Operator's Fatigue in Field Operation of Hand Tractors

Abstract A hand tractor was modified to enable operation in a seated position. The physiological effects of the new seated position were compared with the effects of the standard design where the operator must walk behind the machine. The study was conducted in three operations, namely, transportation on a tarmacadam road, rota-tilling and rota-puddling of the hand tractor under different field conditions. Parameters such as vibration intensity in root mean square (rms) acceleration, heart rate, oxygen consumption rate and work-related body pain of operators were evaluated to study the fatigue on the operators. The energy expenditure rate was computed for various operations. The experiments were statistically designed and replicated. The results indicate that vibration intensity in rms acceleration in all the gear settings and all the conditions was minimum in the range of 1750–1850 min−1. The vibration intensity in rms acceleration was observed maximum as 45 m s−2 without the seat whereas this value was 20 m s−2 with the seating arrangement. It was observed that the seating posture requires about 25% less energy in transportation, 29% in rota-tilling and 10% in rota-puddling as compared to walking behind. The work-related body pain was also reduced on an average by 27% due to seating arrangement.

[1]  Hilkka Riihimäki,et al.  Intervention on seat adjustment among drivers of forest tractors , 1997 .

[2]  G. Borg.  Perceived exertion as an indicator of somatic stress. , 2019, Scandinavian journal of rehabilitation medicine.

[3]  D B Chaffin,et al.  Shoulder posture and localized muscle fatigue and discomfort. , 1989, Ergonomics.

[4]  N Nevala-Puranen,et al.  Reduction of farmers' postural load during occupationally oriented medical rehabilitation. , 1995, Applied ergonomics.

[5]  L. Burström,et al.  Absorption of vibration energy in the human hand and arm. , 1994, Ergonomics.

[6]  Etienne Grandjean.  Fitting the task to the man , 1969 .

[7]  I Kuorinka,et al.  Subjective discomfort in a simulated repetitive task. , 1983, Ergonomics.

[8]  C. R. Mehta,et al.  Ride Vibrations on a 7·5 kW Rotary Power Tiller , 1997 .

[9]  L P Gite,et al.  Anthropometric survey for agricultural machinery design: an Indian case study. , 1989, Applied ergonomics.

[10]  D. D. Reynolds,et al.  Hand-arm vibration, part I: Analytical model of the vibration response characteristics of the hand , 1977 .

[11]  H Broman,et al.  Arm positioning in manual tasks. An electromyographic study of localized muscle fatigue. , 1980, Ergonomics.

[12]  S Milosević,et al.  Drivers' fatigue studies. , 1997, Ergonomics.

[13]  Mark S. Sanders,et al.  Human Factors in Engineering and Design , 2016 .

[14]  Anna Sörensson,et al.  The influence of shock-type vibrations on the absorption of mechanical energy in the hand and arm , 1999 .

[15]  Lage Burström,et al.  Power absorption in women and men exposed to hand–arm vibration , 2003, International archives of occupational and environmental health.

[16]  V K Tewari,et al.  Anthropometric data of Indian farm workers--a module analysis. , 1997, Applied ergonomics.

[17]  D. D. Reynolds,et al.  Dynamic response of the hand-arm system to a sinusoidal input , 1972 .