Foot Morphological Difference between Habitually Unshod Runners and Shod Runners through Inverse Modelling

Abstract

With the increasing popularity of barefoot running, the difference of foot morphology between habitually unshod runners and shod runners is becoming one concern leading to running injuries. The purpose of this study was to analyze the foot skeletal morphological characteristics between habitually unshod runner and shod runner through inverse modelling. A total of eight subjects, including four habitually unshod runners and four habitually shod runners participated in the Computed Tomography (CT) foot scanning test and Mimics was utilized to rebuild foot model and the Inter-Metatarsal Angle (IMA), Metatarsal-Phalangeal Angle (MPA), and Inter-Phalangeal Distance (IPD) were measured to illustrate the morphology difference. The results showed that the Inter-Phalangeal Distance and Inter-Metatarsal Angle of unshod runners were obviously bigger than those of habitually shod feet. And the difference of Inter-Metatarsal Angle between unshod runner and shod runner was also distinct. Not only can this finding be proven of foot morphology variations, but also it can confirm the development of nature foot from unshod running to shod running.