Muscle Activity During Gait

Original Editor - Wanda van Niekerk based on the course by Alexandra Kopelovich
Top Contributors - Wanda van Niekerk and Jess Bell  

Gait Kinetics and Joint Moment[edit | edit source]

Gait kinetics investigates the forces and moments of the gait cycle. This includes the study of ground reaction forces (GRF), joint torque, plantar pressure distribution and muscle activity.[1] The body should be in equilibrium during gait, therefore, the external ground reaction forces (GRF) (external moment) should be balanced by the internal muscle forces (internal moment).[2] Different muscles perform different actions at every phase to create an internal moment against the external joint moment. Ground reaction force vectors create the direction of moment and the muscle will act in the opposite direction. If the ground reaction force falls anterior to the axis of the joint, the proximal segment of the joint will move anteriorly; if the ground reaction force falls posterior to the axis of the joint, the proximal segment of the joint with move posteriorly. Muscles can contract concentrically or eccentrically to overcome the external moment. During a concentric muscle contraction, the muscle shortens and there is movement at the joint, whereas during an eccentric contraction the muscle lengthens while producing force.

Read more:

Breakdown of Kinematics and Kinetics During the Gait Cycle[edit | edit source]

Stance Phase[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.[3]

Kinematics and Kinetics at Initial Contact[4]
Joint Kinematics Kinetics
External Forces Internal Forces/ Muscle Action
Ankle Ankle moves from 0° neutral at initial contact to 5° of plantarflexion at foot flat GRF posterior to axis of rotation of the ankle joint

External plantar flexor moment created

Internal dorsiflexor moment

Eccentric contraction of dorsiflexors (tibialis anterior, extensor digitorum longus, extensor hallucis longus)

Knee Knee moves from 0° extension at initial contact to 15° flexion at foot flat GRF anterior to axis of rotation of the knee joint

External extensor moment created

Internal flexor moment

Concentric contraction of knee flexors (hamstrings)

Eccentric contraction of knee extensors (quadriceps)

The range of motion change in the knee joint (0° - 15°), results in the shifting of GRF from anterior to posterior - this will result in external flexor torque, and the knee extensors will work eccentrically to control the knee

Hip Hip moves from 20° flexion at initial contact to 15° of flexion at foot flat GRF anterior to axis of rotation of the hip joint

External flexor moment created

Internal extensor moment

Concentric contraction of hip extensors (gluteus maximus)

Foot Flat (Loading Response)

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.[3]

Kinematics and Kinetics at Foot Flat[4]
Joint Kinematics Kinetics
External Forces Internal Forces/Muscle Action
Ankle Ankle moves from 5° of plantarflexion during foot flat to 5° of dorsiflexion at midstance GRF posterior to axis of rotation of ankle joint

External plantar flexor moment created

Internal dorsiflexor moment

Concentric contraction of dorsiflexors

Eccentric contraction of plantarflexors (gastrocnemius, soleus)

The range of motion change in the ankle from 5° plantarflexion to 5° dorsiflexion results in the shifting of GRF from posterior to anterior, thus the posterior musculature (plantarflexors) is used eccentrically to control dorsiflexion.

Knee Knee moves from 15° flexion at foot flat to 5° flexion at midstance GRF posterior to axis of rotation of the knee joint

External flexor moment created

Internal extensor moment

Concentric contraction of knee extensors

Hip Hip moves from 15° flexion at foot flat to 0° at midstance GRF anterior to axis of rotation of the hip joint

External flexor moment created

Internal extensor moment

Concentric contraction of hip extensors

Midstance

Begins when the contralateral foot leaves the ground and continues until the 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.[3]

Kinematics and Kinetics at Midstance[4]
Joint Kinematics Kinetics
External Forces Internal forces/Muscle Actions
Ankle Ankle moves from 5° dorsiflexion at midstance to 0° of dorsiflexion at heel off GRF anterior to axis of rotation of the ankle

External dorsiflexor moment

Internal plantarflexor moment

Concentric contraction of plantarflexors

Knee Knee moves from 5° flexion at midstance to 0° flexion at heel off GRF anterior to axis of rotation of the knee joint

External extensor moment

Internal flexor moment

Eccentric contraction of knee flexors

Hip Hip moves from 0° flexion at midstance to 10° - 20° of extension at foot flat GRF posterior to axis of rotation of the hip joint

External extensor moment

Internal flexor moment

Eccentric contraction of hip flexors (iliopsoas)

Heel Off (or Terminal Stance)

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.[3]

Kinematics and Kinetics at Heel Off[4]
Joint Kinematics Kinetics
External Forces Internal Forces/Muscle Actions
Ankle Ankle moves from 0° at heel off to 20° plantarflexion at toe off GRF anterior to the axis of rotation of the ankle

