may have to slow down.
  4. CSHO data indicates that the work shift is routinely at least 10 hours long. This is a very stressful policy which will exacerbate any harmful effects present in a particular task. Studies have shown that the productivity of employees is greatly reduced beyond eight hours. When forced to work beyond their most productive hours employees will slow down unless this is not possible due to machine pacing. To keep up with the machine pacing employees are forced to over exert and are placed under a stress condition. This can lead to a build up of hormones in the blood system, sloppiness in following safe work practices, and a general tightening and tension of the musculoskeletal system all of which are consistent with the accentuation of ergonomically harmful activities. Preventing injury, especially in repetitive motion situations, is dependant on obtaining sufficient rest for the affected body part. Extending the work day reduces the amount of time available for rest and recuperation, since most employees have fixed time requirements for away from work responsibilities. Maintaining a consistent schedule of long work days will generally enhance the harmful effects of stressors present in the workplace making the affected employee more susceptible to injury.
Awkward Postures:

Known Hazard

The knife currently in use requires repeated exertion of finger force usually with the wrist in a deviated posture. The in-line design of the knife forces the wrist to deviate and the slick handle material requires the use of additional finger force to maintain adequate control of the tool. Deviating the wrist bends the tendon unit over the bony and ligamentous elements of the wrist. When the tendon unit is pulled taut by exerting finger force there can be contact trauma which can abrade, fray, and irritate the tendon and/or its sheath creating inflammation, swelling, and hinderance to movement. Repeatedly exerting finger force or exerting finger force for a prolonged period of time, especially when the wrist is deviated is consistent with the development of UECTDs such as tendinitis, tenosynovitis, stenosing tenosynovitis, muscle strain, 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. Provide bent handle knives for any operations where the majority of the time is spent with the wrist in a deviated posture. If possible segment tasks such that a tool can be designed for a particular cut, then the item can be moved to another employee where the next cut is performed with another specialty knife.
  3. Limit the amount of time employees spend performing cutting tasks with a deviated wrist, by rotation, task redesign, or rest periods.
Known Hazard

Employees use repeated, extended and elevated reaches to access meat from the conveyors and to throw meat or bone to upper conveyors. Frequent reaches present a hazard as extending the arm creates a weak position in terms of arm strength. Fully extending the arm 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 acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears. In addition to acute muscle and tendon fatigue and failure there can be chronic tendon wear and tear, inflammation, and thickening from repeated extended and elevated reaches which are consistent with the development of UECTDs such as bursitis, tendinitis, and rotator cuff injuries.

Known Control


  1. Reduce the distance employees must reach to access meat from the conveyor. Reduce the size of the conveyor belt and the cutting boards to the minimum depth necessary to perform the task. Generally, reaches should be limited to no more than 16 to 17 inches.
  2. Reduce the height of the overhead conveyors. The ones in use for the depicted tasks appear to be about twice as high as is necessary to allow passage of the meat underneath. All repetitive tasks should be able to be performed with the elbows kept in close to the torso and elevated hand positions limited to about shoulder height.
Forceful Exertions:

Known Hazard

Employees must forcefully grasp the meat hooks and knives for prolonged periods of time. The knife hand can relax at times when meat is brought to the table but the hook hand is in almost constant use. Exerting force for prolonged periods of time can stress, stretch, and strain the finger tendons and activation muscles of the forearm. When the tendons are over exerted and not given adequate recuperation time they can get frayed, stretched, scarred, and inflamed which can lead to injuries such as tendinitis, stenosing tenosynovitis, or stenosing tenosynovitis crepitans (trigger finger)

Known Control


  1. Limit the amount of time employees spend with knives and hooks in their hand by rotation, and rest. The work day for tasks which require highly repetitive motions or which require prolonged periods of force exertion should be limited to no more than 8 hours a day with only occasional extended day shifts.
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

