Effect of unstable surface sitting on paretic anterior tibial muscle following stroke.

INTRODUCTION

Postural reactions have been used to facilitate dorsiflexor activity following stroke. However, the effectiveness of this method is not clear in the literature. This study is designed to test the effect of postural reactions provoked by sitting in an unstable surface on dorsiflexor activity in acute stroke.

METHODS

Fifteen first-time acute hemispheric cerebral infarct patients with hemiplegia and 15 age-matched healthy adults participated in the study. Subjects performed static sitting, forward reach and lateral reach on a stool and Swiss ball. The anterior tibial activity was recorded in the normal and affected lower limbs in hemiplegic patients and both lower limbs of healthy adults. Non-parametric testing was used with alpha less than 0.05.

RESULTS

All the subjects showed an increase in anterior tibial activity in Swiss ball sitting compared to stool sitting. Lateral reaching resulted in higher levels of anterior tibial activity among the participants. In hemiplegic patients, anterior tibial activity in the affected side was lesser than in the normal side on stable and unstable surfaces. In healthy adults there was no inter-limb difference. The normal side activity in stroke patients was greater than that recorded in healthy individuals (p < 0.05). The anterior tibial activity in the affected side reached values equal to those of healthy adults when using the Swiss ball.

CONCLUSION

Postural reactions provoked from sitting on a unstable surface is effective in facilitating dorsiflexor activity in acute stroke.