Symposium - Gait and posture

Question 1

what is gait

Answer 1

it is translocates centre of body mass in the direction of locomotion

Question 2

what does normal gait relies on?

Answer 2

Joint - intact bones and well functioning joints,

muscle - adequate muscle strength

nerves - relies on both CNS & PNS

Vision

also relies on vestibular and auditory systems

Question 3

why does the gait changes in elderly?

Answer 3

decrease muscle size, decrease strength and flexibility

Question 4

what are the major changes of the gait in elderly

Answer 4

reduction in overall velocity, reduction in the step/stride length - generally velocity is preserved by taking more steps instead of increasing stride

Question 5

where is the centre of gravity lie in the body

Answer 5

lies anterior to S2 vertebra, slightly posterior to hip joints, anterior to knee and ankle joints

Question 6

what is the most stable position for hips and knees

Answer 6

extension - minimises need for muscular contraction during standing

Question 7

what is forward sway

Answer 7

due to the centre of gravity being anterior to the ankle joint, the natural movement is to fall forward

Question 8

how is forward sway counteracted?

Answer 8

counteracted by contraction of plantar flexor muscles

Question 9

what are the 2 phrases of the walking cycles?

Answer 9

stance phase (foot in contact with ground;60%), swing phrase (foots in the air;40%)

Question 10

what are the sequences of the walking cycles

Answer 10

heel strike (initial contact)- loading response (foot flat) - midstance - terminal stance (heel off) - preswing (toe off) - initial & mid swing - terminal swing

Question 11

what is double & single support in the gait cycle

Answer 11

double support = both feet on the ground

Question 12

what are the 5 sequences in the stance phase

Answer 12

heel strike - loading response - mid-stance-terminal stance- pre-swing

Question 13

what are the 3 sequences within the swing phase

Answer 13

initial swing - mid-swing - terminal swing

Question 14

what is dynamic contraction

Answer 14

it is muscle contracts with a change in length

Question 15

what is isometric contraction?

Answer 15

it is muscles contracts without changing in length

Question 16

what controls the lowering of forefoot to the ground

Answer 16

eccentric contraction of tibialis anterior

Question 17

what is eccentric contraction

Answer 17

lengthening of muscles

Question 18

what is concentric contraction

Answer 18

muscle shortens while contracting

Question 19

how is deceleration of forward momentum achieved

Answer 19

hip extension by gluteus maximus

Question 20

when does the stance phase starts ?

Answer 20

when the heel strikes ground

Question 21

what preserve the longitudinal arch of foot?

Answer 21

the intrinsic muscle of the foot

Question 22

when does the loading response start?

Answer 22

when the foot comes into full contact with ground

Question 23

what is require to prevent knee buckling under weight

Answer 23

knee extension - by quadriceps femoris

Question 24

when does mid-stance begin

Answer 24

it starts when the opposite limb swings past the stance limb

Question 25

what is required to stabilise the pelvis during mid-stance phase

Answer 25

abduction of hip is required to stabilise the hip

Question 26

how is stabilisation of the hip achieve during the mid-stance?

Answer 26

contraction of gluteus medius, gluteus minimus and tensor fasia lata

Question 27

when does terminal stance start

Answer 27

it is when the heel starts to lift off ground

Question 28

how is the lift off motion achieved?

Answer 28

it is achieved by plantar flexion

Question 29

what take place in the pre-swing phase?

Answer 29

plantar flexion of digits in order to push off ground and accelerate mass forward

Question 30

what is important for toe off ?

Answer 30

hallux (the big toe) ie stabilisation of the hallux is important

Question 31

what is apropulsive gait

Answer 31

it is weak push off

Question 32

what will apropulsive gait cause?

Answer 32

it will cause shorter stride length & decreased gait velocity

Question 33

what carries limb forward in the initial & swing phase

Answer 33

hip flexion - iliopsoas and rectus fermoris

Question 34

what happens in the initial & mid-swing phase?

Answer 34

hip flexion, toes & foot dorsiflexed (allow foot to clear the ground), knee flexion (to shorten limb), contralateral abductors of hip, neck rotates to keep face pointing forward

Question 35

what is the angle for knee flexion to shorten the limb

Answer 35

65 degree

Question 36

what happens in the terminal swing

Answer 36

knee flexion changes to extension to place foot for heel strike - quadriceps

dorsiflexion of ankle - tibialis anterior

deceleration of the limb - by eccentric contraction of hamstring

Question 37

why does limb circumduct for the swinging part of the gait cycle

Answer 37

it is because limited knee flexion means limb can not be shortened & swinging leg moves in an arc rather than straight-forwards

Question 38

what happens foot can not be doriflexed

Answer 38

footdrop - likely damages to common fibular nerve

Question 39

why does the centre of gravity remains almost constant during walking?

Answer 39

rotation of the pelvis allow the reduction of the vertical drop - stance limn = internal rotate pelvis, swing limb = external rotation of the pelvis

Question 40

how else is the pelvis moved to minimise rise in centre of gravity

Answer 40

pelvis drop to swing side

Question 41

what minimise the lateral shift of centre of gravity?

Answer 41

hip adduction