Objective evaluation of peroneal response to sudden inversion stress.

The purposes of this paper are to describe an objective technique developed to assess the dynamic response of the peroneal muscles to a sudden inversion motion and to report the results obtained from testing injured and noninjured ankles. A platform was constructed to drop the ankle into a controlled degree of inversion while measuring the time to peroneal response and the angular rotation. Thirty volunteers were tested, 15 of whom had experienced a unilateral ankle sprain 3- 10 months prior to testing. Results show a trend toward delayed peroneal response and greater angular displacement at the time of peroneal response in injured ankles but analysis of variance showed no significant difference. The total angular displacement in the injured ankles was significantly greater. This objective technique could be used to evaluate treatment regimens and, by testing ankles soon after injury and serially, to evaluate readiness to return to activity. J Orthop Sports Phys Ther 1985;7(3):107-109.