RESUMEN
OBJECTIVE: To examine the effectiveness of knowledge of results precision in the acquisition and retention of a simulated manipulative procedure. DESIGN: A controlled trial was conducted, with subjects assigned to 1 of 2 interventions by means of a stratified random technique. METHODS: Seventy-one healthy male and female chiropractic student volunteers were asked to control the application of force of a simulated chiropractic manipulative procedure. Two feedback conditions (quantitative and qualitative), 2 performance conditions (light and heavy force levels), and 3 delay intervals (1, 5, and 8 days) were studied. Acquisition trials were divided into 10 blocks of 5 trials for a total of 50 trials. All subjects performed 2 blocks of 10 trials (total of 20 trials) during the no-feedback retention phase. Absolute constant error (/CE/) was analyzed as the measure of performance accuracy, and variable error (VE) was used to determine performance consistency. RESULTS: No significant main effect for the 2 feedback groups was found for /CE/ and VE during the acquisition phase. A significant main effect for force was found for /CE/ and VE, indicating that subjects were more accurate during light conditions than heavy conditions. There was a significant main effect for trial blocks for both /CE/ and VE, indicating that groups became more accurate and consistent as a result of practice. During the retention phase, a significant main effect for retention group conditions was identified for /CE/ but not for VE. This indicates that the retention groups differed in accuracy but were similar in consistency. Post hoc analyses indicated that subjects were less accurate as time between acquisition and retention trials increased. There was a significant main effect for trial blocks for VE but not for /CE/, suggesting that groups became more consistent between trial blocks. A significant group trial block interaction was revealed for /CE/. No other main effects or interactions in the analyses were significant for /CE/ or VE. CONCLUSION: The findings of this study suggest that practice sessions with kinetic devices (simulators) and performance feedback, whether quantitative or qualitative, may be useful when implemented to assist the performance of complex motor skills. There is not enough evidence to support the idea that the training used in this study could generate lasting learning effects.