Radiology Pt1 - Lower Limb Msk

Front 1

Pectineus

Back 1

Medial thigh muscle with dual innervation, between anterior and adductor groups. Crosses both joints.

Front 2

Adductor Magnus

Back 2

Posteromedial thigh muscle with dual innervation, between the adductor and posterior groups. Crosses the hip.

Front 3

Biceps Femoris

Back 3

Posterior thigh muscle with two heads. Has dual innervation (one to each head) and crosses both joints. Between the posterior and anterior groups.

Front 4

Anterior compartment

Back 4

Quadriceps group (rectus femoris, vasti lateralis, intermedius, medialis), sartorius
Part of pectineus (called adductor) and biceps femoris (called post)

Supplied by the femoral nerve

Front 5

Posterior compartment

Back 5

Biceps femoris, semimembranosus, semitendinosus,
Part of adductor magnus (called adductor)

Supplied by the sciatic nerve

Front 6

Adductor compartment

Back 6

Gracilis, pectineus, obturator externus and adductor longus, brevis and magnus

Supplied by obturator nerve

Front 7

Sartorius

Back 7

The longest muscle in the body, curves over the thigh from lateral to medial. Crosses both joints.

O: ASIS.

I: Passes behind the medial condyle of the knee, and then curves anteriorly to join the pes anserinus inserting into the medial upper portion of the tibia.

A: flexion, abduction and lateral rotation of the hip. Flexion of the knee - yogi position.

Neuro: femoral nerve (L2, L3, L4)

Front 8

Rectus femoris

Back 8

The most anterior of the quadriceps muscles, attaches to the patella via the common quadriceps tendon.

O:2 tendinous origins - AIIS (straight tendon) and above the brim of the acetabulum (reflected tendon)

I: Common tendon to base of patella.

A: Extends knee, flexes hip

Neuro: Femoral nerve

Front 9

Vastus group

Back 9

3 muscles of the quadriceps group, the vastus lateralis, intermedius and medialis

VASTUS LATERALIS
O: Upper inter-trochanteric line, lateral greater trochanter, and lateral lip of linea aspera (upper half). Postero-lateral aspect of femur in upper 2/3rds

I: Common quadriceps tendon into patella.

A: Extends knee. Cant flex hip as originates below hip joint.

Neuro: femoral nerve

VASTUS MEDIALIS
O: Postero-medial border of the femur from lesser trochanter down to the medial supratrochanteric line.

I: Common quadriceps tendon.

A: Extends knee

N: Femoral nerve

VASTUS INTERMEDIUS
O: Anterolateral femur from intertrochanteric line to distal 1/3rd.

I: Common quadriceps tendon

A: extends knee

N: femoral nerve

R: Underneath rectus femoris, and adherent to vastus lateralis.

Front 10

Articularis genu

Back 10

A small muscle arising above the knee on the femur deep to vastus intermedius. Also called subcrureus.

O: Anterior surface of lower 1/3rd of knee

I: Knee joint capsule

A: Lifts the subpatellar bursa caudally during extension, preventing impingement.

N: Femoral nerve (L2-L4)

Front 11

Adductor brevis

Back 11

A triangular muscle, the most superior of the adductor compartment.

O: Outer surface of the bony symphysis and inferior pubic ramus. Anterior to broad origin of obturator externus.

I: Between lesser trochanter and linea aspera, behind adductor longus and pectineus.

A: Adducts hip.

N: obturator nerve

R: anterior to adductor magnus, and the obturator neurovasular bundle.

Front 12

Adductor longus

Back 12

The most ventral of the adductor muscles.

O: External surface of bony symphysis/superior pubic ramus

I: Middle third of the medial lip of linea aspera

A: Adducts and laterally rotates thigh. Can assist flexion and anteversion as well.

N: Obturator nerve (L2, L3, L4)

R: Forms the medial wall of the femoral triangle. Most ventral adductor, on top of adductor magnus and part of brevis.

Front 13

Adductor minimus

Back 13

Small flat muscle in the upper part of adductor magnus. Often seperated from adductor magnus by branch of superior perforating branch of profunda femoris.

O: Inferior pubic ramus at anterior-most part of adductor magnus.

I: Inserted onto back of femur at medial part of linea aspera.

Neuro: Obturator (which also supplies all magnus attached to linea aspera, while tibial branch of sciatic supplies part attached to adductor tubercle)

V: Accessory muscle developmentally from obturator externus sits between adductors minimus and brevis

Front 14

Adductor magnus

Back 14

A large fan shaped muscle with dual innervation in the adductor compartment. Has 2 parts, the adductor and hamstring.