Several employees depicted on the submitted video documentation are too tall for the cutting area in which they are stationed. These employees must continually flex the torso forward to gain adequate access to the items to be worked on. Working with the torso flexed forward even when there is no load or only a light load lifted creates a hidden lifting task with the weight of the entire upper body requiring support. Increasing the flexion of the torso increases the compressive forces on the low back as muscle force must continually be increased to counteract the downward force created by the load lifted and the weight of the upper body. Compressive forces generated on the spine of the low back are increased as muscle force is increased, since the spine is the focal point for the antagonistic forces created by contraction of the back muscles and the downward pull of the load. Frequent torso flexions are consistent with the development of low back injuries such as muscle strain and disk herniation. 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 adjustable work areas where they can work in ergonomically desirable postures. Employees should be able to work while maintaining the back in a vertical posture with less than 6 to 10 degrees of forward bend. Work should be positioned at elbow height or slightly lower as measured when the arms hang straight down to the side. If permanently mounted stations are used they should be adjusted for the tallest employees and platforms should be provided for shorter employees.
TASK # 9 Tape time- 00:16:33 & 00:18:10

RIB BONER - This task appears to have essentially the same hazards associated with it that the TASK # 8 boners have. Strategies which were applicable for that operation should be appropriate in this task also.

TASK # 10 Tape time- 00:17:53

TRIMMING CAP MEAT - Employees retrieve met from a conveyor which runs directly in front of their station. They then use a straight in-line knife to trim non-meat items away from the meat. After trimming is accomplished the meat is moved to another employee located directly to the side of the trimmer for further processing. Employees stand for the duration of the task.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately 30 to 35 cuts per minute.

Known Hazard

There are frequent exertions of finger force, extended reaches, prolonged grasping of hooks, 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 associated with this task 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.
  3. Employees are performing cuts at about 1800 repetitions per hour. Repetitions in excess of 1500 to 2000 repetitions per hour have been shown to cause tendon and sheath swelling. Generally, repetitions should be kept below 1500 per hour especially for employees who show symptoms of repetitive motion injuries. Employees who show symptoms may have to slow down.
  4. CSHO data indicates that the work shift is routinely at least 10 hours long. This is a very stressful policy which will exacerbate any harmful effects present in a particular task. Studies have shown that the productivity of employees is greatly reduced beyond eight hours. When forced to work beyond their most productive hours employees will slow down unless this is not possible due to machine pacing. To keep up with the machine pacing employees are forced to over exert and are placed under a stress condition. This can lead to a build up of hormones in the blood system, sloppiness in following safe work practices, and a general tightening and tension of the musculoskeletal system all of which are consistent with the accentuation of ergonomically harmful activities. Preventing injury, especially in repetitive motion situations, is dependant on obtaining sufficient rest for the affected body part. Extending the work day reduces the amount of time available for rest and recuperation, since most employees have fixed time requirements for away from work responsibilities. Maintaining a consistent schedule of long work days will generally enhance the harmful effects of stressors present in the workplace making the affected employee more susceptible to injury.
Awkward Postures:

Known Hazard

Employees use repeated, extended reaches to access meat from the conveyors. Frequent reaches present a hazard as extending the arm creates a weak position in terms of arm strength. Fully extending the arm 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 acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears. In addition to acute muscle and tendon fatigue and failure there can be chronic tendon wear and tear, inflammation, and thickening from repeated extended and elevated reaches which are consistent with the development of UECTDs such as bursitis, tendinitis, and rotator cuff injuries.

Known Control


  1. Reduce the distance employees must reach to access meat from the conveyor. Reduce the size of the conveyor belt and the cutting boards to the minimum depth necessary to perform the task. Generally, reaches should be limited to no more than 16 to 17 inches.
Forceful Exertions:

Known Hazard

Employees must forcefully grasp the meat hook and knives for prolonged periods of time. The knife hand can relax at times when meat is brought to the table but the hook hand is in almost constant use. Exerting force for prolonged periods of time can stress, stretch, and strain the finger tendons and activation muscles of the forearm. When the tendons ore over exerted and not given adequate recuperation time they can get frayed, stretched, scarred, and inflamed which can lead to injuries such as tendinitis, stenosing tenosynovitis, or stenosing tenosynovitis crepitans (trigger finger)

