lower limb anatomy

Question 1

Dermatomes over lower leg

Answer 1

● Describe the dermatomes of the lower limb
● L 1 2 3 4 and 5 wind around leg in an inferomedial direction
● L1 is over the inguinal region
● L2 is over the middle and lateral aspect of the anterior thigh
● L3 is over the knee
● L4 is over the medial malleolus
● L5 supplies the medial foot and the great toe
● S1 S2 supply the back of the leg, which becomes the lateral foot
● There is an axial line down posteromedial aspect of leg

Question 2

Please describe the cutaneous nerves of the lower limb

Answer 2

● Lateral thigh = Lateral cutaneous nerve of thigh L2 L3
● Anterior and medial thigh = Anterior cutaneous branch of femoral nerve,
intermediate and medial femoral cutaneous nerves, obturator nerve
● Posterior thigh = Posterior cutaneous nerve of the thigh (S1- S3)
● Lateral leg from knee to mid calf = lateral cutaneous nerve of calf and leg
● Anterolateral leg from mid calf = superficial fibular nerve
● Posterolateral leg from mid calf = sural nerve
● Medial leg = saphenous nerve
● Dorsum of the foot (except 1st webspace) = superficial fibular nerve
● 1st webspace = deep fibular nerve
● Heel = Medial calcaneal branch of tibial nerve
● Sole of the foot except heel = medial and lateral branches of tibial nerve

Question 3

picture of lower limb dermatome

Answer 3

Question 4

picture of lower limb nerves

Answer 4

Question 5

What are the myotomes of the lower limb

Answer 5

● Hip flexion L2/L3
● Hip Extension L4/L5
● Knee Extension L3/L4
● Knee Flexion L5/S1
● Ankle Dorsi Flexion L4/L5
● Ankle Plantar Flexion S1/S2
● Ankle Inversion L4
● Eversion L5/S1
● Big Toe Extension L5/S1
● Big Toe Flexion S1/S2

Question 6

Pelvis - you must be able to look at a pelvic xray and name all the key landmarks
What are the bony landmarks of the pelvis?

Answer 6

● 3 bones - ilium, ischium, pubis
● Anterior surface - ASIS, AIIS, pubic symphysis, superior and inferior pubic rami
● Laterally - iliac crest
● Posterior surface- PSIS and PIIS, greater and lesser sciatic notches, ischial
spine
● Inferiorly - ischial tuberosities

Question 7

What are the main articulations within the pelvic girdle?

Answer 7

● Sacroiliac joints
● Pubic symphysis
● Acetabulum articulating with the femur

Question 8

What attaches to the anterior inferior iliac spine?

Answer 8

Rectus femoris

Question 9

What attaches to the anterior superior iliac spine?

Answer 9

Sartorius

Question 10

Describe the course of the iliac arteries

Answer 10

● Common iliac arteries originate from the aorta around L3 -L5
● Follows the medial border of psoas to the pelvic brim
● Divides at the level of L5- S1
● Internal iliac artery enters the pelvis
● External iliac artery follows iliopsoas and ends at the inguinal ligament where it
becomes the femoral artery at the mid inguinal point

Question 11

Hip
What are the factors maintaining stability of the hip joint?

Answer 11

● Bony Articulations
○ Acetabular socket, formed by the ilium, ischium and pubis
○ Articulates with the femoral head for transfer of weight
○ Reinforced by labrum

● Ligaments
○ Capsule
○ Iliofemoral
○ Ischiofemoral
○ Pubofemoral
○ Transverse acetabular ligament

● Muscles
○ Short muscles are important, especially gluteus medius and minimus

Question 12

What is the least stable position of the hip?

Answer 12

Flexed and adducted (i.e. seated position → bad for car accidents)

Question 13

Describe the attachments of the ligaments of the hip

Answer 13

● iliofemoral ligament
○ From the anterior inferior iliac spine and acetabular rim to the
intertrochanteric line

● Pubofemoral ligament
○ From obturator crest of pubis, blends with medial aspect of iliofemoral
ligament

● Ischiofemoral ligament (weakest)
○ Posterior acetabular rim, spirals superolaterally to the base of the greater
trochanter

● Transverse acetabular ligament - bridges the acetabular notch
● Ligament of the head of the of the femur, to the fovea of the head

Question 14

Where might you find a pathological fracture around the hip joint?