O: Inferior pubic ramus

I: Adductor portion - Linea aspera and its cranial extension along the medial femur, lower 2/3rds.
Hamstring portion - The adductor tubercle on the medial femoral epicondyle.

A: Adducts thigh. Acts to laterally (adductor portion) and medially (hamstrong portion) rotate the thigh in various positions.

Neuro:
Adductor portion - Obturator nerve, posterior branch
Hamstring portion - Sciatic nerve, tibial branch

R: The only things behind add. magnus are the posterior compartment. The rest of the adductor compartment, including muscles, vessels and nerves are anterior.

Front 15

Pectineus

Back 15

A flat quadrangular muscle in the adductor group that has dual innervation.

O: Superior pubic ramus, on the ileopectineal line

I: Pectineal line of femur, which runs between the lesser trochanter and linea aspera

A: Main hip flexor. Aids in adduction and medial rotation.

Neuro: Mainly femoral nerve (L2, L3), with small branch from obturator nerve in 20%

R: Anterior to adductor muscles (brevis, magnus) and superior to longus. Forms part of the floor of the femoral triangle meidally, thus is deep to femoral vein, and superficially lateral are the femoral artery and nerve.

Front 16

Gracilis

Back 16

A long thin muscle in the adductor compartment that crosses both joints, and is part of the pes anserinus.

O: Inferior pubic ramus medially, along the bony symphysis.

I: Passes behind the medial condyle of the femur, and the medial condyle of the tibia, and inserts as a flattened tendon into the medial tibia below the condyle. It forms part of the pes anserinus.

A: Adductor

Neuro: obturator.

R: The pes anserinus is made up of the 3 tendons of sartorius, gracilis and semitendinosus, in order of cranial to caudal insertions on the medial tibia.

The pes anserinus is seperated from the medial collateral ligament by a bursa.

Front 17

Obturator externus

Back 17

A small triangular muscle of the adductor compartment, arising on the posterior pelvis.

O: The anterior medial border of the obturator canal/edge of bony symphysis.

I: Runs around posterior joint capsule laterally to insert into the trochanteric fossa of femur.

A: Adducts, laterally rotates.

Neuro - obturator nerve

Front 18

Semimembranosus

Back 18

The most medial hamstring muscle, crosses both joints.

O: Ischial tuberosity medial and superior to biceps femoris and semitendinosus

I: A broad aponeurosis gives off several insertion slips, the biggest to a groove on the posteromedial aspect of the medial tibial condyle.
Other attachments include the oblique popliteal ligament, which itself attaches to the lateral femoral condyle across the joint, and the tibal collateral ligament.

A: Extend hip joint, flexes knee. Helps medially rotate the knee and hip.

Neuro: Sciatic nerve (L5, S1, S2)

Front 19

Semitendinosus

Back 19

A long hamstring muscle in between semiembranosus and biceps femoris, named becuase of it's very long tendon to insertion. Forms part of the pes anserinus.

O: medial lower ischial tuberosity, from a common origin with the biceps femoris, below the origin of semimembranosus.

I: The long tendon runs from mid thigh, medial to the popliteal fossa and curves around the medial condyle/medial collateral ligament to insert into the upper medial tidia.

A: Extends hip, flexes knee. Medially rotates the knee.

Neuro: Sciatic (tibial div) nerve (L5, S1, S2)

R: The pes anserinus is made up of the 3 tendons of sartorius, gracilis and semitendinosus, in order of cranial to caudal insertions on the medial tibia.

The pes anserinus is seperated from the medial collateral ligament by a bursa.

Front 20

Biceps femoris

Back 20

A bipennate muscle of the hamstring group that crosses both joints.

O: Long head - ischial tuberosity and sacrotuberous ligament
Short head - lateral edge of linea aspera throughout most of the length of femur (gluteus maximus to 5cm from lateral condyle) and lateral intermuscular septum.

I: Lateral head of fibular. The tendon actually divides in two, around the lateral collateral ligament.

R: The common peroneal nerve runs on the medial side of the tendon (ie the lateral hamstring tendon)

A: Flexes knee, extends hip (via long head)

Neuro: Long head - Sciatic (tibial) nerve L5, S1
Short head - Sciatic (common fibular) nerve L5, S1

Front 21

Femur

Back 21

A paired long bone of the lower limb that supports the thigh.

