Biomechanics Of Gait Flashcards
Step length vs. Stride length
Step length = heel contact to heel contact of contralateral foot
Stride length = heel contact to heel contact of ipsilateral foot
Foot angle
Normal is about 7 deg
Velocity increases = foot angle increases
Step width
Distance between r and l heels during gait
Normal = 5-10cm
Increased base = increase stability and decreased energy efficiency
Cadence
Number of steps per minute
Velocity
Distance over time
Best index of walking ability
As velocity increases, time in double-limb supports decreases
Review moments and LOG
Again
Review primary muscle activities during gait
Again
Socket fit prosthesis
GRF’s are transmitted through the prosthesis to the LE
Foot and pylon may provide some shock absorption
Spatial orientation of socket relative to the foot influence the magnitude and direction of GRFs
What are goals for prosthetic alignment for transtibial amputation
- Facilitate heel strike at initial contact
- Provide adequate single limb stability during stance
- Ensure toe clearance during swing
What are goals for prosthetic alignment for transfemoral amputation
- Comfy containment of residual limb
- Stability during stance esp. at knee
- Smooth transition to swing phase
- Acceptable appearance.
What is bench alignment for TTA
Pylon = generally vertical
Foot = top of foot is parallel to floor and medial border of foot is parallel to line of progression
5 deg pre-flexion
Center of knee joint bisects line between posterior and middle 1/3’s of foot
Bench alignment for TFA
5 deg flexion (positive degrees of contracture)
5-7 deg Adduction
Energy costs of prosthetic gait
energy required increases as the length of the residual limb decreases…
1. Weight of prosthesis
2. Quality of socket fit
3. Accuracy of prosthetic alignment
4. Functional characteristics of the components.
