Effects of tuning of ankle foot orthoses-footwear combination using wedges on stance phase knee hyperextension in children with cerebral palsy - preliminary results.

PURPOSE: This pilot study investigated the feasibility of reducing stance phase knee hyperextension in children with cerebral palsy by tuning the ankle foot orthoses-footwear combination (AFO-FC) using different sizes of wedges.

METHODS

Five children with cerebral palsy underwent three dimensional gait analysis and tuning of their AFO-FC using wedges. Data analysis was carried out by comparing relevant gait parameters between the non-tuned and tuned prescription.

RESULTS

Knee hyperextension during stance significantly decreased, and the shank to vertical angle was closer to normal after tuning. Although none of the other parameters showed statistically significant changes, the wide confidence intervals and lack of power indicated the likelihood of a type II error. Further, it was noted that the influence of tuning on temporal-spatial parameters was different between children with diplegia and those with hemiplegia. It was estimated that a sample size of 15 is required to detect significant changes at p = 0.05 and power of 0.8.

CONCLUSIONS

The findings of this study clearly indicate the potential clinical utility of tuning using wedges to correct knee hyperextension during the stance phase in children with cerebral palsy. However, observations support the need for an adequately powered study to assess the long-term effects of tuning on gait parameters, activity level and quality of life.