Abstract :
Introduction & Objective: Even after automated industrial operations,
manual handling is still evident with development of physiological fatigue
alongwith ergonomic risk factors which invariably reduces human
performance capacity. A cross-sectional scientific study was conducted in
an automobile industry to assess physiological strain & ergonomic risk
factors with an aim to make job comfortable & less risky.
Method: Study was conducted on 8 randomly selected employees of frame
assembly section in an automobile industry. Job was manual unloading of
automobile engine weighing 30 kg from conveyor tray, carrying it to
another conveyor 2 meter apart & mounting on frame body. Resting HR,
BSA & BMI of the workers were computed. Peak HR, oxygen saturation &
later, recovery HR was recorded. NIOSH lifting index (LI) & RULA score for
postural stress were assessed.
Result: Work-site dimensions of conveyor tray carrying engines- vertical
height 52 cm from ground, horizontal distance 15 cm & frequency approx.
3/ min. Physiological work stress assessment (peak heart rate, oxygen
uptake & energy expenditure) were 129.5±7.07 beats/min, 1.27±0.15
lit/min & 6.42±0.71 kcal/min respectively. Physiological recovery was
98.95±11.47, 91.10±10.23 & 83.70±7.35 beats/min. Mean oxygen
saturation was 98.12% & mean resting heart rate 74.63 beats/min. LI was
4.04±0.53 and mean postural stress through RULA score was assessed to be
4.55±0.42
Conclusion: Physiological strain and postural strain were high. The cause of
high RULA score & LI could be ascertained to job at shoulder height; vertical
factor of LI was primarily responsible for which recommendation was
conveyed for worksite design modification (subsequently done &
recorded).
Keyword :
NIOSH lifting index, RULA, Physiological strain parameter, physiological recovery status, mechanical manipulator.