KINES 300 Lecture Notes - Lecture 21: Subtalar Joint, Plantar Fascia, Calcaneus
22 May 2020
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Document Summary
Kinematics at talocrural and subtalar joints in open and closed chain. Talus is convex mover on concave tibia and fibula. Joint coupling subtalar joint and tibial rotation. Subtalar close packed = supination, lose packed = pronation. Ligament restraints to inversion/eversion talocrural/subtalar motion calcaneus inversion, talus abd calcaneus eversion, talus add tibia er tibia ir. Closed chain concentric/eccentric primary movers at ankle. Posterior tibialis works eccentrically to control arch. Intrinsic foot muscles: allow for adaptation of the foot and arch maintenance. Windlass mechanism: extension of big toe stretches plantar fascia to create a rigid foot for push-off. Influence of foot/ankle pronation/supination on hip, knee, rear foot posture. Toe flexors work a ton to try and compensate. Rearfoot varus looks like supination, compensate with pronation. Calcaneus is inverted when subtalar joint is neutral. Forefoot valgus- looks like pronation, supination to compensate. Forefoot varus- looks like supination, pronation to compensate. Compensation can lead to overpronation, everted calcaneus, ir tibia, decreased foot rigidity.
