Reduced errors in overhand throwing practice of children with and without disability: analysis of movement components

Background: Fundamental movement skills (FMS) are believed to be essential pre-requisites for more complex movements that children perform in different forms of physical activity. Training FMS is therefore valuable in motor development. In particular, children with intellectual disability (ID) who have impaired intellectual functioning have been shown to have FMS delay. Previous research had shown that reducing practice errors during FMS training is beneficial for children, especially those with ID (Capio et al., 2013a, 2013b). To facilitate further understanding of such approach follow-up research is important. Purpose(s): This research consists of two studies that further examined the impact of error-reduced training in improving movement patterns of the FMS of overhand throwing in children with and without ID. Method(s): Study 1 involved typically developing children (n = 108; age = 9.16+/-.96 years), while study 2 involved children with mild to moderate ID (n = 39; age = 7.38+/-2.09 years). Participants practiced 120 trials of overhand throwing in either an outcome error-reduced (ER) or an outcome error-strewn (ES) practice condition. Task difficulty was manipulated so that the ER group had significantly more successful practice trials than the ES group. A pretest-posttest design was adopted to examine change in overhand throwing movement pattern, based on the Test of Gross Motor Development-2. Overhand throwing components consisted of: hand/arm windup, hip/shoulder rotation, weight-shift, and follow-through. A performance measure of throwing accuracy was also conducted. Participants in study 2 were observed during free play, subsequently recording frequency of unprompted throwing. Result(s): In study 1, analysis of variance of the change in movement components showed that practice condition (ER vs. ES) had a significant effect on only the followthrough component (F(106,1) = 4.929, p = .029). The ER group displayed significant improvements in the diagonal follow-through component, whereas the ES group did not. Children in the ER condition displayed greater improvement in throwing accuracy (F(104,3) = 5.87, p = .017). Followup correlations showed that improved throwing accuracy was associated with improved hand/arm windup (r = .226, p = .019) and hip/shoulder rotation (r = .239, p = .013) components. In study 2, practice condition had a significant effect on hip/shoulder rotation (F(37,1) = 6.813, p = .013), and followthrough (F(37,1) = 8.002, p = .008) components. The ER group displayed greater improvements in these two components compared to the ES group. Children in the ER condition displayed greater increase in unprompted throwing frequency during free play (F(37,1) = 22.056, p < .001). Correlational analysis showed that increased throwing frequency was associated with improved hip/shoulder rotation (r = .311, p = .045) and follow-through (r = .326, p = .043). Conclusion(s): The results suggest that ER training of overhand throwing benefits the distal component - followthrough - in typically developing children. In children with ID, follow-through and rotational trunk movements are improved. Associations with throwing accuracy and unprompted throwing during free play suggest that the beneficial effects on movement components are likely to translate to performance outcomes. Implications: Error-reduced training appears to facilitate improvements in trunk rotation and follow-through components of overhand throwing in children. Whether these improvements are associated with kinematic constraints can be explored in future research, possibly through more quantitative methodology (e.g. 3-D motion analysis). Nevertheless, these consistent findings imply that error-reduced training could be considered by physiotherapists in facilitating FMS development of children.