Reproductibility of carpenters' work after cold exposure

Abstract

The purpose of the study was to analyse the effect of cold on manual performance. Ten carpenters performed three tasks (nailing, sawing, screwing), before and after exposure to cold. They rated their exertion, EMG activity was recorded from six arm-shoulder muscles, and performance was video-filmed. The subjects were exposed to one hour of cold (15°C ambient temperature, the dominant hand being cooled by a fan and cold water spray). Hand skin temperature was measured and the sensation of cold was rated. The number of work movements and the time taken for each task were recorded. The quality of the work performed at the first and second trials was compared. Cold stress was very individually perceived. EMG activity increased in finger flexors, wrist extensors and shoulder elevators. Rating of perceived exertion while nailing was higher. More time was needed to perform each of the tasks, but the quality of the work was mainly the same. Incidents indicating accident risks were observed.