Answer 14

Pubic rami, neck of femur or the proximal shaft

Question 15

Femur
Please describe the main bony features of the proximal femur

Answer 15

● Femoral head - fovea for the ligament of the head of femur
● Neck
● Greater trochanter
● Lesser trochanter
● Intertrochanteric line (anterior) and intertrochanteric crest (posterior)
● Quadrate tubercle (which is on the intertrochanteric crest)
● Pectineal line and Gluteal tuberosity join to form the Linea aspera with medial
and lateral lips

Question 16

Describe the bony features of the middle and lower end of the femur
you should be able to point these out on an image of the bone

Answer 16

● Linea aspera
● Medial supracondylar ridge - which is an inferior continuation of the medial lip of
the linea aspera, interrupted to allow passage of the femoral artery, ends as the
adductor tubercle
● The lateral supracondylar ridge descends to the lateral epicondyle
● Lateral and medial condyles separated by the intercondylar fossa
● Adductor tubercle on medial epicondyle
● Attachment of the medial ligament

Question 17

Which muscles attach to the linea aspera?

Answer 17

Vastus medialis, vastus lateralis, adductor brevis, adductor longus, adductor magnus
and short head of biceps femoris

Question 18

Muscles acting on the hip
Describe the anatomy of the iliopsoas muscle

Answer 18

Iliopsoas consists of the iliacus and psoas major muscles
Psoas Major

● Superior attachment
○ Transverse processes of the lumbar vertebrae
○ Sides of vertebral bodies T12 - L5
○ Intervertebral discs T12 - L5

● Inferior attachment
○ Single tendon to the lesser trochanter of the femur

● Innervation
○ Anterior rami of L1, L2 and L3
Iliacus

● Superior attachment
○ Superior ⅔ of iliac fossa
○ Ala of sacrum
○ Anterior sacro-iliac ligaments

● Inferior attachments
○ Lesser trochanter of femur and shaft inferior to it
○ Psoas major tendon

● Innervation
○ Femoral nerve L2- L4

Question 18

Which artery is most likely to be damaged by a fracture to the midshaft of the
femur?

Answer 18

The profunda femoris

Question 19

What are the lateral rotators of the femur and where do they originate? & insert.

Answer 19

● Piriformis - anterior sacrum and sacrotuberous ligament to the greater trochanter
● Obturator internus- pelvic surface of obturator membrane and surrounding bones,
to the greater trochanter
● Superior gemellus - ischial spine to the greater trochanter
● Inferior gemellus - ischial tuberosity to the greater trochanter
● Quadratus femoris - lateral border of ischial tuberosity, attaches to the quadrate
tubercle on the intertrochanteric crest
● Gluteus maximus - ilium, posterior to the posterior gluteal line, dorsal surface of
the sacrum and coccyx, sacrotuberous ligament

Question 20

Describe the actions of the gluteus maximus muscle

Answer 20

● Straightens the leg at the hip during walking, running, climbing.
● Assists in raising to stand from a seated position
● Tensor of the fascia lata and its connection with the iliotibial band
● Steadies the femur during standing

Question 21

Femoral Triangle (asked every couple of years - must know this,)
What are the borders and contents of the femoral triangle

Answer 21

Boundaries:
● lateral border = Medial border of sartorius
● medial border = lateral border of adductor longus
● superior border = inguinal ligament
● floor = iliacus, psoas, pectineus and adductor brevis
Contents: (NAVEL, from lateral to medial) = Femoral Nerve, Femoral Artery, Femoral
Vein, Empty Space, Lymphatics

Question 22

What are the surface markings when trying to locate the femoral vein?

