This study investigated foot strike patterns and collision forces between habitually barefoot runners and shod runners. Researchers found that habitually shod runners predominantly used a rear-foot strike pattern while barefoot runners used a fore-foot or mid-foot strike pattern. Rear-foot striking when shod was attributed to the cushioned heel of shoes orienting the sole to have less dorsiflexion. Differences in foot strike patterns could have implications for injury rates as rear-foot striking results in higher rates of loading. More research is needed to determine if runners who do not rear-foot strike have reduced injury risks.