The influence of minimalist footwear and stride length reduction on lower-extremity running mechanics and cumulative loading.
OBJECTIVE
To examine the effects of shoe type and stride length reduction on lower-extremity running mechanics and cumulative loading.


METHODS
Within-subject with four conditions: (1) control shoe at preferred stride length; (2) control shoe at 90% preferred stride length; (3) minimalist shoe at preferred stride length; (4) minimalist shoe at 90% preferred stride length.


METHODS
Fourteen young healthy males ran overground at their preferred speed while motion capture, force platform, and plantar pressure data were collected. Peak moments, impulse, mechanical work, and cumulative impulse were calculated at the metatarsophalangeal, ankle, and knee joint, and compared between conditions using a 2×2 factor repeated measures ANOVA.


RESULTS
In general, running in minimalist footwear increased measures of loading at the metatarsophalangeal joint and ankle joint (mean increases of 7.3% and 5.9%, respectively), but decreased measures of loading at the knee (mean decrease of 7.3%). Conversely, running with reduced stride length decreased single-stance measures of loading at the ankle and knee joint (ranging from -0.9% to -20.5%), though cumulative impulse was higher at the ankle and lower at the knee.


CONCLUSIONS
Running in minimalist shoes increased loads at the metatarsophalangeal and ankle joint, which may explain some of the incidence of overuse injuries observed in minimalist shoe users. Decreased ankle loads at 90% preferred stride length were not necessarily sufficient to reduce cumulative loads when impulse and loading cycles were weighted equally. Knee loads decreased more when running at 90% preferred stride length (16.2% mean reduction) versus running in a minimalist shoe (7.3% mean reduction), but both load reduction mechanisms appeared to have an additive effect (22.2% mean reduction).
Human Performance Laboratory and Biomedical Engineering Graduate Program, University of Calgary, Canada. Electronic address: cfirming@ucalgary.ca.
Colin R
CR
Firminger
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Canada.
W Brent
WB
Edwards
D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena / Q000502:physiology; D016022:Case-Control Studies; D005684:Gait / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D012420:Running / Q000502:physiology*; D012775:Shoes; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult
Ankle joint; Inverse dynamics; Knee joint; Metatarsophalangeal joint; Running injury; Shoes