Study Design: Single group, post-test design using the uninvolved lower extremity as the experimental control. Objectives: To determine relationships between ankle swelling and flexor digitorum longus and peroneus longus H-reflex amplitude and latency. Background: Primary capsuloligamentous injury, neural injury, and joint effusion and swelling may contribute to H-reflex changes following inversion ankle sprain. The relationship between ankle swelling and invertor or evertor H-reflexes has not been reported. Methods and Measures: Fifteen subjects with acute grade I or II inversion ankle sprains (mean ± SD) 6.5 ± 3 days after onset participated in this study. Swelling was estimated using a tape measure and the figure-of-eight girth assessment method. H-reflexes were determined using standard techniques. Paired t-tests were used to compare mean differences in ankle girth (swelling) and ankle invertor or evertor H-reflex amplitude and latency between the involved and uninvolved limbs. Pearson product moment correlations were used to assess relationships between swelling and H-reflex variables. Results: Involved limb ankle girth was increased with respect to the uninvolved limb (1.5 ± 0.9 cm) and the involved ankle flexor digitorum longus latency was delayed (0.72 ± 0.7 ms). There was a moderate positive association (r = 0.73) between the latency delay in the involved ankle flexor digitorum longus and swelling. There were no significant differences in H-reflex amplitude and peroneus longus latency between ankles. Conclusions: Grade I or II inversion sprains and the related swelling appear to delay involved ankle flexor digitorum longus latency to a greater extent than peroneus longus latency. Clinicians need to direct greater attention to the ankle invertors when designing and implementing ankle rehabilitation programs, particularly during the swelling management phase of treatment.

J Orthop Sports Phys Ther. 1999;29(6):339-344.

Key Words: neuromuscular inhibition, electromyography, latency

Strengthening of the evertor muscles is widely advocated as a key component of lateral ankle sprain rehabilitation, but our clinical observation of impaired invertor muscle performance among many patients suggested the need for this study of isokinetic performance deficiencies. Subjects were 30 physically active adolescents, ages 14-19 years, who had recently sustained a lateral ankle sprain or who had symptoms of chronic lateral ankle instability. Eversion/inversion testing was performed on a Biodex isokinetic dynamometer at speeds of 30 and 120°/sec. Analysis of variance results demonstrated significantly greater (p < .05) invertor deficits than evertor deficits for both peak torque and average power at both tests speeds. The findings of this study suggest that a lateral ankle ligament injury may be associated with an invertor muscle performance deficiency, and that restoration of a normal evertor/invertor strength relationship may be accomplished through performance of an isotonic ankle strengthening program.

J Orthop Sports Phys Ther. 1997;26(2):78-86.

Key Words: ankle sprain, ankle instability, isokinetic testing