Comparison of Instruments for Recording Muscle Strength

This study compared the effectiveness of the following four instruments for recording muscle strength: cable tensiometer, Wakim-Porter strain gauge, spring scale, and Newman myometer. As reflected by objectivity coefficients, the cable tensiometer had the greatest precision for strength testing. It was the most stable and generally useful of the instruments; and was free of most of the faults of the other devices. The strain gauge had a satisfactory degree of precision; but was extremely sensitive to slight tensions, including changes in room temperature. Both the spring scale and the Newman myometer had deficiencies which limited their usefulness.