Muscle Activity in Gait

Question 1

key roles of hip extensors

Answer 1

activated in terminal swing prior to initial contact to initiate hip ext and prepare LE for weight acceptance at the beginning of stance

Question 2

key role of hip flexors

Answer 2

advance LE forward during initial swing and lift LE to allow for toe clearance during swing

Question 3

key role of hip abductors

Answer 3

control the slight lowering of the contralateral pelvis on the side of the swing limb then provide pelvic stability in stance

Question 4

key role of hip adductors

Answer 4

assist with initiation of hip flexion after toe off

Question 5

key role of knee extensors

Answer 5

eccentrically control knee flexion in loading response then act concentrically to extend the knee and support body in midstance

Question 6

key role of knee flexors

Answer 6

decelerate knee extension in preparation for placement of the foot on the ground

Question 7

key role of ankle DF

Answer 7

eccentric activation to control PF of the ankle at initial contact until foot comes in contact with the ground

Question 8

key role of ankle PF

Answer 8

eccentric contraction moving into midstance to control tibial advancement

concentric contraction at terminal stance to propel forward

Question 9

key role of ankle invertors

Answer 9

eccentrically contract to control pronation until midstance then concentrically contracts to supinate the foot for push off in terminal stance/preswing

Question 10

key role of ankle evertors

Answer 10

active as co-contraction to counter strong inversion effect occurring during loading response to midstance

Question 11

foot force

Answer 11

force applied to the ground by the foot

Question 12

ground reaction force

Answer 12

force applied to the foot by the ground

Question 13

center of pressure

Answer 13

point where all the floor-foot forces act

come together - change as you’re walking

Question 14

muscle activation in the sagittal plane during initial contact: hip

Answer 14

hip: extensors contract concentrically

Question 15

muscle activation in the sagittal plane during initial contact: knee

Answer 15

knee: eccentric flexor contraction to counteract extension torque

extensors transition from concentric to eccentric contraction in preparation for loading response

Question 16

muscle activation in the sagittal plane during initial contact: ankle

Answer 16

ankle: DF contract concentrically

Question 17

muscle activation in the sagittal plane during loading response: hip

Answer 17

concentric contraction of extensors

Question 18

muscle activation in the sagittal plane during loading response: knee

Answer 18

eccentric contraction of knee extensors

Question 19

muscle activation in the sagittal plane during loading response: ankle

Answer 19

eccentric contraction of DF –> transition to eccentric contraction of ankle PF in late LR

Question 20

muscle activation in the sagittal plane during mid stance: hip

Answer 20

little hip activity

Question 21

muscle activation in the sagittal plane during mid stance: knee

Answer 21

eccentric contraction of knee extensors in beginning of mid stance with transition to concentric contraction of knee extensors by the end of mid stance phase

Question 22

muscle activation in the sagittal plane during mid stance: ankle

Answer 22

eccentric contraction of ankle PF

Question 23

muscle activation in the sagittal plane during terminal stance: hip

Answer 23

minimal activity

some activation of anterior fiber of TFL to possible restrain hyperextension of the hip

Question 24

muscle activation in the sagittal plane during terminal stance: knee

Answer 24

no knee extensor activity

tibial position maintained by gastroc

Question 25

muscle activation in the sagittal plane during terminal stance: ankle

Answer 25

concentric contraction of ankle PF to prevent tibial collapse with heel rise

Question 26

muscle activation in the sagittal plane during pre-swing: hip

Answer 26

concentric contraction of hip flexors

Question 27

muscle activation in the sagittal plane during pre-swing: knee

Answer 27

flexion is mainly passive

minimal concentric contraction of knee flexors

Question 28

muscle activation in the sagittal plane during pre-swing: ankle

Answer 28

ankle PF activity ceases in early preswing and passive tension contributes to ankle moving into PF

ankle DF concentric contraction initiated at the end of pre swing phase

Question 29

muscle activation in the sagittal plane during initial swing: hip

Answer 29

continued concentric contraction of hip flexors

Question 30

muscle activation in the sagittal plane during initial swing: knee

Answer 30

concentric contraction of knee flexors

flexion continues to be aided by flexion at the hip

Question 31

muscle activation in the sagittal plane during initial swing: ankle

Answer 31

concentric contraction of ankle DF

Question 32

muscle activation in the sagittal plane during mid swing: hip

Answer 32

continued concentric contraction of hip flexors

initiation of eccentric hip extensors to control hip flexion

Question 33

muscle activation in the sagittal plane during mid swing: knee

Answer 33

knee extension created by momentum

knee flexors contract eccentrically at the end of the mid swing phase to control extension

Question 34

muscle activation in the sagittal plane during mid swing: ankle

Answer 34

continued concentric contraction of DF

Question 35

muscle activation in the sagittal plane during terminal swing: hip

Answer 35

concentric contraction of hip extensors

Question 36

muscle activation in the sagittal plane during terminal swing: knee

Answer 36

concentric contraction of knee extensors to insure full extension

peak knee flexor eccentric contraction to decelerate thigh

Question 37

muscle activation in the sagittal plane during terminal swing: ankle

Answer 37

continued concentric contraction of DF

Question 38

muscle activation in the frontal plane during loading response: hip

Answer 38

abductors contract eccentrically

Question 39

muscle activation in the frontal plane during loading response: ankle

Answer 39

invertors contract eccentrically

Question 40

muscle activation in the frontal plane during midstance: hip

Answer 40

abductors contract eccentrically then concentrically

Question 41

muscle activation in the frontal plane during midstance: ankle

Answer 41

invertors contract eccentrically

Question 42

muscle activation in the frontal plane during terminal stance and pre swing: hip

Answer 42

abductors contract concentrically

Question 43

muscle activation in the frontal plane during terminal stance and pre swing: ankle

Answer 43

invertors contract concentrically

Question 44

muscle activation in the frontal plane during initial, mid and terminal swing: hip

Answer 44

adductor contract concentrically

Question 45

muscle activation in the frontal plane during initial, mid, terminal swing: ankle

Answer 45

evertors contract concentrically