Muscle Activation: Gait

Question 1

Initial Contact

Answer 1

Ankle: isometric contraction of pretibials
Knee: quads prep for next phase, HS counter extension torque
Hip: hip extensors active, HS shut down

Question 2

Loading Response

Answer 2

Subtalar joint: both anterior and posterior tibial muscles (eccentric)
Ankle: pretibials (eccentric), soleus and gastroc act to control tibial advancement
Knee: quads (eccentric), diminished HS activity
Hip: hip extensors and abductors active

Question 3

Midstance

Answer 3

Subtalar: posterior tibialis, soleus, and peroneals (all eccentric)
Ankle: soleus and gastroc contract (eccentric) to control forward progression of the tibia
Knee: quads stabilize knee until knee extension torque begins, calf muscles restrain tibia allowing femur to advance faster
Hip: abductors active

Question 4

Terminal Stance

Answer 4

MTP: calf muscle activity peaks, posterior tibialis and soleus contract concentrically
FOREFOOT ROCKER
Subtalar: posterior tibialis and soleus (concentric), peroneals (isometric)
Ankle: calf muscle activity peaks
Knee: calf muscles continue to stabilize knee by restraining tibia, biceps femoris may be active
Hip: posterior fibers of TFL cease, anterior fibers of TFL may become active

Question 5

Pre-Swing

Answer 5

MTP: calf muscle activity ceases
Subtalar: anterior tibialis begins to contract
Ankle: calf muscle activity ceases, pretibial muscle activity initiated
Knee: minimal knee flexor activity from gracilis, rectus femoris may be active
Hip: adductor longus (concentric), rectus femoris may be active

Question 6

Initial Swing

Answer 6

MTP: EHL & EDL peak in activity
Subtalar: anterior tibialis stabilizes medially
Ankle: pretibial muscles contract (concentric) to initiate DF
Knee: peak in activity of biceps femoris short head, sartorius, and gracilis
Hip: iliacus, gracilis, sartorius, and adductor longus active

Question 7

Mid-Swing

Answer 7

Subtalar: anterior tibialis stabilizes medially
Ankle: pretibial muscles contract (concentric)
Knee: short head of biceps femoris may control rate of extension, HS active in late phase
Hip: HS become active in late phase

Question 8

Terminal Swing

Answer 8

Subtalar: anterior tibialis stabilizes medially
Ankle: pretibial muscles contract isometrically
Knee: quads active (concentric), HS peak in activity
Hip: HS peak in activity, adductor magnus, glute max. & med., and TFL become active