Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya.

Measured step frequency was uncorrelated with FSA either within or between groups ( Fig 2B ), but preferred step frequency correlated strongly with FSA in the population as a whole (r = 0.692; p<0.001) and within the habitually shod runners (r = 0.652; p = 0.002), and approached conventional levels of significance within the habitually barefoot groups (r = 0.333; p = 0.07) ( Fig 2C ).

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