Each of these movements of the foot/ankle cause a change in the tibia/fibula position. A change in tibia/fibula position causes a change in femur and patella position. Change in femur position cause a reaction in pelvic position and all the way up the body.
Pronation is something commonly talked about and often treated by using an arch support or custom orthotic and stability shoes. But what causes pronation? The causes of pronation can be many things, and often a lot of them combined together. Hallux valgus which is the combination of abduction of the first metatarsal and adduction of the phalanges and this changes the line of pull of the flexor hallucis longus and abductor hallucis and causes further adduction of the big toe and a collapsing of the medial arch. The collapsing of the medial arch will cause pronation and eversion of the foot. This subsequently causes internal tibial rotation which causes internal femur rotation.
But what if internal femur rotation happened first? The internal tibial rotation would cause eversion and pronation of the foot. This would cause pes cavus (a collapsing of the medial arch or flat feet) and the changes this creates during gait would start causing hallux valgus. Since the body is a unit, a change in position or posture of one bone or joint will cause a chain reaction up and down the body affecting every other joint in your body. (Today I'm just focusing on the foot and leg and in a future blog posts will talk about the rest of the body.)
Read part 3 of this discussion: How hip and spine posture influence each other and cause pain.
Read part 4 of this discussion: How upper back and shoulder posture influence each other and cause pain.