Normal Gait Flashcards
what are 3 functions of a pronatory foot in gait
- adaptation
- shock absorption
- torque conversion
what are 3 functions of a supinatory foot in gait
- rigid lever
- stable base for propulsion
- heel raise as tibia moves over foot
what relationship proximal rotation have with foot position
when get rotatory forces at femur or tibia w/ gait or mvmt –> creates proximal torque into supinatory or pronatory functions
when does swing begin and end
toe off to IC of same limb
when does 1 gait cycle begin and end
IC to IC of same limb
when does stance phase begin and end
IC to toe off of same limb
when does loading response begin and end
begins at heel contact and ends at opposite toe off
what are the 3 rockers of gait
heel
ankle
forefoot
when are the 2 periods of DLS time during the stance phase of gait
initial contact
preswing
what is the heel rocker and what is its purpose
tibia starts to move over foot
- helps w nice fluid transition for gait
what is the significance of foot position in loading response
ST pronation unlocks mid-tarsal joints and allows foot to become more mobile and adapt to uneven surfaces to absorb GRF/shock
when is the heel rocker in gait
initial contact
when is the ankle rocker in gait
midstance
what is the ankle rocker and what is its function
allows body weight to smoothly transition over foot
- COG moves over new SLS BOS
function of mobile vs rigid foot
mobile foot = loading response
rigid lever = push off
when does SLS time begin and end in the stance phase of gait
midstance to terminal stance
what is the forefoot rocker and what is its function
tibia moves over foot until DF ends, then get heel rise
- body moves ahead BOS to continue fluid gait
when is the forefoot rocker in gait
terminal stance
how does COG and BOS change between DLS and SLS times
DLS:
- COG is low
- COG is in middle of BOS
SLS:
- COG is high
- COG is lateral in BOS
what is the angle of gait
longitudinal axis of foot and line of progression (angle body is moving)
avg = 7deg toe out
what is the base of gait
horizontal distance from one HS to next HS
avg = 3.5in
what is step length
distance from IC of one foot to IC of opp foot
what is stride length
distance b/w 2 consecutive ICs of same foot
avg = 4.5ft
what is cadence
step rate
#of steps/min
avg = 101-122 steps/min
women = faster
slows w age
how is cadence related to stance and swing time in gait
as cadence inc, stance and swing time both dec
what is cadence and gait speed predictive values of (5)
functional decline
mortality
fall risk
functional and physiological decline
QOL
what are 2 clinical tests for measuring gait speed/cadence
10m WT
TUG
when does maximal pronation occur with WBing
foot flat
when does resupination occur with WBing
during mid-stance
what are the triplanar motions happening w OKC ST pronation
calcaneal:
- eversion
- ABD
- DF
what are the triplanar motions happening w CKC ST pronation
calcaneal eversion
talar ADD/PF - drops down & in
tibial IR
what is the only similar motion b/w OKC and CKC pronation
calcaneal eversion
what happens all the way up the chain with CKC pronation
calcaneal eversion
talar ADD/PF
tibial IR
- unlocks knee/reverses screw home
knee flexion
hip IR
- moving acetabulum and femoral alignment
ant pelvic tilt
inc lumbar lordosis
what are the triplanar motions happening w OKC ST supination
calcaneal:
- inversion
- ADD
- PF
what are the triplanar motions happening w CKC ST supination
calcaneal inversion
talar ABD/DF -> moves up and in
tibial ER
what is the only similar mvmt between OKC and CKC supination
calcaneal inversion
what happens all the way up the chain with CKC supination
calcaneal inversion
talar ABD/DF
- elevation of arch
tibial ER
- screw home mechanism
knee ext
hip ER
post pelvic tilt
dec lumbar lordosis
what is midtarsal joint mobility dependent on
STJ position
how does a pronated STJ impact midtarsal mobility and why
inc mobility, low arch
- axis of joints are parallel which allows for mobility
how does a supinated STJ impact midtarsal mobility and why
dec mobility, high arch
- axis of joints are crossed/perp to and become more rigid
why would we as PT care more about stance than swing phase
more problems occur in stance
- much more relevant to us
what are 2 functions required of a more mobile foot with loading response
shock absorpion
adapt to surface terrain
what is the equivalent of GRF to body weight with loading response
vertical load of 110-125% of body weight
how is the GRF related to cadence
load inc as cadence inc
when does propulsion start in gait
heel rise
what is the relationship of amt of GRF, foot position, and midstance
vertical load ~75% of BW
- lot of GRF absorbed in loading response –> foot doesn’t have to be pronated and can re-supinate in midstance to become a rigid lever
what are GRF in propulsion (terminal stance & preswing)
vertical load >125% of BW
what torque conversion in the loading response
femoral rotation absorbed by STJ CKC pronation
- as heel strike, hip IR -> tibial IR -> talus drops down and in -> pronation -> absorbs shock and adapts to ground
what is the ER force created and accelerated by in mid stance
created by swing of leg and opposite arm
- accelerated by ERs and glut concentric contraction
what is the purpose of knee flexion in the loading response
shock absorption
accomodate GRF
why is co-contraction of ms in loading response important
maintains a stable knee
what ms are working during midstance
ms contracting, but more passive bc ext moment as body moves over leg
- gastroc decelerates so knee doesn’t snap back
why is PF initiated passively in loading response
GRF vertical on heel
why do muscles work eccentrically to decel PF in loading response
don’t want foot to slap onto floor
- controlling and preventing rapid PF
why is DF passive in midstance
tibia advancing over fixed foot
what is the purpose of eccentric contractions to decel DF in midstance
prevent excessive DF
why and when does DF become PF in stance
run out of DF some point after midstance d/t ms restriction or TC joint restriction
- when you run out of DF, get passive PF as heel rises
when does PF become active in propulsion
accelerated gait
how do the GS complex work to make PF in propulsion when gait is inc
resists DF during heel rise
controls higher GRF
what muscle has the best orientation to the STJ and what is the significance of this
post tib
- gives best mechanical advantage to decelerate pronation
why is how well we control pronation in the loading response significant to midstance
how well we control pronation dictates how well we can re-supinate in midstance
- if still pronating when should be starting to supinate, that dictates how much they will be able to resupinate
what is a ms that is not large but works hard the entirety of stance phase
post tib
what is supination in propulsion driven by
ER of the limb
when is max control of MTJ needed
propulsion (terminal stance to preswing)
windlass effect - peak tensile forces/strain on plantar fascia supporting the foot
what is an example of a treatment if someone is presenting w exessive pronation
ecc glut
what is a rule of thumb if treating someone w excessive motion at any point in the gait cycle
look at what ms should be ecc working or stabilizing –> then work on them
