The contact phase of the Stance part of gait is all about internal rotation and pronation of the entire lower extremity, therefore, supination and external rotation at this time causes trouble.
The image below demonstrating the inversion seen at the heel following heel contact in over supinators.
As we strike the ground with each step, our foot continues the internal rotation of the leg for shock absorption and mobility to adapt to the ground. We pronate our subtalar joint with heel eversion and talar adduction and internal rotation. This motion can be limited, normal, or excessive, but it has to exist. If instead, we land of the ground and supinate our subtalar joint, we do not adapt to the ground well (laterally unstable), and we have poor shock absorption (very jarring gait).Supination tendencies can be in the foot, ankle, leg, shoe gear, activities, and the surfaces that we walk or run on. Therefore, a normal functioning foot may only supinate in a laterally broken down shoe, following a severe lateral ankle sprain, when this normal foot is below high degrees of tibial or genu varum, or when it is compensating for high degrees of genu valgum. 3 months in a CAM walker for some injury can make your peroneal tendons so weak that you supinate since it is hard to stabilize your lateral column. Review this checklist of overuse supination based injuries:
- 4th/5th metatarsal stress fracture
- Cuboid syndrome
- Peroneal tendonitis
- Inversion Ankle Sprains
- Medial Ankle Impingement Syndrome
- Fibular stress fractures
- Tibial stress fractures
- Medial Knee Compartment syndrome
- Hip Arthralgias
- Sacro-iliac Symptoms
- Low Back Pain
The causes of these will be related to poor shock absorption, lateral foot and leg overloading, or medial ankle or knee joint compression. How do you make these connections in practice? Get into the habit of asking patients for all of their current symptoms (foot to back at least) as you embark to fix their pronation, supination, leg length, poor shock absorption, etc. Slowly, you will see that the treatment for their foot also helped their leg, knee, hip and back. I have attached a video showing contact phase supination with obvious lateral weight shift foot and leg.