Answer 22

What are the surface markings when trying to locate the femoral vein?
● Use the anatomical landmark for the femoral artery
● Femoral artery is found below the inguinal ligament, midway between the ASIS
and the pubic tubercle
● Femoral vein is just medial to the artery

Question 23

Nerves
Describe the origin and course of the sciatic nerve and the muscles it supplies

Answer 23

The sciatic nerve originates from the sacral plexus and supplies the muscles in the
posterior compartment of the thigh

Course
● It enters the gluteal region via the greater sciatic foramen, inferior to piriformis
and deep to gluteus maximus
● Descends in the midline posterior thigh deep to the biceps femoris and lying on
the adductor magnus
● Bifurcates into tibial and common fibular nerves before the apex of the popliteal
fossa

Supply
● Common fibular part - supplies short head of the biceps femoris
● Tibial part - supplies the rest, including long head of biceps femoris,
semitendinosus, semimembranosus and the hamstring portion of adductor
magnus

Question 24

Describe the course of the femoral vein in the femoral triangle

Answer 24

● Starts as popliteal vein
● Travels medial to the femoral artery, lateral to the femoral canal
● Ends as the external iliac vein
● The great saphenous vein drains to the femoral vein through the cribriform
● The profunda femoris veins also drain into the femoral vein

Question 25

What are the clinical features of a severed sciatic nerve in the upper thigh?
Motor and sensory deficits.

Answer 25

Motor
Sciatic nerve supplies posterior thigh muscles and depending on the level of injury these
may all be affected, causing loss of hip extension and knee flexion. There will be loss of
motor supply to all lower leg and foot muscles, causing loss of ankle flexion, extension,
inversion and eversion. Toes movements will also be lost.

Sensory
Loss of sensation to the skin of most of the leg and foot. In particular, the posterior and
lateral lower leg, sole of foot, lateral portion and the dorsum of the foot.

Question 26

What is the origin and course of the femoral nerve?

Answer 26

Originates from spinal roots L2, L3, L4

Question 27

What are the branches of the femoral nerve?

Answer 27

Motor Nerves
● Nerve to sartorius
● Nerves to quadriceps i.e. nerve to rectus femoris, nerve to vastus medialis, nerve
to vastus lateralis, nerve to vastus intermedius

Sensory nerves
● Medial femoral cutaneous nerve
● Intermediate femoral cutaneous nerve
● Saphenous nerve
● Articular branches to the hip and knee joints

Question 28

Arteries
Describe the course and relationships of the femoral artery

Answer 28

● A continuation of the external iliac artery
● Enters the femoral triangle deep to the midpoint of the inguinal ligament (midpoint
between the ASIS and the pubic tubercle)
● Lies lateral to the femoral vein, deep to the fascia, anterior to the iliopsoas and
pectineus, and medial to the femoral nerve
● Continues down the thigh, deep to sartorius
● Passes though the adductor canal, where it lies anterior to the femoral vein
● Becomes the popliteal artery at the adductor hiatus

Question 29

Describe the branches of the femoral artery

Answer 29

● Profunda femoris branches off in the femoral triangle
● Medial and lateral circumflex femoral arteries. Medial supplies the neck of femur
● 4 Superficial cutaneous branches given off anteriorly in the femoral triangle -
superficial circumflex iliac, superficial epigastric, superficial and deep external
pudendal

Question 30

Describe the anastamoses associated with the femoral artery

Answer 30

● Trochanteric (head of femur) via the medial and lateral circumflex femoral
arteries
● Cruciate (lesser trochanter) via the medial/lateral circumflex femoral arteries and
the inferior gluteal artery
● Geniculate (knee) via the popliteal, femoral and tibial arteries.

Question 31

Describe the blood supply to the head of the femur

Answer 31

● Medial and lateral circumflex arteries from the profunda femoris
● Branch to form reticular arteries, which feed under the posterior unattached
capsule or through the iliofemoral ligament
● The supply is from distal to proximal, which has implications for fractures in the
region
● There is also a small artery to the head of the femur, which is a branch of the
obturator artery, but this is less important

Question 32

Why is this important if the patient has a subcapital (intracapsular) fractured neck
of femur?

Answer 32

● Risk of avascular necrosis of the femoral head
● Because the major supply of the hip joint comes from branches of the circumflex
femoral arteries
● These arteries pass under the border of the hip capsule and can be torn or
disrupted in an intracapsular fracture

Question 33

Muscles of the anterior thigh
Must be able to identify muscles of the thigh on an image.
What are the quadriceps muscles? Where do the originate and insert?

