Academic
Publications
Changes in running mechanics and spring–mass behavior induced by a mountain ultra-marathon race

Changes in running mechanics and spring–mass behavior induced by a mountain ultra-marathon race,10.1016/j.jbiomech.2011.01.028,Journal of Biomechanics

Changes in running mechanics and spring–mass behavior induced by a mountain ultra-marathon race   (Citations: 1)
BibTex | RIS | RefWorks Download
Changes in running mechanics and spring–mass behavior due to fatigue induced by a mountain ultra-marathon race (MUM, 166km, total positive and negative elevation of 9500m) were studied in 18 ultra-marathon runners. Mechanical measurements were undertaken pre- and 3h post-MUM at 12kmh−1 on a 7m long pressure walkway: contact (tc), aerial (ta) times, step frequency (f), and running velocity (v) were sampled and averaged over 5–8 steps. From these variables, spring–mass parameters of peak vertical ground reaction force (Fmax), vertical downward displacement of the center of mass (Δz), leg length change (ΔL), vertical (kvert) and leg (kleg) stiffness were computed. After the MUM, there was a significant increase in f (5.9±5.5%; P<0.001) associated with reduced ta (−18.5±17.4%; P<0.001) with no change in tc, and a significant decrease in both Δz and Fmax (−11.6±10.5 and −6.3±7.3%, respectively; P<0.001). kvert increased by 5.6±11.7% (P=0.053), and kleg remained unchanged. These results show that 3h post-MUM, subjects ran with a reduced vertical oscillation of their spring–mass system. This is consistent with (i) previous studies concerning muscular structure/function impairment in running and (ii) the hypothesis that these changes in the running pattern could be associated with lower overall impact (especially during the braking phase) supported by the locomotor system at each step, potentially leading to reduced pain during running.
Journal: Journal of Biomechanics - J BIOMECH , vol. 44, no. 6, pp. 1104-1107, 2011
Cumulative Annual
View Publication
The following links allow you to view full publications. These links are maintained by other sources not affiliated with Microsoft Academic Search.
    • ...These results were consistent with those reported by Morin et al. (2011a) after a mountain ultra-marathon run (166 km, 37.9 ± 6.2 h, total positive and negative elevation of 9,500 m), i.e...
    • ...These changes may contribute to attenuate the potentially harmful eccentric phase and overall load faced by their musculo-skeletal system at each step (Morin et al. 2011a, b), which may not be an issue of importance during exhaustive runs of shorter durations...
    • ...The present results bring indirect support to the hypothesis put forward in previous ULD studies (Morin et al. 2011a, b) that the significant changes in the running pattern observed after ULD are not related to the decrease in strength capability of the lower limb extensors...
    • ...To explain the changes in running pattern observed after 24TR and mountain ultra-marathon runs (Morin et al. 2011a, b) and the Paris‐Beijing running trip (Millet et al. 2009), we proposed the hypothesis that subjects used a safer and ‘‘protective’’ running pattern, allowing them to attenuate the potentially harmful impact and support phases of the running step, and the associated braking/eccentric effort...

    Jean-Benoit Morinet al. High-intensity sprint fatigue does not alter constant-submaximal veloc...

Sort by: