Changes in the Medial Plantar Arch After Prolonged Running in Different Running Shoes Measured by Cone Beam CT

Introduction: Running long distances results in transient flattening of the medial foot arch with the navicular bone moving medially and distally. This could be part of the explanation for the increased injury risk in running long distances. We hypothesized that stability running shoes would result in lesser navicular displacement compared to carbon shoes after running 90 min on hard surface. Methods: Twenty healthy male recreational runners with normal feet assessed with foot posture index score 0–5 were recruited. We performed cone beam CT (CBCT) scanning non‐weight bearing (NWB) and weight bearing (WB) before running 90 min and WB immediately after the run. Participants performed one run in stability shoes and repeated the run in carbon shoes on the exact same route maintaining the same speed 1–4 weeks apart. Results: The navicular height changed significantly from NWB 33.3 mm (SD 3.6) to WB 30.7 mm (SD 4.1, p < 0.001), and from WB before the run 30.7 mm (SD 4.1) to WB after the run 30.1 mm (SD 4.0, p = 0.02). No measurable differences were observed between shoe types. A majority of the runners claimed less perceived exertion and more comfort in the carbon shoes. Conclusion: Deformation of the medial plantar arch is measurable after a 90 min run assessed by navicular displacement on CBCT. Novel carbon shoes seem to support the medial foot arch as much as stability shoes.