Foot and Ankle

Question 1

What are the 7 tarsus of the foot?

Answer 1

• calcaneus
• talus
• navicular
• cuboid
• cuneiforms (3)

Question 2

Why are there 5 metatarsus (3 phalanges per metatarsal), but only 14 phalanges?

Answer 2

Only 2 phalanges articulate with the first metatarsal, while the other 4 metatarsus articulate with 3 phalanges

Question 3

Describe the fascia of the foot in terms of dorsal and plantar aspects:

Answer 3

• dorsal: thin and continuous with extensor retinaculum
• plantar: plantar fascia, central part thickens to form plantar aponeurosis (becomes tendinous)

Question 4

• a part of the plantar fascia and arises from calcaneous posteriorly
• consists of longitudinally arranged band of dense connective tissue
• covers entire length of sole
• divides into five bands (enclose digital tendons)
• helps support the longitudinal foot arches

Answer 4

plantar aponeurosis

Question 5

• plantar aponeurosis inflammation at proximal attachment (calcaneus)
• pain is most severe after sitting and getting out of bed
• causes: running, high impact exercise, worn out shoes, overweight
• may lead to: bony process (“heel spur” or “calcaneal spur”) may develop especially from medial calcaneal tubercle

Answer 5

plantar fasciitis

Question 6

What are the 2 muscles present in the dorsum of foot?

• innervation?

Answer 6

• extensor hallucis brevis (1st phalanx)
• extensor digitorum brevis (2nd-4th phalanges): joins respective long tendons approximately at the MP joint

(these muscles form a fleshy mass on lateral part of dorsum of foot, anterior to lateral malleolus)

• innervation: deep fibular N.

Question 7

What is the arrangement of the plantar foot muscles and what is their role?

Answer 7

• arranged in 4 layers
• these muscles are synergists: help maintain foot arches and stand on uneven ground

Question 8

What are the plantar muscles of the first layer? (3)

Answer 8

(3 short muscles that extend from calcaneous to phalanges)

• abductor digiti minimi
• flexor digitorum brevis
• abductor hallucis

Question 9

What are the plantar muscles of the second layer? (2)

Answer 9

(keeps toes in line and prevents them turning laterally when flexor digitorum longus is contracting)

• quadratus plantae: joins tendon of FDL to calcaneous, assits FDL in flexing lateral four digits
• lumbricals: originate from FDL tendons, medial aspect of extensor expansion, flex mp joint, extend pip and dip joints

*FHL and FDL tendons are located in this layer, but not considered a part of 2nd layer plantar muscles*

Question 10

What are the plantar muscles present in the third layer? (3-4)

Answer 10

(3 short muscles to first and fifth digits (anterior half of foot))

• flexor digiti minimi brevis
• adductor hallucis: transverse head and oblique head
• flexor hallucis brevis: two heads (medial and lateral) cover plantar surface of first metatarsal, tendons have sesamoid bones, protect first metatarsal head and tendon of FHL when standing/walking

Question 11

What are the plantar muscles of the fourth layer?

Answer 11

(interossei between metatarsals)

• 3 plantar interossei: “pad” digits 3, 4, and 5 toward 2nd digit
• 4 dorsal interossei: “dab” digits 2, 3, and 4 away from midline of 2nd digit

*fibularis longus and tibialis posterior tendons are also in this layer*

Question 12

• a foot deformity characterized by lateral deviation of great toe
• surrounding tissues swell and resultant pressure/friction against shoe causes bursa to form
• if the bursa becomes tender/inflammed, this is a bursa
• inflammed areas of thick skin, corns, may form over proximal interphalangeal joints
• possible causes: wearing pointy heeled shoes

Answer 12

hallux valgus

Question 13

What is one of the main causes of toe deformities?

What are the 4 main types of toe deformities?

Answer 13

• in part, because of shortened flexor muscles which can override lumbrical function
• mallet toe (flexion in distal IP joint), hammer toe, claw toe, trigger toe (extended mp, flex ip)

Question 14

• toe deformity (usually of 2nd toe)
• proximal phalanx is permanently hyperextended at metatarso-phalangeal joint
• middle phalanx is plantarflexed at the proximal interphalangeal joint
• distal phalanx is extended

Answer 14

hammer toe

Question 15

• toe deformity characterized by hyperextension of metatarso-phalangeal joints
• flexion of the distal and proximal interphalangeal joints

Answer 15

claw toes

Question 16

What nerves innervate the plantar portion of the foot?

Answer 16

• tibial N. divides posterior to medial malleolus into: medial and lateral plantar Ns.
• supply all intrinsic muscles of foot (except 2 intrinsic dorsum muscles) by the deep branches
• supply plantar skin by the superficial branches

Question 17

What nerves innervate the cutaneous dorsal portion of anterior ankle and foot?

Answer 17

• most of anterior foot: superficial fibular N.
• interspace between 1st and 2nd digits: deep fibular N.
• branches off sural N.: lateral aspect of foot

Question 18

Medial plantar N.

• Course:
• Muscles innervated:

Answer 18

Medial plantar N.

• Course: passes deep to abductor hallucis, runs anteriorly between abdudctor hallucis and flexor digitorum brevis, terminates near metatarsal bases by dividing into four sensory branches (medial 3 and 1/2 digits)
• Muscles innervated: abductor hallucis and FDB (1st layer), medial 1st lumbrical (2nd layer), FHB (3rd layer)

Question 19

Lateral plantar N.

• Course:
• Muscles innervated:

Answer 19

Lateral plantar N.

• Course: passes deep to abductor hallucis, runs anterolaterally deep to flexor digitorum brevis, terminates by dividing into superficial and deep branches
• Muscles innervated: abductor digiti minimi, quadratus plantae, lateral 3 lumbricals, adductor hallucis, FDMB, interossei

Question 20

What arteries supply the foot?

