Rockers and Roll
The fulcrum for the 1st Rocker (Heel Rocker).
What is the calcaneus?
Sagittal knee position during Initial Contact.
What is 0-5° of flexion?
Required Ankle ROM for successful "Toe Clearance" during Mid-Swing.
What is 0° (neutral)?
The motion of a body without regard to the forces that produce it.
What is kinematics?
At Initial Contact, the GRF is posterior to the ankle, creating this torque.
What is a plantarflexion torque?
This rocker involves "controlled tibial advancement" over a stationary foot.
What is the Ankle Rocker (2nd Rocker)?
Required knee flexion for "Toe Clearance" in Initial Swing.
What is 60°?
Required Ankle ROM for the Forefoot Rocker in Terminal Stance.
What is 10° of dorsiflexion?
The perpendicular distance between the axis of rotation and the line of force.
What is the moment arm?
During Loading Response, a posterior GRF creates this external torque at the knee.
What is a flexion torque?
The phase of gait where the Forefoot Rocker (3rd) occurs.
What is Terminal Stance?
Peak hip flexion achieved during Mid-Swing.
What is 25°?
Subtalar joint ROM during Mid-Stance to allow for shock absorption.
What is 5°-7° of eversion?
Tissue property where stiffness increases as the speed of loading increases.
What is rate sensitivity (or viscoelasticity)?
In Mid-Stance, the GRF moves anterior to the knee joint, creating this torque.
What is an extension torque?
The "Toe Rocker" (4th) occurs during this specific gait phase.
What is Pre-Swing?
Maximum hip (thigh) extension reached at the end of Terminal Stance.
What is 20°?
During Pre-Swing, the ankle moves into this many degrees of plantarflexion.
What is 15°?
The ratio of the internal moment arm to the external moment arm.
What is mechanical advantage?
The external torque demand at the hip during Loading Response.
What is a flexion torque?
The force providing 15° of PF during the 4th Rocker.
What is passive elastic recoil (Achilles tendon)?
The degree of Hallux MTP extension required for the Forefoot Rocker.
What is 30°?
The Hallux MTP extension ROM required during the Toe Rocker (Pre-Swing).
What is 60°?
A progressive strain of a material when exposed to a constant load over time.
What is creep?
The external torque demand at the ankle during Terminal Stance.
What is peak dorsiflexion torque?