Investigation of measured and modeled hand forces and resulting forces at the low back during the pull phase of a lifting task.
Designing for Everyone, Proceedings of the Eleventh Congress of the International Ergonomics Association, Paris, 1991. Queinnec Y, Daniellou F, Chapon A, eds., London: Taylor and Francis, 1991 Sep; 1:75-77
A study was conducted to measure horizontal and vertical forces applied to the load during a floor to knuckle height lifting task and compare them to acceleration and load derived hand forces calculated by a dynamic biomechanical model Dynalift. Two experiments were designed to investigate the effects of speed of lift, frequency of lift, load, and weight on the measured peak applied hand forces to the load. The study subjects included five college students. The measured peak horizontal and vertical hand forces were significantly greater than peak hand forces calculated using the Dynalift model. The speed of lift, frequency of lift, and percent maximal acceptable weight of lift had significant effects on peak hand force. For the fast speed of lift the peak measured vertical hand forces were three to 3.5 times larger than the magnitude of the load. At slow speeds they were approximately double the load. Peak measured horizontal hand forces were about equal to the magnitude of the load for the fast speed, but the peak horizontal hand force was only half the load for slow speeds. Only fast lifts had significantly greater peak L5/S1 compression and shear forces calculated when the measured hand forces were input into the model than when the hand forces were calculated only with acceleration and load information. The increase in peak L5/S1 compression was 104 to 111% that of modeled without input of measured hand forces.
NIOSH-Grant; Musculoskeletal-system; Manual-materials-handling; Manual-lifting; Work-capacity; Humans; Ergonomics; Biomechanics; Biophysics
Industrial Engineering Texas Tech University PO Box 4130 Lubbock, TX 79409
Queinnec-Y; Daniellou-F; Chapon-A
Designing for Everyone, Proceedings of the Eleventh Congress of the International Ergonomics Association, Paris, 1991
Texas Tech University, Lubbock, Texas