Answer 33

● Rectus femoris
○ Origin: from the AIIS and ilium superior to the acetabulum,
○ Insertion: via quadriceps tendon to the tibial tuberosity

● Vastus medialis
○ Origin: intertrochanteric line and medial lip offline aspera
○ Insertion: Quadriceps tendon and medial patella

● Vastus lateralis
○ Origin: Greater trochanter and lateral lip of linea aspera
○ Insertion: Quadriceps tendon and patella retinacula

● Vastus intermedius
○ Origin: anterior and lateral shaft of femur
○ Insertion: Quadriceps tendon

Question 34

What are the actions of the quadriceps muscles?

Answer 34

They extend the knee
Rectus femoris also assists in hip flexion

Question 35

What is the nerve supply to the quadriceps?

Answer 35

Femoral nerve L2, L3, L4

Question 36

The Knee
Please demonstrate the bony features on this xray of a knee:

Answer 36

You must be able to identify main features on an xray of the knee
These include:
● Features of the femur - medial and lateral condyles & epicondyles, the adductor
tubercle
● Features on the tibia - medial and lateral condyles that form the tibial plateau.
The intercondylar eminence in the middle of the plateau which is formed by the
medial and lateral intercondylar tubercles. Further distally on the tibia is the tibial
tuberosity
● Features of the fibula - the head and the tibiofibular joint which is where it
articulates with the tibia
● Also the patella

Question 37

What factors stabilise the knee joint?

Answer 37

● Muscular and ligamentous factors. Little to no bony contribution
● In the knee, it’s primarily the strength and actions of surrounding muscles and
their tendons. Most important = quadriceps femoris especially the vastus lateralis
and medialis
● Ligaments connecting the femur and tibia - the main ones being the anterior and
posterior cruciates and medial and lateral collaterals.

Question 38

Describe the movement of the knee joint and the muscles involved

Answer 38

● Extension - quadriceps femoris
● Flexion - semitendonosis, semimembranosus, biceps femoris
● Medial rotation when flexed - semitendinosus, semimembranosus. When non
weight bearing and knee extended - popliteus
● Lateral rotation when flexed - biceps femoris

Question 39

Describe the process of the locking and unlocking of the knee as the joint is
extended and flexed.

Answer 39

● When going from flexion to extension, the lateral condyle completes its extension
just short of full extension, the lateral condyle then rotates forward around a taut
ACL and the medial condyle glides backwards as full extension approaches. The
result is approximately 10 degrees of hyperextension.
● In this position the knee is passively ‘locked’
● The knee unlocks through contraction of the popliteus, rotating the femur laterally
on the tibial plateau to allow flexion

Question 40

Ligaments
Describe the anatomical features and attachments of the cruciate ligaments

Answer 40

(if you cross your legs while standing, your legs form the arrangements of the cruciates
for whichever leg is in front)
● Anterior and posterior cruciates (posterior is shorter and stronger)
● Intracapsular but extrasynovial
● Cross each other in the form of an X, with the anterior lying in front
● Anterior Cruciate: arises from the anterior intercondylar eminence, passes
superiorly and posterolaterally to insert on the medial aspect of the lateral
femoral condyle.
● Posterior Cruciate: arises from the posterior intercondylar area of the tibia,
passes superiorly and anteromedially to insert on the lateral aspect of the medial
femoral condyle.

Question 41

What are the actions of the cruciates?

Answer 41

● Most important factor in stabilising the knee
● Anterior cruciate prevents posterior movement of the femur on the tibia - limiting
hyperextension of the knee
● Posterior cruciate limits anterior movement of the femur on the tibia and prevents
hyperflexion of the knee

Question 42

Please identify the other ligaments of the knee joint and their attachments

Answer 42

● Patellar ligament - apex of patella to the tibial tuberosity
● Fibular (or lateral) collateral ligament - from the lateral epicondyle of the femur to
the lateral surface of the fibular head
● Tibial (medial) collateral ligament - medial epicondyle of the femur to the lateral
and superior aspect of the tibia. Has a deep component that attached to the
medial meniscus
● posterior oblique
● arcuate ligament

Question 43

What are the actions of the collateral ligaments?

Answer 43

They are taut in extension and relax in flexion. Assist with knee stability ion extension.

Question 44

Menisci and capsule
What are the attachments of the menisci?

