Mohammadreza Doustan; Leila Farzad; Esmaeel Saemi; Maliheh Niknam
Abstract
The aim of this study was to investigate the effect of handedness and task difficulty on effective target width and temporal accuracy of the Fitts’ speed-accuracy tradeoff task. The present study was semi-experimental and the tools used included Edinburgh handedness questionnaire, light pen, speed-accuracy ...
Read More
The aim of this study was to investigate the effect of handedness and task difficulty on effective target width and temporal accuracy of the Fitts’ speed-accuracy tradeoff task. The present study was semi-experimental and the tools used included Edinburgh handedness questionnaire, light pen, speed-accuracy measurement device, laptop, chronometer, and metronome. The statistical population consisted of students aged between 14 and 15. The sample included 20 students who participated in this study by convenience sampling method. They were divided into two groups: left-hand and right-hand (each group 10 subjects). Each participant performed 4 trials (each trial 30 seconds) of dual target tapping task in rhythm with the metronome sound. The trials consisted of two easy and difficult tasks and each subject performed each task with dominant and not-dominant hands in rhythm with the metronome sound set up at 300 milliseconds. For statistical analysis of data, variance analysis with repeated measures was used at the significance level of 0.05. The results showed that in dominant hand, the handedness and difficulty of the task had no significant effect on the effective width of the target (P=0.973, P=0.611). Also, the handedness did not affect the average time lag (P=0.135, P=0.785), but in non-dominant hand, the average time lag was more for the difficult task than the simple task (P=0.001). In difficult tasks, participants seem to be trying to keep the spatial error rate constant by reducing the speed of the movement and to sacrifice speed for the spatial accuracy. Also, the time error (mean lag) is more influenced by the difficulty of the task than the handedness.
Mojtaba Jalalvand; Abbas Bahram; Afkham Daneshfar; Saeed Arsham
Abstract
Aim: This study aimed to determine effect of self-control of task difficulty on accurate and movement pattern golf putting. Methodology: 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 ...
Read More
Aim: This study aimed to determine effect of self-control of task difficulty on accurate and movement pattern golf putting. Methodology: 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. Results: 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 < 0.001). In acquisition and test phases, the golf putting movement pattern was better than that of yoked group (ps < 0.001). Conclusion: The efficacy of self-control of task difficulty is explained with reference to the challenge point framework.
Masoud Zahiry; Shahrzad Tahmasebi Borujeni; Mehdi Aghapour; Nastaran Majdi Nasab
Abstract
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 ...
Read More
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.
Ali Farsi; Hadis Kavianpoor
Abstract
The purpose of present study was to determine the effect of different levels of balance task difficulty and visual feedback on balance in elderly women. Fourteen healthy elderly women (mean age 57/65 yr) were selected voluntarily. Participants were asked to stand still on a stability platform under each ...
Read More
The purpose of present study was to determine the effect of different levels of balance task difficulty and visual feedback on balance in elderly women. Fourteen healthy elderly women (mean age 57/65 yr) were selected voluntarily. Participants were asked to stand still on a stability platform under each of two conditions (with visual feedback and without visual feedback) in three levels of difficulty (6, 8, 10). Stability index scores (Overall, Anterior- Posterior and Medial- Lateral) were calculated by Biodex Balance System. Duration of each test was 20 seconds and rest times were 20 seconds. Results showed that with increasing task difficulty, score of Medial- Lateral balance (p= 0/02) increased significantly. In addition, There was a significant reduction in the scores of Overall balance (p= 0/001), anterior - posterior balance (p= 0/01) and medial - lateral balance (p= 0/01) in visual feedback condition compared with without feedback condition. Overall, the results of this study showed that increasing task difficulty increases postural sway and availability of visual feedback can improve balance and reduce the postural sway.
