biomechanics foot ankle: gait stance phase gait60% of cycle –initial contact –loading response...
Post on 22-Dec-2015
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Biomechanics foot ankle: Gait• Stance Phase Gait 60% of cycle
– Initial contact– Loading response– Midstance– Terminal Stance– Preswing
• Swing Phase Gait 40% of Cycle– Early swing– Mid-Swing– Terminal Swing
Initial Contact
• Ankle jt. is in neutral• STJ is slightly
supinated• Anterior Tibialis and
EDL are on eccentrically
Loading Response
• Ankle moves rapidly into 10 degrees PF
• Pretibial mm action• Tibia is pulled anterior• Knee flexes• STJ-Calcaneus everts
4-6 degrees (closed chain pronation)
• ?mm controls this• Midtarsals?
Loading Response
• Closed Chain Pronation: Loose packed position at STJ and in midtarsal region-allows for shock absorption– Calcaneal eversion– Talus horizontally adducts– Tibia Internally Rotates– Knee Flexes– Femur internally rotates
Midstance
• Ankle DFs to 5-10 degrees
• Gastroc & Soleus working eccentrically
• Knee extends near neutral (Gastroc stabilizes the knee)
Terminal Stance
• Ankle DFs to 10 degrees
• 1st MTP extends to 30• Calf mms still on• STJ-supinating• Midtarsals?• 1st Ray control• Knee in full extension
Terminal Stance
• Closed chain supination: subtalar joint and midtarsals go into a closed pack position. Makes a rigid lever for push off.
• Calcaneal inversion• Talar horizontal abduction• Tibial external rotation• Knee extension• Femur external rotation