MSK Session 12 Flashcards Preview

Semester 2 > MSK Session 12 > Flashcards

Flashcards in MSK Session 12 Deck (107):
1

What is the function of the ankle joint in upright posture?

Bear all body weight as it transfers to foot

2

What is the clinical importance of the ankle joint?

Arterial pulses of limb can be examined here

3

Where do venous and lymph drainages undergo particular changes so that their low pressure systems can return fluid to the body?

Ankles

4

How do arteries, motor nerves and tendons enter the foot?

Turning forwards

5

How do veins, sensory nerves and lymphatics exit the foot?

Turning upwards

6

What prevents bow-stringing of the long tendons of leg muscles at the ankle?

Crural fascia

7

How does the foot support body weight?

Establishes broad base for bearing body weight
Robust
Absorbs shock

8

What two opposing functions does the foot have?

Supporting body weight and organ of locomotion

9

What features of the foot allow it to be an organ of locomotion?

Loose to permit movement but stable when moving
Permits movement on flat, sloping and uneven surfaces
Lightweight
Able to lift body weight during initiation of movement

10

What forms the ankle joint proper?

Articulation of tibia and fibula w/talus

11

How many articular surfaces are there in the ankle joint proper?

6

12

What are the articular surfaces of the ankle joint proper lined with?

Hyaline cartilage

13

What are key landmarks in distal superficial venous drainage of the lower limb?

Malleoli

14

Where do the tibia and fibula articulate with each other?

Most of their lengths

15

What is the proximal articulation of the tibia and fibula?

Tibio-fibular articulation

16

What type of joint is the proximal articulation of the tibia and fibula?

Plane type synovial

17

What is the intermediate articulation of the tibia and fibula?

Interosseous membrane

18

What is the distal articulation of the tibia and fibula?

Tibio-fibular syndesmosis

19

What type of joint is the distal articualtion of the tibia and fibula?

Fibrous

20

Which two ligaments tie the ends of the tibia and fibula together in the tibio-fibular syndesmosis?

Anterior and posterior tibio-fibular ligaments

21

Which ligament deepens the articulatory surfaces of the tibio-fibular syndesmosis?

Posterior tibio/fibular

22

What type of joint is the ankle joint proper?

Mortise and tenon
Ginglymus
Rolling hinge synovial

23

Why is the ankle joint described as a mortise and tenon joint?

Leg bones form recess (mortise)
Superiorly rounded talus fills recess (tenon)

24

What allows changes between extremes of plantarflexion and dorsiflexion at the ankle joint?

Superiorly rounded talus allows rolling in a plane

25

Which are the joint stabilising surfaces of the ankle joint?

Malleolus
Posterior distal tibio-fibular ligament
Transverse tibio-fibular ligament

26

Which are the weight bearing surfaces of the ankle joint?

Tibia
Talus
(Fibula takes ~17% so contributes to stability)

27

Which bones of the foot form the medial longitudinal arch?

Calcaneus
Talus
Navicular
3 cuneiforms
1-3 metatarsals

28

Which bones of the foot form the lateral longitudinal arch?

Calcaneus
Cuboid
4th + 5th metatarsals

29

Which bones of the foot form the transverse arch?

Tarsals and metatarsals

30

What strengthens the transverse arch of the foot?

Long tendon of leg muscles

31

Why must the segmented structure of the foot be arranged in an arch?

Can only weight bare if in an arch

32

How many arches are present in the foot at birth?

3

33

Why may the foot appear flat in children

Subcutaneous fat pad masks arches present

34

In which two direction are the arches of the foot arranged?

2 antero-posteriorly
1 transverse medio-lateral

35

What type of attachments does the talus have?

Purely ligamentous

36

Where is the long axis of the talus directed?

Forwards and medially

37

What is the significance of the direction of the long axis of the talus?

Tibia and fibular can roll over and direct weight in its deviated path

38

How is the dorsal aspect of the talus identified?

Superiorly convex medial and lateral edges
Central portion concave

39

How does the posterior articular surface (body) of the talus compare to the anterior articular surface (head)?

Narrower

40

What are the three parts of the talus bone?

Head, neck and body

41

What does the plantar surface of the talus form?

Talo-calcaneal (sub-talar) joints

42

What is visible on the inferior view of the talus?

Sulcus tali

43

What type of joint is the subtalar joint?

Uniaxial hinge

44

What allows side to side motion of the foot?

3 parts of subtalar joint

45

How is the talus orientated in relation to the calcaneus?

Slightly obliquely on anterior surface

46

What separates the two articulations of the talus and calcaneus?

Tarsal canal (sinus tarsi)

47

What is the anterior talocalcaneal articulation?

Convex talus on concave calcaneus

48

What is the posterior talocalcaneal articulation?

Concave talus accommodates convex calcaneus

49

What allows us to walk on sloping/uneven ground by allowing the use of the sides of the feet?

Subtalar joint facilitating version and inversion

50

How far can the foot usually be everted?

15 degrees

51

How far can the foot usually be inverted?

30 degrees

52

Which surfaces articulate in dorsiflexion?

Anterior option of talar trochlea occupies and completely fills mortise

53

What is joint stability like in dorsiflexion?

Maximum

54

Adjustments at what contribute to stability of ankle joint in extreme dorsiflexion when the malleoli spread?

Tibio-fibular syndesmosis

55

What innervates dorsiflexion?

Fibular division of sciatic nerve (L4-5 same as for great toe)

56

Which muscles cause dorsiflexion?

Tibialis anterior
Assistance from extensor digitorum longus and extensor hallucis longus

57

What articulates in plantar flexion?

