Lecture 11: Gait cycle Flashcards
Where does the line of gravity run in relation to the hip
Line of gravity is posterior to the hip
This locks the hip in extension
Where does the line of gravity run in relation to the knee
Line of gravity runs anterior to the knee
This pushes the knee into extension
What is the state of the posterior and anterior capsular ligaments of the hip at extension
The anterior capsular ligaments are tort (tight) and the posterior capsular ligaments are loose
What is the state of the collateral ligaments when the knee is at extension when standing?
The collateral ligaments are tight. This supports the joint.
What is the state of the cruciate ligaments when the knee is at extension when standing?
The cruciate ligaments pull tight
T/F
The ankle is locked when standing due to the line of gravity
FALSE.
It does NOT lock
What are the agonists and antagonists in hip flexion?
Agonists:
- Iliopsoas & rectus femoris
Antagonists:
- Gluteus maximus and Hamstrings
What are the agonists and antagonists in hip extension?
Agonists:
- Gluteus maximus and Hamstrings
Antagonists:
- Iliopsoas & rectus femoris
What are the agonists and antagonists in knee extension?
Agonists:
- Quadriceps femoris
Antagonists:
- Hamstrings and gastrocnemius
What are the agonists and antagonists in knee flexion?
Agonists:
- Hamstrings and gastrocnemius
Antagonists:
- Quadriceps femoris
What are the agonists and antagonists in ankle plantarflexion?
Agonists:
- Triceps surae
Antagonists:
- Tibialis anterior
What are the agonists and antagonists in ankle dorsiflexion?
Agonists:
- Tibialis anterior
Antagonists:
- Triceps sucrae
Describe stance in bipedalism
The foot on the ground as the body is moving to bring the limb behind us
Describe Swing in bipedalism
Bringing the limb infront of the body
What are the two transition phases between Stance and Swing
Heel strike and toe off.
The heel striking the ground and the toes pushing off the ground to leave stance phase and move into swing phase
How many phases in the gait cycle
6
Explain the Six phases of the gait cycle
Early Stance + Heel strike = heel first touches the ground.
Mid Stance = body moves forward, limb moves behind. Lowering foot to ground, foot is flat on the ground
Late stance + toe off = bringing body forward, limb is behind. Lift heel and toe pushes off allowing for us to propel forward
Early swing = Bringing the foot off the ground
Mid swing = clearing the foot from the ground, bringing the leg out infront of the body
Late swing = getting ready to go back to early stance
What happens at Early stance?
Hip is in flexion (moving into extension)
Agonists: Gluteus maximus & Hamstrings
Knee is in extension (locked for stability)
Stabilisers: Quadriceps femoris, hamstrings and gastrocnemius
Ankle is in dorsiflexion (stable as best bony congruence) but moving into plantarflexion
Agonists: Triceps surae
Antagonist: Tibialis anterior (controls the speed that the foot is dropping to the ground)
Why are the muscles acting on the knee during early stance acting as stabilizers not agonists
Because the knee is locked for stability. This causes the muscles to act isometrically to keep the knee stable.
What happens at Mid stance?
Hip continues to move into extension
Agonists: Gluteus maximus & Hamstrings
Ankle continues to move into plantarflexion
Agonists: Triceps surae
Knee is moving from extension to slight flexion
Agonists: Hamstrings and gastrocnemius
What happens at Late stance?
Late stance including toe off
Hip is in extension
Agonists: Gluteus maximus & Hamstrings
Ankle is in full plantarflexion
Agonists: Triceps surae (strong for propulsion, needs to pull hard soon to swing the foot off the ground)
Knee goes back to extension due to position of the body
Agonists: Hamstrings and gastrocnemius contracting ready for next movement. Ready to flex the knee and keep the foot off the ground
What happens at Early swing?
Hip is in extension moving into flexion
Agonists: Iliapsoas & rectus femoris
Antagonists: Gluteus maximus & hamstrings (control rate of swing)
Ankle is in dorsiflexion as to lift toes from dragging on ground
Agonists: Tibialis anterior
Knee in flexion
Agonists: Hamstrings and gastrocnemius keeping foot off the ground by flexing knee
What happens at mid swing?
Hip is in flexion
Agonists: Iliapsoas & rectus femoris
Antagonists: Gluteus maximus & hamstrings (control rate of swing)
Ankle is in dorsiflexion as to lift toes from dragging on ground
Agonists: Tibialis anterior
Knee in flexion
Agonists: Hamstrings and gastrocnemius keeping foot off the ground by flexing knee
What happens at late swing?
Hip is in flexion (almost full flexion)
Agonists: Iliapsoas & rectus femoris
Ankle is in dorsiflexion (most stable) moving to prepare for heel strike
Agonists: Tibialis anterior
Stabiliser: Triceps surae to keep ankle stable
Triceps surae acts as a stabilizer. It acts isometrically to prevent any further dorsiflexion and prevents itself from doing plantarflexion.
It holds the joint stable so when the heel strikes the ground, the joint wont move.
Knee is moving into extension
Agonists: Quadriceps femoris
Moves the knee into full extension ready for heel strike
Why are the antagonists for the ankle not active in mid stance
Because the foot is on the ground so the Tibialis anterior does not need to control the speed at which it is moving towards the ground
What is the role of the Triceps surae in Late swing
Triceps surae acts as a stabilizer. It acts isometrically to prevent any further dorsiflexion and prevents itself from doing plantarflexion.
Holds the joint stable so when the heel strikes the ground, the joint wont move.
What would happen if you werent flexing your knee a little at mid stance
*If you werent flexing the knee a little you would be bobbing up and down like a trotting horse. This is a stylistic choice/adaption
