Local sensation changes and altered hip muscle function following severe ankle sprain.

BACKGROUND AND PURPOSE Changes in sensory information have been shown to influence muscle function locally. Some clinicians, however, believe that the influence may be more extensive. To investigate this clinical concept, subjects with severe ankle sprain were assessed for local sensation changes and proximal hip/back muscle function. SUBJECTS Of a total of 361 potential subjects whose medical histories were assessed, 20 men (age 18-35 years) who had previously sustained a severe unilateral ankle sprain and 11 matched "control" subjects with no previous lower-limb injury participated in the study. METHODS Using this experimental model, tests of vibration sensation in the ankle (indicating sensation changes) as well as surface electromyography of muscle recruitment patterns for hip extension (indicating muscle function proximally) of the biceps femoris, gluteus maximus, and lumbar erector spinae muscles were made on both sides of the unilaterally injured and matched control subjects. RESULTS Significant decreases in vibration perception and significant delays in gluteus maximus muscle recruitment during hip extension were found in the injured group. CONCLUSION AND DISCUSSION The author concludes that both local sensory and proximal muscle function changes are associated with unilateral severe ankle sprain.