Muscles of the Foot

Question 1

Quadratus Plantae

Answer 1

Origin: medial and lateral sides of plantar surface of calcaneus

Insertion: posterolateral edge of flexor digitorum longus tendon

Innervation: lateral plantar nerve

Action: corrects for oblique pull of flexor digitorum longus tendon, thus assists in flexion of toes

Blood Supply: medial and lateral plantar arteries an deep plantar arterial arch

Question 2

Lumbricals

Answer 2

Origin: tendons of flexor digitorum longus

Insertion: medial side of dorsal digital expansions of lateral 4 digits

Innervation: medial one: medial plantar nerve; lateral three: lateral plantar nerve

Action: flexes proximal phalanges of MTP joint, extends phalanges at PIP and DIP joints

Blood Supply: lateral plantar artery and plantar metatarsal arteries

Question 3

Plantar Interossei

Answer 3

Origin: bases and medial sides of 3rd through 5th metatarsals

Insertion: medial sides of bases of proximal phalanges of 3rd through 5th digits

Innervation: lateral plantar nerve

Action: adducts digits 2-4 and flex metatarsophalangeal joint and extend phalanges

Blood Supply: lateral plantar artery and plantar arch, plantar metatarsal and plantar digital arteries

Question 4

Flexor Digiti Minimi Brevis

Answer 4

Origin: base of 5th metatarsal

Insertion: lateral base of proximal phalanx of 5th digit

Innervation: superficial branch of lateral plantar nerve

Action: flexes proximal phalanx of 5th digit

Blood Supply: lateral plantar artery, plantar digital artery to 5th digit, arcuate artery

Question 5

Flexor Digitorum Brevis

Answer 5

Origin: medial tubercle of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septum

Insertion: both sides of middle phalanges of lateral four digits

Innervation: medial plantar nerve

Action: flexes 2nd through 5th digits

Blood Supply: medial and lateral plantar arteries and plantar arch, plantar metatarsal and plantar digital arteries

Question 6

Flexor Hallucis Brevis

Answer 6

Origin: plantar surfaces of cuboid and lateral cuneiform

Insertion: both sides of base of proximal phalanx of 1st digit

Innervation: medial plantar nerve

Action: flexes proximal phalanx of 1st digit

Blood Supply: medial plantar artery, first plantar metatarsal artery

Question 7

Abductor Digiti Minimi

Answer 7

Origin: medial and lateral tubercles of tuberosity of calcaneous, plantar aponeurosis, and intermuscular septum

Insertion: lateral side of base of proximal phalanx of 5th digit

Innervation: lateral plantar nerve

Action: abducts and flexes 5th digit

Blood Supply: medial-lateral plantar artery, plantar metatarsal and plantar digital arteries to 5th digit

Question 8

Abductor Hallucis

Answer 8

Origin: medial tubercle of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septum

Insertion: medial side of base of proximal phalanx of 1st digit

Innervation: medial plantar nerve

Action: abducts and flexes 1st digit

Blood Supply: medial plantar and 1st plantar metatarsal arteries

Question 9

Adductor Hallucis

Answer 9

Origin: oblique head: bases of 2nd through 4th metatarsals; transverse head: ligaments of metatarsophalangeal joints of digits 3-5

Insertion: tendons of both heads lateral to side of base of proximal phalanx of 1st digit

Innervation: deep branch of lateral plantar nerve

Action: adducts 1st digit, maintains transverse arch of foot

Blood Supply: medial and lateral plantar arteries and plantar arch, plantar metatarsal arteries

Question 10

Dorsal Interossei

Answer 10

(four muscles)

Origin: adjacent sides of 1st through 5th metatarsals

Insertion: 1st: medial side of proximal phalanx of 2nd digit; 2nd through 4th: lateral sides of digits 2-4

Innervation: lateral plantar nerve

Action: abduct 2nd through 4th toes, flex metatarsophalangeal joints, and extend phalanges

Blood Supply: arcuate artery, dorsal and plantar metatarsal arteries

Question 11

Extensor Digitorum Brevis and Extensor Hallucis Brevis

Answer 11

Origin: superolateral surface of calcaneus, lateral talocalcaneal ligament, cruciate crural ligament

Insertion: first tendon into dorsal surface of base of proximal phalanx of great toe; other 3 tendons into lateral sides of tendons of extensor digitorum longus to digits 2-4

Innervation: deep fibular nerve

Action: aids the extensor digitorum longus in extending 4 medial digits at the metatarsophalangeal and interphalangeal joint

Blood Supply: dorsalis pedis, lateral tarsal, arcuate, and fibular arteries

Region: anterior thigh