Muscle Activity During Gait
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Top Contributors - Wanda van Niekerk, Jess Bell and Lucinda hampton
Breakdown of Gait Cycle Sub-Phases[edit | edit source]
Initial Contact (or Heel Strike)
The moment the foot touches the ground and begins the first phase of double support. Its function is to establish contact with the ground surface and initiate weight acceptance.
Kinematics/Joint Motion | Kinetics | ||
---|---|---|---|
External forces | Internal Forces | ||
Ankle | Neutral, 0° | Ground reaction force posterior to ankle joint
Plantarflexion moment created |
Dorsiflexors activated:
Eccentric contraction of ankle dorsiflexors to slow plantar flexion during the range of motion change from initial contact to foot flat |
Knee |
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Neutral, 0° | Eccentric contraction of dorsiflexors ( tibialis anterior, extensor digitorum longus, extensor hallucis longus) |
Knee | 5° flexion | Eccentric extensors |
Hip | 30° flexion | Concentric extensors and eccentric flexors |
Loading Response (or Foot Flat) - 0-10%
Begins with initial contact and continues until the contralateral foot leaves the ground. The foot continues to accept weight and absorb shock by rolling into pronation.[2]
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Rapid plantarflexion to 10° | Eccentric dorsiflexors |
Knee | Flexes to 10-15° | Eccentric extensors and concentric flexors |
Hip | Gradual extension | Concentric extensors |
Midstance - 10-30%
Begins when the contralateral foot leaves the ground and continues until ipsilateral heel lifts off the ground. The body is supported by a single leg and begins to move from force absorption at impact to force propulsion forward.[2]
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Gradual dorsiflexion | Eccentric plantarflexors and concentric dorsiflexors |
Knee | Begins to extend | Concentric extensors |
Hip | Gradual extension | Concentric extensors |
Terminal Stance (or Heel Off) - 30-50%
Begins when the heel leaves the floor and continues until the contralateral foot contacts the ground. In addition to single limb support and stability, this event serves to propel the body forward. Bodyweight is divided over the metatarsal heads.[2]
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Gradual dorsiflexion until a maximum of 10° before beginning to plantarflex | Eccentric plantarflexors, then
concentric plantarflexors |
Knee | Continues extending until a maximum of 5° of flexion before beginning to flex | Concentric extensors, then
eccentric extensors and concentric flexors |
Hip | Extends until a maximum of 10° extension | Eccentric flexors |
Pre-Swing (or Toe Off) - 50-60%
Begins when the contralateral foot contacts the ground and continues until the ipsilateral foot leaves the ground. Provides the final burst of propulsion as the toes leave the ground.[3]
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Begins to plantarflex rapidly before foot leaves the ground | Concentric plantarflexors |
Knee | Begins to flex rapidly | Eccentric extensors |
Hip | Begins to flex before foot leaves the ground | Concentric flexors |
Early Swing - 60-75%
Begins when the foot leaves the ground until it is aligned with the contralateral ankle. This event functions to advance the limb and shorten the limb for foot clearance.
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Continues to plantarflex until a maximum of 20° before
moving back towards a neutral position |
Eccentric dorsiflexors, then
concentric dorsiflexors and eccentric plantarflexors |
Knee | Rapid knee flexion until a maximum of about 60° | Eccentric extensors and concentric flexors |
Hip | Gradually flexes | Concentric flexors |
Mid-Swing - 75-85%
Begins from the ankle and foot alignment and continues until the swing leg tibia is vertical. As in early swing, it functions to advance the limb and shorten the limb for foot clearance.
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Maintains a neutral position | Concentric dorsiflexors |
Knee | Begins to extend | Eccentric flexors |
Hip | Continues to flex until a maximum of just over 30° | Concentric flexors |
Late Swing/Deceleration - 85-100%
Begins when the swing leg tibia is vertical and ends with initial contact. Limb advancement slows in preparation.
Kinematics/Joint Motion | Muscle Action | |
---|---|---|
Ankle | Maintains a neutral position | Concentric dorsiflexors |
Knee | Extends until full extension, and flexes just slightly before initial contact | Eccentric flexors, then concentric flexors |
Hip | Hip remains flexed to around 30 ° | Concentric flexors and eccentric extensors,
then concentric extensors |
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