# Gait: intro, ankle, knee Flashcards Preview

## Analysis of Movement > Gait: intro, ankle, knee > Flashcards

Flashcards in Gait: intro, ankle, knee Deck (90)
1
Q

What what phase, stance or swing, do we spend most of our time on the limb of focus?

A

60% of time in stance phase

40% of time in swing

2
Q

What is the difference between step length and stride length? What are normal values?

A
• step length = right foot to left foot: 72 cm

- stride length = right foot to right foot: 144 cm

3
Q

When is the first phase of double-limb support?

A

4
Q

How many degrees of foot angle are normal?

A

5-7 degrees of toe-out

5
Q

If someone has a greater than normal angle of toe out, what is this called?

A

duck toe

6
Q

A

number of steps per minute; a temporal descriptor of gait

7
Q

What are the 3 temporal descriptors of gait?

A

step time
stride time

8
Q

What is gait cycle time also called?

A

stride time

9
Q

T/F: Step length = gait cycle step.

A

false, stride length = gait cycle step

10
Q

What are normal values for step width?

A

8-10cm

11
Q

When increasing walking speed, what happens to stance time and swing time?

A

With increased walking speed

• stance time decreases
• swing time increases
12
Q

T/F: Step length increases when we increase walk speed.

A

true

13
Q

T/F: With the gait cycle, we start with more concentric activity, and then switch to eccentric activity towards the end of the cycle.

A

false, we go from eccentric to concentric

14
Q

What percentage does initial contact consist of in the gait cycle?

A

0-2%

15
Q

Where are the ground reaction forces for initial contact?

A

posterior to ankle
anterior to knee
slightly anterior to hip

16
Q

When is the first double-limb support period?

A

17
Q

A

posterior to knee
posterior to ankle
slightly anterior to hip

18
Q

A

from initial contact until the other foot is lifted for swing

19
Q

A

the knee extensors!! GRF is posterior to knee here, and KEs must eccentrically control this knee flexion

20
Q

When is the second double stance phase?

A

preswing

21
Q

A

0-10%

22
Q

When does the first half of single limb support occur?

A

midstance

23
Q

Where is the opposite limb when the stance limb is in midstance?

A

midswing

24
Q

What is the position of the limb in early midstance, and then late midstance?

