Typical Gait Flashcards
List some examples of external forces
gravity,
Ground reaction force (most important)
What is Torque
Force * length of moment arm. or
Force * MA
If the GFR is in front of the knee (hyper-extended) what kind of internal and external moments is required
External- GFR tries to extend knee
Internal-Knee Flexors, hamstrings, gastrocs
If the GFR is behind the knee (slightly flexed knee) what kind of internal and external moments are going on?
External - knee is flexed
Internal - Quadriceps
What is a gait cycle?
Initial contact to initial contact (1 stride)
What is a step?
Initial contact on right to initial contact on left
What is the most important part of stance phase?
stability and forward progression
What is the most important in swing phase?
forward limb advancement (usually occurs with momentum and not muscle activity)
What are the reasons for the determinants of gait?
to minimize energy expenditure
When is COM lowest?
double limb support
When is COM highest?
single limb stance
What is the compass gait?
1st Determinant
hip flexion/extension
pelvis moves through a series of arcs
What is pelvic rotation?
2nd determinant
Rotation in transverse plane that functionally legthens limb. Reduces drop in COM
What is pelvic tilt determinant
3rd Determinant
Lateral pelvic tilt during swing phase.
Reduces the rise in COM at midstance
What is Stance knee flexion
4th determinant
Knee flexion during weight acceptance
Reduces abrupt rise in COM during loading response
What is ankle plantar flexion
5th Determinant
Ankle PF and foot pronation that shortens limb during loading response. Allows for a smooth transition from double support to swing
What is the role of the foot to decrease COM
Ankle DF in early stance/initial contact with heel
Ankle PF in late stance
Lengthens limb during double limb support to reduce drop in COM
What is Lateral pelvic displacement?
6th Determinant
Moves COM nearer to supporting foot
What are the 6 determinants of gait?
- Compass Gait
- Pelvic Rotation
- Pelvic Tilt
- Stance knee flexion
- ankle PF
- Lateral pelvic displacement
What is the critical event with IC?
contact with heel
What is the critical event with LR?
Hip stability
controlled knee flexion
ankle PF/heel rocker
What is the critical event with Midstance?
Controlled tibial advancement-ankle rocker
What is the critical event with terminal stance?
Ankle locked in DF with heel rise - forefoot rocker
What is the critical event with preswing?
passive knee flexion, weight shift
What is the critical event with Initial swing
Hip flexion, knee flexion, and thigh advances
What is the critical event with midswing?
hip flexion, knee extends and ankle DF to neutral
What is the critical event with terminal swing?
knee extension, hip/knee deceleration, ankle DF
