A Prospective Study on Medial Tibial Stress Syndrome in Runners

Abstract

Medial tibial stress syndrome (MTSS) is one of the most common overuse injuries in runners. Previous studies have indicated hip muscle strength, passive range of motion (ROM), and running kinematics as possible contributing factors. However, to date, no studies have combined measurements of all these areas into a single prospective study. PURPOSE: To prospectively examine differences in muscle strength, ROM, and kinematics between runners who do and do not develop MTSS. METHODS: 24 runners (sex: 13 male, 11 female; age: 20.1 ± 1.2 years; weekly mileage: 53.2 ± 20.8 miles) participated in this study. Participants underwent a clinical exam documenting lower limb alignment and ROM; were evaluated for hip abductor, external and internal rotator, and extensor strength using a hand held dynamometer; and completed a 3D running gait analysis during which a 12-camera motion capture system was used to record kinematics while they ran on a treadmill. Participants were followed for two years during which time any injuries were diagnosed and recorded by the teams’ athletic trainer. Independent t-tests were used to compare differences between runners who did (INJ) and did not (CON) develop MTSS. Logistic regression was used evaluate which variables were best predictors of group membership. RESULTS: After two seasons 8 of the 24 athletes developed MTSS. There were no differences in ROM measures between INJ and CON groups, however, the INJ group demonstrated weaker hip abductors than the CON group (16.0 ± 3.6 vs 21.9 ± 6.0 % body weight, p = 0.01, ES = 1.4). Compared to the CON group, the INJ group had higher contralateral pelvic drop (6.4 ± 1.4 vs. 4.5 ± 2.0°, p = .02, ES = 1.1), higher peak rearfoot eversion (8.2 ± 4.3 vs. 4.6 ± 1.9°, p = .02, ES = 1.1), and longer durations of rearfoot eversion (79.4 ± 8.5 vs. 55.5 ± 10.3 % stance, p < .001, ES = 2.5) during stance phase. The logistic regression (χ2 = 18.1, p < .001) revealed every 1% stance increase in duration of rearfoot eversion increased odds of being in the INJ group by 1.26 (p = .015, 95% CI 1.04 - 1.54). CONCLUSION: Both proximal and distal biomechanics appear to contribute to MTSS development. Thus, screening for individuals at risk of developing this common overuse injury should include evaluation of both regions, with particular attention to the duration of rearfoot eversion.