P: 3 joints - acetabular joint, tibiofemoral and patellofemoral

4 PROMINENCES

The femoral head:
The hemispheric articular prominence projected superior, medial and anterior from the top of the femur via the femoral neck. The head is covered with articular cartilege apart from at the fovea capitis femoris (medial, inferior and posterior) which is a non articular depression which holds the attachment for the ligament of the head of the femur. Importantly blood supply is retrograde along the neck of the femur and adjacent joint capsule, so the head can undergo AVN if fracture of the neck occurs.

Greater trochanter:
A irregular quadrilateral emminence projected lateral and posterior from the top of the femur, slightly lower than the head.
The lateral aspect holds a posterosuperior to anteroinferior line which is the insertion for gluteus medius. Gluteus maximus runs over the upper lateral surface, with a bursa interposed.
The medial surface holds the trochanteric fossa at the base, somewhat posteriorly, which is the site of insertion for obturator externus. Obturator interus and the gemellus muscles insert above and anterior to this (mid upper medial surface)
At the very top is the insertion for piriformis. Anteriorly gluteus minimus attaches, and at the very base of the greater trochanter laterally is the origin of vastus lateralis

Lesser trochanter:
A small conical emminence from the lower posterior femoral neck.
The psoas major and iliacus unsert into the peak of the LT.
3 lines radiate from it, the lateral line of the intertrochanteric crest, the medial line continuous with the lower border of the neck of the femur, and the inferior line which is continuous with the linea aspera.

The distal extremity:
Cuboid in form, holds the medial and lateral condyles, seperated by the intercondylar fossa, which is almost non-existant anteriorly but large posteriorly. The lateral condyle is broader than the lateral. The anterior and posterior cruciate ligaments attach into the walls of the intercondylar fossa.
The epicondyles are prominences above the condyles. These give rise to the medial and lateral collateral ligaments. Posterior to the medial epicondyle is the origin of the gastrocnemius (medial head) and behind the lateral epicondyle is the origin of the lateral head of gastrocnemius. Below this is a groove between the epicondly and the articular surface, which holds the origin of the popliteus muscle. Above the lateral epicondyle is the origin of the plantaris muscle.

The body of the femur carries several landmarks also:
The Linea Aspera is the most major one, a 3 line crest which arises from 2 oblique lines below the lesser (medial ridge) and greater trochanters (lateral ridge). These converge and form, along with the intermediate line, the linea aspera, which covers the middle 1/2 of the femur posteriorly. The medial and lateral lines diverge to the medial and lateral epicondyles respectively.

Front 22

Pelvis

Back 22

a

Front 23

Patella

Back 23

A triangular sesamoid bone, the largest in the body.

P:
Lateral and medial articular facets posteriorly divided by vertical ridge.

The lateral facet is long and shallow, the medial facet is short and steeper angulated.

The lower 25% of the patella in non-articulating.

L:
QUADRICEPS TENDON:
Quadriceps tendon proper into the superior non-articular portion of the patella.

MEDIAL RETINACULUM COMPLEX:
The superior portion is formed by the vastus medialis obliquus muscle, which arises from adductor tubercle or adductor magnus tendon and inserts into the superomedial patella. The medial patellofemoral ligament is closely adherent (deep) to this.

The middle portion of the retinaculum is made of the superficial MCL fibres.

The inferior portion is formed by the patellotibial ligament which runs from inferior patella to the tibia at the level of gracilis insertion.

LATERAL RETINACULUM:
3 layers from patella to vastus lateralis, superficial to deep
Iliotibial tract
Vastus lateralis
Joint capsule

PATELLAR TENDON:
Patellar tendon extends from inferior pole to tibial tuberosity. Composed of rectus femoris fibres.

V:
Bipartite patella - a unfused upper outer section, which may not 'match' with the remaining bone. Cartilage is continuous over the 'defect'.

Front 24

Tibia

Back 24

The heavy medial bone of the lower leg

P:
The tibial plateau
Tibial tuberosity
The body
Medial malleolus

TIBIAL PLATEAU:
Intercondylar emminence, between the condyles there is a prominence with 2 tubercles laterally a a plateau centrally, which holds attachments for the cruciate ligaments and the menisci
Medial and lateral condyles are the articular portions, and are the foundation for the menisci. The semimembranosus inserts into the medial condyle, and the iliotibial tract into the lateral condyle. A small part of the biceps femoris attaches into the lateral condyle (mainly inserts on the fibula).

The lateral condyle has a small articular facet with the fibular head.

TIBIAL TUBEROSITY:
A proximal smooth area holds the patellar ligament, a distal rough portion is seperated from the skin by the infrapatellar bursa.

