Ch 6 - Prosthetics and Orthotics: Gait Analysis Flashcards
What is stride length?
Distance b/w corresponding successive points of contact of the same foot (distance b/w heel strike to heel strike of same foot)
What is step length?
Linear distance in plane of progression between successive contact points of opposite feet (distance b/w heel strike of one foot with heel strike of opposite foot)
Two phases of the gait cycle and what percentage with normal walking speed is the distribution of time in each one?
Stance phase and swing phase
60% stance, 40% swing
Walking faster dec time in stance
What is the stance phase?
Time period limb is in contact with the ground
What are the subdivisions of stance phase?
"I Like My Tea Presweetened" Initial contact Loading Response Midstance Terminal Stance Preswing
Describe Initial Contact (heel foot strike).
Instant foot contacts ground
Describe Loading Response (foot flat).
Initial contact to lifting of contralateral limb off the ground
Weight shift occurs
Describe Midstance.
Lift of contralateral limb from ground to point where ankles are aligned in frontal (coronal) plane
Describe Terminal stance (heel off).
Ankle alignment in frontal plane to just before initial contact of contralateral (the swinging) limb
Describe Preswing (toe off).
Initial contact of contralateral limb to just prior to ipsilateral limb lifting from ground (unload weight)
When does double-limb support occur?
Beginning and end of stance phase when both feet are in contact with the floor
Describe double-limb support as walking speed increases.
Time in double-limb decreases with increased speed.
No double-limbs support period is considered running
When does single-limb support occur?
When opposite foot is lifted for swing phase
What % of time in a normal gait cycle is spent in single-limb vs double-limb support?
Single-limb: 80%
Double-limb: 20%
What is cadence?
Number of steps per unit of time
Comfortable walking speed = 80 m/min or 3 mph
How is walking speed slowed?
Reducing the cadence or by decreasing step or stride length
Where is Center of gravity (COG) located?
5 cm anterior to the S2 vertebra
How does Center of gravity (COG) change during normal gait?
Displaced 5 cm (less than 2 inches) horizontally and 5 cm vertically during an average adult
male step
When is Center of gravity (COG) lowest?
During loading response
When is Center of gravity (COG) highest?
During midstance
Describe base of support.
Space outlined by the feet and any assistive device in contact with the ground
Normal base of support (distance between heels) = 6 to 10 cm
How is falling avoided?
COG remains positioned over the base of support
What is swing phase?
Time period foot is in air for limb advancement
Describe the subdivisions of swing phase.
“In My Teapot”
Initial Swing
Midswing
Terminal Swing
Describe initial swing.
Lift of the extremity from the ground to position of maximum knee flexion