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.