Gait Flashcards
gait definition
a repeating process of intentional, controlled falls
- also intentionally putting ourselves off balance to later catch ourself
line of progression
the hypothetical line corresponding to the direction you’re following as you walk
- the average between each leg LOP
double vs single support
- double = both legs bearing weight
- single = one leg bears weight
stance phase of gait
from IC to TO
- stand on limb of interest
- takes up 60% of gait cycle for one limb
swing phase of gait
from TO to IC
- limb of interest is moving
- takes up other 40% of gait cycle for one limb
phases of stance
- loading
- mid-stance
- terminal stance
- pre-swing
loading phase
1st phase of stance
- 0-10% of gait cycle
- from IC to OTO
- absorb energy and stabilize limb, making sure it’s ready to absorb weight
midstance phase
2nd phase of stance
- 10-40% of gait cycle
- a transitional phase, NOT a moment in time
- OTO (when we finish loading) to HR
- COM passes over fixed foot - we start to fall as we run out of room and our heel rises marking the end of this phase
terminal stance phase
3rd phase of stance
- 40-50% of gait cycle
- HR to OIC
- COM moves in front of forefoot - more falling
pre-swing phase
4th phase of stance
- 50-60% of gait cycle
- from OIC to TO
- unloading weight from leg of interest to the other limb so we can prepare to swing our interest limb
phases of swing
- initial swing
- mid-swing
- terminal swing
dual pendulum motion of leg
- describes hip as 1st pendulum and knee as 2nd pendulum
- motion used to advance limb: hip swings leg forward and knee flicks out at the end
initial swing phase
1st phase of swing
- 10-15% of gait cycle
- TO to FA
- swinging leg with the intention of accelerating the limb and clearing the ground
- minimum foot clearance considered here
mid swing phase
2nd phase of swing
- 10-15% of gait cycle
- FA to TV
- goal is to accelerate limb of interest
terminal swing phase
3rd phase of swing
- 10-15% of gait cycle
- TV to IC
- goal is to decelerate limb of interest before it goes into stance phase again
foot adjacent
when swinging leg of interest, the point where both feet are in line with one another
minimum foot clearance
- the very small amount of space required for someone’s foot of interest to clear the ground
- part of the initial swing phase
- normal is 1.2-1.5 cm
- not very much room for people with pathologies that cause them to not meet the MFC
tibia vertical
where tibia is vertical in space - straight up and down
temporal and spacial parameters (TSP)
- what are they
- name them
things we can measure and compare to normal values:
- stride length
- toe-out angle
- step width/walking base
- step length
- cadence
- speed
stride length
- the total distance you cover with the same foot in anterior to posterior direction
- the swing and stance phases for one foot
toe-out angle
- the angle formed by the line of progression to the reference line of the foot
- normal is 7°
step width/walking base
- horizontal distance between the centres of 2 heels
- normal is 10-15 cm
- any values greater than normal make walking inefficient (ex. morbid obesity)
step length
- distance from heel to heel between left and right feet in anterior to posterior direction
- normal is 65-70cm
cadence
- step frequency
- normal is 110-115 steps/min
speed
- can be calculated - see notes and practice
- comfortable walking speed for normal adult is 1.2-1.4 m/s or 4.5-5 km/h
what is the purpose of pronation when walking
- what does it look like in terms of rearfoot and forefoot
- helps absorb/soften energy of impact
- rearfoot eversion starts pronation process
- forefoot abduction - toes separate and point more laterally as talus comes down and forward
what is the purpose of supination when walking
- makes the foot a rigid lever for propulsion
- rearfoot inversion
- forefoot adduction - toes point more medially which brings the foot back together so it can be rigid
loading phase actions of:
- ankle
- foot
- knee
- hip
start steady then absorb
- ankle - heel rocker, PF 5-10°
- foot - slightly supinated before loading, switched to more pronated
- knee - flexion to 15°
- hip - flexed 30° at IC
midstance phase actions of:
- foot
- ankle
- knee
- hip
COM passes over centre of foot but remains within the vertical margins of the foot
- foot - shifts to supinated
- ankle - ankle rocker, DF to peak 10° as COM passes
- knee - starts slightly flexed and finishes in full extension
- hip - extends slightly
terminal stance phase actions of:
- MTP joints
- foot
- ankle
- knee
- hip
COM moves beyond toes to cause falling
- MTP joints - forefoot rocker mechanism - MTPJ extend as heel rises
- foot - supinated
- ankle - PF to push off ground
- knee - slight flexion
- hip - extends to peak 20°
pre-swing phase actions of:
- foot
- ankle
- knee
- hip
finishing propulsion and unloading interest limb
- foot - supinated
- ankle - PF to peak 20°
- knee - flexion approaching 30-40°
- hip - flexes to approach neutral (coming out of extension)
swing phase actions of:
- foot
- ankle
- knee
- hip
- foot - supinated
- ankle - DF to neutral for foot clearance
- knee - flexes to 60° during initial swing then extends after FA
- hip - flexion to advance limb
COM movement in gait vertical trajectory
- highest point?
- lowest point?
- described as inverted pendulum that rises and falls 4-5 cm
- highest point is middle of midstance as COM is right over top of foot
- lowest point in double support phase IC or approaching OTO
COM movement in gait medial-lateral trajectories
- most medial?
- most lateral?
- COM moves 4-5 cm medial-lateral as we walk
- most lateral - single support all weight shifts to one foot
- most medial - double support phase
head, arms, trunk (HAT) motion
- analogy: HAT are passengers along for the ride and legs are the locomotor that makes things happen
- HAT accounts for 2/3 of body mass
arm swing with gait (HAT rotation)
- arm swings with opposite leg
- we see opposing pelvic rotation of the swinging arm
- as we walk, shoulders turn 10° with each step
pelvic rotation transverse plane with regards to the hip extended
- pelvis rotates to same side as extended
ex. L foot in front makes pelvis look to face the right (and the R hip is extended)
pelvis motion in frontal plane during gait
refers to left or right tilt of pelvis
- hiking shortens functional reach
- dropping increases functional reach
- look at opposite side of pelvis as the leg of interest
- total arc is approximately 10° of hike and drop
neutral and most dropped position of pelvic tilt in gait
- neutral - double support
- most dropped in single support