Normal Gait Muscle Activation Flashcards
What are the ankle kinetics in IC/heel strike?
DF are active
What are the knee kinetics in IC/heel strike?
Quads & hamstrings still active from Tsw; Quads eccentric; TFL contract to counteract internal rotation of the tibia and adduction (varus) torque (eccentric, TFL slows it down)
What are the ankle kinetics at LR/foot flat?
Dorsiflexors eccentrically
Stops foot slap
What are the knee kinetics at LR/foot flat?
Quads & hamstrings still active from Tsw; Quads eccentric; TFL contract to counteract internal rotation of the tibia and adduction (varus) torque (eccentric, TFL slows it down)
What are the hip kinetics at LR/foot flat?
Hip extensors are all active (3 hamstrings, adductor magnus and gluteus maximus
Gluteus medius fires when unsupported side of pelvis drops
Internal rotation is decelerated by the gluteus maximus
What are the ankle kinetics at Midstance?
Plantar flexors minimally 25% MMT eccentrically
Control tibia from ant translation over foot
What are the knee kinetics at Midstance?
Quads active till Body Vector moves anteriorly; IT band provides lateral stability (concentric); Soleus lightens the load on quads by restraining the tibia (prevents anterior translation of tibia, allows for better knee extension)
What are the hip kinetics at mid stance?
Body vector moves posteriorly; Gluteus medius still working; TFL helps
What are the ankle kinetics at terminal stance/heel off?
Plantar flexors to 80% MMT-switch to concentric
Far away from BOS
What are the knee kinetics at terminal stance/heel off?
3 extensor forces on the knee:
• Strong soleus activity
• BV anterior
• IT band
• Counteracting these forces are the popliteus and gastroc
• Unlocks the knee. Start to use hamstrings then
End of Tst: knee starts to flex
• Tibial stability is lost
Gastroc and popliteus keep firing
What are the hip kinetics at terminal stance/heel off?
TFL continues to supply abductor force
What are the ankle kinetics at preswing/toe off?
Decrease in plantar flexors
What are the knee kinetics at pre swing/toe off?
No more foot stability and knee rolls forward
Gastroc and popliteus still active
Rectus femoris (active for hip flexion keep the knee from flexing too far)
What are the hip kinetics are pre swing/toe off?
Rectus femoris activates
What are the ankle kinetics at initial swing/acceleration?
Dorsiflexors to 25 % MMT
What are the knee kinetics at initial swing/acceleration?
Knee flexes further from rapid hip flexion momentum
Short head of the biceps femoris causes further knee flexion
Sartorious and gracilus help knee flexion
Checked by Rectus femoris
What are the hip kinetics at initial swing//acceleration?
Momentum & gracilis, sartorius
What are the ankle kinetics at mid swing?
Dorsiflexors to 40% concentric and then isometric
What are the knee kinetics at mid swing?
Passive extension
What are the ankle kinetics at terminal swing/deacceleration?
Dorsiflexors still firing
What are the knee kinetics at terminal swing/de acceleration?
Quads activate to lift tibia and foot
Hamstrings active to decelerate and prevent excessive knee extension
what are the hip kinetics at terminal swing/de acceleration?
Hamstrings to stop leg; gluteus maximus and adductor magnus also fire; Gluteus medius at the end of the phase
