Biomechanics foot ankle: Gait

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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

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Initial Contact

• Ankle jt. is in neutral
• STJ is slightly supinated
• Anterior Tibialis and EDL are on eccentrically

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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?

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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

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Midstance

• Ankle DFs to 5-10 degrees
• Gastroc Soleus working eccentrically
• Knee extends near neutral (Gastroc stabilizes the
  knee)

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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

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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

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PreSwing

• Knee rapidly flexing
• 1st MTP 30-70 DF
• Ankle to 20 degrees PF
• Lift off!

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Initial Swing

• Ankle is dorsiflexing
• Eccentric contraction of Anterior tibialis, EHL,
  EDL.

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Midswing

• Ankle is in neutral position, dorsiflexors are
  still on.

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Terminal Swing

• Ankle is still in neutral