sole

Plantar aponeurosis

· covers whole sole

Origin

· calcaneus

· medial and lateral tubercles

· posterior aspect below tendo Achilles

Path

· fans out over sole

· septum penetrates sole from each edge

· separates FDB from abductors of 1st and 5th toes

· attached to 1st and 5th MTs

Insertion

· into each of 5 toes

· by 5 slips

· bifurcate for flexor tendons

· insert into flexor sheaths and transverse ligaments

Muscle layers

1st layer 3 muscles AbH, FDB, AbDM

arteries and nerves

2nd layer 2 tendons FHL, FDL

small muscles FA, lumb

3rd layer 3 muscles FHB, AdH, FDMB

4th layer 2 tendons TP, PL

small muscles inter

first layer

· 3 muscles

· extend length of sole

Abductor hallucis

Origin

· medial tubercle of calcaneus

Insertion

· medial side of prox phalanx of great toe

Flexor digitorum brevis

Origin

· medial tubercle of calcaneus

Insertion

· middle phalanx of each toe

· like FDS in hand

Abductor digiti minimi

Origin

· medial and lateral tubercles of calcaneus

· deep to FDB

Insertion

· lateral side of prox phalanx of little toe

second layer

· tendon of FHL

· tendon of FDL and its associated muscles

· lumbricals

· flexor accessorius

Tendon of FHL

Path

· tendon leaves muscle just at lower edge of tibia

· ‘beef to heel’

· grooves posterior process of talus

· passes beneath flexor retinaculum

· lies in groove on undersurface of sustentaculum tali

· passes like bowstring under medial border of foot

· at master knot of Henry

· crossed by tendons of FDL

· gives slip to medial 2 (2nd and 3rd toes)

· lies in groove between sesamoids under head of 1st MT

Insertion

· base of distal phalanx of great toe

Tendon of FDL

Path

· passes beneath flexor retinaculum

· enters sole on medial side of FHL

· at master knot of Henry

· crosses tendon of FHL

· divides into 4 tendons

· medial 2 tendons receive slip from FHL

· tendons receive insertion of flexor accessorius

· tendons pass forwards in sole deep to FDB

· give off lumbricals

Insertion

· base of distal phalanges of lesser toes

· like FDP in hand

Flexor accessorius

· (quadratus plantae)

Origin

· medial head

· large and fleshy

· from medial tubercle of calcaneus and whole medial aspect of calcaneus

· lateral head

· small and tendinous

· from lateral tubercle of calcaneus

· at master knot of Henry

· divides into 4 tendons

· inserts into tendons of FDL

Lumbricals

Origin

· 4 lumbricals arise from tendons of FDL

· medial one is unicipital

· arises from own tendon

· supplied by medial plantar n

· lateral three are bicipital

· arise from adjacent tendons

· supplied by lateral plantar n

· pass on medial side of MTP jts of lesser toes

· lie plantar to deep transverse ligament

Insertion

· medial side of extensor expansion

third layer

· 3 muscles

· confined to metatarsal region of sole

Flexor hallucis brevis

· undersurface of 1st MT

Origin

· undersurface of

· cuboid

· cuneiforms (blends with insertion of TP)

Insertion

· splits into 2

· medial

· into medial sesamoid

· blends with abductor hallucis

· lateral

· into lateral sesamoid

· blends with adductor hallucis

Adductor hallucis

Origin

· large oblique and small transverse head

· oblique head

· bases of 2nd, 3rd and 4th MTs

· long plantar ligament where roofs over PL

· transverse head

· deep transverse ligament

· plantar surface of lesser MTP jts

Insertion

· lateral side of prox phalanx of great toe

Flexor digiti minimi brevis

· undersurface of 5th MT

Origin

· base of 5th MT

Insertion

· base of proximal phalanx of 5th toe

· medial to AbDM

fourth layer

· tendons of TP and PL

· interossei

Tendon of TP

Path

· grooves posterior aspect of medial malleolus

· passes above sustentaculum tali

Insertion

· into tuberosity of navicular

· fibrous bands to

· sustentaculum tali

· cuneiforms and cuboid

· 2nd, 3rd, 4th MT

Tendon of PL

Path

· passes below peroneal trochlea

· enters sole of foot

· lies in groove in cuboid (against posterior edge)

