Purpose: The purpose of this study was to determine if running in a minimalist shoe results in a reduction in ground reaction forces and alters kinematics over standard shoe running. The secondary purpose of this study was to determine if within-session accommodation to a novel minimalist shoe occurs.
Methods: Subjects were 14 male, rearfoot striking runners who had never run in a minimalist shoe. Subjects were tested while running 3.35 m/s for 10 minutes on an instrumented treadmill in a minimalist and a standard shoe as 3-D lower extremity kinematics and kinetics were evaluated. Data were collected at minute 1 and then again after 10 minutes of running in both shoe conditions to evaluate accommodation to the shoe conditions.
Results: Shoe x time interactions were not found for any of the variables of interest. Minimalist shoe running resulted in no changes in step length (p=0.967) nor step rate (p=0.230). At footstrike, greater knee flexion (p=0.001) and greater dorsiflexion angle (p=0.025) were noted in the minimalist shoe. Vertical impact peak (p=0.017) and average vertical loading rate (p<0.000) were greater during minimalist shoe running. There were main effects of time as dorsiflexion angle decreased (p=0.035), foot inclination at footstrike decreased (p=0.048) and knee flexion at footstrike increased (p=0.002), yet the vertical impact peak (p=0.002) and average vertical loading rate (p<0.000) increased.
Conclusions: Running in a minimalist shoe appears to, at least in the short-term, increase loading of the lower extremity over standard shoe running. The accommodation period resulted in less favorable landing mechanics in both shoes. These findings bring into question whether minimal shoes will provide enough feedback to induce an alteration that is similar to barefoot running.
(C) 2013 American College of Sports Medicine