gait analysis Flashcards
what makes up the gait cycle?
60% stance and 40% swing
what quantifies as one complete gait cycle?
heel strike of 1 foot to heel strike of the same foot
what are the traditional phases of the gait cycle?
heel strike
foot flat
midstance
heel off
toe off
acceleration
midswing
deceleration
what are the rancho los amigos (RLA) terminology for the phases in the gait cycle?
initial contact
loading response
midstance
terminal stance
preswing
initial swing
midswing
terminal swing
what is needed for a phase?
a contraction type change
direction type change
add or take away force
a start and an end
what is the RLA definition for initial contact?
instant heel contacts the ground
what is the RLA definition for loading response?
from heel contact to foot flat. “phase” continues until contralateral limb lifts off the ground
what is a double support phase mean?
when both feet are on the ground
What does the loading response phase end and start?
Ends double support phase, beginning stance phase
How can double support time increase or when would we expect to see it. Increase?
With decrease cadence. Would expect to see it with balance/vestibular disorders and/or age (young or old)
What percent of the gait cycle are we in double stance phase for?
22%
What is the RLA definition of mid stance phase?
From foot flat position until the body is supported over the weight bearing limb. Begins when the contra lateral extremity lifts off the ground
What is the RLA definition of terminal stance?
From mid stance through heel off of the WB extremity. From mid stance until initial contact of contra lateral extremity
What is the RLA definition of preswing phase?
From heel off until toe off of the WB extremity
What is the RLA definition of initial swing?
From toe off until maximum knee flexión of ipsilateral extremity (thigh is perpendicular to the floor)
What is the RLA definition of mid swing?
From maximum knee flexión until tibia is in a vertical position
What is the RLA definition of terminal swing phase?
From vertical tibia position until just before initial contact of the ipsilateral extremity
What quantifies a step?
Initial contact of one foot to initial contact of other foot
What quantifies one stride?
1 Gait cycle (heel contact of one foot to heel contact of the same foot)
Where is the COM in the body?
Anterior to S2
Which planes are displaced during gait?
Sagittal and frontal plane
What occurs in the sagittal plane during gait?
5 cm displacement superior-inferior
Max during simultaneous mid stance and mid swing
Min during double support
What occurs in the frontal plane during gait?
Max just after mid stance as BW is shifted over stance limb
Increased step width allows greater med./lat. displacement of COM
Narrow width= less energy expended= increased efficiency
during gait adjustments are made by the pelvis, hips, knees, and ankles… why is this?
to preserve energy
when does the lateral pelvic tilt/hemipelvic depression occur?
during midswing
what happens during the lateral pelvic tilt?
COM reaches highest point, slight depression of unsupported limb minimizes rise of COM
who is the agonist and antagonist during the lateral pelvic tilt?
agonist- gravity
antagonist- skeletal muscle
which movement reduces the rise of the COM during midstance?
knee flexion
coordinations of knee, ankle and foot kinematic interactions are to create what?
a smooth sinusoidal curve
what are the positions of the knee, talocrural joint and subtalar joint from initial contact through loading response?
knee flexion
TC PF
subtalar pronation
what is occurring from initial contact through loading response from the knee down?
relative shortening of extremity preventing an abrupt rise in COM after heel strike
without this we would see a sharp rise in COM as tibia would be over talus
what are the positions of the knee, talocrural joint and subtalar joint from midstance through terminal stance?
knee extension
TC PF
subtalar supination
what is occurring from midstance through terminal stance from the knee down?
COM is lowering, slows decent of COM by a relative lengthening of stance limb