Middle Eastern Journal of Disability Studies

Abstract
Background & Objectives: The natural development of children follows a predictable pattern. However, there are situations in which problems arise in this process, and the child does not go through the stages of normal growth. Developmental coordination disorder is one of the most important disorders that a significant percentage of children face. Developmental coordination disorder is used to explain problems in the development of motor skills. Many methods and factors can affect and improve the overall development of children with developmental coordination disorder, especially motor development. Today, nonlinear teaching methods have improved children's learning speed by creating variety, manipulation, and noticeable changes in the way of presenting exercises and games. So, the present study aimed to investigate the effect of manipulating task constraints by nonlinear training methods on learning basic ball skills in children with developmental coordination disorder.
Methods: The method of current research was quasi–experimental. The statistical population included 5–to7–year–old girls with growth coordination disorder in Mashhad City, Iran, in 2022. The participants were 30 girls aged 5 to 7 years who were eligible volunteers with developmental coordination disorder, who were purposefully identified through Developmental Coordination Disorder Questionnaire (DCDQ–7) (Wilson et al., 2009) and Movement Assessment Battery for Children–2 (MABC–2) (Henderson et al., 2007) included in the study and randomly divided into two groups of 15 people including; 1) nonlinear training and 2) Linear training (control). To evaluate ball skills in both groups in the pretest and posttest, we used the Test of Gross Motor Development (TGMD–3) (Ulrich, 2017). The ecological task analysis method was used to manipulate the task constraints and design the training program using the nonlinear training method. In this method, the researcher first determines the main components of the task and the effect on the task's difficulty level; by manipulating and applying noticeable changes, the task's difficulty level was adjusted according to the individual characteristics of children with developmental coordination disorder. Thus, the presented exercises were designed from easy to advanced level so that the training interventions cover all the desired movement skills. According to the group program, the subjects implemented the desired program and interventions for 4 weeks and three sessions of 60 minutes each week. Descriptive statistics, including frequency, mean, and standard deviation and inferential statistics including covariance analysis were used to analyze the data. SPSS version 24 software was used for data analysis. The significance level of the tests was 0.05.
Results: The results show the effect of the training intervention of manipulation of task constraints by nonlinear training method on the variable of ball skills (p<0.001) and the subtests of two–handed hitting the ball (p<0.001), one–handed dribbling (p < 0.001), two–handed catching (p<0.001), kicking the ball (p<0.001), and throwing from below (p<0.001). However, no significant difference was observed between the two groups in the sub–tests of throwing over the shoulder (p=0.180) and forehand (p=0.241).
Conclusion: Based on the research findings, manipulation of task constraints by nonlinear training method affects learning the basic motor skills of children with developmental coordination disorder. By using this educational approach, instructors can challenge the learner to work harder towards new coordinated patterns and help learners use internal unconscious processes to create the ability to produce functional patterns in people.