An investigation of the variability in human performance during manual material handling activities.
Proceedings of the Human Factors and Ergonomics Society 38th Annual Meeting, October 24-28, 1994, Nashville, Tennessee. Santa Monica, CA: Human Factors and Ergonomics Society, 1994 Nov; 38(Ind Erg):578-582
The variability of kinetic parameters describing human performance of manual material handling activities was investigated, as well as the effects of different variables on the magnitude of this variability. The motion of the lumbar trunk of seven male college students performing lifting tasks under various conditions was monitored using the Lumbar Motion Monitor. A biomechanical model was used to calculate instantaneous dynamic external torque about the lumbosacral joint. Significant variability in the magnitude of the peak velocity and acceleration in the sagittal plane was seen, along with significant amounts of motion in the coronal and transverse planes. Examination of the trunk motion data using the biomechanical model indicated a significant effect due to the load weight with greater weight levels having higher levels of variability. Poor coupling at near maximal load levels generated the greatest variability in the sagittal plane, but not in the transverse or coronal planes. The authors conclude that consideration of only average performance profiles underestimates peak torque by between 5% and 15% and underscores the need for stochastic modeling of biomechanical systems.
NIOSH-Grant; Musculoskeletal-system-disorders; Manual-lifting; Manual-materials-handling; Biomechanics; Biophysics
Industrial Engineering North Carolina State Universit Box 7906 Raleigh, NC 27695
Issue of Publication
Proceedings of the Human Factors and Ergonomics Society 38th Annual Meeting, October 24-28, 1994, Nashville, Tennessee, People & Technology in Harmony
North Carolina State University Raleigh, Raleigh, North Carolina