title: The effect of foot strike pattern on achilles tendon load during running.
abstract: In this study we compared Achilles tendon loading parameters during barefoot running among females with different foot strike patterns using open-source computer muscle modeling software to provide dynamic simulations of running. Muscle forces of the gastrocnemius and soleus were estimated from experimental data collected in a motion capture laboratory during barefoot running for 11 runners utilizing a rearfoot strike (RFS) and 8 runners utilizing a non-RFS (NRFS) pattern. Our results show that peak Achilles tendon force occurred earlier in stance phase (p = 0.007), which contributed to a 15% increase in average Achilles tendon loading rate among participants adopting a NRFS pattern (p = 0.06). Stance time, step length, and the estimated number of steps per mile were similar between groups. However, runners with a NRFS pattern experienced 11% greater Achilles tendon impulse each step (p = 0.05) and nearly significantly greater Achilles tendon impulse per mile run (p = 0.06). This difference equates to an additional 47.7 body weights for each mile run with a NRFS pattern. Runners considering a NRFS pattern may want to account for these novel stressors and adapt training programs accordingly.
authors: La Crosse Institute for Movement Science, Department of Health Professions-Physical Therapy Program, University of Wisconsin-La Crosse, La Crosse, WI, USA.
authors: Thomas
authors: T
authors: Almonroeder
authors: John D
authors: JD
authors: Willson
authors: Thomas W
authors: TW
authors: Kernozek
mesh_terms: D000125:Achilles Tendon / Q000502:physiology*; D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D003198:Computer Simulation; D005528:Foot / Q000502:physiology*; D006801:Humans; D008297:Male; D008954:Models, Biological; D012420:Running / Q000502:physiology*; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult