Normally aligned knee

The residual limb-prosthetic socket stresses are influenced by the fit of the socket and the alignment of the prosthesis. For transdbial amputees, medial-lateral stability is influenced by foot placement. Foot inset (or outset) may result in varas (or valgus) moments applied to the limb. Similarly, anterior-posterior stability is influenced by the fore-aft position (extension-flexion moment) of the foot, foot plantarflexion/dorsiflexion (extension-flexion moment), and heel durometer (soft heel increases foot plantarflexion). For transtibial amputees with normal knee extensors, knee flexion moments on heel strike are desired, as for individuals without amputation. 

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