Answer 20

terminals branches of anterior and posterior tibial As.

Question 21

Describe the foot As. in terms of branching and anastamoses:

Answer 21

• tibial A. branches off into lateral malleolar A. and lateral tarsal A.
• tibial A. continues to descend into the dorsal pedis A. which runs anteromedially to first interosseous space and divides into: arcuate A. and deep plantar A.
• loops between these As. create the dorsal arch
• plantar and dorsal artery arch interact and create anastamosis

Question 22

• dorsal pedis A. branch
• runs laterally across metatarsal bases (deep to extensor tendons)
• gives rise to 2nd-5th dorsal metatarsal As. which give rise to dorsal digital As.

Answer 22

arcuate A.

Question 23

• dorsal pedis A. branch
• passes through first interosseous space
• joins lateral plantar A. to form the plantar arch
• gives rise to first dorsal metatarsal A.

Answer 23

deep plantar A.

Question 24

• artery derived from posterior tibial A.
• passes distally between abductor hallucis and FDB
• gives rise to medial 2 plantar metatarsal and plantar digital As.

Answer 24

medial plantar A.

Question 25

- artery derived from posterior tibial A. - runs w/ lateral plantar nerve (superficial to quadratus plantae) - terminates by joining deep plantar A. forming the plantar arterial arch - gives rise to 3rd-6th plantar metatarsal and plantar digital As.

Answer 25

lateral plantar A.

Question 26

What the functions of foot arches? What are the 2 different kinds of foot arches?

Answer 26

- functions: absorb shock during weightbearing, makes foot adaptable to surface/weight changes - longitudinal arch (medial/lateral parts) and transverse arch

Question 27

- type of foot arch - medial part formed by calcaneus, talus, navicular, 3 cuneiforms, and medial 3 metatarsals - lateral part formed by calcaneus, cuboid, and lateral 2 metatarsals

Answer 27

longitudinal arch

Question 28

What are the "important" dyanmic stabilizers of longitudinal foot arch? Passive stabilizers?

Answer 28

- dynamic: flexor hallucis longus and tibialis posterior - passive: long plantar ligament, plantar calcaneocuboid ligament (short plantar L.), plantar calcaneonavicular ligament (spring L.)

Question 29

- type of foot arch - runs between medial and lateral longitudinal arches - formed by cuboid, 3 cuneiforms, and metatarsal bones

Answer 29

transverse arch

Question 30

What are stabilizers of the transverse arch in the tarsal arch, metatarsal arch, and forefoot?

Answer 30

- tarsal: tibialis posterior and fibularis longus (active/dynamic) - metatarsal: adductor hallucis (oblique and transverse head) (active/dynamic) - forefoot: plantar ligaments and deep transverse metatarsal ligament (passive)

Question 31

Loss of transverse arch: Loss of longitudinal arch:

Answer 31

- pes transversoplanus - pes planus

Question 32

- condition that results usually from fallen medial parts of longitudinal arch - plantar ligaments and plantar aponeurosis become abnormally stretched - plantar calcaneonavicular ligament can no longer support talus head, causing talar head to displace inferomedially and becomes prominent

Answer 32

pes planus (flatfeet)

Question 33

Ankle (talocrural) joint - Articulating bones and associated dynamics: - Type of joint: - Capsule type:

Answer 33

Ankle (talocrural) joint - Articulating bones and associated dynamics: **tibia and fibula** (inferior ends) and **talus** (trochlea): 3-sided mortise (deep socket) formed by 2 malleoli and inferior tibia, malleoli grip on trochlea strongest during dorsiflexion (wide anterior part moves posteriorly, spreading leg bones) - Type of joint: **hinge synovial joint** (dorsiflexion and plantarflexion) - Capsule type: **articular capsule** (thin anteriorly and posteriorly, each side supported by strong medial/lateral collateral ligaments)

Question 34

Medial/Deltoid ligament: - Stabilization: - Four parts:

Answer 34

Medial/Deltoid ligament: - Stabilization: of the ankle joint during **eversion** - Four parts (named from **leg bone to foot bone**): **anterior tibiotalar**, **tibionavicular**, **tibiocalcaneal,** **posterior tibiotalar**

Question 35

Lateral ankle ligaments: - 3 discrete ligaments: - named from: - clinical relevance:

Answer 35

Lateral ankle ligaments: - 3 discrete ligaments (that attach to lateral malleolus to talus and calcaneus): **posterior tibiofibular L.** and **anterior tibiofibular L.** (tibiofibular syndesmosis Ls.), and **anterior talofibular L.** - named from: **foot bone to leg bone** - clinical relevance: likely where the tearing/injury occurs for **high ankle sprains**

Question 36

Describe the joints in the foot that involve tarsus, metatarsus, and phalanges: What are the 2 important intertarsal joints?

Answer 36

- Describe the joints in the foot that involve tarsus, metatarsus, and phalanges: **small and tightly joined by ligaments, only slight movement occurs between them** - 2 important intertarsal joints: **transverse tarsal joint** and **subtalar joint** (talocalcanean joint)

Question 37

- important intertarsal joint in the foot - formed by two separate joints aligned transversely: **talonavicular joint** and **calcaneocuboid joint** - together, they permit slight rotation and add to **inversion** and **eversion** at the talocalcaneal joint - **transection across this joint is standard method for surgical amputation of foot**

Answer 37

transverse tarsal joint

Question 38

- important intertarsal joint - where talus rests on calcaneus - main movements: inversion and eversion - fibrous capsule supported by interosseous talocalcaneal L.

Answer 38

subtalar (talocalcanean) joint

Question 39

- most frequent injured joint in the body - ligament fiber tears are almost always due to inversion injury

Answer 39

ankle sprain