Answer 44

● Attached to the intercondylar area of the tibia, C shaped fibrocartilage
● Thickens towards the joint margins
● External parts attached to the capsule
● 2 ligaments - coronary ligaments from the articular margins of the femur and tibia
● Medial meniscus: anterior horn attached to the intercondylar area of the tibia in
front of the ACL and the posterior horn in front of the PCL. Firmly attached to the
deep medial collateral ligament. Less mobile than the lateral meniscus.
● Lateral meniscus: both horns attached to the intercondylar area of the tibia
immediately in front of and behind the intercondylar spine

Question 45

Describe the capsular attachments of the knee

Answer 45

● Attached to the margins of the articular surfaces
● Femoral attachments -to the proximal margin of the condyles posteriorly.
● Anteriorly there is a deficit allowing for the suprapatellar bursa, capsule blends
with the patella retinacula and ligament
● Laterally - passage of popliteus tendon, attached to the head of the fibula
● Medially - deep component of the MCL and meniscus
● There is a weak attachment to both menisci

Question 46

Describe the articulations between the tibia and the fibula

Answer 46

Tibiofibular joint superiorly and the tibiofibular syndesmosis inferior.
TF joint - synovial joint between the fibular head and the tibial condyle
TF syndesmosis - a compound fibrous joint which is part of the interosseous membrane
and the anterior/posterior tibiofibular ligaments

Question 47

Popliteal Fossa
What are the boundaries and contents of the popliteal fossa? (note - they can
show you the dissection image from the book)

Answer 47

● Superior border: biceps femoris laterally and the semimembranosus medially
● Inferior border: medial and lateral heads of gastroc as well as the plantaris
muscle laterally
● Contents (from medial to lateral) popliteal artery, popliteal vein (from the small
saphenous), tibial nerve which branches to the common fibular nerve - note, that
can help you decide if it is the left or right side because the common fibular nerve
always goes towards the fibula which is lateral

Question 48

Nerves
Outline the course of the common fibular nerve and its branches

Answer 48

● Originates from the sciatic nerve as it bifurcates in the apex of the popliteal fossa
● Passes over the posterior part of the head of the fibula and then winds around
the fibula neck
● Divides into the superior and deep fibular nerve and also gives a branch to the
knee joint
● The common fibular nerve supplies the skin of the posterior leg
● The superficial branch does the motor supply to the lateral compartment and the
sensory supply to the distal ⅓ of the anterior leg and foot
● The deep branch provides the motor supply to the anterior muscles of the lef and
the dorsum of the foot, as well as the sensory supply to the first webspace (a

Question 49

What functional deficit results from injury to the common fibular nerve and why?

Answer 49

● Foot drop - loss of innervation of extensor muscle function (tibialis anterior,
extensor digitorum longus, fibularis tertius, extensor hallucis longus)
● High stepping gait
● Inability to evert foot - due to loss of innervation to fibularis longus and brevis
● Sensory loss to 1st webspace, dorsum of foot

Question 50

Outline the course of the tibial nerve

Answer 50

● Formed at the apex of the popliteal fossa by the bifurcation of the sciatic nerve
● Runs vertically in the popliteal fossa with the popliteal artery, passing between
the heads of gastroc and deep to the tendinous arch of the soleus
● Runs inferiorly in the tib post with the posterior tibial vessels
● Divides into medial and lateral plantar nerves under the flexor retinaculum
● Has only one cutaneous branch that is the sural nerve

Question 51

What functional deficit results from a tibial nerve injury at the knee and why?

Answer 51

● Motor loss: Unable to stand on tiptoes due to the loss of plantar flexors - soleus ,
tibialis posterior, flexor digitorum longus and flexor hallucis longus. Also loss of
ability to flex the toes. Inversion weakened but still possible due to tibialis anterior
● Sensory loss: Loss of sensation over the sole of the foot from loss of the medial
calcaneal, medial and lateral plantar nerves.

Question 52

Vascular Supply
How does the popliteal artery supply the leg and foot?

