Gait Cycle Flashcards
difference between walking and gait?
walking is locomotion–> 2 legs alternating to provide both support and propulsion
gait is a manner or style of walking
4 components of locomotion
- propulsion
- stance stability
- shock absorption
- Energy conservation
Non functional movement of the COM is ——–
Energy expensive
Any deviation of COM from the line of progression———the energy cost
increases
what is the major factor in minimizing the body’s expenditure of Energy?
minimizing the movement of the body’s COM during locomotion
movement of the body’s center of Mass reflects
collective movement of the body
gait cycle is
a single sequence of functions of one limb
gait cycle has 2 phases
- stance phase
2. swing phase
stance phase
begins with heel contacts and ends with toe off
swing phase
begins with toe off and ends at heel contact
in normal walking stance phase is how much of GC?
60%
in normal walking swing phase is how much of a GC?
40%
in slow walking
stance phase % increases
in fast walking
stance phase % decreases
what is terminal double limb support
from heel strike to opposite toe off 8-12%
what is the initial double support
opposite heel strike to contra-lateral toe off 8-12%
what is the most critical phase for maintaining balance during walking
DLS
what percentage of the metabolic energy expended during walking happens in DLS
60-70%
step
advancement of a single foot
cadence
steps in a minute
stride
advancement of both feet
walking speed (velocity)
time taken to walk a set distance
stride length
right step length + left step length
walking speed
stride length/Gait cycle
what are some spatial parameters of gait
- stride length
- step length
- step width
- foot angle
stride length
heel contact to heel contact of the same foot ( 2steps)
step length
heel contact to heel contact of the other foot ( 1 step)
step width
distance between heel centers
foot angle
degree of toe-out ( long axis of the foot) with line of progression
if you are still confused google the image ..then it will make sense
toe in/toe out
is the angle between the line of progression and the line connecting the heel point to the fwd point on the foot .
the angle for toe-ouT is
posiTive
the angle for toe-in is
Negative
3 functional patterns of weight acceptance
- shock absorption
- initial limb stability
- preservation of progression
Phases of weight acceptance
- initial contact
2. Loading Response
Phases of single limb support
mid-stance
terminal stance
Phases of limb advacement
pre-swing
initial swing
mid swing
terminal swing
heel strike is necessary for the body to
absorb shock
speed-slowing the movement of the foot to the floor so it doesnt slap
joint angles : Bending and internally rotating (twisting inwards) the hip and knee, contact on lateral side
heel contact is what percentage of GC
0-2%
chorcot foot syndrome
abnormal initial contact
events in the loading response
- pronation of the foot (Rolling inwards)
- foot comes into contact with the ground
- soft tissues expand
- arches lower
- soft tissue loosen the joints whithin the foot and lower Ex
- loosening of the joint causes the lower limbs to internally rotate–> this causes the force generated by the weight of the body to be absorbed as it is transferred vertically over one foot
the foot functions as a mobile adapter , it is also able to adapt to
uneven ground conditions
foot position in early stance to Mid stance
foot is pronated (4º)
Foot is Mobile (Flexible)
Enhances Balance
Loading response is how many percent of the GC?
0-10%
What is the function of Loading Response?
- Shock absorption (DLS)
- weight bearing stability
- Preservation of Progression
What is the position of hip in Loading response?
Extending internally rotating
What is the position of knee in Loading response?
Flexing to ~15º
What is the position of ankle in Loading response?
Plantarflexes to meet the ground
What is the position of subtalar in Loading response?
Pronating
loading response is composed of?
heel strike–> foot flat–> toe off ( for the other foot)
The other foot that we are talking about is still in foot flat
Events in Midstance ?
- weight is taken to the right limb and the left limb is swinging through to take the next step (stopping rotation+ PE to KE conversion)
- As midstance progresses only the right limb stays in contact with the ground ( as the left limb is swinging through the air to take the next step)
- As the left leg swings through the air and weight in taken onto the right limb, the opossite starts to happen, with the hip and knee beginning to straighten and stop rotating inwards.
- The ankle joint bends more and the foot should stop rolling inward
Midstance is what portion of GC?
10-30% of GC
Midstance is what portion of stance?
50%
What is the function of Midtstance?
Progression over foot (ankle rocker)
limb and trunk stability
1st half of single limb support
What is the position of hip in midstance ?
Hip is extending
What is the position of knee in midstance ?
Knee is extending
What is the position of ankle in midstance ?
Ankle is dorsiflexing
What is the position of subtalar in midstance ?
subtalar is supinating ( where neutral position occurs)
Heel off portion of Midstance
Right leg instead of absorbing shock, needs to become rigid to push-off onto the next step
-The ankle begins to flex again after bending to 100 degrees at the end of midstance , load is taken onto the forefoot and pressure is directed between the 1st and 2nd toes, allowing the big toe joint to bend .
terminal stance is what portion of the GC?
