13 - Anterior Lateral Leg and Foot and LL Joints

Question 1

bones of the foot

Answer 1

7 tarsal bones, 5 metatarsal bones and 14 phalanges.

Question 2

hindfoot

Answer 2

calcaneus and talus

Question 3

midfoot

Answer 3

cuboid, navicular and 3 cuneiforms

Question 4

forefoot

Answer 4

5 metatarsals and 14 phalanges

Question 5

muscles of the lateral compartment of the leg

Answer 5

fibularis brevis and longus

Question 6

actions of the lateral compartment of the leg

Answer 6

evert and plantarflex

Question 7

innervation of the lateral compartment of the leg

Answer 7

superficial fibular nerve

Question 8

blood supply of the lateral compartment of the leg

Answer 8

perforating branches of the fibular a

Question 9

extensor expansions

Answer 9

The extensor tendons pass onto the dorsal aspects of the digits and expand over the phalanges to form complex dorsal digital expansions.
Each extensor expansion has a proximal extensor hood

Question 10

extensor hood

Answer 10

part of extensor expansion
proximal part
triangular in shape and wraps around the MP joints to attach to ligaments in the sole of the foot
Apex expands into 3 bands: central (attaches to middle phalanges) and two lateral (insert on distal phalanges

Question 11

where do many intrinsic muscles of the sole of the foot insert

Answer 11

lateral bands of the extensor expansion

allows forces to be distributed over the dorsum of the entire digit

Question 12

where does anterior tibial artery change its name and to what

Answer 12

changes to dorsalis pedis artery after it passes between malleoli and enters the dorsum of the foot

Question 13

where is the pulse of the dorsalis pedis felt

Answer 13

dorsum of the foot as the artery passes over the tarsal bones between the tendon of extensor hallucis longus and the 1st tendon of extensor digitorum longus
OVEN FELT TO TEST FOR PERIPHERAL VASCULAR DISEASE

Question 14

what does dorsalis pedis artery split into and therefore end

Answer 14

divides into deep plantar and 1st dorsal metatarsal arteries

Question 15

common fibular nerve

Answer 15

L4-S2
terminates by dividing into the superficial and deep fibular nerves just after it wraps around the neck of the fibula. Due to it’s superficial location and proximity to the fibular neck, it is easily injured. Fractures of the proximal fibula may sever this nerve resulting in paralysis of all the muscles in the anterior and lateral compartments of the leg (foot drop) and loss of cutaneous innervation to the lateral aspect of the leg and dorsum of the foot.

Question 16

superficial fascia of the foot

Answer 16

• has fibrous septa that act to
• divide it into fat-filled compartments creating shock-absorbing pads o’ fat.
• Anchor the skin to the underlying deep fascia in order to improve the ‘grip’ of the sole

Question 17

plantar fascia

Answer 17

deep fascia on the sole of the foot which helps hold the foot together, protects the plantar surface of the foot and helps support the longitudinal arches of the foot.

Question 18

plantar aponeurosis

Answer 18

• central thickening of the plantar fascia
• longitudinally arranged bands go from the calcaneal tuberosity to the digital sheaths and proximal phalanges
• converts foot into solid lever for gait cycle

Question 19

intermuscular septa of mid and forefoot

Answer 19

• two of them
• extend into the mid- and fore-foot from the plantar aponeurosis
• divide foot into medial, central and lateral compartments
• interosseous compartment is located between metatarsals

Question 20

intrinsic muscle layers in the sole of the foot and function

Answer 20

• 4 groups
• resist forces that flatten longitudinal arch
• stabilise foot for propulsion by maintaining the transverse arches
• produce minor movements of inversion/ eversion to maneuver on unstable ground
• maintain balance

Question 21

blood supply of the sole of the foot

Answer 21

branches of the posterior tibial and dorsalis pedis arteries.

Question 22

bifurcation of posterior tibial a.

Answer 22

• medial and lateral plantar aa. as it passes through the tarsal tunnel
• travel between 1st and 2nd muscle layers of the foot

Question 23

lateral plantar artery anastomoses

Answer 23

• anastamoses with deep plantar artery (branch of dorsalis pedis a.
• this anastomosis forms deep plantar arterial arch which traverses sole of the foot between 3rd and 4th muscle layers at level of matatarsal bases

Question 24

innervation of sole of the foot

Answer 24

-tibial nerve, medial and lateral plantar
nerves, as well as the sural & saphenous nerves.
-medial plantar nerve innervates four intrinsic muscles of the foot
-remaining intrinsic muscles of the foot are all innervated by the lateral plantar nerve.

