S.A. Dean, J.J. Hannigan,B.K Newcomb,B.C. Krevitz, C.D. Pollard

Oregon State University-Cascades, Bend, OR

Over the course of a research study examining the effect of a 6-week transition to maximal shoes on running biomechanics, two female participants withdrew due to injury: one with Achilles tendinopathy (AT), the other with Medial Tibial Stress Syndrome (MTSS). PURPOSE: To examine the biomechanical factors at initial testing that may have led to injury and subsequent withdrawal from the study. METHODS: For the larger study, running biomechanics were examined prior to and following a six-week transition to maximal shoes in twenty-eight recreational runners. Ankle kinematics and vertical ground reaction forces (vGRF) were examined using an 8-camera three-dimensional motion capture system and two force platforms in two shoe conditions: maximal footwear (rearfoot: 37 mm, forefoot: 33mm) and traditional footwear (rearfoot: 33 mm, forefoot: 23 mm). Two participants were unable to complete the full study due to injury during the six-week transition. One participant (MTSS, 38 years old) described “tightness in shins and ankles” while wearing the maximal shoe within the first week, which progressed to sharp pain in the right medial tibia during the fourth week. The other participant (AT, 46 years old) began experiencing an “ache” in their left Achilles tendon in week one, and by week five, could no longer run or walk without pain while wearing the maximal footwear. RESULTS: Both cases demonstrated prolonged eversion during stance phase in the maximal shoe (AT & MTSS: 99% of stance phase), which was longer than in the traditional shoe (AT: 80% of stance phase; MTSS: 95% of stance phase). Further investigation of vGRF data revealed the loading rate of the participant with MTSS (82.75 BW/s) was slightly lower, while that of the one with AT (59.78 BW/s) was significantly lower than the average for the healthy participants (85.85 BW/s), further implicating prolonged eversion as a factor for injury. CONCLUSION: Prolonged eversion has been previously cited as a risk factor for developing both AT and MTSS. Because prolonged eversion was higher in the maximal shoe for both participants who developed these injuries, it is possible the maximal shoe was a contributing factor for injury. Further research on the relationship between maximal footwear and injury is warranted.

Research supported by Oregon State University - Cascades Campus

This document is currently not available here.