"A review was conducted of the physiological factors which can be used in developing guidelines for manual lifting tasks. Local muscle strength and fatigue are affected by biomechanical factors (cross sectional area of the muscle, work posture, speed of lifting, muscle availability, and whether the lift is one handed or two handed) and physiological factors (duration of force exertion, frequency of repetition). Metabolic limits in lifting tasks were discussed under the following headings: measuring the metabolic cost of lifting activities; factors influencing the metabolic costs of lifting tasks (beginning posture and the vertical travel distance, lifting technique, workload, lifting versus lowering, special lifting situations); the relationship between psychophysically acceptable weights and the metabolic coast of lifting; oxygen consumption prediction models; and determining lifting task limits based on aerobic capacities. Assumptions made in generating frequency correction factors for the lifting guidelines including components of the frequency connection factor table, baseline aerobic capacity assumptions, workload criteria, frequency factor calculations, and determining the lifting frequency and duration were discussed."

Support: Digital