Isometric strength of agricultural workers of Meghalaya: A case study of an Indian population

Abstract

A worker has to exert force using both hand and leg to operate farm tools and equipment. Sometimes torque is also applied, such as when operating steering. The capabilities of the operators have considerable effects on design features and control of farm machinery. However, very little data are available on capabilities of different population segments of Indian agricultural workers. Therefore, a study was carried out to collect these data on male and female agricultural workers of Meghalaya belonging to the Khasi, Jaintia and Garo tribal communities with Mongolian origins. Data were collected on 100 subjects from different parts of Meghalaya state in the north eastern hill region of India of which 52 were male subjects and 48 were female subjects. The 5th and 95th percentile values of different strength parameters were estimated, which needs to be taken in to consideration while designing the various machinery controls. Mean leg strength (right) and foot strength (right) of female agricultural workers (334.1 44.1 N and 199.4 29.4 N) was found to be significantly lower (p < 0.01) than their male counterparts (525.6 40.2 N and 342.9 49.1 N). Similarly, leg and foot strength of female workers in the preferred leg was found to be 63.6 and 58.1% that of male workers. Steering strength is an important design criterion on the basis of which the steering systems of tractors and other self propelled devices are designed, and the mean steering torque was found to be 65.3 8.0 and 49.2 10.7 N m for male and female agricultural workers, respectively. The steering force capability of female agricultural workers was observed to be 75.3% that of male agricultural workers. Relevance to industry: The strength values and design criteria presented in this paper may be used for setting limits for design of manually operated tools and equipment involving push/pull activities, leg strength, torque limits in agriculture as well as in other industrial jobs.