Upper-limb Postures and Movements during Diamond Polishing.

Previous occupational health studies of diamond polishers have identified high rates of musculoskeletal disorders of the hands and arms in this population, specifically, ulnar neuropathy in the right elbow. These disorders may be due to the repetitive and forceful motions of the upper extremity required to manipulate the hand-held polishing tools. A video-based, biomechanical analysis of the upper extremities of polishers at several diamond-processing factories in Israel was conducted. Detailed motion measurements of the wrists, elbows, and shoulders of polishers were made while the subjects performed their usual work. During a typical workday, the basic polishing cycle, which involves a series of stereotyped hand and arm movements, is repeated more than 5,000 times. Sustained, extreme flexion of the right elbow, which is the arm holding the eyepiece, may account for the higher rates of ulnar neuropathy in this extremity.