Kinematics of the pelvis and lumbar spine during kneeling, stooping, and standing lifts.
Proceedings of the Human Factors and Ergonomics Society 42nd Annual Meeting, October 5-9, 1998, Chicago, Illinois, Human-System Interaction: The Sky's No Limit. Santa Monica, CA: Human Factors and Ergonomics Society, 1998 Oct 42(Posters):1621
Six underground miners (mean age=42 years) performed twelve lifting tasks (in kneeling, stooping, and standing postures), during which kinematic data of the pelvis and lumber spine were collected. The lifting task involved lifting heavy electrical cable from the ground to a ceiling of variable height. Postures evaluated included kneeling (lifts to 1.2 and 1.5 meters), stooping (lifts to 1.2 and 1.5 meters), and standing (lifts to 1.8 and 2.1 meters). Lumbopelvic flexion was significantly lower in kneeling tests than in other postures (p<0.001). Pelvic flexion averaged 2-4 degrees when kneeling, while lumbar flexion averaged 16-20 degrees. Stooping tasks resulted in the highest lumbopelvic flexion (p<0.001). Overall Flexion averaged 60 degrees when stooping under a 1.2 meter ceiling, and averaged 45 degrees under a 1.5 meter ceiling. The pelvic contribution to flexion in stooping tasks averaged 12-16 degrees, the balance resulting from lumbar flexion. Standing lifts resulted in lumbopelvic flexion that averaged slightly lower than stooping tasks. Overall flexion during standing tasks ranged from 31-48 degrees, with approximately 75% due to lumbar flexion. Results of this study will be used to develop recommendations for lifting in restricted postures.
Posture; Back-injuries; Occupational-hazards; Ergonomics; Mining-industry; Safety-practices; Underground-mining
National Institute for Occupational Safety and Health, P.O. Box 18070, Pittsburgh Research Laboratory, Pittsburgh, PA 15236
Issue of Publication
Proceedings of the Human Factors and Ergonomics Society 42nd Annual Meeting, October 5-9, 1998, Chicago, Illinois, Human-System Interaction: The Sky's No Limit