TIBIAL BODY:
The anterior body is divided by the anterior border, running from the tuberosity to the anterior part of the medial malleolus.
The lateral body holds origins for the anterior muscle compartment, along with adjacen fibula -
Tibialis anterior (upper half of lateral surface)
Extensor digitorum longus (mainly fibula)
Peroneus tertius (mainly fibula, not always present)
Extensor hallucis (mainly fibula, between TA and EDL)

The medial anterior body is covered proximally by the insertion of the pes anserinus (sartorius, semitendinosus and gracilis).

The posterior body carries the soleus line, which runs obliquely from the fibular head to the medial border. The soleus arises here (and the post. fibula).

A vertical ridge runs down the posterior tibia, between the 2 muscle origins:
The tibialis posterior arises from the lateral posterior tibia, in the upper 1/2.
The flexor digitorum longus arises from the medial posterior tibia, from below the soleal line, covering around 1/2 the tibial height.

MEDIAL MALLEOLUS:
Holds a smooth crescentic facet for the talar dome laterally.

The distal tibia above the medial malleolus also holds the fibular notch laterally, where the distal tibio-fibular syndesmosis is.

Front 25

Fibular

Back 25

The thinner bone of the lower leg, provides muscular attachments.

P: 2 prominences - the fibular head and the lateral malleolus.

FIBULAR HEAD:
A round facet medially articulates with the lateral tibial condyle, faced slightly upwards.
The blunt apex (or styloid process) projects up from the posterolateral aspect.
The common peroneal nerve runs around the head laterally, and can be compressed externally posterolateral to the neck.

THE SHAFT:
Has 3 surfaces: anterior, lateral and posterior.

The anterior surface holds origins for the extensor digitorum longus (upper 3/4 of fibula) and the extensor hallucis (middle 1/2 of fibula). The peroneus tertius, when present, also arises from the distal 1/4 of the anterior surface.

The posterior surface (medially) holds the origins of the posterior muscles - soleus in upper 1/3rd, the flexor hallucis longus in mid 1/3rd and the peroneus brevis in the lower 1/3rd.

The lateral surface (which faces somewhat anteriorly) holds origins for the lateral muscles -
Peroneus longus from upper 2/3rds
Peroneus brevis from lower 2/3rds (medial to longus at origin, but is overlapped by it quickly)
There are 2 muscles - peroneus quartus and peroneus digiti minimi which are uncommonly present (10-30%) and run from the distal peroneal muscles to the foot.

LATERAL MALLEOLUS:
Longer than the medial malleolus by ~1cm.

Front 26

Psoas major

Back 26

The psoas is a large pelvic muscle, part of the hip flexor group.

O: Deep part - transverse processes of lumbar vertebral column
Superficial part - Lateral sufaces of T12, L1-4 and discs.

I: Joins with the iliacus to form iliopsoas, running lateral to the ASIS and medial to the iliopubic emminence, running to the lesser trochanter of the femur.

A: Flexion and external rotation of the hip. Laterally flexes the lumbar spine and, if acting bilaterally, raises the trunk.

N: Lumbar plexus via anterior branches of L1-L3.

R: The lumbar plexus runs between the deep and superficial layers.
The iliopsoas is seperated from the bone adjacent to the iliopubic emminence by the iliopectineal bursa.
The iliac subtendinous bursa seperates the tendon from the lesser trochanter above the insertion.

Front 27

Psoas minor

Back 27

Present in about 50% of the population, the psoas minor is a slender trunk flexor.

O: T12 and L1 transverse processes (variable)

I: Iliopectineal emminence and inominate line.

A: Weak trunk flexor

N: Lumbar plexus ant roots (L1-L3)

Front 28

Iliacus

Back 28

A flat triangular pelvic muscle

O: Iliac fossa broadly beneath iliac spine

I: Joins psoas major to form iliopsoas which crosses the ilium adjacent to the iliopubic emminence (seperated by iliopectineal bursa) to insert into lesser trochanter

A: Flexes hip. Raises trunk while supine (ie helps psoas)

N: Femoral nerve L2, L3, L4

Front 29

Gluteus maximus

Back 29

The most superficial of the 3 gluteal muscles of the buttocks

O: Posterior gluteal line of the upper ilium and upper ilium and posterior iliac crest, posterior lower sacrum and coccyx, sacrotuberous ligament and the erector spinae aponeurosis

I: The muscle passes downward across the greater trochanter and inserts into the iliotibial band of the fascia lata and the gluteal tuberosity on the femur in between the vastus lateralis and adductor magnus.

A: Extension and external rotation of hip, adduction.
Erects trunk and stabilises pelvis vs spine in standing and sitting.

