Week 8 (Gait Cycle) Flashcards
Normal value of speed
1.4m/s
Normal value of cadence
90-120 steps/min
Normal value of step length
0.72m
Normal value of stride length
1.44m
Joint angles: ankle
- Heel strike: ankle in plantar grade
- Foot flat: ankle lowers into plantar flexion
- Stance: ankle comes into more dorsiflexion as hips move in front of the body throughout stance
- Toe-off: powerful plantar flexion push-off
- Swing: dorsiflexion in first half which is maintained for the rest of swing
Joint angles: knee
- Heel strike: knee is in little flexion then flexes more for knee yield
- Stance: extends in mid stance to keep leg straight
- Late stance: flexes to clear foot off the ground
- Swing: continues smoothly into more flexion to keep clearing the foot before extending out in mid to late swing to swing the leg forward
- Late swing: in some flexion to hit the ground again
Joint angles: hip
- Heel strike: hips start in flexion
- Stance: hip gradually going into extension from initial flexed position
- Toe-off: hip flexes to pull the leg off the ground
- Swing: hip flexes and continues before evening out and dipping down before next heel strike
What is the main difference in joint angles when walking fast and slow?
More knee flexion in fast walking
Less knee flexion in slow walking
During stance, our hip is in adduction or abduction?
Adduction
Pelvic shift: what happens at weight acceptance?
Individual shifts laterally to keep COM close to stance foot and pelvis drops on unsupported side
Important components during stance phase?
- Extension of hip throughout
- Flexion of knee on heel strike then extension through mid stance and flexion prior to toe-off
- Dorsiflexion of the ankle until the end of stance and then fast plantar flexion
- Lateral horizontal shift of the pelvis and trunk
Important components during swing phase?
- Flexion of knee with hip in extension
- Hip flexion
- Dorsiflexion of ankle throughout
- Slight lateral pelvic tilt downwards
- Rotation of pelvis forward
- Extension of knee prior to heel strike
Power =
Energy/time
Concentric contraction creates what type of power
Positive
Eccentric contraction creates what type of power
Negative
Clinical measurements of walking
- Timed 10m walk test (common)
- 6 min walk test
- Item 5 of MAS scale
Clinical measurements of stair ability
- Item 5 of MAS scale
- Timed ascent/descent of flight stairs
Kinematics of stair ascent
- Knee going into flexion and hip going into extension to straighten the stance leg on the step
- Ankle doesn’t change much
- In swing, hip and knee come into flexion to step up the next step and come back down for the next step
Kinetics of stair ascent
- Almost all concentric; need to be able to lift bw
- Knee and hip initially generating most power
- Before-toe off, ankle takes over to push up
Kinematics of stair descent
- Knee comes into flexion
- Ankle and hip don’t change much
- Need to be able to lift knee to come down to next step
- Angle of knee flexion change as we go down
Kinetics of stair descent
Almost all eccentric to control lowering of body
- Starts off being controlled at ankle before controlled at knees as you move further down the stair
<0.4m/s are
Household ambulators
0.4-0.8m/s are
Limited community ambulators
0.8> are
Community ambulatory
What position is the hip, knee and ankle in during heel strike
Hip: flexion
Knee: slight flexion
Ankle: plantargrade or slight df
What position is the hip, knee and ankle in during stance phase
Hip: extension movement
Knee: extension movement
Ankle: dorsiflexion
What position is the hip, knee and ankle in during toe-off
Hip: extension
Knee: flexion
Ankle: plantarflexion
What position is the hip, knee and ankle in during swing phase
Hip: flexion movement
Knee: extension movement
Ankle: dorsiflexion
What are the 2 power outputs for the ankle
A1: eccentric dorsiflexors to control knee going over foot during mid-stance and terminal stance
A2: concentric plantar flexors to push-off during pre-swing
What are the 4 power outputs for the knee
K1: eccentric knee extensors to control knee flexion during loading response
K2: concentric knee extensors to initiate knee extension during mid stance
K3: eccentric knee flexors to control knee flexion from plantar flexion push-off during pre-swing
K4: eccentric knee flexors decelerate the swinging extremity during terminal swing
What are the 3 power outputs for the hip
H1: concentric hip extensor when hips move from flexion into extension during loading response
H2: eccentric hip flexors to control body moving over the midline during mid stance
H3: concentric hip flexors to powerfully pull-off during pre-swing and initial swing