Question 25

between which muscle layers do the lateral plantar artery and nerve run

Answer 25

- 1st and 2nd | - joins with deep plantar a. to form plantar arch

Question 26

between which muscle layers does plantar arch run

Answer 26

-3rd and 4th

Question 27

between which muscle layers do medial plantar a and n run

Answer 27

1st and 2nd

Question 28

hip joint classification

Answer 28

multi-axial ball and socket type of synovial joint

Question 29

articular surfaces of hip joint

Answer 29

- head of femur with the lunate surface of the acetabulum. - the acetabular notch is bridged by the transverse acetabular ligament - the acetabular labrum is a - fovea capitis in the head of the femur, attached to acetabulum by the round ligament of the head of the femur (ligamentum teres femoris capitis).

Question 30

lunate surface

Answer 30

C-shaped with an inferior deficiency | called the acetabular notch (bridged by transverse acetabular ligament which also articulates with head of femur)

Question 31

acetabular labrum

Answer 31

fibrocartilaginous ring that increases the depth of the acetabulum and the area of contact between the articulating surfaces

Question 32

capsular ligaments

Answer 32

The fibrous joint capsule is reinforced externally by three ligaments, all of which have fibres that spiral around the joint: iliofemoral ligament, pubofemoral ligament, ischiofemoral ligament

Question 33

iliofemoral ligament

Answer 33

extremely strong Y-shaped ligament that lies anterior to the hip. The ‘stem’ of the Y attaches to the anterior inferior iliac spine, the fibres run anteroinferiorly across the hip joint to insert on the intertrochanteric line. It primarily limits extension of the hip joint

Question 34

pubofemoral ligament

Answer 34

lies anteroinferior to the hip. It originates on the iliopubic eminence, spirals inferolaterally around the femoral neck to blend with the iliofemoral ligament and fibres of the joint capsule. It primarily limits extension and abduction of the hip joint.

Question 35

ischiofemoral ligament

Answer 35

lies posterior to the hip. It arises from the ischium, posterior to the hip joint, and extends superolaterally to blend with the fibres of the joint capsule. It primarily limits extension of the hip joint.

Question 36

blood supply to hip joint

Answer 36

primarily from the medial and lateral circumflex femoral arteries (off the profunda femoris). **In the adult, the medial circumflex femoral artery is the most important source of blood to the femoral head and adjacent neck. Retinacular arteries branch off the medial (and lateral) circumflex femoral arteries and travel up the femoral neck to reach the femoral head. Fractures of the femoral neck may lacerate the retinacular arteries and the femoral head may become necrotic and die.

Question 37

knee joint classification

Answer 37

Hinge-type of synovial joint, allowing for flexion and extension (with some anterior and posterior rolling & gliding)

Question 38

articular surfaces of knee

Answer 38

- patellofemoral joint is included in the knee joint capsule, the proximal tibiofibular joint IS NOT. - main articulation occurs between the articular surfaces of the medial and lateral femoral condyles and the articular surfaces of the medial and lateral tibial condyles on the tibial plateau.

Question 39

medial and lateral menisci

Answer 39

- crescent-shaped fibrocartilaginous disks with thick peripheries that intervene between the distal femur and proximal tibia. - increase the area of contact between the femur and tibia, reducing the stresses at the joint - shock absorbers, dissipate the forces.

Question 40

which meniscus is more frequently injured and why

Answer 40

-The medial meniscus has an attachment to the medial collateral ligament, it is less mobile than the lateral meniscus, and therefore more frequently injured.

Question 41

what determines stability of the knee joint

Answer 41

depends on the strength of the muscles crossing it and on the following ligaments: fibular/lateral collateral ligament, tibial/medial collateral ligament, anterior cruciate ligament, posterior cruciate ligament

Question 42

fibular/lateral collateral ligament

Answer 42

-extracapsular - a very strong ligament extending from the lateral epicondyle of femur to the fibular head. It is separated from the lateral meniscus by both the tendon of popliteus and the fibrous joint capsule. It prevents adduction of the knee joint and works with the tibial collateral ligament to limit rotation of the tibia on the femur. It is also tense in knee extension.

Question 43

tibial/medial collateral ligament

Answer 43

-extracapsular - from the medial epicondyle of the femur to the proximal and medial aspect of the tibia. Its deep fibres blend with the joint capsule and are firmly attached to the medial meniscus. It limits abduction of the knee and works with the fibular collateral ligament to limit rotation of the tibia on the femur. It is also tense in knee extension.

