How Accurately Can Elbow Flexion Force Be Estimated?

Abstract

The purpose of this study was to determine how accurately healthy young subjects could produce a muscular force that was 50% of their maximum and to determine the influence of several independent variables on the accuracy. On each of three nonconsecutive days, 14 men and 19 women (18 to 46 yr. old) performed three maximal elbow-flexion efforts and three efforts that they estimated to be 50% of their maximum. Isometric force was measured with a hand-held dynamometer. The estimated forces ranged from 18.3 to 81.7% of maximum. The error in force from 50% was related to whether the dominant or nondominant extremity was tested, but it was unrelated to whether maximal or submaximal efforts were performed first and to the day of testing. When the accurate generation of a submaximal force is required, naive subjects may require feedback.