Known Control


  1. Limit the amount of time employees spend with knives and hooks in their hand by rotation, and rest. The work day for tasks which require highly repetitive motions or which require prolonged periods of force exertion should be limited to no more than 8 hours a day with only occasional extended shifts.
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 # 11 Tape time- 00:19:00

H-BONERS - Employees retrieve bone-in meat items from a conveyor and remove the bone from the meat by slicing it with an in-line traditional knife. It appears that the meat is replaced to the original conveyor and the bone is thrown up to a different elevated conveyor. Employees stand for the duration of the task.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately 45 to 70 cuts performed each minute.

Known Hazard

There are frequent finger exertions, extended reaches, prolonged grasping of hooks, forceful exertions in an upward direction, 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 associated with this task 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.
  3. Slower employees are performing cuts at about 2700 repetitions per hour. Repetitions in excess of 1500 to 2000 repetitions per hour have been shown to cause tendon and sheath swelling. Generally, repetitions should be kept below 1500 per hour especially for employees who show symptoms of repetitive motion injuries. Employees who show symptoms may have to slow down.
  4. CSHO data indicates that the work shift is routinely at least 10 hours long. This is a very stressful policy which will exacerbate any harmful effects present in a particular task. Studies have shown that the productivity of employees is greatly reduced beyond eight hours. When forced to work beyond their most productive hours employees will slow down unless this is not possible due to machine pacing. To keep up with the machine pacing employees are forced to over exert and are placed under a stress condition. This can lead to a build up of hormones in the blood system, sloppiness in following safe work practices, and a general tightening and tension of the musculoskeletal system all of which are consistent with the accentuation of ergonomically harmful activities. Preventing injury, especially in repetitive motion situations, is dependant on obtaining sufficient rest for the affected body part. Extending the work day reduces the amount of time available for rest and recuperation, since most employees have fixed time requirements for away from work responsibilities. Maintaining a consistent schedule of long work days will generally enhance the harmful effects of stressors present in the workplace making the affected employee more susceptible to injury.
Awkward Postures:

Known Hazard

Employees use repeated, extended and elevated reaches to access meat from the conveyors and to throw meat or bone to upper conveyors. Frequent reaches present a hazard as extending the arm creates a weak position in terms of arm strength. Fully extending the arm 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 acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears. In addition to acute muscle and tendon fatigue and failure there can be chronic tendon wear and tear, inflammation, and thickening from repeated extended and elevated reaches which are consistent with the development of UECTDs such as bursitis, tendinitis, and rotator cuff injuries.

Known Control


  1. Reduce the distance employees must reach to access meat from the conveyor. Reduce the size of the conveyor belt and the cutting boards to the minimum depth necessary to perform the task. Generally, reaches should be limited to no more than 16 to 17 inches.
  2. Reduce the height of the overhead conveyors. The ones in use for the depicted tasks appear to be about twice as high as is necessary to allow passage of the meat underneath. All repetitive tasks should be able to be performed with the elbows kept in close to the torso and elevated hand positions limited to about shoulder height.
Forceful Exertions:

Known Hazard

Employees must forcefully grasp the meat hooks and knives for prolonged periods of time. The knife hand can relax at times when meat is brought to the table but the hook hand is in almost constant use. Exerting force for prolonged periods of time can stress, stretch, and strain the finger tendons and activation muscles of the forearm. When the tendons ore over exerted and not given adequate recuperation time they can get frayed, stretched, scarred, and inflamed which can lead to injuries such as tendinitis, stenosing tenosynovitis, or stenosing tenosynovitis crepitans (trigger finger)

Known Control


  1. Limit the amount of time employees spend with knives and hooks in their hand by rotation, and rest. The work day for tasks which require highly repetitive motions or which require prolonged periods of force exertion should be limited to no more than 8 hours a day with only occasional extended day shifts.
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 # 12 Tape time- 00:20:31

TOP BUTT BONERS - Employees retrieve bone-in meat items from a conveyor and remove the bone from the meat by slicing it with an in-line traditional knife. It appears that the meat is replaced to the original conveyor and the bone is thrown up to a different elevated conveyor. Employees stand for the duration of the task.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately 35 to 40 cuts performed each minute.

