Abstract: On December 14, 2007, Employee #1, a farm worker, was digging potatoes in a field, using a tractor and a PTO-driven (apparently power take-off-driven) potato digger. Upon observing that the digger had become clogged with soil and debris, he stopped the tractor and dismounted but did not turn off the engine or disengage the PTO. He began to clear the clog in front of the potato digger, when his sweatshirt became entangled on part of the unguarded operational PTO driveline between the tractor and digger. As the sweatshirt was being wrapped around the driveline, he started to pull his sweatshirt off but the left sleeve began to dig into his arm. He was able to free himself only when his elbow became dislocated. Employee #1 was treated at the site by emergency personnel and then transported to UC Davis Medical Center in Sacramento. He underwent surgery to repair his elbow and a deep laceration to his arm. Employee #1 was released from the hospital on December 17, 2007.