Development of Reach Envelopes for Optimum Location of Tractor Controls Based on Central Indian Male Agricultural Workers

Tractor operator's comfort and safety have received considerable attention abroad particularly with respect to operator's workplace, noise and vibration. It is necessary to design various controls and work place on tractors with due consideration to the anthropometric data of Indian agricultural workers so as to achieve higher performance and efficiency with better comfort and safety of the operators. Therefore, the present study was aimed to develop the hand and leg reach envelopes based on anthropometric data of Central Indian male agricultural workers (N=825) to optimise the location of tractor control levers. The important anthropometric data of agricultural workers used for development of hand and leg reach envelopes were age, weight, stature, elbow grip length, shoulder grip length, elbow rest height, sitting acromial height, knee height sitting, popliteal height sitting, buttock popliteal length, buttock knee length, foot length etc. The mean, 5^th percentile and 95^th percentile data were used to develop the reach envelopes. The analysis of optimum hand reach envelope indicated that the workers hand could reach within the range of 431–636 mm forward and 252–405 mm above the seat reference point (SRP). Similarly, the 5^th percentile leg reach envelope indicated that the workers leg could reach within the range of 460–894 mm forward and 374 mm below the SRP. Therefore, it may be concluded that the frequently operated controls in tractors like steering wheel, clutch pedal, brake pedal, accelerator pedal etc. should be placed in optimum hand and leg reach envelopes for the user population.