N: Inferior gluteal nerve L5, S1, S2 from sacral plexus

Front 30

Gluteus medius

Back 30

The second largest gluteal muscles, which is deep and lateral to gluteus maximus

O: Outer ilium between iliac crest and posterior gluteal line above and anterior gluteal line below

I: An oblique ridge on the lateral surface of the greater trochanter

A: Abducts thigh and stabilises body during gait on one leg (trendelenburg)

N: Superior gluteal nerve L4, L5, S1 from sacral plexus

Front 31

Gluteus minimis

Back 31

The deepest gluteal muscle

O: Outer ilium between the superior and inferior gluteal lines, and from the margin of the greater sciatic notch.

I: Anterior border of greater trochanter

A: Abducts thigh, and supports trunk during gait. Internal rotation when the hip is extended, external rotation when the hip is flexed.

N: Superior gluteal nerve L4, L5, S1 from sacral plexus

R: There is a bursa between the gluteus minimis and the greater trochanter

Front 32

Tensor fascia latae

Back 32

O: Posterior outer lip of iliac crest, outer surface of ASIS

I: fascia lata/iliotibial band

A: Abduct thigh, assists internal rotation. Steadies the pelvis on the femur.
A major muscle of walking and horseriding.

N: superior gluteal nerve L4, L5 S1

Front 33

Quadratus femoris

Back 33

A small flat quadrilateral muscle acting across the hip joint

O: Lateral ischial tuberosity.

I: Passes laterally to the posterior femur, to the quadrate tubercle on the intertrochanteric crest and the quadrate line, which passes down to bisect the lesser tubercle.

A: Adductor and strong lateral rotator

N: nerve to quadratus femoris L4 L5 from sacral plexus

Front 34

Inferior gemellus

Back 34

A posterior hip muscle. The superior and inferior gemellus are either side of the obturator internus muscle.

O: Upper part of the ischial tuberosity, immediately below the obturator interus groove.

I: Medial greater trochanter posteriorly

A: Lateral rotation of thigh

N: nerve to quadratus femoris L4, L5 from sacral plexus

Front 35

Obturator internus

Back 35

The posterior hip muscle that runs between superior and inferior gemellus

O: Surrounds the inner aspect of the medial part of the obturator foramen on the inferior pubic ramus

I: Runs through the kesser sciatic foramen to insert onto the medial aspect of the greater trochanter posteriorly

A: lateral rotator, abductor, stabilises hip during walking

N: nerve to obturator internus (L5, S1 from sacral plexus)

Front 36

Superior gemellus

Back 36

A small paired muscle that sits above the obturator internus (inf. gemellus is below)

O: Outer surface of ischial spine superiorly

I: medial posterior greater trochanter

A: Lateral rotator

N: Nerve to obturator internus S1, S2, S3 from sacral plexus

Front 37

Piriformis

Back 37

A hip muscle that runs from the front of the sacrum to the posterior femur

O: Anterior sacrum, Ilium adjacent.

I: Passes through the greater sciatic foramen and inserts on the posterior aspect of the greater trochanter of the femur.

R: runs superiorly to the superior gemellus

A: Lateral rotator, abducts flexed thigh. Important in walking to shift body weight

N: nerve to piriformis L5, S1, S2 from sacral plexus

V: 15-30% of piriformis is pierced by common fibular nerve (of sciatic) and can entrap it when inflammed

Front 38

Tibialis anterior

Back 38

O: Upper half lateral tibia. Becomes tendinous ~1/2 way down

I: Runs under superior extensor retinaculum, around the medial portion of the medial malleolus. Then under inferior extensor retinaculum, and inserts into the base of the first metatarsal and medial cuneiform.

A: Dorsiflexor/invertor

N: Deep fibular (L4-S3 via sacral plexus)

R: The anterior tibial artery and deep fibular nerve run between the tibialis anterior and the tibia in the upper half of the tibia, until T.A turns medial.

Front 39

Extensor hallucis longus

Back 39

O: Mid portion of the anterior surface of fibula.

I: Dorsal side of the distal phalanx of the big toe.

A: Extends great toe, assists in dorsiflexion of the foot. Weak invertor.

N: Deep fibular nerve (L4-S3 from sciatic - sacral plexus)

R: Passes under superior and inferior extensor retinacula

Front 40

Extensor digitorum longus

Back 40

O: Lateral condyle of the tibia, and upper 3/4 of the fibula shaft.

I: Dorsal surface, middle and distal phalanges of lateral 4 toes.

A: Extends toes. Dorsiflexes foot.

N: Fibular nerve (L4-S3 from sciatic/sacral plexus)

R: Deep fibular nerve passes between the origins of EDL and TA. The superficial fibular nerve runs between EDL and the fibularis muscles.

