Triceps denervation as a predictor of elbow flexion contractures in C5 and C6 tetraplegia.

OBJECTIVE

To determine whether the existence of elbow flexion contractures in persons with C5 or C6 tetraplegia is related to a lack of residual voluntary triceps function and triceps denervation (ie, lower motoneuron damage).

DESIGN

A retrospective study of impairment data from 74 arms to identify the incidence of elbow flexion contractures and the contributing factors toward this deformity.

SETTING

Five spinal cord injury (SCI) rehabilitation centers in the United States, 1 in England, and 1 in Australia.

PARTICIPANTS

Forty-three subjects with motor complete C5 or C6 traumatic SCI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Active and passive elbow extension, triceps voluntary muscle strength, and triceps response to electric stimulation.

RESULTS

Subjects with weak voluntary triceps had significantly fewer and less severe elbow flexion contractures than those with paralyzed triceps ( P =.024). Subjects with completely denervated triceps (ie, no response to electric stimulation) had significantly more elbow flexion contractures than subjects with even a weak response to electric stimulation ( P =.003). Overall, 51% of the arms could not be passively extended to zero. Forty-six percent of the arms classified as C5 lacked full passive elbow extension, compared with 63% of the arms classified as C6 ( P =.302).

CONCLUSIONS

A relationship has been found between elbow flexion contractures and lack of residual voluntary triceps and triceps denervation in subjects with C5 or C6 tetraplegia. There should be a greater awareness of the elbow flexion contractures that may develop as a result of this relationship. A better understanding of this deformity and its characteristics can lead to more effective clinical treatment and prevention strategies.