جستجوی مقالات مرتبط با کلیدواژه « نقطه چالش » در نشریات گروه « تربیت بدنی »

Aim: This study aimed to determine effect of self-control of task difficulty on accurate and movement pattern golf putting.
Thirty novice undergraduate students (14 Female and 16 male; average age 21.1 ± 1.64 years) were quasi-randomly assigned to two groups. Before performing each trial during the acquisition phase, the self-control group was told they could choose any of the pre-set distances from the target: (25, 50, 75, 100, 125, 150, 175 and, 200 cm). Each self-control participant’s practice schedule was served as the predetermined practice schedule for each corresponding yoked participant. Participants practiced eight blocks of 10 trials. To analyze the radial error (in acquisition and tests phases) and the movement pattern score (in tests) mixed variance analysis with repeated measures on the last factor was used. The movement pattern score in acquisition phase was analyzed using t test.
Based on the results, radial errors across different groups in the acquisition phase did not vary, but the radial error of the self-control group in retention, single task transfer and dual-task transfer tests was lower compared to the yoked group (ps The efficacy of self-control of task difficulty is explained with reference to the challenge point framework.

Challenge point framework is a theoretical framework to understand the effects of exercise variables in motor learning. According to this framework, contextual interference and knowledge of results (KR) feedback have a close relationship with the skill level and task difficulty. So, the aim of this study was to investigate the effect of exercises based on challenge point framework on postural control in patients with multiple sclerosis. The postural control of 22 MS patients (age range 20 - 65 years) from patients of Ahvaz MS Association who were randomly selected and assigned to experimental and control groups was measured by the force platform. Subjects in the experimental group performed exercise for 12 sessions, 3 sessions per week and 45 minutes each session. The control group did not receive any interventions. The data were analyzed by mixed analysis of variance and analysis of variance with repeated measures (P≥0.05). The findings showed that the postural control of experimental group significantly improved compared with the control group as a result of four weeks of exercise protocol. Also, postural control of the experimental group significantly developed in the posttest compared with the pretest. So this study supported challenge point framework and instructors and practitioners can use this protocol for effective clinical interventions to improve balance and postural sways in MS patients.

This study aimed at investigating the effect of blocked, incremental systematic and random contextual interferences on acquisition, retention and transfer of volleyball skills based on changes in a generalized motor program. In fact, this study was conducted to answer this question that whether regular increment of contextual interference level is more effective on learning volleyball service skill than blocked or random practice schedules. 30 students (mean age 23±4 yr, 3 groups and each 10 subjects) participated in this study. The groups were different in practices of the three services. Subjects performed simple, overhead and single arm skills from a distance (9 m from the volleyball net) with different practices. Each participant practiced 108 trials of each service, totally 324 trials during 9 sessions (each session 36 trials). The results indicated that incremental practice resulted in a better performance in retention and transfer tests than blocked and random practices (P˂0.05). In general, it was suggested that the practice should be scheduled so that it can start from low interference and gradually and systematically continues towards high interference in order to facilitate learning of several generalized motor skills.