Segmental Proportions Based on Anthropometry of Female Agricultural Workers, India

Introduction

The word ‘anthropometry’ means measurement of the human body. Anthropometry is the science of measurement and the art of application that establishes the physical geometry, mass properties, and strength capabilities of the human body [1]. It involves the systematic measurement of the physical properties of the human body, primarily dimensional descriptors of body size and shape. The knowledge of body dimensions is essential for designers of equipment and work places. The anthropometric measurements are essential for the correct design of the work areas [2, 3, 4].

India is an agriculture-based country. A large section of Indian population engages in agriculture. Although agriculture is generally recognized as the nation’s most hazardous industry and displays high rates of MSDs with evidence in which the ergonomic risk factors are involved and be pointed out, there is very little history of application of ergonomic approaches in agricultural equipment design. About 6.5% of the power used in crop production and related activities in the country is contributed by about 241 million workers, of which about 42% (i.e. 101 million) are female workers. Thus, the human workers play a major role in the country’s agriculture and due to that, attention needs to be given to their capabilities and limitations during design and operation of various farm equipment’s, so as to get higher productivity, enhanced comfort and ensure better safety [5, 6]. Manually operated equipment’s are extensively used in Indian agriculture for various farm operations starting from seedbed preparation to post-harvest operations.

The ergonomic principles or human factors are considered in machine design to enhance effectiveness, efficiency, safety and comfort of the users/operators of the equipment. In most cases, constraints are been experienced in adoption of improved machineries being utilized in other parts of the country; the adopted equipment at times need to be modified before being introduced into other countries or regions to suit agricultural workers of the region for which body dimensions limits of local populations was required. Because of Yadav, et al. [7] pointed out that there was considerable difference between the anthropometric data of Indian and westerns. To design any product for human use, engineers have to rely on anthropometric data, otherwise the resulting product may turn out to be ergonomically incompatible [8].

Gite and Yadav [9] noted that the design and dimensions of agricultural tools and implements have great bearing on the body dimensions and physical built of the users, requiring compatibility essentially between machine devices and worker body dimensions. Dewangan, et al. [10] suggested that the only way to fulfill this objective is to create database of anthropometric dimensions of the user population. Therefore, a sample study was conducted to collect and analyse the anthropometric data of female agricultural workers of Gujarat state for the ergonomic design of farm equipment and workplaces.

Materials and Methods

An anthropometric survey was carried out in Gujarat states of India. For the collection of data, survey was carried out in all the districts of the Gujarat states. Total 382 subjects in the age group 22–54 years of age were randomly chosen from state. Simple random sampling was used to select farm women. The selected female workers were engaged in various agricultural operations on the farms. Subjects were screened so that those in normal health without any serious disease or physical handicapped were selected. Total 38 body dimensions including weight were identified for measurement, which were important in the design of agricultural equipment and workplace.

The standard terminologies of selected anthropometric dimensions and measurement landmarks for as suggested in the anthropometric source book are shown in Figure 1 [11, 12]. The team of researchers was trained for a week on how to recognize the dimensions to be measured, to use measuring instruments and to record data into a log sheet. Subjects were chosen randomly, having normal appearance and having no physical disabilities. Before the measurements were made, the subjects were given an explanation about the purpose of the study. Only subjects who gave their consent were considered further. All subjects wore light clothing without foot wears. For standing dimensions, subjects were asked to stand upright on the base of the anthropometer, facing forward, and arms hanging beside the body. For sitting dimensions, subjects were asked to sit erect on a chair without armrests, with knees bent 90°and feet flat on the surface, facing forward, and arms hanging beside the body.

Forty (40) anthropometric body dimensions considered useful for design of agricultural equipment/machines. There were 17 body measurements in standing posture, 15 measurements in sitting posture and six measurements in either sitting or standing posture. In addition, two antropometric indices viz. body mass index (BMI) and relative sitting height (RSH) were calculated from the measured anthropometric data. The BMI is defined as the body mass (kg) divided by the square of the stature (m), whereas the RSH is the ratio of sitting height to stature. All the measurements of each subject were taken three times.

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The data was further analysed and in addition to the descriptive values, 5thand 95thpercentile values were also calculated. Each group of data was included in statistical analysis. Collected data were first entered in Microsoft Excel and then for statistical analysis were transferred to

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Figure 3: Segmental proportions as a function of stature (H) for different percentile female agricultural workers of central India in sitting posture. (i: sitting height, j: eye height (sitting), k: acromion height (sitting), l: elbow rest height, m: popliteal height (sitting), n: knee height (sitting), o: shoulder grip length, p: elbow grip length, q: buttock popliteal length, r: buttock knee length).

The data set for each dimension in the sample’s group were checked to ensure that they represent a normal distribution. Furthermore, 18 particular body dimensions were chosen to illustrate the differences of segment proportions of 5th and 95th percentile female agricultural workers in both standing posture namely eye height, acromial height, olecranon height, trochanteric height, knee height, biacromial breadth, elbow-elbow breadth and hip breadth were selected (Figure 2). In addition, ten body dimension measured in sitting posture namely sitting height, eye height (sitting), shoulder grip length, elbow grip length, buttock popliteal length and buttock knee length were selected (Figure 3).

Conclusions

Total 382 healthy female agricultural workers were selected as subjects for taking anthropometric data. They were in the age group of 22-54 years. During the survey, all together 38 body dimensions were precisely recorded from each subject. The segmental proportions of anthropometric data as a function of stature, in standing posture namely knee height, elbow-elbow breadth and hip breadth; and in sitting posture namely elbow rest height increased considerably with measure of stature from 5th to 95th percentile. It was observed that there was a large variation in the anthropometric data when the results were compared with the anthropometric data of different states of India. The selected subjects were taller than female agricultural workers from north-eastern and eastern states of India but shorter than the northern states of India. The similar trend was observed for most of the body dimensions. When anthropometric data compared to the American, British, Portuguese, Swedish, Turkish and Nigerian female workers it can be seen that Indian female population are shorter in stature, sitting height, buttock knee length, buttock popliteal length and hip breadth. The large difference found in anthropometric dimensions of different population groups indicated that a distinctive nature of the anthropometry. Therefore, there is requirement of suitably modifying or redesigning of existing farm equipment before introducing these to the Indian farm workers.