Anthropometry and Ergonomics: An Urgency for Farm Mechanization in Nepal
“Let the words speak” by SOMES-ERC in association with Ednep.com. This article by Raksha Niraula stood second in the competition.
Nepal is an overwhelmingly agricultural country in terms of population engagement with various studies suggesting two-third of population engaged in some form of agriculture. The contribution of agriculture to national GDP stands at 26.98%, although it has been at a decreasing trend [1]. Year-on-year the remittance inflow in the country has been at an increasing rate, which explains the booming rate of outmigration observed among youths, mainly the male population. It was reported that remittance alone contributed to 29% of GDP in FY 2018/19 [2].
The growing shift of employment from agricultural to non-agricultural sector could be checked to a certain extent by making farming easier or reducing drudgery. This could be achieved by anthropometric study resulting in design of ergonomically-sound farm tools.
Anthropometry and it’s importance
By women-centric innovations, I am emphasizing on the anthropometric design of the farm tools, equipment and machineries. Anthropometry is the science of measurement and the art of application that establishes the physical geometry, mass properties and strength capabilities of human body [3]. It involves the systematic measurement of the physical properties of the human body, primarily dimensional descriptors of body size and shape [3].
Variation in anthropometric dimensions is significant across gender, race and age. Within a particular group also the anthropometry differs due to nutritional status and nature of work. In order to optimize the performance and efficiency while enhancing comfort and safety to the operator, it is necessary to design tools, equipment and workplaces keeping in view of the anthropometric data of the agricultural workers [4].
Anthropometric body dimensions play quintessential role in human-machine interaction. Anthropometric data helps the designers to develop and introduce machines suiting to the requirements of the population so that human drudgery in operation could be minimized and operators’ comfort enhanced.
Ergonomics and it’s importance
Ergonomics or human factors engineering is the application of psychological and physiological principles to the engineering and design of products, processes, and systems [5]. Ergonomics aims at reducing human error, increasing productivity and optimizing comfort and safety in the interaction between humans and other elements of a system [5]. The principles of ergonomics are useful in the design of small things such as chair to a large machine such as a combine harvester.
Out of many disciplines which act as building blocks to modern ergonomics such as psychology, industrial design, anthropometry, biomechanics, physiology and so on, anthropometry play the most significant role as it is concerned with the fundamental measurement and geometry of the human body. It should be noted that without anthropometry, an ergonomically sound device, machine or instrument cannot be designed.
Ergonomics play a vital role in agriculture especially in human-machine or human-tool interaction. One good use of principles of ergonomics in agriculture is the design of tractors, with noise and vibration reduction in the cabin given due importance for the comfort of the operator. The angle and length of steering wheel is not just a random value, but a due consideration is given to factors such as height of the person, hand reach, torque capacity in sitting condition and so on.
Anthropometric measurements in design of farm tools
Various body dimensions and strength parameters are considered while designing farm tools and implements.
Guidelines have been issued by national institutions or international agencies such as by International Organization for Standardization. ISO 7250:2017 deals with “basic human body measurement for technological design” i.e. it describes anthropogenic measurements which can be used as a basis for comparison of population groups and for the creation of anthropometric databases, including the technique for collecting and analyzing such data [6].
As no such guidelines has been drafted yet in Nepal, guidelines and documents of India could also be used as a reference because of similarity in agro-climatic conditions in both countries. Human Engineering and Safety in Agriculture (HESA) is one such project sanctioned by Indian Council of Agricultural Research (ICAR) which has identified 76 body dimensions important for agricultural implement design [7].
The 76 measurements stated by HESA could be categorized into three groups based on how it is taken – standing, sitting and standing/sitting measurements [7]. 37 measurements including weight, stature, vertical reach, eye height, elbow height, knee height, waist back length, chest and waist circumferences are measured in standing position [7]. 16 measurements including height, vertical grip reach, thigh clearance height and functional leg length are measured in sitting position while 22 measurements including grip diameter, grip span, maximum grip length, hand length and foot breath could be calculated in any position [7].
Status of anthropometric studies of agricultural workers in India
India is at a forefront in whole of South Asia and among the leaders in Asia when it comes to studies related to anthropometry and ergonomics of agricultural workers. Out of over hundred published papers, some important research has been discussed in this section.
The first anthropometric study of agricultural workers could be traced back to as early as 1981 carried on both male and female subjects but with only one anthropometric parameter considered [8].
