Isometric muscle strength of male agricultural workers of India and the design of tractor controls

A man’s working capacity depends significantly on his muscular strength. There is a lack of muscular strength data for the Indian population. Therefore, this study was conducted to generate data of the isometric muscle strength of agricultural workers for the efficient and safe design of agricultural machines. Sixteen isometric muscular strength parameters were identified that were suitable for the design of agricultural hand tools and equipment. Each of these dimensions was precisely measured from 379 male agricultural workers from the northeastern region of India. Their ages ranged from 18 to 60 years. The collected data were statistically analyzed. The muscular strength was the highest for the right leg (363.2 N) and the lowest for the left hand push strength (112.4 N). A comparison of mean values indicated that the right handgrip strength was 15.1% higher than the left handgrip strength. The right hand push strength was 4.7% higher than the left hand push strength, and the right hand pull strength was 4.9% higher than the left hand pull strength. The push and pull strengths as well as the leg and foot strengths were significantly (p < 0.01) different. From the data, it is clear that muscular strength decreases with increasing age. However, there is hardly any correlation (lower than −0.17) between the age and strength parameters. The correlation among the various strength parameters was the highest (0.86) between the right and left handgrip strengths. In general, the push and pull strength, leg and foot strength, torque strength with both hands and torque strength with the preferred hand were the parameters that were most positively correlated.The data were intended to be used for the design and the design modification of agricultural hand tools and equipment with the goal of reducing drudgery and increasing the level of efficiency, safety and comfort to the users. Therefore, an attempt was made to illustrate the relevance of these data in the design of tractor controls.Relevance to industryIn India, about 150 million farm machinery and over 3 million tractors are currently in use. The present study provides the basic data for the design of various agricultural hand tools and machinery, which will be helpful for the tractor and agricultural machinery designers.