The Ankle Joint and the Foot

What are the plantiflexors of the foot?

*gastrocnemius flexor hallucis longus *soleus fibularis longus tibialis posterior fibularis brevis flexor digitorum longus

What are the dorsiflexors of the foot?

*tibialis anterior extensor digitorum longus fibularis tertius extensor hallucis longus

What is the action of muscles in maintaining the arches of the feet?

1) Both the intrinsic and extrinsic muscles (tendons of the long flexors, fibularis longus, etc.) act as elastic ties or springs that help maintain the arches. 2) In the normal foot, the bony and ligamentous structures are the primary supports of the arches and require no muscular aid until the stress is increased by walking or shifting the load.

What arteries supply the dorsum of the foot?

1) DORSALIS PEDIS ARTERY 2) ARCUATE ARTERY: from dorsalis pedis 3) DEEP PLANTAR ARTERY: from dorsalis pedis

What are the arches of the foot?*

1) LONGITUDINAL ARCH: Medial Part (more important) and Lateral Part 2) TRANSVERSE ARCH 3) Because of these arches, body weight is divided about equally between the CALCANEUS and the heads of the METATARSALS.

What arteries supply the sole of the foot?

1) MEDIAL PLANTAR ARTERY 2) LATERAL PLANTAR ARTERY 3) The posterior tibial artery divides into the MEDIAL and LATERAL PLANTAR arteries posterior to the medial malleolus.

What are the three compartments that the plantar aponeurosis (medial and lateral vertical septa) divide the foot into?

1) Medial Compartment 2) Middle Compartment 3) Lateral Compartment

What is innervated by the superficial fibular nerve in the foot?**

1) NO intrinsic muscles of the foot: innervates the lateral compartment of the leg - some of these tendons travel to the foot. 2) skin of most of dorsal surface except between first two toes and lateral 1 ½ toes

Name the Plantar ligaments and aponeurosis that maintain the arches:

1) Plantar aponeurosis 2) Plantar calcaneonavicular ligament ("spring" ligament) 3) Long plantar ligament 4) Plantar calcaneocuboid ligament (short plantar ligament)

What are the Intertarsal Joints of Inversion and Eversion?*

1) Subtalar Joint 2) Talocalcaneonavicular Joint 3) Transverse Tarsal Joint This page has some good animations: http://www.jointinjury.com/ankle/page3.htm

Describe the dorsalis pedis artery:****

1) The anterior tibial artery changes its name to the DORSALIS PEDIS as it crosses the ankle joint. AKA TALOCRURAL JOINT 2) The dorsalis pedis pulse can be felt on the dorsum of the foot where the artery passes over the navicular and cuneiform bones. This is just lateral to the tendon of the extensor hallucis longus. (Note that in 14% of people this artery is small, absent or in a different position PERFORATING BRANCH OF THE FIBULAR ARTERY.) 3) In the first interosseous space, the dorsalis pedis divides into the: ARCUATE ARTERY and DEEP PLANTAR ARTERY.

What is the precise location of the sesamoid bones? ***

1) The medial sesamoid bone is located in the tendon of flexor hallucis brevis which it shares with the ABDUCTOR HALLUCIS. 2) The lateral sesamoid bone is locates in the tendon of the flexor hallucis brevis (lateral head) which it shares with ADDUCTOR HALLUCIS

What is the position of greatest stability for the talocrural joint? *

1) The superior surface of the talus is wider anteriorly than posteriorly. 2) Therefore, in dorsiflexion it fits more tightly in the boxlike mortise formed by the inferior ends of the tibia and fibula. 3) In plantarflexion the talus is looser in the mortise and the joint is less stable.

Describe the lateral ligament of the articular capsule of the ankle joint:****

1) This actually consists of three separate ligaments that attach the lateral malleolus to the talus and calcaneus. 2) Anterior talofibular - lateral malleolus to talus; not strong 3) Posterior talofibular - lateral malleolus to posterior part of talus; thick and fairly strong 4) Calcaneofibular - lateral malleolus to calcaneus 5) These ligaments are weaker than on the medial side. Most ankle "sprains" are inversion injuries (i.e., the foot is forcefully inverted) where the lateral ligaments are stretched and/or torn. The ankle is the most frequently injured major joint of the body.

