Gait

Question 1

forces applied to prosthetic and orthotic devices are _________

Answer 1

external forces

Question 2

list the spatial descriptors of gait

Answer 2

1. stride length
2. step length
3. degree of toe-out (foot angle)
   
   • 5-7 degrees normal
4. step width
   
   • 8-10 cm average

Question 3

_______ step length is often seen in amputees. Why?

Answer 3

asymmetrical

potentially due to spending less time in stance phase on involved side

results in shortening swing time and step length on noninvolved side

Question 4

list the temporal descriptors of gait

Answer 4

1. stride time
2. step time
3. cadence
   
   • number of steps per minute (most important of these 3)

Question 5

describe the spatio-temporal descriptor of gait that is the most important

Answer 5

gait speed

distance covered in a given amount of time

(step length * cadence)

(normal healthy is 1.37 m/sec)

Question 6

T/F: it is common for prosthetic user to have reduced gait speed

Answer 6

TRUE

Question 7

List some reasons for decreased gait speed in amputees

Answer 7

1. new amputee might be afraid/decreased confidence → move slower and more cautious​
2. poor gait training
3. pre amputation, the pt may not have had normal gait speed

Question 8

what are the key features during IC/LR?

Answer 8

1. Shock absorption
   
   • PF
   • knee flexion
   • pronation
   • hip adduction
2. forward propulsion through hip extension

Question 9

what are the key features of gait during midstance?

Answer 9

1. shock absorption
2. stabilize in single limb support
3. forward progression of the tibia
   
   • CK DF in able bodied gait

Question 10

what are the key features of gait during terminal stance?

Answer 10

1. continued stabilization in single limb support
2. forward propulsion through PF
3. forward progression

Question 11

what are the key features of gait during pre-swing?

Answer 11

1. continued forward propulsion through PF
2. continued forward progression

Question 12

what are the key features of gait during inital swing?

Answer 12

1. forward propulsion of swing leg through hip flexion
2. foot clearance
   
   • DF
   • knee flexion

Question 13

what are the key features of gait during midswing?

Answer 13

forward propulsion of swing leg through hip flexion

Question 14

what are the key features of gait during terminal swing?

Answer 14

1. preparation for IC
   
   • controlled knee extension
   • ankle positioned into less supination

Question 15

what key muscles are activated at the hip throughout gait and what are their roles?

Answer 15

1. Hip extensors
   
   • activated at TSw prior to IC to initate hip ext and prepare LE for weight acceptance at the beginning of stance
2. Hip flexors
   
   • advance LE forward during ISw and lift LE to allow for toe clearance during swing
3. Hip abductors’
   
   • control the slight lowering of the contralateral pelvis on the side of the swing limb
4. Hip adductors
   
   • assist w/initation of hip flexion after toe off

Question 16

how does a TFA initate knee extension?

Answer 16

through hip extension

they will start to extend the hip as soon as the heel makes contact

this is why bench alignment promotes 5º hip flexion in order to make it easier for glutes to fire and extend the hip

Question 17

what key muscles are activated at the knee and what are their roles in normal gait?

Answer 17

1. knee extensors
   
   • eccentrically control knee flexion in LR then act concentrically to extend knee and support body in MSt
2. knee flexors
   
   • decelerate knee extension in prep for placement of the foot on the ground

Question 18

since amputee’s do not have ankle/pretibial muscles what occurs at the “ankle” during IC/LR?

Answer 18

foot slap

if the heel bumper or prosthetic foot is either too soft or firm, you may observe a delay or an acceleration of that foot flat process

Question 19

how does the loss of PF due to amputation or weakness impact gait?

Answer 19

1. shorter contralateral step length
2. reduced gait speed
3. impaired balance

*most noticable in MSt where gastroc is normally most active

Question 20

how is knee flexion achieved in amputees?

Answer 20

no mechanism is needed if:

1. the individual can flex their hip
2. ambulate fast enough to produce momentum

Question 21

what is the assocation between amputation level and energy consumption during gait?

Answer 21

as the level of the amputation moves more proximal, the energy efficiency and biomechanical efficiency decreases

Question 22

T/F: dysvascular amputees tend to have faster gait speeds than traumatic amputees?

Answer 22

FALSE
traumatic amputees tends to be more efficient and don’t see as large of a decrease in walking speed, stride length, and cadence

Question 23

what are the general goals we want to reach with TTA gait?

Answer 23

**gait that is as close to normal as possible

key alignment issue is the socket/foot relationship

want to observe them effectively shifting weight over the prosthetic limb during PSw by looking at their pelvic, trunk, and head position

Question 24

what is the difference between pistoning and bell-clapping?

Answer 24

pistoning → movement that occurs up/down as the residuum moves away from the socket due to a poor fit

bell-clapping → movement that occurs anterior/poosterior due to poor fit

Question 25

Pistoning can result in what negative outcomes?

Answer 25

1. decreased stability 2. decreased confidence 3. excessive pressure/shearing forces

Question 26

what is the difference between able-bodied gait energy consumption and TFA and TTA?

Answer 26

TTA → 16-28% more O2 consumption TFA → 60-110% above normal

Question 27

Overall, "normal" prosthetic gait is a function of what factors?

Answer 27

1. socket fit 2. prosthetic alignment 3. components 4. user ability