Towards standardization of muscle strength testing

Male subjects (N = 24) exerted maximal horizontal forces either trying to maintain a constant level over 5 seconds, or increasing steadily to the subjective maximum, or in vigorous jerks of the body. Statistical analysis (p ≤ 0.01) indicated that these different techniques of force generation can result in different peak impulses. For the force maintained over 5 seconds, different scores (peak, and 12 averages during the exertion period) were extracted from the recorded force curves. Many of the resulting scores were significantly different from the others. Thus, a number of distinctly different “strength” scores resulted either from different techniques of force generation used by the subjects, or from different statistical treatments of the same raw data by the experimenter. To standardize measures of “strength,” a definition of strength, a checklist to control experimental techniques, and a regimen to calculate the strength index are proposed.