Mechanical energy analyses of the human during local carriage on a treadmill.

Abstract

Variations of the mechanical energy levels of the body segments, as affected by different backpack loads were investigated, to determine if mechanical energy analyses rather than metabolic measures could be used to evaluate load carriage devices. Six male subjects were required to walk upon a level treadmill at 5·54km/hour while they carried five loads ranging from 15·16 to 33·85kg, in a specially designed backpack. Cinefilm was taken, digitized and filtered. Kinematic data, energy levels of the segments of a 15 member linked-segment model and overall work indices were calculated. Expired air was collected and metabolic cost determined. Results showed that about 1/3 of the mechanical work done by all body segments represents energy exchanges within segments and another 1/3 between segments, the major increase in the mechanical work done was in the load itself and virtually no alternations in gait pattern were made by the subjects to accommodate heavier loads. Some undesirable exchanges of energy were evid...