Answer 52

● Popliteal artery divides into posterior and anterior tibia; arteries at the lower
border of the popliteus.
● The fibular artery (which supplies posterior and lateral compartments) branches
of the posterior tibial artery. The bit before they divide is sometimes called the
tibioperoneal trunk.
● Posterior tibial artery runs in the posterior compartment and is then palpable
posterior to the medial malleolus. It then divides into the medial and lateral
plantar arteries to the sole of the foot.
● The anterior tibial artery runs in the anterior compartment and then crossed
=anteriorly over the ankle to become the dorsalis pedis

Question 53

Commencing with its origin in the foot, describe the course and relations of the
long saphenous vein

Answer 53

● Commences at the medial side of the dorsal venous arch
● Courses upward in front of the medial malleolus
● Crosses behind the medial border of the tibia and passes behind the knee
● Travels up the medial aspect of the thigh to pass through the cribirofm fascia
where it joins the femoral vein
● Perforating veins connect the long saphenous to the deep system in the foot, the
mid calf and the thigh

Question 54

Anterior Compartment of the leg
Identify the muscles of the anterior compartment of the leg and describe their
attachments

Answer 54

● Tibialis anterior
○ Originates from the lateral condyle and the superior lateral surface of the
tibia and the interosseous membrane.
○ Attaches to the medial cuneiform and base of the first metatarsal.
○ Dorsiflexes and everts the foot

● Extensor digitorum longus
○ Originates from the lateral condyle of the tibia and the superior-medial
fibula and interosseous membrane
○ Attaches to the middle and distal phalanges of the lateral 4 digits
○ Dorsiflexes ankle and extends the lateral 4 digits

● Extensor hallucis longus
○ Arises from the middle anterior fibula and the interosseous membrane
○ Attaches to the dorsum of the base of the distal phalanx of the great toe
○ Dorsiflexes the ankle and extends the toe

● Fibularis tertius
○ Originates from the inferior ⅓ of the anterior fibula and the interosseous
membrane
○ Attaches at the base of the 5th metatarsal
○ Dorsiflexes and everts the foot

Question 55

What nerves supply the muscles of the anterior compartment?

Answer 55

● The deep fibular nerve
● Tibialis anterior is supplied by L4/L5 whereas the others are L5/S1

Question 56

Lateral compartment
Identify and describe the fibularis muscles

Answer 56

Fibularis Longus, Brevis and Tertius (which is actually in the anterior compartment &
already covered)
Fibularis Longus
● Originates from the head and upper shaft of the fibula
● Passes deep to the superior fibular retinaculum, behind the lateral malleolus then
deep to the inferior retinaculum
● It then passes inferior to the fibular trochlear of the calcaneus, through a groove
on the cuboid and crosses the sole of the foot to insert on the base of the first
metatarsal and the medial cuneiform
Fibularis Brevis
● Originates on the distal shaft of the fibula.
● Passes behind the lateral malleolus and superior to the fibular trochlea of the
calcaneus.
● Inserts on the base of the 5th metatarsal

Question 57

What nerve supplies the fibularis longus and brevis

Answer 57

Fibularis longus and brevis are supplied buy the superficial fibular nerve
Fibularis tertius is supplied by the deep fibular nerve

Question 58

What are the actions of the fibular muscles?

Answer 58

● Evert the foot
● Stabilise the foot in the ‘toe-off’ phase of walking and running
● Weak plantar flexion by fibularis longus and brevis as they run posterior to the
axis of the ankle joint
● Fibularis tertius has a weak dorsiflexor action (more in line with the other anterior
compartment muscles)

Question 59

What joints are involved with inversion and eversion of the foot ?

Answer 59

● Subtalar or the talocalcaneal joint
● Transverse tarsal joint - which includes the calcaneocuboid and the talonavicular
joints

Question 60

Posterior compartment of the leg
What are the muscles in the posterior compartment of the leg

Answer 60

Superficial
● Gastrocnemius
● Soleus
● Plantaris

Deep
● Popliteus
● Flexor digitorum longus
● Tibialis posterior
● Flexor hallucis longus

Question 61

What are the attachments of the superficial muscles?

