Reaction torques and operator stress while using powered nutrunners.
Reaction torque measures of six different nutrunners were correlated with EMG measures and subjective ratings of perceived exertion for different work surface orientations, joint stiffnesses, rpm levels, air pressure levels and handle configurations. Using an underpowered tool or using a softer joint resulted in larger impulses and worse ratings. A pulse-type shut-off mechanism produced the lowest reaction torque and the best rating. Overall, ratings correlated directly with the impulse level. The subjects were good judges of stress levels, and subjective ratings were valid measures of operators stress.
Freivalds
A
A
Department of Industrial & Management Systems Engineering, Pennsylvania State University, University Park, PA 16802, USA.
Eklund
J
J