Muscular contracture as a component of low back pain: evaluation criteria and significance of relaxant therapy.

The measurement of diastasis of the spinous processes and of muscular action potentials by means of bio-feedback equipment is a clinically valid means to evaluate the extent of reflex muscular contracture. The methods were used to study the relaxant effect of pridinol mesylate on the lumbar extensor muscles in subjects with acute low back pain. It was found that pridinol mesylate significantly reduced the contracture of the extensor lumbar muscles in low back pain when given per os or parenterally.