External dorsiflexor moment

Internal plantarflexor moment

Concentric contraction of plantarflexors

Knee Knee moves from 0° at heel off to 30° flexion at toe off GRF anterior to the axis of rotation of the knee

External extensor moment

Internal flexor moment

Concentric contraction of knee flexors

Hip Hip moves from 10° extension at heel off to 20° extension at toe off GRF posterior to the axis of rotation of the hip joint

External extensor moment

Internal flexor moment

Eccentric contraction of hip flexors

Toe Off (or Preswing)

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 and Kinetics at Toe Off[4]
Joint Kinematics Kinetics
External Forces Internal Forces/Muscle Actions
Ankle Ankle moves from 20° plantarflexion at toe off to 10° plantar flexion at early swing GRF anterior to the axis of rotation of the ankle joint

External dorsiflexor moment

Internal plantarflexor moment

Eccentric contraction of plantarflexors

Concentric contraction of dorsiflexors to propel the foot up

Knee Knee moves from 30° flexion at toe off to 60° flexion at early swing GRF posterior to the axis of rotation of the knee joint

External flexor moment

Internal extensor moment

Eccentric contraction of knee extensors

Concentric contraction of knee flexors

Hip Hip moves from 10° - 20° extension at toe off to 20° flexion at early swing GRF posterior to the axis of rotation of the hip joint

External extensor moment

Internal flexor moment

Concentric contraction of hip flexors

Swing Phase[edit | edit source]

Ground reaction forces are not applicable to the swing phase as there is no contact with the ground. However, the muscles still contract concentrically or eccentrically as needed.[2]

Early Swing

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.[3]

Muscle Actions at Early Swing[5]
Kinematics/Joint Motion Muscle Action
Ankle Ankle moves from 20° of plantarflexion at toe off to 10° of plantarflexion at early swing Concentric contraction of dorsiflexors
Knee Knee moves from 30° flexion at toe off to 60° flexion at early swing Eccentric contraction of knee extensors and concentric contraction of knee flexors
Hip Hip moves into flexion Concentric contraction of hip flexors

Mid-Swing

Begins from the ankle and foot alignment and continues until the tibia of the swing leg is vertical. As in early swing, it functions to advance the limb and shorten the limb for foot clearance.[3]

Muscle Action at Mid-Swing[5]
Kinematics/Joint Motion Muscle Action
Ankle Ankle moves from 10° of plantarflexion at early swing to 0° of plantarflexion at mid-swing Concentric contraction of dorsiflexors
Knee Knee moves from 60° flexion at early swing to 30° flexion at mid-swing Eccentric contraction of knee flexors
Hip Hip moves from 20° flexion at early swing to 30° flexion at mid-swing Concentric contraction of hip flexors

Late Swing/Deceleration

Begins when the swing leg tibia is vertical and ends with initial contact. Limb advancement slows in preparation.[3]

Muscle Action at Late Swing[5]
Kinematics/Joint Motion Muscle Action
Ankle Maintains a neutral position Concentric and isometric contraction of dorsiflexors
Knee Knee moves from 3o° flexion at mid-swing to o° flexion at late swing Eccentric contraction of knee flexors, then concentric contraction of knee flexors
Hip Hip moves from 20°-30° flexion at mid-swing to 30° flexion at late swing Concentric contraction of hip flexors

References[edit | edit source]

  1. Liu X, Zhao C, Zheng B, Guo Q, Duan X, Wulamu A, Zhang D. Wearable devices for gait analysis in intelligent healthcare. Frontiers in Computer Science. 2021 May 13;3:661676.
  2. 2.0 2.1 Hazari A, Maiya AG, Nagda TV. Kinematics and Kinetics of Gait. InConceptual Biomechanics and Kinesiology 2021 (pp. 181-196). Springer, Singapore.
  3. 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 Magee DJ, Manske RC. Orthopedic physical assessment-E-Book. Elsevier Health Sciences; 2020 Dec 11.
  4. 4.0 4.1 4.2 4.3 4.4 Webster JB, Darter BJ. Principles of normal and pathologic gait. InAtlas of Orthoses and Assistive Devices 2019 Jan 1 (pp. 49-62). Elsevier.
  5. 5.0 5.1 5.2 Richie DH. Human Walking: The Gait Cycle. In Pathomechanics of Common Foot Disorders. Springer; 2021.
  6. Alexandra Kopelovich. Ground Reaction Force During the Gait Cycle. Available from:https://www.youtube.com/watch?v=Y2RHvicAM2o[last accessed 15/09/2022]
  7. Alexandra Kopelovich. Gait Muscular Activity & Action. Available from: https://www.youtube.com/watch?v=WuG87mRiY-8[last accessed 15/09/2022]