Anatomy Unit 42: Plantar Foot

Front 1

Plantar Aponeurosis

Back 1

Tough fascial layer, superficial to the muscle layers. Has lateral and medial extensions called plantar fascia.

Front 2

First Layer of Intrinsic foot muscles

Back 2

Flexor Digitorum Brevis
Abductor Hallucis brevis
Abductor digiti minimi

Front 3

Second Layer of Intrinsic foot muscles

Back 3

Tendons of flexro digitorum longis
Tendons of flexor hallucis longus
Lumbricals
Quadratus plantae

Front 4

Third Layer of Intrinsic foot muscles

Back 4

Flexor hallucis brevis
Flexor digit minimi
Adductor Hallucis muscle

Front 5

Forth Layer of Intrinsic foot muscles

Back 5

7 interosseus muscles

Front 6

Medial compartment

Back 6

Flexor hallucis brevis
abductor hallucis
Tendon of the flexor allucis longus

Front 7

Flexor hallucis Brevis muscle

Back 7

Origin: Cuboid and lateral cuneform bones.
Inserts: On both sides of base of first phalanx (via sesmoid bones).
Action: Flexes great toe
Innervation: Medial plantar nerve

Front 8

Abductor hallucis Muscle

Back 8

Origin: Calcaneus and surrounding fascia
Inserts: Medial side of base of proximal phalanx on great toe
Action: Abducts and flexes hallux
Innervation: Medial plantar nerve

Front 9

Lateral Compartment

Back 9

Flexor digiti minimi brevis muscle
Abductor Digiti minimi muscle
Tendon of the flexor digitorum longus to 5th toe

Front 10

Flexor Digiti Minimi Muscle

Back 10

Origin: Base of 5th metatarsal
Inserts: Lateral side of base of proximal phalanx.
Action: Flexes MTP joint of 5th digit
Innervation: Lateral plantar Nerve

Front 11

Abductor Digiti Minimi Muscle

Back 11

Origin: Calcaneus and surrounding fascia
Inserts: Lateral side of base of proximal phalanx of 5th toe
Action: Abducts and flexes 5th digit
Innervation: Lateral plantar nerve

Front 12

Central Compartment

Back 12

Flexor digitorum Brevis
Quadratus plantae
4 Lumbricals
Tendon of flexor digitorum longus

Front 13

Flexor Digitorum Brevis muscle

Back 13

Origin: Calcaneus and deep surface of plantar aponeurosis
Inersts: Middle phalanx Dividing around longus tendon.
Action: Flexes digits 2-5
Innervation: Medial plantar Nerve

Front 14

Quadratus Plantae Muscle

Back 14

Origin: Medial and lateral sides of calcaneus
Inserts: Tendon of flexor digitorum longus.
Action: Assists flexor digitorum longues in flexing lateral 4 digits.
Innervation: Lateral planter nerve

Front 15

Lumbrical Muscles

Back 15

Origin: Tendons of flexor digitorum longus
Inserts: Medial side of extensor expansion
Action: Flexes proximal phalynx, extends middle and dista; phalanges
Innervation: 1 medial - Medial plantar nerve
3 lateral - lateral plantar nerve

Front 16

Adductor/Interosseus compartment

Back 16

Oblique and transverse heads of adductor halucis muscle
3 plantar interosseus muscles (adduct)
4 dorsal interosseus muscles (abduct)

Front 17

Adductor Halucis muscle

Back 17

Origin: Oblique head - Bases of metatarsals 2-4
Transverse head - MTP joint capsule
Inserts: With lateral tendon of flexor hallucis brevis on lateral side of base of proximal phalanx.
Action: Adducts hallucis and helps maintain transverse arch
Innervation: Lateral plantar nerve

Front 18

Plantar Interosseus muscles

Back 18

Origin: Unipenate. 3rd, 4th, and 5th metatarsal bones.
Inserts: Base of first proximal phalanges of correspinding toes, medial side.
Action: Adducts toes
Innervation: lateral plantar nerve

Front 19

Dorsal Interosseus muscles

Back 19

Origin: Bipenate. From adjacent metatarsal bones
Inserts: First 2 insert on opposite sides of 2nd toe. Other 2 insert on lateral side of 3rd and 4th toes.
Action: Abducts toes
Innervation: Lateral plantar nerve

Front 20

Medial plantar nerve

Back 20

Terminal branch of tibial artery. Enters foot passing deep to abductor hallucis muscle. Innervates abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and medial lumbrical muscle. Cutaneous sensation to medial 3.5 toes.

Front 21

Lateral plantar nerve

Back 21

Terminal branch of tibial nerve. Enters foot with medial plantar nerve but passes laterally between flexor digitorum brevis and quadratus plantae. Innervates muscles on dorsum of foot medial dosent. Divides into superficial and deep branches.
Superficial - flexor dig. min, interosseus muscles
Deep - Follows deep plantar arch and innervates remaining muscles

Front 22

Medial Plantar artery

Back 22

Branch of the posterior tibial artery. Stays medial on dorsal foot. May attempt to make a superficial arch connecting to lateral.

Front 23

Lateral Planar Artery

Back 23

Branch of posterior tibial artery. Forms deep plantar arch by joining perforating branches of the dorsalis pedis artery and anastamoses with the arcuate artery.
Deep plantar arch gives off plntar metacarpal arteries > plantar digital arteries.

Front 24

What do feet sit on when we are standing?

Back 24

Calcaneus, 2-5th metatarsals, and sesemoid bones of first metatarsal.