The Relative Effectiveness of Three Forms of Visual Knowledge of Results on Peak Torque Output

Therapists often search for more efficient and effective ways to provide patients with information regarding their performance. The purpose of this study was to determine whether certain types of machine-based visual displays could be used as a source of error-correction information to facilitate the immediate and/or delayed performance of a maximal effort isokinetic movement of the knee. The relative effectiveness of the knowledge of results (KR) provided by visual displays that differed in degree of precision and presentation schedule were compared during a practice and retention test phase. Twenty-four healthy male subjects ( age = 22 years) performed isokinetic extension and flexion of the knee at low (120°/sec) and high (240°/sec) exercise speeds. A no-KR maximal effort pretest was followed by two practice sessions during which three groups each received one form of visual KR and a fourth group practiced without KR. A no-KR maximal effort posttest was administered to all groups following a 1-day rest interval. Although visual KR did not result in any significant differences in mean peak torque output during practice, between-group comparisons of pretest to posttest changes in mean peak torque indicated that groups receiving visual KR in addition to practice demonstrated significantly greater (p < .03) improvements in mean peak torque in three of the four conditions tested when compared with the group that practiced without KR. On the basis of these results, certain forms of visual KR appear to provide an importanterror-correction function and promote the development of cognitive strategies that can be used to guide execution of maximal effort exercise in the absence of KR. Training patients to use machine-based visual displays in clinical settings will not only promote greater patient independence within the clinical setting but may also help the patient develop cognitive strategies that can be used to guide performance outside a supervised clinical setting.