Effects of load and posture on the recruitment of trunk muscles.
Gallagher-S; Marras-WS; Davis-KG
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):1071-1075
Seven male subjects performed 8 cable lifting and hanging tasks, while trunk kinematics and electromyographic data often trunk muscles were obtained. The objectives of the study were to evaluate trunk muscle recruitment and spine loads resulting from performance of this task in different postures and with different load magnitudes. The eight tasks were combinations of four postures (standing, stooping, kneeling on one knee or both knees) and two levels of load (0 N or 100 N load added to existing cable weight). Results indicated that changes in posture and changes in load magnitude both affected muscle co-activation; however, the influence of these variables were quite different in nature. Increased load magnitude resulted in a generalized increase in the co-activation of all trunk muscles, no matter which posture was employed (p < 0.05). Changes in posture significantly affected trunk muscle recruitment patterns (p < 0.05); however, the posture effect typically involved a relatively small subset of trunk muscles. No significant interactions were detected (p > 0.05), indicating that posture and load effects are both independent and additive.
Muscles; Posture; Spinal-cord-disorders; Muscle-stress; Back-injuries; Manual-lifting; Ergonomics; Workplace-studies; Miners; Mining-industry; Coal-miners; Coal-mining; Spinal-cord; Muscle-contraction; Musculoskeletal-system; Materials-handling; Manual-materials-handling; Manual-lifting
Issue of Publication
Proceedings of the Human Factors and Ergonomics Society 46th Annual Meeting, September 29 - October 4, 2002, Baltimore, Maryland, Bringing Fundamentals & New Opportunities