Describe the lateral plantar artery:**

1) This artery joins the DEEP PLANTAR artery to form the PLANTAR ARCH,

Describe the deltoid ligament: *

1) This extends from the medial malleolus to three tarsal bones: the talus, navicular and the calcaneus. 2) The deltoid ligament is very strong and the medial malleolus is often torn off in eversion injuries rather than tearing the deltoid ligament.

What is the functional transverse tarsal joint?*****

1) This is a functional joint that is the line of division between the fore part of the foot and the hind part. 2) It consists medially of the talonavicular part of the talocalcaneonavicular joint and laterally of the calcaneocuboid joint.

Describe the medial plantar artery:

1) This is the smaller of the two terminal branches of the posterior tibial artery. 2) It supplies the medial surface of the great toe.

Describe the articular capsule of the ankle joint:

1) This is thin anteriorly and posteriorly, but is supported on the medial and lateral aspect of the joint by strong collateral ligaments. 2) DELTOID LIGAMENT: Medially 3) "LATERAL LIGAMENT": Laterally

Where is the talocalcaneonavicular joint?*

1) This is where the head of the talus articulates with a socket formed by the posterior surface of: -- the navicular bone, --the spring ligament, --the sustentaculum tali --the articular surface of the calcaneus.

Describe the Plantar aponeurosis:

1) This supports both longitudinal arches. 2) The medial part attaches to the sesamoid bones of the great toe and gives particular strength to the medial longitudinal arch when standing on the toes. 3) extends from the calcaneus to the proximal phalanges and fibrous tendon sheaths of the digits. This strong fibrous structure is important in supporting the longitudinal arch of the foot. 4) Vertical septa (medial and lateral) extend into the sole of the foot from the edges of the aponeurosis, dividing it into three compartments.

What are the articular surfaces of the ankle joint?

1) Tibia - distal surface and lateral surface of medial malleolus. 2) Fibula - medial surface of lateral malleolus articulates with lateral surface of talus. 3) Talus - three articular facets which articulate with the inferior surfaces of the tibia and the two malleoli.

What muscles are found in the lateral compartment of the foot?

1) abductor digiti minimi- superficial 2) flexor digiti minimi brevis

What are the superficial muscles of the foot (first layer)

1) abductor hallucis 2) flexor digitorum brevis - Tendons insert on middle phalanx of lateral four toes, splitting to allow passage of long flexor tendon to distal phalanx. 3) abductor digiti minimi All three muscles extend from the calcaneus to the phalanges. As a group they assist in maintenance of the arches of the foot.

What muscles are found in the medial compartment of the foot?

1) abductor hallucis - superficial 2) flexor hallucis brevis 3) tendon of flexor hallucis longus

What are the articulations of the talus? *

1) calcaneous 2) fibula 3) navicular 4) tibia

What is innervated by the Deep fibular nerve in the foot?**

1) extensor digitorum brevis 2) dorsal skin between first two toes

What muscles are on the dorsum of the foot? *

1) extensor digitorum brevis: The most medial portion of this muscle passing to the great toe is sometimes called the extensor hallucis brevis. 2) Extends from calcaneus to proximal phalanx of great toe and tendons of extensor digitorum longus to toes two, three and four.

What muscles are found in the middle compartment of the foot?

1) flexor digitorum brevis- superficial 2) quadratus plantae 3) lumbricals 4) tendon of flexor digitorum longus 5) adductor hallucis

What is the plantar arch?***

1) the major arterial supply of the sole of the foot. 2)The arch gives off plantar metatarsal arteries which divide into common digital arteries. 3) Made up of the deep and lateral plantar arteries 4) The radial and ulnar arteries also form an arch.

