- Supination:
- supination of foot is a combination of inward rotation at the ankle, adduction of the hindfoot, inversion of the forefoot, and medial arch elevation;
- subtalar joint supination is 3 planes of motion simultaneously:
- adduction
- inversion
- plantarflexion
- as foot supinates the lateral structures tighten;
- continued supination and adduction force may rupture portions of lateral collateral ligaments or avulse these ligaments from their bony attachment sites on the distal fibula, resulting in an ankle sprain;
- Pronation:
- subtalar joint pronation is also 3 planes of motion simultaneously
- abduction of forefoot;
- eversion of hindfoot;
- dorsiflexion
- medial arch depressed;
- deficiency of medial forefoot post;
- hyperpronation can be a developmental response to tibia vara;
- excessive foot pronation has been speculated to be a cause of leg and foot problems among runners;
- changes in shoe design does improve foot alignment over running barefoot in a pt w/ forefoot pronation