Evaluating the effects of interface factors on the torque exertion capabilities of operating handwheels

This study intends to assess factors affecting human torque exertion capabilities of operating valve handwheels (maximum volitional torque exertion of wrist radial/ulnar deviation, R/U MVTE). Forty student subjects (20 males and 20 females) participated in this study. In addition to gender and subject factors, gloves (one layer of cotton, two layers of cotton and rubber gloves), operating height (elbow, shoulder and overhead), handwheel size and shape were selected. Barehanded condition was also involved. The results indicate that all the main effects and the first order interactions were significant. The gloved R/U MVTEs were found to be greater than the barehanded R/U MVTE. For operating height, shoulder height gave the greatest R/U MVTE, followed by elbow and overhead heights. The handwheel diameters ranging from 75 to 95 mm for males and 65 to 80 mm for females were found to have the greater R/U shear force. The average R/U MVTE of operating valve handwheel for females was about 63% (3.8/6.05) of that of males.