Lecture 10 Flashcards
How do humans achieve energy-efficient standing?
By having specific anatomical features at joints that allow for minimal muscular support, mainly at the ankle joint.
What anatomical feature helps maintain a stable, upright stance without energy expenditure at the hip?
The line of gravity being posterior to the hip joint, pushing it into extension and tightening the ligaments.
How does the line of gravity affect the knee joint in bipedal standing?
It is anterior to the knee joint, pushing it into extension and locking it without energy expenditure.
What is the role of the plantarflexors at the ankle during standing?
To stabilize the joint as the line of gravity pushes it into dorsiflexion, consuming energy.
Define the basic pattern of the gait cycle.
The gait cycle includes the stance phase, swing phase, and transitions like heel strike and toe off.
What occurs at the hip during early stance?
The hip moves from flexion into extension with the help of gluteus maximus and hamstrings.
What muscles stabilize the knee during early stance?
The quadriceps femoris, hamstrings, and gastrocnemius.
How does the ankle move during early stance?
The ankle moves from dorsiflexion to plantarflexion with triceps surae as the agonist and tibialis anterior controlling the foot drop rate.
Describe the muscle activity at the hip during mid stance.
The hip continues moving into extension, with gluteus maximus and hamstrings as the agonists.
What happens at the knee during mid stance?
The knee moves from extension into slight flexion, with hamstrings and gastrocnemius as agonists.
What is the role of triceps surae during mid stance?
It continues to move the ankle into plantarflexion.
What occurs at the hip during late stance (toe off)?
The hip is in extension with gluteus maximus and hamstrings as agonists.
Describe the knee’s position and muscle activity during late stance.
The knee is in extension with hamstrings and gastrocnemius preparing for the next movement.
What is the ankle’s position during late stance, and which muscle is the agonist?
The ankle is in full plantarflexion with triceps surae as the agonist for propulsion.
What muscles are active at the hip during early swing?
Iliopsoas and rectus femoris as agonists, with gluteus maximus and hamstrings controlling the swing rate.