Posterior portion of talar trochlea occupies mortise

58

What allows some rotation for AB/AD-duction?

Posterior talar trochlea not filling mortise

59

Why is dorsiflexion less stable than plantar flexion?

Smaller articulation

60

What is the innervation of plantar flexion?

Tibial division of sciatic (S1-2)

61

Which muscles cause plantar flexion?

Gastrocnemius
Soleus
Assistance from tibialis posterior, FHL and FDL

62

Which ligament is the strongest of the ankle joint?

Medial

63

Where is the deltoid ligament positioned?

Originates from apex of medial malleolus and fans downwards in triangular shape to tarsal bones

64

Where do the anterior fibres of the medial ligament stretch down to?

Tibio-navicular

65

Where do the middle fibres of the medial ligament of the ankle joint stretch down to?

Calcaneo-tibial

66

Describe the posterior fibres of the deltoid ligament.

Talo-tibial which pass backwards and laterally

67

What is the deep ligament of the ankle joint?

Fibres attached to medial malleolus and medial talus

68

Which fibres of the deltoid ligament is the deep ligament of the ankle joint related to?

Tibio-navicular

69

What do the anterior and posterior fibres of the lateral ligament of the ankle join?

Lateral malleolus and talus

70

What do the intermediate fibres of the lateral ligament of the ankle join?

Lateral malleolus and calcaneus

71

Why does trauma to the ankle usually result in injury to both medial and lateral aspects of the joint?

Joint forms arming of bones and ligaments

72

What causes a Pott's fracture?

Excessive eversion of the foot w/abduction and external rotation

73

What is a Pott's fracture?

Bimalleolar ankle fractures

74

Describe the mechanism of injury in Pott's fracture.

Pull on medial ligament often causes avulsion of medial malleolus
Talus moves laterally
Lateral malleolus sheared off

75

What injury to the fibula is commonly caused in Pott's fracture?

# superior to tibio-fibular syndesmosis

76

What happens if the tibia is carried anteriorly in Pott's fracture?

Posterior margin of distal tibia is sheared off by talus

77

What type of bones are the tarsals?

Short

78

What are the characteristics of the tarsals that classify them as short bones?

Irregular
Cuboidal
6 articular surfaces

79

What is the anterior talofibular ligament?

Flat, weak band that extends anteromedially from lateral malleolus to neck of talus

80

What is the posterior talofibular ligament?

Thick, strong band horizontal medially and posteriorly that passes from malleolar fossa to lateral tubercle of talus

81

Which ligament is a round cord that joins the lateral malleolus to lateral calcaneus?

Calcaneofibular

82

What is the nerve supply to the ankle joint?

Derived from tibial nerve and deep fibular

83

What is the blood supply of the ankle joint?

Arteries derived from malleolar branches of the fibular, anterior and posterior tibial arteries

84

What limits dorsiflexion by the muscles in the anterior leg compartment?

Passive resistance of triceps surae to stretching
Tension in medial and lateral ligaments

85

How is the gait cycle split into two phases?

40% swing
60% stance

86

What are the three stages of the stance phase in the gait cycle?

Heel strike
Support
Toe-off

87

What are the functions of gluteus maximus, quadriceps femoris and the muscles in the anterior compartment of the leg during heel-strike?

Gluteus maximus: decelerates lower limb
Quadriceps femoris: keeps leg extended at knee and hip
Anterior compartment: maintain ankle dorsiflexion

88

What is the function of quadriceps femoris in the support stage of the stance phase?

Keeps leg extended to accept body weight

89

What do the foot inverters and everters do in the support stage in the stance phase of the gait cycle?

Stabilise foot?

90

What is the function of gluteus medius and tensor fascia lata in the support stage of the stance phase in the gait cycle?

Steady pelvis

91

Which muscles are involved in the toe-off stage of the stance phase?

Hamstrings extend hip
Quadriceps femoris maintain extended knee
Posterior leg plantarflexes ankle

92

Which muscles are involved in the swing phase of the gait cycle?

Iliopsoas
Rectus femoris
Quadriceps femoris
Anterior compartment of leg

93

What is the function of iliopsoas and refute femoris in the swing phase of the gait cycle?

Keep hip flexed and resist gravity

94

What is the function of quadriceps femoris in the swing phase of the gait cycle?

Extend knee to position foot for landing

95

What role do the muscles in the anterior compartment of the leg play in the swing phase of the gait cycle?

Maintain ankle dorsiflexion

96

What are the 5 stages of the gait cycle?

Heel strike
Support
Toe-off
Leg lift
Swing

97

What causes Trendelenberg gait?

Lesion of superior gluteal nerve

98

Why does the pelvis drop on the side of the raised leg in a Trendelenberg gait?

Abductor muscles on opposite side of pelvis are paralysed

99

Describe the movements of the trunk in Trendelenberg gait.

Lurches to opposite side of pelvic drop then whips back but overcompensates

100

What is an antalgic gait?

When the patient spends less time on painful limb

101

How is an antalgic gait identified?

Examine cadence

102

What causes foot drop?

Lesion of common/deep fibular nerve

103

What is observed in foot drop?

Foot dragged on floor

104

How do patients with foot drop compensate for their lost plantarflexion?

High stepparent gait
Eversion flick
Waddling gait
Swing-out gait

105

Why do guardsmen fall forwards when they faint?

Centre of gravity passes just anterior to ankle joint

106

What are the components of the deltoid ligament?

Tibionavicular
Tibiocalcaneal
Anterior and posterior tibiotalar

107

Which three tarsals are attached to the medial ligament of the ankle?

Talus
Calcaneus
Deltoid