The Mechanism of Hip Dislocation Related to the Use of Abduction Bar and Hip Compression Bandage in Patients With Spastic Cerebral Palsy

Abstract

Objective The aims of the study were to identify the differences of forces in the hip adductors between with or without the abduction bar and to evaluate the effect of hip compression bandage on the spasticity of the adductor muscles. Design Thirty-three patients with cerebral palsy (Gross Motor Functional Classification System IV and V) were prospectively included. Surface electromyography was taken by attaching electromyography on the adductor and abductor muscles. Theraband was used as hip compression bandage. Surface electromyography were taken when spasticity provoked with and without abduction bar, as well as with both abduction bar and hip compression bandage. Root mean square values were measured. Results Root mean square values were significantly increased with abduction bar in the adductor longus, adductor magnus, and tensor fascia lata muscles. Adductor Sum and Net Adduction Index showed significant increases after the use of abduction bar. After applying hip compression bandage, the Net Adduction Index was significantly decreased. Conclusions Our results showed significant changes in the adductor muscles' amplitude, Adduction Sum, and Net Adduction Index. These results indicate that forces that worsen hip dislocation may develop, and therefore, abduction bar should either not be used for spastic cerebral palsy patients or should only be used with hip compression wrapping in place as well.