Known Hazard

There are frequent wrist deviations while exerting finger force, extended reaches, prolonged grasping of hooks, forceful exertions in an upward direction, 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 associated with this task 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.
  3. Employees are performing cuts at about 1900 repetitions per hour. Repetitions in excess of 1500 to 2000 repetitions per hour have been shown to cause tendon and sheath swelling. Generally, repetitions should be kept below 1500 per hour especially for employees who show symptoms of repetitive motion injuries. Employees who show symptoms may have to slow down.
  4. CSHO data indicates that the work shift is routinely at least 10 hours long. This is a very stressful policy which will exacerbate any harmful effects present in a particular task. Studies have shown that the productivity of employees is greatly reduced beyond eight hours. When forced to work beyond their most productive hours employees will slow down unless this is not possible due to machine pacing. To keep up with the machine pacing employees are forced to over exert and are placed under a stress condition. This can lead to a build up of hormones in the blood system, sloppiness in following safe work practices, and a general tightening and tension of the musculoskeletal system all of which are consistent with the accentuation of ergonomically harmful activities. Preventing injury, especially in repetitive motion situations, is dependant on obtaining sufficient rest for the affected body part. Extending the work day reduces the amount of time available for rest and recuperation, since most employees have fixed time requirements for away from work responsibilities. Maintaining a consistent schedule of long work days will generally enhance the harmful effects of stressors present in the workplace making the affected employee more susceptible to injury.
Awkward Postures:

Known Hazard

Employees use repeated, extended and elevated reaches to access meat from the conveyors and to throw meat or bone to upper conveyors. Frequent reaches present a hazard as extending the arm creates a weak position in terms of arm strength. Fully extending the arm 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 acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears. In addition to acute muscle and tendon fatigue and failure there can be chronic tendon wear and tear, inflammation, and thickening from repeated extended and elevated reaches which are consistent with the development of UECTDs such as bursitis, tendinitis, and rotator cuff injuries.

Known Control


  1. Reduce the distance employees must reach to access meat from the conveyor. Reduce the size of the conveyor belt and the cutting boards to the minimum depth necessary to perform the task. Generally, reaches should be limited to no more than 16 to 17 inches.
  2. Reduce the height of the overhead conveyors. The ones in use for the depicted tasks appear to be about twice as high as is necessary to allow passage of the meat underneath. All repetitive tasks should be able to be performed with the elbows kept in close to the torso and elevated hand positions limited to about shoulder height.
Forceful Exertions:

Known Hazard

Employees must forcefully grasp the meat hooks and knives for prolonged periods of time. The knife hand can relax at times when meat is brought to the table but the hook hand is in almost constant use. Exerting force for prolonged periods of time can stress, stretch, and strain the finger tendons and activation muscles of the forearm. When the tendons ore over exerted and not given adequate recuperation time they can get frayed, stretched, scarred, and inflamed which can lead to injuries such as tendinitis, stenosing tenosynovitis, or stenosing tenosynovitis crepitans (trigger finger)

Known Control


  1. Limit the amount of time employees spend with knives and hooks in their hand by rotation, and rest. The work day for tasks which require highly repetitive motions or which require prolonged periods of force exertion should be limited to no more than 8 hours a day with only occasional extended day shifts.
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 # 13 Tape time- 00:22:00

FLAPMEAT PULLERS AND TRIMMERS - Meat items are presented to the employees by a conveyor belt which runs directly in front of the work station. The meat item is pulled from the conveyor, the flap meat is cut and pulled away from the rest of the unit and given to the trim employee who stands next to the puller. The trim employee cuts off non-meat items and places the finished piece back onto the conveyor. Pullers sometime trim away small pieces of meat which are placed in a box behind the work station. Both employees use straight in-line knives and stand for the duration of the task.

