Effect of External Attentional Focus Instructions with Different Distances on Balance and Muscular Activity Amongst Children with Mental Retardation

The aim of this study was to survey the effect of distal and proximal external attentional focus instructions on postural sways and muscular electrical activity amongst children with mental retardation.

For this purpose, 30 child 10- 12 years old (M= 11.2) were selected from exceptional children schools and divided into three 10- person groups (distal external attentional focus, proximal external attentional focus and control) randomly. We used the Biodex Stability System to measure postural sways and Electromyogram to measure the muscular electrical activity. The participants at pre-test phase performed 10 trials (each trial 20 seconds) without instruction. Then each group, according with their group schedule, participated in three training sessions (each session included 10 trials). Finally, the participants performed 10 trials without instruction as a post-test. During the pre and post- test phases, the electrical activity of Soleus and Tibialis Anterior muscles was recorded. For intra-group comparisons, paired t- test and covariance analysis were used and for between-group comparisons, ANOVA test was used.

The results showed that the balance performance of distal external focus group was better than the other groups significantly. Also, the performance of proximal external focus group was better than the control group (P<0/05). The comparisons of muscles electrical activity indicated that the electrical activity of Soleus muscle in distal external focus group was less than the proximal external focus group. But, in case of Tibialis Anterior muscles, the electrical muscle activity in the distal and proximal external focus groups was less than the control group significantly (P<0/05).

The findings of the present study showed that shifting the attentional focus away to closer distances has relatively better results on the balance and postural sways of children with mental retardation and supports the constrained action hypothesis.