Wrist and forearm postures and velocities in repetitve precision tasks.
Shyhalla-K; Paquet-V; Drury-C
Proceedings of the Human Factors and Ergonomics Society 46th Annual Meeting, September 29 - October 4, 2002, Baltimore, Maryland, Bringing Fundamentals & New Opportunities. Santa Monica, CA: Human Factors and Ergonomics Society, 2002 Sep; 46(Ind Erg):1041-1045
Precision work has been shown to impose physical demands over and above similar work that does not require precision. but few studies have evaluated the effects of such work on the musculoskeletal stress of the upper extremities. Repetitive tasks that involved moving between a Home disk and a precision target were studied. The movements from the Home to the target were divided into a ballistic phase, followed by a slower homing-in phase. Work in two layouts, with the target in front of, or to the side of the Home disk, and three levels of precision were investigated for each phase of the home-to-target movement. Wrist and forearm postures and joint velocities were significantly different (P < 0.05) during the ballistic and homing in phases of travel for 21 of the 24 indices considered. Postures changed rapidly during the ballistic. but were sustained during the homing-in phase. Work in the forward versus side layouts produced statistically different joint angles and velocities (P < 0.05) for 17 of the 24 indices considered. Different levels of task precision elicited statistically differences in 5 of the 12 joint velocities (P < 0.05). Interactions were also important. The phase of movement factor produced statistically significant interactions with layouts (P < 0.05) for 11 of 12 postures and 5 of 12 velocities. and with levels of precision (P < 0.05) for 5 of 12 velocities. With such important interaction effects, it is clear that breaking repetitive precision tasks into distinct phases promotes a better understanding of how precision work affects the musculoskeletal stress of the upper extremities. Graphical representations also show differences in how joint velocities were impacted by levels of precision for the forward and side layouts.
Physiological-function; Musculoskeletal-system; Musculoskeletal-system-disorders; Stress; Posture; Ergonomics; Humans; Task-performance; Muscle-stress; Human-factors-engineering; Muscular-disorders; Muscle-tension; Statistical-analysis; Injury-prevention; Neck-injuries; Arm-injuries; Cumulative-trauma; Cumulative-trauma-disorders; Repetitive-work
Issue of Publication
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
Proceedings of the Human Factors and Ergonomics Society 46th Annual Meeting, September 29 - October 4, 2002, Baltimore, Maryland, Bringing Fundamentals & New Opportunities
University of Buffalo, Buffalo, New York