| Effects of stride length and running mileage on a probabilistic stress fracture model. | |
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MedLine Citation:
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PMID: 19915501 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The fatigue life of bone is inversely related to strain magnitude. Decreasing stride length is a potential mechanism of strain reduction during running. If stride length is decreased, the number of loading cycles will increase for a given mileage. It is unclear if increased loading cycles are detrimental to skeletal health despite reductions in strain. PURPOSE: To determine the effects of stride length and running mileage on the probability of tibial stress fracture. METHODS: Ten male subjects ran overground at their preferred running velocity during two conditions: preferred stride length and 10% reduction in preferred stride length. Force platform and kinematic data were collected concurrently. A combination of experimental and musculoskeletal modeling techniques was used to determine joint contact forces acting on the distal tibia. Peak instantaneous joint contact forces served as inputs to a finite element model to estimate tibial strains during stance. Stress fracture probability for stride length conditions and three running mileages (3, 5, and 7 miles x d(-1)) were determined using a probabilistic model of bone damage, repair, and adaptation. Differences in stress fracture probability were compared between conditions using a 2 x 3 repeated-measures ANOVA. RESULTS: The main effects of stride length (P = 0.017) and running mileage (P = 0.001) were significant. Reducing stride length decreased the probability of stress fracture by 3% to 6%. Increasing running mileage increased the probability of stress fracture by 4% to 10%. CONCLUSIONS: Results suggest that strain magnitude plays a more important role in stress fracture development than the total number of loading cycles. Runners wishing to decrease their probability for tibial stress fracture may benefit from a 10% reduction in stride length. |
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Authors:
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W Brent Edwards; David Taylor; Thomas J Rudolphi; Jason C Gillette; Timothy R Derrick |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Medicine and science in sports and exercise Volume: 41 ISSN: 1530-0315 ISO Abbreviation: Med Sci Sports Exerc Publication Date: 2009 Dec |
Date Detail:
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Created Date: 2009-11-20 Completed Date: 2010-02-18 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8005433 Medline TA: Med Sci Sports Exerc Country: United States |
Other Details:
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Languages: eng Pagination: 2177-84 Citation Subset: IM; S |
Affiliation:
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Department of Kinesiology, Iowa State University, Ames, IA 50011-1160, USA. edwards9@iastate.edu |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Cumulative Trauma Disorders Fractures, Stress / etiology, physiopathology, prevention & control* Gait / physiology* Humans Male Models, Statistical Muscle, Skeletal Running / physiology* Tibia / injuries Young Adult |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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