Bridging performance of adults with hemiparesis: sliding of the paretic limb.

BACKGROUND

Individuals with hemiparesis resulting from cerebrovascular accident often demonstrate uncontrollable sliding of the paretic lower extremity when attempting to lift their pelvis from a hook-lying position (bridging), during bed mobility. This disorder is often attributed to hypertonicity of the knee extensors, though this assumption has not been confirmed experimentally.

PURPOSE: To determine the interaction of limb sliding during bridging with impairments of motor control, knee moments, and spasticity.

METHODS

Twenty-seven adults with hemiparesis were assigned to 2 groups on the basis of their ability to perform bridging on a smooth surface. The association of the dichotomous parameter of bridging performance (success/failure) with the other parameters was determined by point biserial correlation, and the predictability of limb sliding was estimated from binary logistic regression. A 2-way repeated-measures analysis of variance was used to determine the differences between knee moments.

RESULTS

The group that could perform bridging without sliding had higher moments of the paretic knee flexors and a higher level of motor control than the other group (P = .001). The moments of the paretic flexors and the level of motor control were also correlated with limb-sliding occurrence (r = 0.61 and 0.74, respectively) and served as the best predictors of bridging performance. The paretic knee's flexion moment was found to be more affected than the extension moment (P= .04).

CONCLUSION

Low level of motor control and reduced strength of the knee flexors are 2 major deterrents of successful bridging in persons with hemiparesis. The predominant decline of the flexors' moment may reflect a more severe disruption of the flexors' cortical innervation or superior recovery of the extensors.