Muscle strength changes as measured by dynamometry following functional rehabilitation in individuals with spinal cord injury

Objective: To objectively quantify muscle strength changes over the course of functional rehabilitation and up to 15 months postdischarge in individuals with spinal cord injury (SCI). Method: Hand-held dynamometry was used to evaluate the strength of six muscle groups in 31 individuals after acute SCI (tetraplegia, n = 13, paraplegia, n = 18). Assessment was performed by a single research therapist at admittance and discharge from functional rehabilitation and 3 months and 15 months after discharge. Results: There were significant increases of mean strength values for all muscle groups between admittance and discharge in individuals with parapalegia (median value between 13% and 22%) and tetraplegia (median value between 33% and 83%). Three months after discharge, only individuals with tetraplegia continued to significantly improve their mean strength for four muscle groups (elbow flexors-extensors and shoulder flexors-extensors). One year later, elbow flexors were significantly improved in both paraplegic and tetraplegic persons, while shoulder extensors showed significant gains only in individuals with paraplegia. Study results showed a large variability in the individual profiles of upper limb strength recovery, particularly in tetraplegic individuals. Although some individuals showed strength gains exceeding 200%, some strength decreases were noted. Conclusion: Recovery of muscle strength in individuals with tetraplegia over individuals with parapalegia continues for a longer period since it depends initially on recovery of muscle innervation. This study quantified strength improvements during rehabilitation and clearly showed that these gains can be maintained or even increased when the person returns to community living. (C) 1999 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.