| Summary: | The purposes of this study were to compare changes in motor pattern and performance of individuals when utilizing internal, external, or dynamic system perspective when learning the fundamental skill of throwing. Forty right hand dominant college age students (18-25 years) participated in this study. Participants were required to throw a baseball size ball to a target with their non-dominant limb. Participants were randomly placed into four conditions. Condition 1 was Internal Focus condition. Participants in this condition received the following instruction: 1) turn so your right shoulder is closer to the mat, 2) when throwing shift your weight from back leg to front leg, and 3) arch your back and first accelerate the trunk, then shoulder, then upper arm, and finally your hand. Condition 2 was the External Focus condition. Participants in this condition received the following instructions: 1) turn sideways so you are facing the south wall, 2) when throwing shift your weight toward the mat, and 3) throw the ball as if your trunk and arm were like a whip, like a horseman driving his horses. Condition 3 was the Control Parameter condition. Participants in this condition were encouraged to scale up on the control parameter of throwing velocity. Participants in the control parameter condition did not receive any additional augmented information. Condition 4 was Control condition. Participants in this condition did not receive any augmented information nor they scale up on the control parameter. Participants were initially provided instructions and demonstration prior to the first trial. Augmented information was then provided after every 5th throw during practice sessions. The Focus and Control conditions were required to throw the ball at a preferred velocity. Participants practiced twice per week for three weeks for a total of 6 sessions. The seventh session was 10 days after the 6th session. Participants were not provided any information during the 7th retention session. Accuracy of throw related to a target center was recorded for each trial. Two cameras were used to capture the throwing motion. A Peak Motion analysis system used to capture and analyze data. A 2-way (4 x 7) Multivariate analysis of variance (MANVOA) was completed on the three dependent measures of segmental lag (Humerus-Trunk, Forearm-Humerus, and Hand-Forearm). MANOVA was followed by Discriminant Function Analysis (DFA) in order to identify significant functions related to the significant MANOVA. Univariate analysis (ANOVA) was used to determine differences in identified functions by each independent factor. Scheffe post hoc analysis identified measures responsible for significant ANOVA. A two-way (conditions x sessions) ANOVA was completed to determine significant differences in radial error and coefficient of variation of radial error. An alpha level of .05 was selected for all statistical parameters. Results indicated that the control parameter and external focus groups were better instigating pattern change than other groups. The Focus groups demonstrated better performance accuracy over practice sessions. Focus groups also retained performance better than the control parameter and control group. It was concluded that scaling up on a control parameter and External Focus promote pattern change better than internal focus. Focus of Attention was better for retention of performance than the control parameter group.
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