Lower extremity injuries are a common occurrence among runners. Recent footwear trends have included minimal and maximal running shoe types. Maximal running shoes are unique because they provide the runner with a highly cushioned midsole in both the rearfoot and forefoot. Little is known about how maximal shoes influence running biomechanics.
PURPOSE: To examine the influence of maximal running shoes on biomechanics prior to and following a 5K run as compared to neutral running shoes.
METHODS: : Fifteen female runners participated in two testing sessions (neutral shoe session and maximal shoe session) with 7-10 days between sessions. Three-dimensional kinematics and kinetics were collected while subjects ran along a 10 meter runway. After five running trials, they completed a 5K treadmill run, and then completed five additional running trials. Variables of interest included impact peak of the vertical ground reaction force, loading rate, and peak eversion. Differences were determined by using a series of two-way repeated measures ANOVA models (shoe x time).
RESULTS: There was a significant main effect for shoe type for impact peak and loading rate. Comparing the neutral shoe to the maximal shoe prior to and following running a 5K, subjects exhibited an increased loading rate [(pre-neutral: 60.83 BWs/sec; pre-maximal: 81.15 BWs/sec) p=0.000, (post-neutral: 61.22 BWs/sec; post-maximal: 79.10 BWs/sec) p=0.008], and increased impact peak [(pre-neutral: 1.58 BWs; pre-maximal: 1.76 BWs) p=0.004, (post-neutral: 1.55 BWs; post-maximal: 1.79 BWs) p=0.003] in the maximal shoe condition. There were no shoe-time interactions and no significant findings for peak eversion.
CONCLUSIONS: Runners exhibited increased impact forces and loading rate when running in a maximal versus neutral shoe. Since increases in these variables have been associated with an increased risk of running related injuries, runners who are new to running in a maximal shoe may be at an increased risk of injury. Therefore, runners should be cautious when switching from a neutral shoe to a maximal shoe; however, further work is necessary to better understand the longer-term impact.