Lumbar flexion and dynamic EMG among persons with single level disk herniation pre- and postsurgery with radicular low-back pain.

OBJECTIVE

The paraspinal muscles often fail to relax on forward flexion in many persons with low-back pain. The goal of this prospective study was to determine whether this abnormal lack of a flexion-relaxation phenomenon corrects after lumbar diskectomy for symptoms of radiculopathy with low-back pain.

DESIGN

Electromyographic testing was performed on 17 patients before and 30 days after lumbar diskectomy.

RESULTS

Although pain improved significantly (P < 0.05), the flexion-relaxation phenomenon did not improve.

CONCLUSIONS

Failure to recover muscle relaxation while pain is relieved suggests another mechanism for paraspinal activity.