Answer 61

● Gastrocnemius
○ the lateral head Originates from the lateral femoral condyle, medal head
from the surface of the femur above the medial femoral condyle
○ Inserts onto the calcaneal tendon with fibres from soleus

● Soleus
○ Arises from the posterior aspect of the superior part ot eh fibula, soleal
line and the medial border of the tibia, with a tendinous arch between
these attachments
○ Inserts onto the calcaneal tendon

● Plantaris
○ Originates at the inferior end of the lateral supracondylar line of the femur

Question 62

Describe the actions of the muscles of the deep compartment

Answer 62

Popliteus
● Pulls the lateral meniscus posteriorly during knee flexion
● Assists the posterior cruciate ligament in preventing anterior displacement of the
femur on the tibial plateau when standing with the knee flexed
● Also unlocks the knee via laterally rotating the femur

FHL
● Flexes all the joints of the great toe
● Supports the medial longitudinal arch of the foot

FDL
● Flexes the lateral 4 digits
● Supports the longitudinal arches of the foot

Tib post
● Plantar flexion and inversion

Question 63

Which muscles form the Achilles tendon?

Answer 63

Gastroc and soleus with sometimes input from plantaris

Question 64

Where does the achilles tendon insert?

Answer 64

The supero-posterior aspect of the calcaneus

Question 65

What is the nerve supply to these muscles?

Answer 65

Tibial nerve, which is a branch of the sciatic nerve

Question 66

What is the blood supply to these muscles?

Answer 66

Gastroc is supplied by the sural artery (a branch of the popliteal)
Soleus is supplied by the posterior tibial and the peroneal arteries

Question 67

Ankle
What structures make up the ankle joint?

Answer 67

Distal ends of the tibia and fibula plus the talus

Question 68

Ankle
What movements occur through this joint?

Answer 68

Plantarflexion and dorsiflexion

Question 69

In what position of the foot is the ankle most unstable and why?

Answer 69

Plantarflexion, because in that position the trochlear (the superior part of the talus which
is most narrow at the posterior end) sits the most loosely in the mortise between the
malleoli

Question 70

What are the ligaments that stabilise the ankle?

Answer 70

Lateral ligaments - from the lateral malleolus
● Anterior talofibular ligament - the weakest, injured in inversion injuries
● Posterior talofibular - strong
● Calcaneofibular ligament

Medial ligament (also called the deltoid) - fans out from the medial malleolus to attach to:
● Talus - anterior and posterior tibiotalar
● Calcaneus - tibiocalcaneal ligament
● Navicular - tibionavicular ligament

Question 71

What structures run posterior to the medial malleolus

Answer 71

From medial to lateral - Tom, Dick and Very Nervous Harry

● Tibialis posterior
● Flexor Digitorum longus
● Posterior tibial Artery
● Posterior tibial Vein
● Tibial Nerve
● Flexor Hallucis longus

Question 72

The foot
Identify the bones of the foot

Answer 72

Talus, calcaneus, cuboid, navicular, cuneiforms (medial, intermediate, lateral),
metatarsals and phalanges

Question 73

Describe the sensory innervation of the foot

Answer 73

● Saphenous nerve supplies the medial dorsum to the base of the big toe
● Superficial fibular nerve supplies the rest of the dorsum
● Deep fibular nerve does the 1st webspace
● Sural nerve does the lateral edge of the foot
● Medial and lateral plantar nerves supply the medial and lateral plantar surface
● Medial calcaneal nerve does the heel

Question 74

Where would you infiltrate to block these nerves?

Answer 74

Posterior tibial nerve - between the achilles tendon and the medial malleolus
Sural nerve - between the achilles tendon and the lateral malleolus

Question 75

Identify the structures lying deep to the extensor retinaculum

Answer 75

From medial to lateral (Timothy Has A Very Nasty Dirty Toe)
● Tibialis Anterior
● Extensor Hallucis Longus
● Ant. Tibial Artery
● Ant. Tibial Vein
● Deep fibular Nerve
● Extensor Digitorum longus
● Fibularis Tertius

Question 76

Describe the venous drainage of the foot

Answer 76

● Superficial and deep veins
● Deep veins are paired with arteries and are internal to the deep fascia
● Superficial veins are not accompanied by arteries and are in the subcutaneous
space
● Perforating veins provide one eway shunting of blood from superficial to deep
● The dorsal venous arch of the metatarsals drains into the dorsal venous arch of
the foot.
● Plantar venous network either becomes the medial marginal vein which becomes
the great saphenous vein, or the lateral marginal vein which becomes the small
saphenous vein