gait Flashcards
normal gait
-series of rhythmical alternating movements of the trunk & limbs - result in forward progression of center of gravity
normal gait cycle
- single sequence of functions by one limb
- begins when reference foot contacts ground
- ends w/ subsequent contact of same foot
step length
-distance between corresponding successive points of heel contact of the opposite foot
stride length
- distance between successive points of heel contact of same foot
- 2x step length
- decreases with age
walking base
- side to side distance between line of 2 feet
- linear distance between midpoint of heel of one foot & same loin on other
- normal: 5-10cm
degree toe out
- angle foot placement
- angle formed by each foot line of progression & line intersect center of heel & 2nd toe
- normal: 7deg
- decreases as speed increases
cadence
- number steps per unit time
- normal: 100-115 steps/min
- short step length increases cadence
- increase cadence - double support time decrease
velocity
- distance covered by body in unit time
- average velocity(m/min) = step length x cadence
comfortable walking speed (CWS)
- least energy consumption per unit distance
- avg: 80m/min
stance time
-amt time spent during stance phase of gait cycle of one extremity
single support time
- amt time spent during the period when only one extremity is on the supporting surface
- 40% gait cycle
double support time
- amt time spent w/ both feet on the ground during gait cycle
- decreases w/ speed
- 20% gait cycle
stride duration
-amt time spent to complete one stride (gait cycle)
step duration
-amt time spent in completion of single step
phases of gait
- 2 phases
- 2 periods double support
- 10% gait cycle
- body supported by single limb 80% gait cycle
phase 1
- stance phase - 60%
- 1 heel contact -initial contact
- 2 foot flat - loading response
- 3 midstance
- 4 heel off - terminal stance
- 5 toe off - pre swing
phase 2
- swing phase - 40%
- 1 acceleration -initial swing
- 2 mid swing
- 3 deceleration - terminal swing
increase walking speed
- stance phase decreases
- swing phase increases
- double support decreases
center of gravity (CG)
- midway between hips
- body uses least energy if CG in straight line
CG vertical displacement
- rhythmic up&down
- highest pt - mid stance
- lowest pt - double support
- avg displacement - 5cm
CG lateral displacement
- rhythmic side-to-side
- lateral limit - mid stance
- avg displacement - 5cm
CG overall displacement
-vertical + lateral displacement
determinants of gait
- 6 optimizations used to minimize excursion of CG
- significantly reduce energy consumption of ambulation
pelvic rotation (determinant of gait)
- forward rotation of pelvis (8deg) swing phase
- reduces angle hip flexion/extension
- longer step length w/o lowering CG