The muscle forms a tendon just before the ankle, which seperates into the 4 slips after the superior extensor retinaculum. Each individual tendon recieves slips from the extensor digitorum brevis and lumbricals, and the interossei

Front 41

Fibularis (peroneus) tertius

Back 41

A lateral slip of the extensor digitorum longus.

O: anterior aspect of distal 1/3rd of fibula.

I: Dorsal aspect of base of 5th metatarsal.

A: Weak dorsiflexion, eversion.

N: Deep fibular (L4-S3 of sciatic/sacral plexus)

R: The tendon passes through the same canal in the superior and inferior extensor retinaculi as the EDL.

Front 42

Anterior compartment of the lower leg

Back 42

Tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius

All supplied by deep fibular nerve

Front 43

Posterior compartment of the lower leg

Back 43

DEEP:
Popliteus, tibialis posterior, flexor digitorum longus, flexor hallucis longus.

All supplied by tibial nerve

SUPERFICIAL:
Gastrocnemius, soleus, plantaris

All supplied by tibial nerve

Front 44

Lateral compartment of the lower leg

Back 44

Fibularis longus and brevis.
Fibularis quartus ~ 10% prevalence
Fibularis digiti minimi ~ 15-30% prevalence

All superficial fibular nerve.

Front 45

Gastrocnemius

Back 45

2 heads, running to the achilles tendon. The most superficial muscle of the posterior compartment.

O: Medial head arises above the medial epicondyle (medial femoral metaphysis) and the lateral head from the posterior femoral lateral condyle.

I: The heads unite and run to the mid leg, where the muscle becomes tendinous. The tendon joins with the soleus tendon to form the strong Achille's tendon. This then inserts into the middle of the posterosuperior angle of the calcaneus. There is a bursa interposed between the bone and tendon.

A: Plantar flexion of ankle, flexor of knee.

N: Tibial nerve (L5, S1 of sciatic/sacral plexus)

Front 46

Soleus

Back 46

The deep large muscle of the calf, under the gastrocnemius. Has an oblique origin.

O: Fibular head, upper 1/3rd of fibular shaft and the soleal line, to the medial tibia.

I: Becomes tendinous about 2/3rds down calf, and joins with the gastrocnemius tendon to form the strong Achille's tendon. This then inserts into the middle of the posterosuperior angle of the calcaneus. There is a bursa interposed between the bone and tendon.

A: Stabilises ankle while walking, plantar flexion

N: tibial nerve (L5, S1 of sciatic/sacral plexus)

Front 47

Achilles tendon

Back 47

The conjoined tendon of the gastrocnemius and soleus in the posterior lower leg. It inserts into the postero-superior portion of the calcaneum, with an interposed bursa between the superior aspect of the bone and the tendon.

Plantaris also either attaches into this tendon, or into calcaneum just medial.

Front 48

Plantaris

Back 48

Small muscle of the superficial calf group.

O: Above the lateral head of gastrocnemius, on the lateral femoral metaphysis.

I: The muscle quickly becomes tendinous at the level of the soleal line, this tendon passes medially and downward between the gastrocnemius and solues muscles.

The plantaris either joins the Achilles tendon or runs medial to it inserts into the calcaneum adjacent.

A: Plantar flex ankle, flex knee (as with gastrocnemius)

N: Tibial nerve (L5, S1 from sciatic/sacral plexus)

V: Absent in 7-10%

Front 49

Flexor hallucis longus

Back 49

Deep muscle of the posterior calf compartment.

O: Posterior fibular shaft, 1/3rd down (below soleus)

I: Passes medialward and down to eventually curl under the foot. It passes through 3 canals
1: Between the medial and lateral talar tubercles on the posterior talus.
2: The groove under the sustentaculum tali (curling forward here, around the talus).
3: The groove between the sesamoid bones under the great toe.

It inserts into the base of the distal phalanx of the great toe.

A: Flexes IPJ and MTPJ of great toe, plantar flexes the foot.

N: Tibial nerve (L5-S1 of the sciatic/sacral plexus)

V: Commonly os trigonum (sesamoid) of the tendon in the region of the posterior talus.

Front 50

Flexor digitorum longus

Back 50

Deep muscle of the posterior calf compartment.

O: Posterior tibia below soleus, ~1/4 of the way down.

I: Becomes tendinous and wraps around the medial malleolus (through a groove in the lower tibia), under the flexor retinaculum.
It crosses the flexor hallucis longus tendon at the Master Know of Henry, and proceeds to insert into the bases of digits 2-5.

