Typical Gait

Question 1

List some examples of external forces

Answer 1

gravity,

Ground reaction force (most important)

Question 2

What is Torque

Answer 2

Force * length of moment arm. or

Force * MA

Question 3

If the GFR is in front of the knee (hyper-extended) what kind of internal and external moments is required

Answer 3

External- GFR tries to extend knee

Internal-Knee Flexors, hamstrings, gastrocs

Question 4

If the GFR is behind the knee (slightly flexed knee) what kind of internal and external moments are going on?

Answer 4

External - knee is flexed

Internal - Quadriceps

Question 5

What is a gait cycle?

Answer 5

Initial contact to initial contact (1 stride)

Question 6

What is a step?

Answer 6

Initial contact on right to initial contact on left

Question 7

What is the most important part of stance phase?

Answer 7

stability and forward progression

Question 8

What is the most important in swing phase?

Answer 8

forward limb advancement (usually occurs with momentum and not muscle activity)

Question 9

What are the reasons for the determinants of gait?

Answer 9

to minimize energy expenditure

Question 10

When is COM lowest?

Answer 10

double limb support

Question 11

When is COM highest?

Answer 11

single limb stance

Question 12

What is the compass gait?

Answer 12

1st Determinant
hip flexion/extension
pelvis moves through a series of arcs

Question 13

What is pelvic rotation?

Answer 13

2nd determinant

Rotation in transverse plane that functionally legthens limb. Reduces drop in COM

Question 14

What is pelvic tilt determinant

Answer 14

3rd Determinant
Lateral pelvic tilt during swing phase.
Reduces the rise in COM at midstance

Question 15

What is Stance knee flexion

Answer 15

4th determinant
Knee flexion during weight acceptance
Reduces abrupt rise in COM during loading response

Question 16

What is ankle plantar flexion

Answer 16

5th Determinant
Ankle PF and foot pronation that shortens limb during loading response. Allows for a smooth transition from double support to swing

Question 17

What is the role of the foot to decrease COM

Answer 17

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

Question 18

What is Lateral pelvic displacement?

Answer 18

6th Determinant

Moves COM nearer to supporting foot

Question 19

What are the 6 determinants of gait?

Answer 19

1. Compass Gait
2. Pelvic Rotation
3. Pelvic Tilt
4. Stance knee flexion
5. ankle PF
6. Lateral pelvic displacement

Question 20

What is the critical event with IC?

Answer 20

contact with heel

Question 21

What is the critical event with LR?

Answer 21

Hip stability
controlled knee flexion
ankle PF/heel rocker

Question 22

What is the critical event with Midstance?

Answer 22

Controlled tibial advancement-ankle rocker

Question 23

What is the critical event with terminal stance?

Answer 23

Ankle locked in DF with heel rise - forefoot rocker

Question 24

What is the critical event with preswing?

Answer 24

passive knee flexion, weight shift

Question 25

What is the critical event with Initial swing

Answer 25

Hip flexion, knee flexion, and thigh advances

Question 26

What is the critical event with midswing?

Answer 26

hip flexion, knee extends and ankle DF to neutral

Question 27

What is the critical event with terminal swing?

Answer 27

knee extension, hip/knee deceleration, ankle DF