Three Critical Concepts: Moving from Subjective to Objective Running Footwear: Shoes Impact Form, and Form Impacts Function Jay Dicharry – MPT, SCS

Do Feet Actually Move Differently? Dicharry et al, JOST - 2009 Categories based on a static navicular drop test – measuring difference in navicular height between seated and standing. Navicular drop during walking and running were then measured.

Conclusion: even hypermobile feet do not necessarily move more than hypomobile feet – feet do not actually move significantly differently.

2 - Do Foot Models Improve Our Understanding? Foot Models do have a long way to go - While skin error is less prevalent in the foot than other areas, such as the thigh, the foot is still a highly complex structure: twenty-six bones, concave and convex relationships between tissues; the dynamic alignment between the joints is still not fully understood. For example, the true axis of the foot, and how it changes through the gait cycle is still in need of more clear definition.

 

           

       

3 – Timing: When does Maximum Pronation Occur? Dicharry et al, JOST - 2009 Conventional wisdom suggests that maximum pronation occurs at mid-stance. The shoe industry has therefore taken steps like placing firmer material on the inside of the shoe to stabilize and support our feet at mid-stance. In reality, peak foot pronation occurs just after mid-stance:

Conclusion: Steps like adding dual-density materials to prevent the rear foot from crashing in are not nessisarily effective. The materials designed to stop the foot from moving are not even touching the ground when they are theoretically most needed. This is important to consider when prescribing shoes based on the effect of timing on running.