A: Flexes ICPJ and MTPJs of toes 2-5. Plantarflexes foot. Inverts foot.

N: Tibial nerve (L5-S1 of sciatic/sacral plexus)

R: Runs under the tibial artery and nerve to the medial malleolus.
The groove it runs in at lower tibia is lateral to the tibialis posterior.

Front 51

Tibialis posterior

Back 51

Deep muscle of the leg, it is the most central posterior muscle and key in stabilising the leg.

O: 2 heads - originating on proximal fibula and tibia at the level of the fibular head.

I: The muscle passes medial as it descends, and passes in a groove behind the medial malleolus, under the flexor retinaculum.

It inserts into many sites - the navicular tuberosity, sustentaculum tali, cuneiforms and bases of metatarsals 2-4.

A: Inversion, plantar-flexion

N: Tibial nerve (L5, S1 of sciatic/sacral plexus)

R: The anterior tibial artery passes between the 2 heads at the origin.

Front 52

Popliteus

Back 52

A small muscle that extends across the popliteal fossa.

O: Lateral condyle of the femur.

I: Posteromedial tibia just proximal to origin of tibial head of soleus.

A: Assists thigh flexion. It works most at extension, ie beginning knee bending. Because it runs from lateral to medial posteriorly it rotates the femur laterally while flexing - it is very important in unlocking the knee when the femur has medially rotated to 'locked' on the tibia.

N: Tibial nerve (L5, S1 of sciatic/sacral plexus)

R: The tendinous origin is associated with the joint capsule and lateral meniscus.

Front 53

Fibularis (peroneus) longus

Back 53

O: Lateral fibular head and most of shaft.

I: Runs posteriorly behind the lateral malleolus in the common canal with the fibularis brevis, under the superior peroneal retinaculum.
It curves areound the malleolus and runs alongside the calcaneum under the inferior peroneal retinaculum.

It passes under the cuboid in a canal covered by the long plantar ligament, and inserts into the plantar surface of the medial cuneiform and 1st metatarsal.

A: Plantar-flexion, eversion

N: Superficial fibular nerve (L4-S3 of sciatic/sacral plexus)

V: The tendon often develops sesamoid bones at the sites of direction change - the lateral malleolus and the plantar surface of the cuboid.

Front 54

Fibularis (peroneus) brevis

Back 54

O: Lateral surface of lower 2/3rds of the fibula, passes down into the common fibularis canal (the retrofibular groove) beneath the superior fibular retinaculum, curves around the posterior aspect of the lateral malleolus anterior to the tendon of fibularis longus.

It passes down anterior to the fibular tubercle of the calcaneum, under the inferior fibular retinaculum, and passes forward to insert into the base of the 5th metatarsal.

A: Plantar flexion, eversion.

N: Superficial fibular nerve (L4-S3 from sciatic/sacral plexus)

Front 55

Pes anserinus

Back 55

The common tendon of sartorius, gracilis and semitendinosus.

It forms just above the knee joint medially, and inserts into the upper antero-medial portion of the tibia.

There is an anserine bursa which can become inflamed between the pes anserinus and the proximal tibia.

Front 56

Anterior ankle tendons

Back 56

The dorsiflexor and extensor tendons all cross the ankle joint anteriorly.

These are (medial to lateral)
Tibialis anterior to 1st MT and medial cuneiform
Extensor hallucis longus to 1st ray
Extensor digitorum longus to rays 2-5
Fibularis tertius to 5th ray

The tendons all pass under the superior and inferior extensor retinacula

Front 57

Posterior ankle compartment

Back 57

The posterior group all pass behind the medial malleolus other than the muscles to the Achilles.

These 3 tendons are (medial to lateral-ish)
Flexor hallucis longus (to 1st ray)
Flexor digitorum longus (to rays 2-5)
Tibialis posterior (to medial cuneiform).

Mnemonic from lat to medial
TOM DICK AND VERY NAUGHTY HARRY
Tib post, f Dig longus, post tib Artery, post tib Vein, tibial Nerve and f Hallucis longus

The 2 tendons into the Achilles are the soleus and goastrocnemius. The plantaris either inserts via the Achilles or into calcaneum just medial to the tendon.

Front 58

Lateral ankle tendons

Back 58

The lateral group passes under the lateral malleolus.

The 2 tendons are fibularis longus and brevis.

Brevis is more anterior, and inserts into base of 5th MT.
Longus is posterior in the distal fibular groove, and passes through a canal under the cuboid to attach to the plantar surface of the 1st MT and medial cuneiform.

Both tendons pass under the superior and inferior fibular retinacula.