Dewangan et al. collected 76 anthropometric dimensions of 400 female farm workers from North-Eastern India for design of hand tools [7]. Gite and Majumder found mean stature and weight of Indian agricultural workers to be 163.3 cm and 54.7 kg for male workers and 151.5 cm and 46.3 kg for female workers [9]. The mean pushing and pulling forces by both hands in standing posture were found to be 224 N and 218 N for male workers and 143 N and 158 N for female workers [9].
Agrawal et al. studied 566 male and 461 female tribal agricultural workers of North-Eastern India and found that the mean weight and stature of female workers to be 89.8% and 93.1% of weight and stature of male agricultural workers [4]. Yadav et al. studied 75 male and 30 female agricultural workers and found the handle strength, leg and foot strength, grip strength and torque strength of female workers to be considerably lower than their male counterparts [10].
Status of anthropometry and ergonomics for farm machinery design in Nepal
Majority of farm tools and equipment are manufactured by local manufacturers or local artisans without appropriate application of ergonomic principles. This results in lower working efficiency and high drudgery. Safety concerns could also arise due to the unsuitable design resulting in injuries.
Although the importance of agriculture in terms of employment has been repeatedly highlighted, no research on anthropometry and ergonomics with regards to farm machinery and tool design has ever been carried out in Nepal. A search through many journals on the internet yielded some anthropometric researches, almost all of which were carried out by either medical institutes or development organizations, with most of them focusing on nutritional aspects only.
With PMAMP functional since FY 2016/17 all-around the country and Farm Machinery Testing and Research Center established in Sarlahi under Nepal Agricultural Research Council (NARC), a due importance should be given to ergonomic studies.
Importance of female-centric ergonomic design of farm tools in Nepal
The trend of “feminization” of agriculture is more vivid today. According to the National Labour Force Survey 2017/18, about 15% more female are engaged in subsistence agricultural production and processing compared to male [11]. As per ILOSTAT database managed by Int’l Labour Organization, 75% of women in Nepal work in agriculture [12].
The outmigration of working male population has significantly altered demographic scenario with regards to agriculture. Between 2001 and 2011 censuses, female-headed households increased from 14.9% to 25.7%, with the World Bank reporting the figure to be 31.3% in 2016 [13][14]. Various agricultural practices have been altered with one report stating that woman left behind to manage farms choose to adopt less labor-intensive crops, reduce the diversity of the crops they grow and even abandon agricultural land [15].
During the design of various farm tools; say sickle, khukuri, spade, etc. which has a handle and a functional component; the local artisan who produce the tools often produce it as a fit to his hand. Often times, households have only one set of tools. Also, various researches have pointed out the difference between the grip diameter of male and female, which vary significantly [16]. This may lead to the higher application of force and put the users at the risk of injuries due to slippage of handle.
Difference in mean height and hand reach of female corresponds to the lower trajectory while using tools such as kodalo, bancharo and spade while the cutting arc of tools such as sickle may also differ. This highlights the need of variation in the design of cutting edge. The blade geometry of sickle could be changed while the thickness and curve of the cutting portion of spade and shovel altered as per the requirement.
It is essential to consider ergonomics in tractors and mini tillers as their use has been increasing. The hand force of female operators could be calculated and checked whether it is inline with the force required in operation of mini tiller i.e. for braking and shifting gear. The handle diameter when compared with inside grip diameter gives the nature of grip. The leg force while seating helps to ergonomically design application of brakes, clutch and accelerator in a tractor.
Hand tools are significantly important to Nepalese agriculture in terms of ergonomic design compared to engine-powered machineries, because every farming household has certain hand tools while not everyone could own a tractor or tiller. This explains why anthropometric considerations and ergonomic design is more important in hand tools than tractors for development of agricultural sector.
Increase in adaptation of mini-tillers could be observed especially in hills. A study has found lower rate of adaptation among female-headed households as compared to male-headed households [17]. It might also be due to lack of information reaching female agricultural workers with one report suggesting that only 31% of extension services delivered reach female farmers compared to 69% of male farmers [18].
Conclusion
The importance of anthropometry and ergonomics is immense in the context of farm mechanization in Nepal. Anthropometric dimensions such as height, hand reach, grip length and so on play a vital role in the performance of any hand tools or farm machineries. Although agriculture employees almost two-thirds of population in Nepal, no research has been carried out regarding ergonomics of farm machineries so far. A special focus must be committed towards study of ergonomics with female agricultural workers as subject as Nepal is observing a trend of feminization in agriculture.
Raksha Niraula is a journalist specializing in development and women empowerment issues. She is pursuing her postgraduate in Economics degree at Post Graduate Campus, Biratnagar.
References
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