Changes in spring-mass behavior and muscle activity during an exhaustive run at (V) over dotO2max

JOURNAL OF BIOMECHANICS

卷:46

Article

Rabita, Giuseppe¹  Couturier, Antoine¹  Dorel, Sylvain^1,2  Hausswirth, Christophe¹  Le Meur, Yann¹ 

[1] INSEP, Natl Inst Sport Expertise & Performance, Res Dept, F-75012 Paris, France

[2] Univ Nantes, Lab Motricite, EA 4334, Nantes, France

关键词: Spring-mass model;    Fatigue;    Force platform;    Lower limb muscles;   

DOI  :  10.1016/j.jbiomech.2013.06.011

来源: Elsevier

【 摘 要 】

Purpose: The aim of this study was to evaluate concomitantly the changes in leg-spring behavior and the associated modifications in the lower limb muscular activity during a constant pace run to exhaustion at severe intensity. Methods: Twelve trained runners performed a running test at the velocity associated with (V) over dotO(2max) (5.1 +/- 0.3 m s(-1); mean time to exhaustion: 353 +/- 69 s). Running step spatiotemporal parameters and spring-mass stiffness were calculated from vertical and horizontal components of ground reaction force measured by a 6.60 m long force platform system. The myoelectrical activity was measured by wireless surface electrodes on eight lower limb muscles. Results: The leg stiffness decreased significantly (-8.9%; P < 0.05) while the vertical stiffness did not change along the exhaustive exercise. Peak vertical force (-3.5%; P < 0.001) and aerial time (-9.7%; P < 0.001) decreased and contact time significantly increased (+4.6%; P < 0.05). The myoelectrical activity decreased significantly for triceps surae but neither vastus medialis nor vastus lateralis presented significant change. Both rectus and biceps femoris increased in the early phase of swing (+14.7%; P < 0.05) and during the pre-activation phase (+16.2%; P < 0.05). Conclusion: The decrease in leg spring-stiffness associated with the decrease in peak vertical ground reaction force was consistent with the decline in plantarflexor activity. The biarticular rectus femoris and biceps femoris seem to play a major role in the mechanical and spatiotemporal adjustments of stride pattern with the occurrence of fatigue during such exhaustive run. (c) 2013 Elsevier Ltd. All rights reserved.

【 授权许可】

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