A
```early = knee flexed, hip flexed
late = knee extended, hip extended```
25
Q

What two muscles make up 93% of the potential plantar flexor torque?

A

gastroc and soleus

26
Q

What muscles preserve the heel rocker?

A

DFs

27
Q

At what phase of gait are we in if the foot is in digigrade?

A

terminal stance

28
Q

Describe the activity of the plantar flexors during gait cycle.

A
• most active in beginning during loading and through midstance to eccentrically control DF
• turn on slightly during preswing when the 2nd arc of plantar flexion occurs, but mostly passive recoil is used for push off (from the stretch they just got during DF)
29
Q

What muscle markedly increases its activity in midstance to control pronation?

A

tib posterior

30
Q

When during gait does PF internal torque peak?

A

at push off, then drops off

31
Q

A

posterior to ankle
posterior to knee
slightly anterior to hip

32
Q

When does the first arc of ankle PF occur in gait?

A

during loading response: get a quick 10 degrees as the foot drops to the floor (controlled by DFs)

33
Q

What should the position of the heel be in at initial contact to activate the heel rocker?

A

90 degrees

34
Q

Where are the GRFs at the ankle during midstance?

A

anterior to ankle, so PFs need to eccentrically control this dorsiflexion happening in midstance

35
Q

What muscle fixes the first met, and when during gait is this important?

A

fib longus fixes first met during terminal stance to take advantage of the forefoot rocker

36
Q

How much sagittal motion is needed at the 1st MTP during gait?

A

55 degrees: windlass effect must occur

37
Q

How many degrees of hip flexion do we need in swing?

A

40 degrees

38
Q

How many degrees of knee flexion do we need during the stance phase of gait?

A

20 degrees

39
Q

When looking at midtarsal motion during gait, what are you looking for?

A

watch the arch fall or rise abnormally during gait cycle, this is the motion at the midtarsal joint

40
Q

At what point after loading does recovery of the arch of the foot occur?

A

with heel rise, so during terminal stance

41
Q

What motion of the tibia allows for the collapse of the arch? When in gait does this happen?

A

IR of tibia during loading to early midstance causes the arch to be lost

42
Q

When during gait is the peak of eversion?

A

during early midstance

43
Q

What is the position of the foot during swing?

A

dorsiflexed and inverted

44
Q

If a patient has hallux rigidis, what would be compromised in their gait?

A

preswing is affected: no toe rocker for push off, so you lose momentum

45
Q

What axes need to be parallel to allow pronation of the foot?

A

talonavicular and calcaneocuboid

46
Q

Plantigrade is related to what phase of gait? What kind of support is it called?

A

midstance: foot flat support

47
Q

T/F: Medial plantar surface is where weight should be loaded in flat foot support, or plantigrade.

A

false, should load on lateral side of foot

48
Q

What muscles do foot inversion?

A

tib anterior, tib posterior, soleus

49
Q

When does the tib posterior activity peak?

A

peaks in LS and mid terminal stance

50
Q

When does soleus activity peak?

A

51
Q

Which is larger, inversion or eversion torque?

A

inversion is larger -> 20-45% of gait cycle

eversion = 0-20%

52
Q

What muscles do eversion?

A

gastroc, fib longus and brevis, EDL, EHL

- activity ranges between LR and TS because they control supination and do pronation

53
Q

What is the sequence of foot support?

A

heel -> lateral aspect of foot -> across forefoot -> to 1st met -> push off!

54
Q

How much knee flexion do we need for swing phase versus stance phase?

A

need 60 degrees KF for swing, 20 for stance

55
Q

Terminal stance consists of what percentage of gait?

A

31-50%`

56
Q

Mid stance consists of what percentage of gait?

A

12-31%

57
Q

In what plane does the knee have most motion?

A

sagittal = KF and KE

58
Q

T/F: When limb is in stance, it’s in slight abduction.

A

true, physiological valgus

59
Q

What provides shock absorption during gait?

A

20 deg knee flexion, abduction, plantar flexion

60
Q

How does the external torque change at the knee as the limb moves forward?

A

GRFs go from being anterior to the knee to being posterior to the knee

61
Q

With internal rotation, does this lock or unlock the knee?

A

62
Q

An internally rotated knee means what for the foot position?

A

foot is pronated

63
Q

T/F: Knee is mostly in ER during stance.

A

false, mostly in IR during stance, knee isn’t locked

64
Q

At what point during gait does the knee move from internal rotation to external rotation?

A

becomes ER at push off (preswing) to allow foot to be supinated and rigid

65
Q

When we describe knee rotation, what are we specifically talking about in terms of bones?

A

rotation of tibia relative to femur

66
Q

What thigh muscles kick in at IC to ensure knee extension?

A

vastus medialis and lateralis, gluteus max via IT band, rectus femoris; some slight hamstring activity to prevent hyperextension

67
Q

What muscle works to counteract adduction during initial contact?

A

TFL; fires before glut med because it’s smaller

68
Q

Describe the knee flexor activity throughout the gait cycle.

A
• eccentrically controls hyperextension during initial contact and then quiets down during midstance
• concentrically fires during preswing and swing phase to flex knee
• eccentrically controls KE during terminal swing also
69
Q

What is the difference between the biceps femoris short head and long head? Which one activates first?

A
• short head only does knee flexion, long head does knee flexion and hip extension
• short head activates first for knee flexion
70
Q

What knee muscle is active through virtually the entire gait cycle?

A

popliteus

71
Q

What quad muscle is also active in toe-off while the others quiet down?

A

rectus femoris to allow hip flexion; other ones do knee extension, and you don’t have that in this phase, you have knee flexion

72
Q

In initial contact, are the quads concentric or eccentric? What’s their purpose in this phase?

A

quads concentrically contract in initial contact to provide stable weight bearing

73
Q

A

74
Q

When are the quads most active?

A

during initial contact through loading, then rectus femoris activates during toe off to give hip flexion for swing

75
Q

How many degrees of total rotation do we get at the knee during gait?

A

8 degrees of total IR/ER

76
Q

Describe the locking and unlocking of the knee during gait.

A
• IC to MS: knee is unlocking
• MS to PS: knee begins to lock for push off
• PS to midswing: knee begins unlocking for swing (b/c it’s in flexion)
• midswing to terminal swing: preparing for IC so it starts to go towards locking
77
Q

What external moment, ab or adduction, is occuring to the leg in midstance?

A

adductor moment b/c the GRFs are medial to the knee; this is why TFL must kick in to prevent that

78
Q

Where are the GRFs in terminal stance?

A

way anterior to ankle
run through knee
slightly posterior to hip

79
Q

Maximal knee extension occurs in what phase?

A
• terminal stance, and then you move quickly into knee flexion and plantar flexion
• allows you to have maximal step length
80
Q

What muscle slows down the passive knee flexion occuring in preswing?

A

rectus femoris: GRFs are very posterior to knee in preswing, so rectus femoris has to control that knee flexion

81
Q

Where are the GRFs for the knee and ankle in preswing?

A

very anterior to ankle

very posterior to knee

82
Q

T/F: Gastroc is very active in preswing.

A

false, only slightly active
- you don’t need it too much for PF due to passive recoil, and you don’t need it for KF too much due to passive KF occuring

83
Q

What are the roles of rectus femoris?

A

eccentric control of knee flexion and hip extension

84
Q

Forward free fall of the body occurs in what phase?

A

terminal stance

85
Q

What critical events must happen in terminal stance?

A

use of forefoot rocker, controlled dorsiflexion by PFs, forward free fall of body with trailing limb

86
Q

What critical events must occur in preswing?

A

toe rocker, passive knee flexion

87
Q

What critical events must happen in initial swing?

A

knee flexion and hip flexion

88
Q

Rectus femoris is especially active in what phase?

A

in preswing because it decelerates the passive knee flexion occuring

89
Q

What allows for the knee flexion in initial swing?

A

forward momentum of thigh, biceps femoris short head, gracilis, and sartorius

90
Q

Describe the sagittal motion of the knee during the entire gait cycle.

A
1. IC = extended to allow stable weight bearing