Front 59

Ankle joint

Back 59

L:
Only discussing ligaments at the ankle mortis -

3 sets of ligaments, the distal tibiofibular ligaments, and the medial and lateral collateral ligaments.

DISTAL TIBIOFIBULAR COMPLEX (Syndesmosis)
4 components -
Anterior tibiofibular - From most distal lateral tibia.
About 2-3cm in cranio-caudal extent, to the level of the talar dome (free lower edge).
Posterior tibiofibular - From most distal lateral tibia.
About 2-3cm in cranio-caudal extent, to the level of the talar dome (free lower edge).
Inferior transverse ligament - the lowest portion of the posterior tibiofibular ligament. Runs as far medial as the lateral border of the malleolar prominence.
Interosseus tibiofibular - A continuation of the interosseus membrane. Runs between the tibia and fibula

Note because the ant and post tibiofibular ligaments have a distal free edge, which runs partially around the talus, they can be confused with talofibular ligaments.

LATERAL COLLATERAL:
3 ligaments:
Anterior talofibular - runs from anterior edge of lateral malleolus to anterior portion of talus (medial surface). Runs in line with the axis of the foot.
Posterior talofibular - runs from posterior edge of lateral malleolus to posterior portion of talus (medial surface). Runs in line with the axis of the foot.
Calcaneofibular - from the tip of the lateral malleolus to a small tubercle on the lateral aspect of the calcaneum. Under fibularis longus and brevis.

MEDIAL COLLATERAL (DELTOID):
Divided into superficial and deep components

SUPERFICIAL:
5 ligaments: they all arise in a continuous band from the medial border of the malleolus, differentiated by insertion site. In order anterior to posterior
Anterior tibiotalar - anteromedial talus
Tibionavicular - tuberosity of navicular bone
Tibiospring - to spring ligament and sustentaculum
Tibiocalcaneal - to sustentaculum tali
Posterior tibiotalar - to prominent tubercle on posteromedial talus.

DEEP:
There are 2 deep components, which are the same as superficial:
Anterior and posterior tibiotalar. These run deep to those components.

SPRING LIGAMENT (Calcaneo-navicular)

Front 60

Tibiofibular joints

Back 60

a

Front 61

Talus

Back 61

a

Front 62

Calcaneum

Back 62

a

Front 63

Navicular

Back 63

a

Front 64

Subtalar/sinus tarsi ligaments

Back 64

Ligaments between the talus and calcaneus (the sinus tarsi is the canal between the bones, largely formed by a hollow on the talar surface). All ligaments insert into the smooth surface on top of the calcaneum between the bones.

Running anterior to posterior are:

Cervical ligament to inferolateral talar neck.

Inferior extensor retinaculum has 3 roots, medial, intermediate and lateral. The intermediate is central, medial is just adjacent. The lateral actually arises from the lateral surface of the calcaneum, seperated from the other 2 by the insertion of flexor digitorum brevis.

Talocalcaneal is strongest and most posterior, just adjacent (anteromedial) to the large subtalar facet. Inserts to medial talar sulcus.

Front 65

Spring ligament

Back 65

Binds calcaneum to navicular bone, and supports the talar head.

3 components:

Superomedial spring ligament: The strongest part, hammock shaped, running from the sustentaculum tali to the superomedial navicular. It wraps around the talar head, extending the facet of the joint as a pseudo-labrum.

Medioplantar oblique: Coronoid fossa to the plantar aspect of navicular anterior to the tuberosity.

Inferoplantar longitudinal: Coronoid fossa to navicular beak.

Front 66

Bifurcate ligament

Back 66

Short, v shaped ligament.

Anterior calacneal process (lateral side) to cuboid and navicular via 2 bands.

Front 67

Plantar ligaments

Back 67

These bind calcaneum to cuboid and support the longitudinal arch

Short plantar:
Anterior tubercle of calcanuem to cuboid on plantar surface.

Long plantar:
Superficial to the short plantar ligament. Originates on the anterior, medial and lateral tubercles of the calcaneum, and passes forward to insert into the plantar surfaces of the cuboid and bases of the 2nd-5th metatarsals

Front 68

Tarsal bones

Back 68

The bones of the foot prior to metatarsals.

Talus at ankle
Calcaneum postero-inferior (the heel)
Navicular in front of these

Then the distal row, medial to lateral -
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform
Cuboid

Front 69

Medial cuneiform

Back 69

a

Front 70

Lateral cuneiform

Back 70

a

Front 71

Cuboid

Back 71

a

Front 72

Lisfranc joint

Back 72

a