A factor analysis of twelve selected maximal isotonic strength performances on the universal gym.

This study sought to isolate and identify the underlying structure of the isotonic strength domain as exhibited on the Universal Gym. Maximal isotonic contractions were elicited from 88 college male subjects involved in a weight training program on 12 selected exercises. Factor analysis was applied to the data to delineate the underlying structure. Analysis of the raw data revealed an unclear nonrobust factor structure. However, when the variance of the anthropometric vaiables of height and weight were statistically held constant from the raw data, subsequent factor analysis of the statiscally controlled data yielded a robust three factor structure. Factor 1 was related to upper extremity and trunk isotonic strength; Factor II, lower extremity isotonic strength; Factor III, trunk and upper extremity isotonic strength. Thus, when evaluating isotonic strength responses on the Universal Gym, upper, lower extremity and trunk measures as body segments should be utilized; also, anthropometric measures of height and weight should be considered.