· held in groove by long plantar ligament

· attached to anterior and posterior ridges

· possesses sesamoid fibrocartilage

· may ossify

· crosses sole obliquely

Insertion

· base of 1st MT (primarily)

· adjoining area on medial cuneiform

Interossei

· Plantar ADduct (PAD)

· Dorsal ABduct (DAB)

· longitudinal axis is 2nd MT

· plantar arises from own MT

· dorsal arises from adjoining MTs

· some not required

· 1st toe has adductor (no plantar IO)

· 1st and 5th toes have adductors (no dorsal IO)

· thus

· 1st space has 1 dorsal IO

· 2nd, 3rd and 4th spaces have both dorsal and plantar IO

· dorsal is more bulky

Plantar

· 3 muscles

· for 3rd, 4th and 5th toes

· on medial side of digit

· originate from MT of own digit

· inserted into medial

· base of proximal phalanx

· extensor expansion

Dorsal

· 4 muscles

· two for 2nd toe (one on each side)

· one for 3rd and 4th toe (on lateral side of digit)

· originate from both bones of their intermetatarsal space

· inserted into

· base of proximal phalanx

· extensor expansion

Nerves and vessels

· between 1st and 2nd muscular layers

tibial nerve

· passes under flexor retinaculum behind medial malleolus

· in contact with tibia

· behind artery

· gives off medial calcanean nn

· supply skin of heel

· bifurcates under middle of retinaculum

· medial and lateral plantar nerves

· artery divides higher (ie. is on outer margin)

plantar nerves

· medial plantar

· larger

· less muscles (AbH, FDB, FHB, 1 lumb)

· more skin (plantar medial 3 1/2 toes and sole)

· lateral plantar

· smaller

· more muscles (FDMB, FA, AbDM, AdH, 2,3,4 lumb, IO)

· less skin (plantar lateral 1 1/2 toes and sole)

Medial plantar nerve

· runs on lateral side of medial plantar a

· appears between AbH and FDB

· gives off cutaneous branches to sole (medial 3 1/2)

· gives off digital branches to medial 3 1/2 toes

· most lateral communicates with branch of lateral plantar n

· supplies

· AbH and FDB

· FHB and 1st lumbrical

Lateral plantar nerve

· runs on medial side of lateral plantar a

· crosses sole obliquely

· gives off cutaneous branches to sole (lateral 1 1/2)

· emerges between FDB and AbDM

· divides in superficial and deep branches

Superficial

· gives off digital branches to lateral 1 1/2 toes

· most medial communicates with branch of medial plantar n

· supplies

· FDMB

· 2 interossei of 4-5 space

Deep

· supplies

· 4 interossei of 2-3 and 3-4 space

· AdH

· lateral 3 lumbricals

posterior tibial artery

· passes under flexor retinaculum

· anterior to nerve

· divides into medial and lateral plantar aa

· proximal to nerve

Medial plantar artery

· smaller

· passes along medial side of nerve

· divides into digital aa to supply great toe

Lateral plantar artery

· larger

· crosses sole obliquely on lateral side of nerve

· gives branch to accompany superficial branch of nerve

· main trunk passes with deep branch of nerve

· forms plantar arch

· curves convexly forward

· across bases of 4th, 3rd and 2nd MTs

· anastomoses to arch

· joined in proximal 1-2 intermetatarsal space by dorsalis pedis a

· joined in other intermetatarsal spaces by perforating branches from arcuate a (from dorsalis pedis)

· arch gives off plantar metatarsal aa to supply lesser 4 digits