Podcast
Questions and Answers
What position is the hip in at the initial contact of gait?
What position is the hip in at the initial contact of gait?
Which muscle group primarily contracts eccentrically to prevent excessive knee flexion during walking?
Which muscle group primarily contracts eccentrically to prevent excessive knee flexion during walking?
During mid-stance, what happens to the knee position?
During mid-stance, what happens to the knee position?
What action do the ankle dorsiflexors perform to keep the foot from slapping the ground?
What action do the ankle dorsiflexors perform to keep the foot from slapping the ground?
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At what stage does the opposite lower extremity begin initial contact?
At what stage does the opposite lower extremity begin initial contact?
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What role do the hip extensors play during gait?
What role do the hip extensors play during gait?
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What is the knee angle during maximal knee flexion in the swing phase?
What is the knee angle during maximal knee flexion in the swing phase?
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How do the hamstrings assist during the swing phase of gait?
How do the hamstrings assist during the swing phase of gait?
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Study Notes
Gait Cycle: Stance Phase
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Initial Contact: Foot contacts ground, knee extends then flexes (shock absorption). Hip is at ~25° flexion, trunk erect and rotated to opposite side. Same-side arm is in shoulder hyperextension. Body weight shifts to stance leg. Quadriceps transition from concentric to eccentric contraction. Hip extensors contract to minimize hip flexion. Erector spinae activate to prevent trunk flexion. Entire plantar surface contacts the ground.
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Loading Response: Body weight continues over stance leg. Ankle moves into ~15° of plantar flexion (PF). Knee flexes to ~20°. Hip transitions from flexion to neutral. Dorsiflexors (DF) contract eccentrically to prevent foot slapping ground. Quads contract eccentrically to control knee flexion. Opposite lower limb is in initial swing phase.
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Midstance: Full weight-bearing on stance leg. PF muscles begin contracting to control leg movement over ankle. Opposite limb is in mid-swing phase. Ankle is ~10-20° PF. Knee near full extension (~0°). Hip is at ~20° hyperextension. Trunk rotation continues towards same side.
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Terminal Stance: Forward propulsion ends. Opposite limb enters terminal stance-initial contact phase. Ankle moves into slight dorsiflexion (~15°) then PF. Knee is nearly fully extended. Hip at ~20° hyperextension. Trunk rotation ongoing.
Gait Cycle: Swing Phase
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Initial Swing: Limb behind body, moving forward to catch up. Swing leg in middle of swing. Ankle begins in plantarflexion, then dorsiflexes. Knee flexes maximally (~60°) and hip flexes maximally (~25°). Limb shortened to clear ground. Opposite limb in terminal stance.
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Mid-Swing: Ankle dorsiflexors are concentrically active to maintain ankle at neutral. Hip is actively flexed. Knee & hip flexes to mid-swing.
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Terminal Swing: Ankle dorsiflexors maintain ankle neutral position in preparation for next heel strike. Opposite lower extremity is in terminal stance and initial contact. Hamstrings contract eccentrically to slow leg movement and to keep the knee from snapping into extension. Hip reaches 25° flexion.
Key Joint Actions (Summary)
- Ankle: Begins in PF, moves to DF, then progressive PF during stance.
- Knee: Extends then flexes progressively during initial contact-midstance. Flexes maximally in swing.
- Hip: Flexed at initial contact, transitions to neutral, then hyperextension. Flexes and extends throughout the swing phase.
- Trunk: Erect, rotated to opposite side during stance, and forward propulsion ends at terminal stance.
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Description
Test your knowledge on the stance phase of the gait cycle. This quiz covers the key phases including initial contact, loading response, and midstance. Understand the biomechanics involved during each phase and the muscle contractions that play a vital role in walking.
