Effects of vision and amount of practice on accuracy and kinematic of dart throwing “Study of the specificity of practice hypothesis”

According to Specificity of practice hypothesis, availability of visual information specially during performing tasks witch vision has an important role in improving the accuracy, causes further performance decrements in No-vision transfer test. The purpose of the current study was to examine the effects of vision and amount of practice on accuracy and kinematic of dart throwing. 20 female students of righthanded who were all novitiate in the skill selected voluntarily and randomly assigned to full vision and No-vision groups.The subjects following participated in pretest, performed acquisition phase that consisted two level of modest and extensive practice (45 trials and 300 trials). 10 minutes after each level of practice, participants completed transfer trials in a no-vision and no-KR condition. Overall, Mixed ANOVA (2×3) in acquisition phase revealed that vision improved Dart throwing accuracy performance. Kinematic analysis revealed no significant difference between two groups in Wrist flexion, Angular displacement of elbow and Angular displacement of shoulder. Whereas after 300 trials of practice, there was significant difference between groups in throwing time and angular velocity of the dart. After extensive practice, Mixed ANOVA (2×2) showed that, withdrawal of vision resulted in specificity of practice effects on dart throwing accuracy, but results of kinematic pattern, regardless of the amount of practice did not support specificity of practice.