Psychophysical Measures of Exertion. Are They Muscle Group Dependent?

The purpose of the present study was to evaluate the applicability of the RPE (CR-10) scale for a number of physical exertions which employ only the upper limb with a variety of muscle group sizes and exertion levels. Ten female and ten male subjects performed pinch and pulling tasks in which four different muscle groups were engaged employing the finger, wrist, forearm and the whole arm. MVC (maximum voluntary contraction) exertion levels, RPE (Borg's CR-10 scale) value, and accuracy of the subjective assessment were measured. The results indicate that the accuracy of psychophysical measures are not muscle dependent although force generating capability is dependent on the muscle group involved. Female subjects were found more accurate in their perception of perceived exertion at lower levels of exertion than male subjects. It also appears that the RPE rating can be used to assess a variety of exertion levels accurately for a range of tasks, involving a range of muscle group sizes and location.