Orthotics CPM Gait Cycle Study Guide
Important Terms and Definitions Related to Gait:
• Kinematics: The study of motion.
• Kinetics: The study of the forces that produce motion.
• Ground Reaction Forces (GRF): The forces acting on the limb by the supporting
surface. A vector quantity comprised of both magnitude and direction.
• Moments: The rotational potential of the forces that act on the joint.
• Isometric contraction: The muscle maintains its length while still generating force.
• Eccentric contraction: The muscle lengthens as it produces force.
• Concentric contraction: The muscle shortens as it contracts, producing movement.
The Gait Cycle:
• The gait cycle can be broken down into two distinct sections – stance phase and
swing phase.
• Stance phase makes up 60% of the gait cycle, and swing phase makes up 40% of
the gait cycle.
• Stance phase is when the leg being examined is in contact with the ground – swing
phase is when the examined leg is no longer in contact with the ground.
• Double Limb Support: The moments in the gait cycle where both feet are in contact
with the ground.
• Single Limb Support: The moments in the gait cycle where only one foot is in contact
with the ground.
, Phases of the Gait Cycle:
• Initial contact: The instance that the foot comes into contact with the ground – the
starting point of stance phase.
• Loading Response: Begins at initial contact and lasts until the contralateral foot
loses contact with the ground.
• Midstance: Begins once the contralateral foot loses contact with the ground and
ends once the ipsilateral foot loses contact with the ground.
• Terminal stance: Begins when the ipsilateral heel loses contact with the ground and
ends once the contralateral foot makes initial contact with the ground.
• Pre-swing: The last phase of stance phase – begins when the contralateral foot
makes initial contact with the ground and ends once the ipsilateral foot leaves the
ground.
• Initial-swing: The start of swing phase – begins when the foot leaves the ground and
ends once the ipsilateral foot becomes aligned with the contralateral ankle.
• Mid-swing: Begins when the ankle and foot are aligned and ends once the swing
phase tibia is vertical.
• Terminal Swing: The end of swing phase – begins once the swing phase tibia is
vertical and ends once the swinging foot makes initial contact with the ground.
•
The 4 Ankle/Foot Rockers:
In order for the body to progress without deviation through the gait cycle – particularly in
the stance limb – rockers of the ankle and foot must be present. There are 4 in total.
• Heel Rocker: The heel acts as a pivot as the ankle moves form a neutral position at
initial contact to roughly 10 degrees of plantarflexion during loading response.
• Ankle Rocker: As midstance begins, the ankle rocker acts as a pivot for the stance
limb to advance over the foot.
• Forefoot Rocker: As the stance limb transitions to terminal stance, the forefoot
becomes the pivot point for allowing accelerated forward progression of the body as
it moves beyond the base of support of the foot.
• Toe Rocker: Toe rocker becomes the pivot point at pre-swing and allows for push off
of the stance limb as it enters the swing phase of the gait cycle.
Important Terms and Definitions Related to Gait:
• Kinematics: The study of motion.
• Kinetics: The study of the forces that produce motion.
• Ground Reaction Forces (GRF): The forces acting on the limb by the supporting
surface. A vector quantity comprised of both magnitude and direction.
• Moments: The rotational potential of the forces that act on the joint.
• Isometric contraction: The muscle maintains its length while still generating force.
• Eccentric contraction: The muscle lengthens as it produces force.
• Concentric contraction: The muscle shortens as it contracts, producing movement.
The Gait Cycle:
• The gait cycle can be broken down into two distinct sections – stance phase and
swing phase.
• Stance phase makes up 60% of the gait cycle, and swing phase makes up 40% of
the gait cycle.
• Stance phase is when the leg being examined is in contact with the ground – swing
phase is when the examined leg is no longer in contact with the ground.
• Double Limb Support: The moments in the gait cycle where both feet are in contact
with the ground.
• Single Limb Support: The moments in the gait cycle where only one foot is in contact
with the ground.
, Phases of the Gait Cycle:
• Initial contact: The instance that the foot comes into contact with the ground – the
starting point of stance phase.
• Loading Response: Begins at initial contact and lasts until the contralateral foot
loses contact with the ground.
• Midstance: Begins once the contralateral foot loses contact with the ground and
ends once the ipsilateral foot loses contact with the ground.
• Terminal stance: Begins when the ipsilateral heel loses contact with the ground and
ends once the contralateral foot makes initial contact with the ground.
• Pre-swing: The last phase of stance phase – begins when the contralateral foot
makes initial contact with the ground and ends once the ipsilateral foot leaves the
ground.
• Initial-swing: The start of swing phase – begins when the foot leaves the ground and
ends once the ipsilateral foot becomes aligned with the contralateral ankle.
• Mid-swing: Begins when the ankle and foot are aligned and ends once the swing
phase tibia is vertical.
• Terminal Swing: The end of swing phase – begins once the swing phase tibia is
vertical and ends once the swinging foot makes initial contact with the ground.
•
The 4 Ankle/Foot Rockers:
In order for the body to progress without deviation through the gait cycle – particularly in
the stance limb – rockers of the ankle and foot must be present. There are 4 in total.
• Heel Rocker: The heel acts as a pivot as the ankle moves form a neutral position at
initial contact to roughly 10 degrees of plantarflexion during loading response.
• Ankle Rocker: As midstance begins, the ankle rocker acts as a pivot for the stance
limb to advance over the foot.
• Forefoot Rocker: As the stance limb transitions to terminal stance, the forefoot
becomes the pivot point for allowing accelerated forward progression of the body as
it moves beyond the base of support of the foot.
• Toe Rocker: Toe rocker becomes the pivot point at pre-swing and allows for push off
of the stance limb as it enters the swing phase of the gait cycle.
