A physiological study of the repetitive lifting capabilities of healthy young males.

In emergencies, it may be necessary for men to manually handle very large quantities of materials. Although data are available for loads carried on the back and there are specific civilian and military recommendations concerning safe maximum loads and acceptable workloads for repetitive lifting, data quantifying maximum capabilities for repetitive lifting tasks are not available. We have therefore undertaken a preliminary study to determine the relationship between lifting rate and time to exhaustion using three standard loads. Eight healthy fit, well-trained young soldiers bi-manually lifted 3 loads lpar;25, 50 and 75percnt; of their maximal lifting capacity (MLC) for a single lift to waist height) from the floor to a platform at waist height (40% stature) situated directly in front of them at lifting rates of 2,3 and 4 lifts min−1 (75% MLC), 4,6 and 8 lifts min−1 (50% MLC) and at 8,10 and 12 lifts min−1 (25% MLC) for one hour or until they became exhausted or were unwilling or unable to continue or main...