Determinants of Gait

Question 1

What is gait cycle?

Answer 1

Full completion of a single limb’s stance phase and swing phase

Question 2

Stride Length?

Answer 2

Full gait cycle

Question 3

Step length?

Answer 3

Length between one foot & opposite foot

Question 4

Cadence?

Answer 4

Number if steps in a given amount of time

Question 5

What can a wider step width mean?

Answer 5

Balance issues, peripheral neuropathy

Question 6

What are some external forces creating torques?

Answer 6

Gravity & Ground reaction force

external forces = external moments

Question 7

What generates internal forces to maintain equilibrium?

Answer 7

Muscle contractions

Question 8

What is the equation for torque?

Answer 8

F*D

force * length of moment arm

Question 9

What is torque?

Answer 9

the ability of any force to cause rotation about an axis

Question 10

What is the GRF?

Answer 10

Ground reaction force

Equal in magnitude the force that the body applies to the floor through the foot

Question 11

What are the 2 peaks in the GRF graph?

Answer 11

1st peak-period between initial contact and loading response

2nd peak- terminal stance and preswing phase

Question 12

What are the external torque counterbalanced by?

Answer 12

Muscles (create internal torque)

Question 13

What happens during single limb support?

Answer 13

Lateral shift of body mass, hip Abductors turn on to keep pelvis level and to maintain GRF

Question 14

What can cause some anatomical mal-alignments of ?

Answer 14

Scoliosis, knee varus/valgus, increased rotation of hips, and posture

Question 15

What kind of moments are created at the knee?

Answer 15

GRF force is just posterior to knee

Creates external flexion moment

Question 16

What kind of internal moment is needed to counteract the posterior GRF at the knee?

Answer 16

Internal extension moment

Quadriceps turn on

Question 17

In a hyperextended knee where is the GRF?

Answer 17

Anterior to the knee

Question 18

With a hyperextended knee what kind of external moment is created, and what internal moment is needed to counteract it?

Answer 18

External extension moment

Internal flexion moment (Hamstrings, gastrocs, posterior knee capsule kick on)

Question 19

What is the CoP?

Answer 19

Center of pressure-cumulative forces in a given area at an instance in time

Question 20

Where is the CoP in the foot while walking?

Answer 20

1. Initial contact - lateral to mid heal

2. Terminal stance - under medial forefoot

Question 21

What are the 6 determinants of gait?

Answer 21

Pelvic rotation
Lateral pelvic tilt
Lateral shift
Knee flexion
Ankle DF
Heel rise

Question 22

Where does pelvic rotation occur?

Answer 22

Transverse Plane

Question 23

What is the pelvic rotation during the swing phase?

Answer 23

Where swing side pelvis moves anteriorly to advance the leg forward. (ex. Left leg moving forward, left side of pelvis goes forward creating rotation to the right)

Question 24

What is the pelvic rotation during the stance phase?

Answer 24

Pelvis moves opposite, (ex. standing on left leg, pelvis rotates back to left)

Question 25

How is the lateral pelvic tilt controlled?

Answer 25

Gluteus Medius muscle (swing side pelvis drops)

Question 26

What does the lateral pelvic tilt control?

Answer 26

Vertical excursion of the COM swing hip falls lower smooths pelvic trajectory

Question 27

How far does the swing side pelvis drop during the swing phase?

Answer 27

1 inch | controlled

Question 28

How far does the body shift laterally while walking?

Answer 28

1-2 inches toward stance leg

Question 29

What can cause the lateral shift to increase or decrease?

Answer 29

Degrease: Knee valgus, feet are closer together Increase: Wider stance, genu valgum

Question 30

What is the stance knee flexion phase?

Answer 30

It's when your knee flexes during weight acceptance

Question 31

Where is the ankle DF important?

Answer 31

Early Stance/IC with heal

Question 32

What does the heel rise when moving into the swing phase do?

Answer 32

Reduces the amount of extensor and flexor muscle activity needed.

Question 33

What are the sagittal kinematics for the lower extremity?

Answer 33

Pelvis-Anterior/posterior tilt Hip-In flexion at IC and move into extension as the body progresses Knee-Knee flexion needed to minimize vertical translation Ankle-PF/DF

Question 34

How many degrees of DF do you need to have normal gait?

Answer 34

10 degrees

Question 35

What are the frontal kinematics for the lower extremity?

Answer 35

Pelvis-Lateral tilt Hip-moves with pelvis (with add until midstance, After midstance hip abd) Knee-Minimal movement (slight varus during stance, valgus during preswing and initial swing) Subtalar-Pronation/Supination

Question 36

What are the transverse kinematics?

Answer 36

Pelvis-Axial rotation or (IR/ER) Hip-IR/ER (slight ER at initial contact and move into IR in late midstance) Knee-Tibia mirrors the femur