Frequency:

Known Hazard

There are frequent wrist deviations while exerting finger force, extended reaches, prolonged grasping of hooks, 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 associated with this task 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

The knife currently in use requires repeated exertion of finger force usually with the wrist in a deviated posture. The in-line design of the knife forces the wrist to deviate and the slick handle material requires the use of additional finger force to maintain adequate control of the tool. Deviating the wrist bends the tendon unit over the bony and ligamentous elements of the wrist. When the tendon unit is pulled taut by exerting finger force there can be contact trauma which can abrade, fray, and irritate the tendon and/or its sheath creating inflammation, swelling, and hinderance to movement. Repeatedly exerting finger force or exerting finger force for a prolonged period of time, especially when the wrist is deviated is consistent with the development of UECTDs such as tendinitis, tenosynovitis, stenosing tenosynovitis, muscle strain, 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. Provide bent handle knives for operations where the majority of the time is spent with the wrist in a deviated posture. If possible segment tasks such that a tool can be designed for a particular cut, then the item can be moved to another employee where the next cut is performed with another specialty knife.
  3. Limit the amount of time employees spend performing cutting tasks with a deviated wrist, by rotation, task redesign, or rest periods.
Known Hazard

Employees use repeated, extended reaches to access meat from the conveyors. Frequent reaches present a hazard as extending the arm creates a weak position in terms of arm strength. Fully extending the arm 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 acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears. In addition to acute muscle and tendon fatigue and failure there can be chronic tendon wear and tear, inflammation, and thickening from repeated extended and elevated reaches which are consistent with the development of UECTDs such as bursitis, tendinitis, and rotator cuff injuries.

Known Control


  1. Reduce the distance employees must reach to access meat from the conveyor. Reduce the size of the conveyor belt and the cutting boards to the minimum depth necessary to perform the task. Generally, reaches should be limited to no more than 16 to 17 inches.
Forceful Exertions:

Known Hazard

Employees must forcefully grasp the meat hooks and knives for prolonged periods of time. The knife hand can relax at times when meat is brought to the table but the hook hand is in almost constant use. Exerting force for prolonged periods of time can stress, stretch, and strain the finger tendons and activation muscles of the forearm. When the tendons ore over exerted and not given adequate recuperation time they can get frayed, stretched, scarred, and inflamed which can lead to injuries such as tendinitis, stenosing tenosynovitis, or stenosing tenosynovitis crepitans (trigger finger)

Known Control


  1. Limit the amount of time employees spend with knives and hooks in their hand by rotation, and rest. The work day for tasks which require highly repetitive motions or which require prolonged periods of force exertion should be limited to no more than 8 hours a day with only occasional extended day shifts.
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

Some employees depicted are too tall for the station. These employees must continually flex the torso forward to gain adequate access to the items to be worked on. Working with the torso flexed forward is consistent with the development of low back injuries and pain. Other employees are too short which accentuates the amount of wrist deviation used to perform the task. Deviation of the wrist while performing repetitive tasks which require finger force is consistent with the development of UECTDs such as tendinitis and carpal tunnel syndrome.

Known Control


  1. Provide employees with adjustable work areas where they can work in ergonomically desirable postures. Employees should be able to work while maintaining the back in a vertical posture with less than 6 to 10 degrees of forward bend. Work should be positioned at elbow height or slightly lower as measured when the arms hang straight down to the side. If permanently mounted stations are used they should be adjusted for the tallest employees and platforms should be provided for shorter employees.
  2. Provide shorter employees with a work platform such that they can work while maintaining the arms in an ergonomically neutral posture.
TASK # 14 Tape time- 00:23:27

FLANKMAN - A large section of meat is brought to the employee while still hanging on the overhead chain conveyor. A slab of meat is cut away from the lower end of the main section and then a second smaller piece is cut from the upper end closest to the hook. Pieces which have been removed are dropped to a conveyor and the main section of meat moves to another area for further processing. Employees use a straight in-line knife and stand for the duration of the task.

