Stiffness Adaptations in Shod Running

Abstract

When mechanical parameters of running are measured, runners have to be accustomed to testing conditions. Nevertheless, habituated runners could still show slight evolutions of their patterns at the beginning of each new running bout. This study investigated runners' stiffness adjustments during shoe and barefoot running and stiffness evolutions of shoes. Twenty-two runners performed two 4-minute bouts at 3.61 m.s-1 shod and barefoot after a 4-min warm-up period. Vertical and leg stiffness decreased during the shoe condition but remained stable in the barefoot condition, p < 0.001. Moreover, an impactor test showed that shoe stiffness increased significantly during the first 4 minutes, p < 0.001. Beyond the 4th minute, shoe properties remained stable. Even if runners were accustomed to the testing condition, as running pattern remained stable during barefoot running, they adjusted their leg and vertical stiffness during shoe running. Moreover, as measurements were taken after a 4-min warm-up period, it could be assumed that shoe properties were stable. Then the stiffness adjustment observed during shoe running might be due to further habituations of the runners to the shod condition. To conclude, it makes sense to run at least 4 minutes before taking measurements in order to avoid runners' stiffness alteration due to shoe property modifications. However, runners could still adapt to the shoe.

Acute and 2 days delayed effects of exhaustive stretch-shortening cycle exercise on barefoot walking and running patterns

“…In both unfatigued and fatigued conditions, however, the gait pattern is usually studied at the time when stabilization of ground reaction forces and gait kinematics has occurred, i.e. after 4-6 min in shod treadmill walk (Taylor et al 1996;Matsas et al 2000) and run (Divert et al 2005;Lavcanska et al 2005). To reveal potential anticipatory adjustments, it is suggested that SSC fatigue eVects should rather be studied at gait initiation.…”

Differences in Kinetics and Coordination between Walking Barefoot and Walking in Rocker Bottom Shoes

“…Landing on the hind-foot in shod running leads to a larger impact force than the more plantarflexed foot strike in BF running (De Wit et al, 2000;Divert et al, 2005). The larger impact force while wearing shoes was also observed in the current study, suggesting similarities in the walking pattern between conventional shoes and RBS rather than similarities between RBS and BF walking.…”

The pursuit of improved running performance: Can changes in cushioning and proprioception influence running economy and injury risk?

“…This suggests a higher centre of mass during stance for BFT running and a stiffer, less compliant leg. Greater leg stiffness has previously been associated with a lower metabolic cost of running, and appears to be a characteristic of BFT running compared with SH running (Divert et al 2005, Heise & Martin 1998). …”