Physiological and psycho–physiological approaches for maximal carrying load estimation

摘要

The present study was conducted on eighty-two scaffolders, which in their daily schedule performed various carrying load activities. The physiological and psycho-physiological approaches were used to determine the maximum carrying load. The scaffolders were divided into 21-30 years, 31-40 years and ≥41 years age groups. In the physiological approach, the experimental data were collected through field and laboratory studies, which included maximum oxygen intake rate, scaffolders heart rate (HR), and its variability. In the psycho-physiological approach, random loads were assigned to identify the load carrying limits of scaffolders belonging to different age groups. The average working HR varied from 125-148 bpm, and the average maximum oxygen intake rate was 1.69 (0.17) l/min, 1.64 (0.23) l/min, and 1.51 (0.19) l/min, respectively, for scaffolders of selected age groups while carrying scaffold poles or boards, guardrails and ladders. The electromyography (EMG) results during load carrying activity in head mode (p<0.02) and shoulder mode (p<0.0.5) found that the trapezoid(r) muscle displayed a gradual increase in EMG values with increased load. In conclusion, maximum load-bearing capacity was estimated for scaffolders of selected age groups using the physiological and psycho-physiological approaches.