Affiliations: Division of Ergonomics & Work Physiology, Department of Physiology, Presidency College, 86/1 College Street, Kolkata 700 073, India
Correspondence:
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Corresponding author: Professor Chandan Mitra, 14/17 A, Golf Club Road, Calcutta-700 033, India. Tel.: +91 033 2413 1383/2417 8645; E-mail: [email protected]
Abstract: The purpose of this study was to examine posture-comfort-performance interrelationships in plucking-based task in a tea garden. Results of coefficient of correlation between the stature bush height ratio (SBHr) and total yield (TY) (permanent: r=0.80, temporary: r=0.81), and SBHr and body part discomfort frequency and severity (BPDFS) (permanent: r=−0.78, temporary: r=−0.77) clearly indicated that performance (TY) was correlated both with the SBHr and BPDFS. Similar correlation studies between duration (TT) and BPDFS revealed that BPDFS increased with progression of time. Analysis of joint angle changes (trunk angle 92%, shoulder angle 63% and neck angle 87%) further suggests that both BPDFS and overall postural shifts (in terms of changes in joint angles) increased with the progression of time (time on task – TT). Body part discomfort (BPD) rank order of different body parts of pluckers (upper body part discomfort scores – permanent: 2.00–6.00, temporary: 1.88–5.88; lower body part discomfort scores – permanent: 2.13–2.88, temporary: 1.88–2.75) further revealed that upper body parts were mostly involved in discomfort development. These results suggest that an overall postural shift may be a good indicator of perceived musculoskeletal discomfort in a tea leaf plucking task where a constrained posture is required. Results of independent test series suggest that there was a good agreement between the predicted and observed values of the different variables (89.6–96.3%). The predictive value of the regression equations may be utilized for estimating values of different interacting variables, and thus, the importance of these regression equations in the supervision of workers engaged in tea plucking is evident. It is therefore proposed that to improve performance, these observations can conveniently be utilized while plucking sectors are allotted to pluckers in a tea garden.