Frequency:

The rate calculated from the video segment submitted for analysis is approximately 4 flanks trimmed every minute.

Known Hazard

There are frequent extended and elevated reaches, 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 associated with this task 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 repeated, elevated reaches to access meat hanging from the chain conveyor. Repeatedly lifting the arm, even while lifting little weight, can lead to chronic wear and tear, and thickening of the unsheathed tendons and bursa of the shoulder which is consistent with the possible development of tendinitis, bursitis, frozen shoulder syndrome and rotator cuff injuries. Frequent elevated reaches are also consistent with the development of acute shoulder, upper arm, and upper back muscle and tendon fatigue and injury such as strains, sprains, and tears.

Known Control


  1. Reorient the employee in relation to the meat by either elevating the employee or lowering the meat such that ergonomically neutral postures can be maintained at all times. Employees should be able to perform their tasks with the elbows in close to the torso and while limiting vertical hand movement to lower than shoulder height.
  2. This employee does not remove the upper piece of meat from all units which pass before him. Change the standard operating procedure such that he does not routinely perform tasks which require elevated arm lifts.
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.
TASK # 15 Tape time- 00:24:26

ROUND LINE - Employees performing this task remove the meat from the hind leg as it is brought to their work station by an overhead chain conveyor. The meat is cut away from bone and allowed to drop to a belt conveyor which runs under the chain conveyor. Employees use a straight in-line knife and stand for the duration of the task.

Frequency:

The line processes about 2000 rounds per day but the actual production per employee is difficult to determine since there are multiple employees working on the line and duties appear to shift intermittently.

Known Hazard

There are frequent, elevated reaches, forceful exertions to pull the meat from the bone, 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 associated with this task 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.
  3. CSHO data indicates that the work shift is routinely at least 10 hours long. This is a very stressful policy which will exacerbate any harmful effects present in a particular task. Studies have shown that the productivity of employees is greatly reduced beyond eight hours. When forced to work beyond their most productive hours employees will slowdown unless this is not possible due to machine pacing. To keep up with the machine pacing employees are forced to over exert and are placed under a stress condition. This can lead to a build up of hormones in the blood system, sloppiness in following safe work practices, and a general tightening and tension of the musculoskeletal system all of which are consistent with the accentuation of ergonomically harmful activities. Preventing injury, especially in repetitive motion situations, is dependant on obtaining sufficient rest for the affected body part. Extending the work day reduces the amount of time available for rest and recuperation, since most employees have fixed time requirements for away from work responsibilities. Maintaining a consistent schedule of long work days will generally enhance the harmful effects of stressors present in the workplace making the affected employee more susceptible to injury.
Workplace Conditions:

Known Hazard

Employees must routinely reach to elevated positions and flex the torso during the cutting process. Additionally they must perform forceful pulling actions to separate the meat from the bone. These stressors are necessary because the workstation is not designed to reduce these actions. Elevated reaches stress the shoulder and are consistent with the development of chronic injuries such as bursitis and rotator cuff injuries and with acute injuries such as musculoskeletal strain and sprain. Flexing the torso stresses the back and is consistent with the development of low back strain. Repeatedly pulling on meat hooks can stress the fingers, arm, and shoulder causing muscle strain and tendon stretch.

Known Control


  1. The work area should be redesigned to reduce the stressors of the task. The overhead chain conveyor should be height adjustable such that it starts low, allowing the lead employee to perform all cuts which are necessary at the top of the leg. Then the chain could gradually elevate allowing employees to perform other necessary cuts as they reach appropriate heights. In this manner all cuts can be performed while maintaining the body in ergonomically neutral postures.
  2. Attach a chain to a lower position on the floor or the lower conveyor and secure it to the large round. As the upper chain conveyor elevates the entire unit the meat could gradually be pulled from the bone without the employee exerting downward force.