30-50%
What is the function of terminal stance?
- progression over forefoot rocker
- heel rises
- other limb in terminal swing
What is the position of hip in terminal stance ?
Hip is extending
What is the position of knee in terminal stance ?
extending maximally then begins to flex
What is the position of ankle in terminal stance ?
plantarflexing repidly
What is the position of subtalar in terminal stance ?
almost maximal supination
events in pre-swing
left heel hits the ground and both legs are momentarily in contact with the ground at the same time.
the big toe is the last to leave the ground as pressure is taken on the other foot. The risk of falling down is high in this phase.
in pre-swing (DLS) the most important factor is
Energy conservation
What is essential in Energy conservation
minimum M-L motion of CoM
What is the primary function in early swing
to clear the limb from the ground, as it passes the other leg
what are the positions of ankle, hip. knee and big-toe joint in initial swing?
they all flex to shorten the limb and enable its passage past the weight bearing leg.
Pre swing is what portion pf the GC?
50-60%
what is the function of pre swing?
position the leg for swing and double limb support
what is the position of hip in pre-swing?
flexing from maximally extended position
what is the position of knee in pre-swing?
flexing
what is the position of ankle in pre-swing?
maximal plantarflexion
what is the position of subtalar in pre-swing?
maximal supination
pre-swing is from X to X
midstance to toe off
what portion of GC is initial swing?
60-73%
what is the function of initial swing?
foot clearing the floor and advancement of the limb from trailing position
What is the position of hip in initial swing?
flexing and externally rotating
What is the position of knee in initial swing?
flexing near maximal
What is the position of ankle in initial swing?
slight dorsiflexion
What is the position of subtalar in initial swing?
rapid pronation
midswing comes immediately after
knee flexion to vertical tibia position
midswing is the point where knee reaches to its
max speed of rotation
terminal swing
- as the center of mass of the body moves forward
- the hip continues to flex
- the knee begins to straighten again to throw the leg forward in order to take the next step
mid-swing is what portion of GC
73-87%
what is the function of mid-swing?
limb advancement
foot clearance
other limb late mid stance
what is the position of hip in mid-swing?
flexing and beginning to internally rotate
what is the position of knee in mid-swing?
beginning to extend from maximal flexion
what is the position of ankle in mid-swing?
dorsiflexion to neutral
what is the position of subtalar in mid-swing?
pronating
terminal swing is ——-
87-100% GC
what is the function of terminal swing?
from vertical tibia to heel contact
limb advancement completed by knee extension
foot clearance
other limb late mid stance
what is the position of hip in terminal swing
flexing and beginning to internally rotate
what is the position of knee in terminal swing
continuing to extend close to full extension
what is the position of ankle in terminal swing
dorsiflexed to neutral
what is the position of subtalar in terminal swing
moving toward slight supination
too little pronation/supination
loss of force dissipation
loss of mobility-balance
stress injury
too much pronation/supination
- relationship to tibial rotation
- associated patellar tracking issues
- soft-tissue stress
control of pronation/supination
shoe design
orthotics
muscle strengthening-posterior tiba
postural changes will change
the center of gravity
limb segment length and walking speed change
the phases of gait and forces
pidiatric gait
wider base of gait
decreased stride length
decreased walking speed
absent heel strike-flat foot strike
decreased knee flexion in loading response
entire extremity externally rotated in swing
no reciprocal arm swing
pediatric gait-Age 2
decreased stride length decreased walking speed no reciprocal arm swing adult-heel strike adult-normal knee flexion adult-closer to normal ex rotation in swing
pediatric gait -age 4
decreased stride length decreased walking speed adult-base of gait adult-reciprocal arm swing adult-heel strike adult-knee flexion adult-normal ex rotation in swing
pediatric gait-age 15
most resembles adult gait
pediatric kinematics-hip extension——-?
Reduced
pediatric kinematic-in terminak swing, hip flexion ———duration
Decreased
pediatric kinematic-knee ————–extended
DOESN’T fully
pediatric kinematic- flexion ———–in swing
reduced
pediatric kinematic- Ankle plantarflexed at————
heel contact
pediatric kinematic-decreased swing phase minimizes
demand for single limb support
pediatric kinematic_ Muscles EMG activities
Increased
geriatric gait
decrease stride length
increased base of gait
increased cycle time leads to decreased single limb support and longer double support time
geriatric kinematics-head has less
less vertical movement and more side to side motion
geriatric kinematics- hip extension/flexion——-
reduced
geriatric kinematics- Knee flexion
reduced in swing
geriatric kinematics-Ankle reduced plantarflexion at
terminal stance
geriatric kinematics-toe trajectory changed in
swing with less heel rise
geriatric kinematics-toe out
increases
geriatric kinematics-elbows more
flexed
geriatric kinematics-shoulders are
extended