Ergonomic Evaluation of Rotary Power Input by Hand and Leg Muscles to Operate Farm Equipment

An ergonomic study was conducted to evaluate common postures to facilitate active combination of body muscles to generate rotational motion in static mode. The study was conducted on five modes of posture, namely handle rotation, hand rocking, single foot pedal, dual foot pedal and foot rotation (cycling) for generating rotary motion. A postural dynamometer was developed for loading and recording power load in above-mentioned modes. The experiments were conducted with six subjects in the age group of 20 to 40 years at five levels of mechanical load. During the experiments, physiological and postural parameters were recorded and data was statistically analyzed. Foot cycling mode was found to be best for mechanical power load up to 60W and dual foot pedal mode for 60 to 75 W. Study established the fact that leg muscles are better suited to provide manual power on sustainable basis as in both modes (cycling and dual foot pedal), leg muscles were primarily used.