Gait Analysis

Question 1

what is gait

Answer 1

• pattern of movement of the limbs during locomotion over a solid substance

Question 2

normal human gait strives to maintain? while moving the body along desired path

Answer 2

• weight bearing stability
• conserving energy
• absorbing shock of floor impact

Question 3

2 reasons why we should measure walking gate

Answer 3

• to find out how we walk (what is normal and why)
• to understand walking as a baseline measure to understand
• -> healthy vs unhealthy
• -> ages
• -> genders
• -> races

Question 4

gait analysis involves measures of?

Answer 4

kinetics, kinematics, EMG

Question 5

pressure mats and insoles hep determine?

Answer 5

• estimates of COP when walking

Question 6

what measurement type gives us the most detailed info about kinetics

Answer 6

• force plates

Question 7

combining kinematics and kinetics can allows us to use what?

Answer 7

inverse dynamics to calculate joint forces, torques and muscle forces

Question 8

name four methodologies of kinematics

Answer 8

• passive marker systems: use reflective markers and multiple cameras
• active marker systems: use active markers that are triggered to illuminate (electromagnetic systems track position of coordinates and orientation of sensors)
• electrical goniometers: electrical device measuring joint angles (simple cheap)
• accelerometers, gyroscopes, magnetometer

Question 9

name the 5 steps of the stance phase in order

Answer 9

• initial contact
• loading response
• mid stance
• terminal stance
• pre swing

Question 10

the stance phase is what percentage of the gait cycle

Answer 10

62%

Question 11

name the 3 steps of the swing phase in order

Answer 11

• initial swing
• mid swing
• terminal swing

Question 12

what percent of the gait cycle is the swing phase?

Answer 12

38%

Question 13

when is the first double support and when is the second double support?

Answer 13

• initial contact

- terminal stance/pre swing

Question 14

what 3 steps of the stance phase involve single leg support

Answer 14

• loading response, mid stance, terminal stance

Question 15

the 2 periods of double stance together take up what percentage of the gait cycle

Answer 15

25%

Question 16

initial contact. begins and ends when? what percent?

Answer 16

• instantaneous point when leading foot touches the ground, 0 %

Question 17

loading response. what percent?

Answer 17

• body weight transferred onto stance limb (0-10%)

Question 18

midstance. what percent?

Answer 18

• contralateral foot leaves the ground and body weight travels along the length of the foot until forefoot (10–30%)

Question 19

Terminal stance. begins and ends when? what percent?

Answer 19

• begins with heels rise, ends when opposite foto contacts the ground (30-50%)

Question 20

preswing. begins and ends when? what percent?

Answer 20

begins with opposite foot contact, ends with ipsilateral toe off, stance limb unloaded and body weight transfered onto opposite limb (50-60%)

Question 21

terminal contact?

Answer 21

instant when the foot leaves the ground

Question 22

initial swing. begins and ends when. what percent?

Answer 22

• begins moment the foot leaves the ground and continues until max knee flexion (60-70%)

Question 23

midswing. begins and ends when, what percent

Answer 23

• following max knee flexion and ends when tibia in in vertical position (70-80%)

Question 24

terminal swing. begins and ends when.

Answer 24

• tibia passes over perpendicular and knee fully extends in preparation for heel contact (85-100%)

Question 25

the joint moment is determined by?

Answer 25

- the muscle moment | - the amplitude and line of action of the Ground reaction force

Question 26

3 functional tasks of walking

Answer 26

- weight acceptance - single limb support - limb advancement

Question 27

explain the inverted pendulum

Answer 27

during the single limb support the body (c of G) vaults over the extended limb with minimal energy expenditure - -> anytime your in the middle stance you shouldnt need alot of muscle/ leg support - -> during double limb support there is a redirection of the whole body ( C of G) over the extended limb and the inverted pendulum continues on the other side (major energy expenditure)

Question 28

6 determinants of gait/ help conserve energy

Answer 28

1. pelvic rotation 2. pelvic obliquity 3. knee flexion in stance phase 4. ankle mechanism 5. foot mechanism 6. lateral displacement of body

Question 29

what does pelvic rotation allow?

Answer 29

allows us to have longer step length and minimizes the movement of the COG

Question 30

what does pelvic obliquity do?

Answer 30

vertical movement of the trunk is less than that of the hip because the pelvic tilt is about the anteroposterior axis, allows COG to be kept more steady

Question 31

what is the knee mechanism in stance phase?

Answer 31

bends shortening the leg mid stance so the COG does not move up

Question 32

what s the ankle mechanism

Answer 32

heel hits first so the COG stays level and then leg lengthens as ankle beds and body comes forward

Question 33

what is the foot mechanism

Answer 33

heel rises and knee bends to keep COG level

Question 34

lateral displacement of the body allows what?

Answer 34

closer together the feet are the less lateral displacement of the body and side to side movement of the COG at the hips,

Question 35

2 things you can look for when comparing normal to abnormal gait

Answer 35

- change in swing to stance ratio | - left/ right asymmetry

Question 36

4 common abnormalities

Answer 36

1. lateral trunk bending 2. anterior trunk bending 3. posterior trunk bending 4. leg length discrepancy

Question 37

what is lateral trunk bending? | what is the purpose of this move?

Answer 37

- bending the trunk towards the side of the supporting limb during the stance phase - to reduce the forces int he abductor muscles and hip joint during single leg stance

Question 38

4 common causes of lateral trunk bending

Answer 38

- painful hip - hip abductor weakness - leg length discrepancy - abnormal hip joint

Question 39

what is anterior trunk bending? | what is its purpose?

Answer 39

- flexes the trunk forward early in the stance phase | - used to move the COG forward moving LOA in front of the knee producing an extension movement

Question 40

a common cause of anterior trunk bending

Answer 40

- poor quad strength, dont want to bend your knee. so leaning forward helps bend knee

Question 41

what is posterior trunk bending? | what is its purpose?

Answer 41

- back bend early in stance | - LOA brought to external force behind the axis of hip joint creating a hip extensor movement

Question 42

a common cause of posterior trunk bending

Answer 42

weak gluts

Question 43

4 gait abnormalities of leg length discrepancy

Answer 43

- circumduction: swing leg outward - hip hiking: pelvis lifted on side of swinging leg - steppage: exaggerated knee and hip flexion to lift foot higher than usual during swing - vaulting: stance phase modification, go up on toes of stance phase