Background: Lower extremity injuries are common among runners. Recent trends in footwear 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. However, little is known about how maximal shoes influence running biomechanics.
Purpose: To examine the influence of maximal running shoes on biomechanics before and after a 5-km (5K) run as compared with neutral running shoes.
Study design: Controlled laboratory study.
Methods: Fifteen female runners participated in 2 testing sessions (neutral shoe session and maximal shoe session), with 7 to 10 days between sessions. Three-dimensional kinematic and kinetic data were collected while participants ran along a 10-m runway. After 5 running trials, participants completed a 5K treadmill run, followed by 5 additional running trials. Variables of interest included impact peak of the vertical ground-reaction force, loading rate, and peak eversion. Differences were determined by use of a series of 2-way repeated-measures analysis of variance models (shoe × time).
Results: A significant main effect was found for shoe type for impact peak and loading rate. When the maximal shoe was compared with the neutral shoe before and after the 5K run, participants exhibited an increased loading rate (mean ± SE: pre-maximal shoe, 81.15 body weights/second [BW/s] and pre-neutral shoe, 60.83 BW/s [P < .001]; post-maximal shoe, 79.10 BW/s and post-neutral shoe, 61.22 BW/s [P = .008]) and increased impact peak (pre-maximal shoe, 1.76 BW and pre-neutral shoe, 1.58 BW [P = .004]; post-maximal shoe, 1.79 BW and post-neutral shoe, 1.55 BW [P = .003]). There were no shoe × time interactions and no significant findings for peak eversion.
Conclusion: Runners exhibited increased impact forces and loading rate when running in a maximal versus neutral shoe. Because 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.
Clinical relevance: Understanding the influence of running footwear as an intervention that affects running biomechanics is important for clinicians so as to reduce patient injury.
Keywords: highly cushioned shoes; impact forces; loading rate.