Question 44

anterior cruiciate ligament

Answer 44

(ACL) –intracapsular/ extrasynovial - attaches anteriorly on the tibia and runs supero-postero-laterally through the intercondylar notch of the femur to insert on the inside of the lateral femoral condyle. It limits extension of the knee and anterior gliding of the tibia (anterior drawer sign) and works with the posterior cruciate ligament to limit medial rotation of the tibia on the femur.

Question 45

posterior cruciate ligament

Answer 45

(PCL) – intracapsular/ extrasynovial - attaches posteriorly on the tibia and runs supero-antero-medially through the intercondylar notch of the femur to insert on inside of the medial femoral condyle. It is mostly tense in flexion (although some fibres are tense in extension), it prevents posterior gliding of the tibia (posterior drawer sign) and works with the anterior cruciate ligament to limit medial rotation of the tibia on the femur.

Question 46

blood supply of the knee

Answer 46

genicular anastomosis

Question 47

superior tibiofubular joint type

Answer 47

- plane synovial | - minimal movement

Question 48

tibiofibular syndesmosis

Answer 48

interosseous membrane

Question 49

inferior tibiofibular joint

Answer 49

- plane synovial - minimal movement - reinforced by the : anterior tibiogibular ligament, posterior tibiofibular ligament

Question 50

interosseous membrane

Answer 50

- holds tibia and fibula tightly together | - syndesmosis

Question 51

talocrural joint

Answer 51

ankle joint | -synovial hinge joint

Question 52

malleolar mortise

Answer 52

- lateral malleolus of the fibula with the inferior surface and medial malleolus of the tibia - pulley shaped trochlea of the talus fits here

Question 53

talar trochlea

Answer 53

wider anteriorly such that the ‘grip’ of the malleoli is stronger in dorsiflexion as the anterior portion of the talus becomes wedged between the distal ends of the leg bones.

Question 54

why is the ankle unstable in plantarflexion

Answer 54

because the trochlea is narrower posteriorly and, therefore lies loosely within the mortise

Question 55

in which position do most injuries of the ankle occur

Answer 55

plantarflexion

Question 56

medial collateral (deltoid) ligament of the ankle

Answer 56

strong compound ligament consisting of four parts that fan out from the medial malleolus of the tibia. -limits eversion/abduction of the ankle

Question 57

lateral collateral ligament of the ankle

Answer 57

compound ligament consisting of three parts that fan out from the lateral malleolus of the fibula. It limits inversion/adduction of the ankle joint. -The anterior talofibular is most commonly injured ligament of the ankle – this results from an ‘inversion’ injury causing an ankle sprain

Question 58

4 major joints of the foot

Answer 58

- subtalar joint (inversion and eversion of foot) - transverse tarsal joint (inversion and eversion of foot) - metatarsophalangeal joint (flexion/extension and abduction/adduction) - interphalangeal joints (proximal and distal: all are hinge joints allowing for flexion and extension)

Question 59

2 functions of the foot

Answer 59

1, support body weight; 2, act as a lever to propel body forward during locomotion

Question 60

purpose of arches of the feet

Answer 60

the ground reaction forces that act on the foot when standing have a tendency to ‘deform’ the foot in such a way as to force dorsiflexion of the anterior aspect of the foot. The foot must resist this tendency by remaining rigid, which is best achieved by maintaining an arched structure.

Question 61

integrity of arches is maintained by:

Answer 61

- Shape of the foot bones - Muscles - plantar ligaments - plantar aponeurosis

Question 62

foot bones that maintain integrity of arches

Answer 62

- Medial arch – the head of the talus forms the keystone | - Lateral arch – cuboid is the keystone

Question 63

muscles that maintain integrity of arches

Answer 63

- Medial arch – tibialis anterior suspends the arch from above (assisted by flexor hallucis longus and the intrinsic mm.) - Lateral arch – fibularis longus and brevis suspend the arch from above (assisted by the intrinsic muscles of the foot)

Question 64

plantar ligaments that maintain integrity of arches

Answer 64

- Medial arch –plantar calcaneonavicular = spring ligament (under the head of the talus), assisted by plantar ligaments - Lateral arch – long and short plantar ligaments (especially the long plantar ligament)

Question 65

plantar aponeurosis that maintain integrity of arches

Answer 65

-Medial and Lateral longitudinal arches – fibres of the plantar aponeurosis run between the calcaneal tuberosity and proximal phalanges. Therefore, whenever the MP joints are extended, the aponeurosis is taut. This is most relevant when a person is walking (at toe-off) or when standing on their toes. In these cases the plantar aponeurosis converts the foot into a solid lever and forms the major support of the longitudinal arches of the foot.