What two factors maintain the arches of the feet?

1. Shape of the interlocking bones. 2. Plantar ligaments and aponeurosis: These are the most important factors in the maintenance of the arches in standing. 3. Action of muscles

What is innervated by the lateral plantar nerve in the foot?***

Everything else: Lateral plantar nerve (innervates remaining plantar muscles) 1) abductor digiti minimi 2) quadratus plantae 3) second, third and fourth lumbricals 4) adductor hallucis 5) flexor digiti minimi brevis 6) plantar and dorsal interossei 7) skin of lateral sole and plantar aspect of last 1 ½ digits

Describe the fourth layer of the foot****

FOURTH LAYER (interossei and two long tendons) 1) plantar interossei (three) Arranged to ADDUCT toward the axis of the SECOND toe (PAD) 2) dorsal interossei (four) Arranged to ABDUCT away from the axis of SECOND toe (DAB) note that the reason the second toe is the median plane of the foot is because the second toe receives the insertions of two dorsal interossei and thus can only be abducted. **** 3) tendon of fibularis longus 4) tendon of tibialis posterior

Describe the arcuate artery:

Gives off three dorsal metatarsal arteries that divide into two dorsal digital arteries.

What is innervated by the medial plantar nerve in the foot? *********

Memorize LAFF: Medial plantar nerve 1) first Lumbrical (to second digit) 2) Abductor hallucis 3) Flexor digitorum brevis 4) Flexor hallucis brevis 5) skin of medial sole and plantar aspect of first 3 ½ digits

Describe the Plantar calcaneocuboid ligament (short plantar ligament):

Nothing super special

Describe the deep plantar artery:**

Passes between the first two metatarsal bones to join the LATERAL PLANTAR artery to form the PLANTAR ARCH.

What is the spring ligament?**********

Plantar calcaneonavicular ligament ("spring" ligament) 1) This is the main support of the medial longitudinal arch 2) the most important ligament in the foot. 3) It supports the talus: forms part of the "socket" for the articulation of the head of the talus in the talocalcaneonavicular joint.

Which muscle in the foot has no homologue in the hand? **

Quadratus plantae: Inserts on tendon of flexor digitorum longus. Innervated by lateral plantar nerve MUSCLE ALLOWS YOU TO FLEX THE TOES WITHOUT HAVING TO GO INTO PLANTARFLEXION - NO EQUIVALENT IN THE HAND.

Describe the second layer of the foot:****

SECOND LAYER (flexor digitorum longus tendons and attached muscles) 1) tendons of flexor digitorum longus - Insert on distal phalanx of lateral four toes and pass through splits in tendons of flexor digitorum brevis 2) quadratus plantae - Inserts on tendon of flexor digitorum longus. 3) lumbricals - Originate from tendons of flexor digitorum longus and pass medially to insert on dorsal digital expansions formed by tendons of toe extensors. Thus the lumbricals flex at the metatarsophalangeal joint and extend at interphalangeal joints. 4) tendon of FLEXOR HALLUCIS LONGUS- passes between the two sesamoid bones located in the tendons of the flexor hallucis brevis.

What is the Subtalar Joint?*****

Subtalar Joint: AKA POSTERIOR TALOCALCANEAL This is the posterior talocalcaneal articulation.

Which joint is not involved in the inversion or eversion of the foot? *

TALOCRURAL (ANKLE JOINT)

What is the sustentaculum tali? from wiki**

THE GROOVE ON THE CALCANEOUS THAT HOLDS THE FLEXOR HALLUCIS LONGUS TENDON. At the upper and forepart of the medial surface of the calcaneus is a horizontal eminence, the sustentaculum tali (alternatively, the talar shelf), which gives attachment to the plantar calcaneo-navicular (spring) ligament, tibiocalcaneal ligament, and medial talocalcaneal ligament. This eminence is concave above, and articulates with the middle calcaneal articular surface of the talus; below, it is grooved for the tendon of the Flexor hallucis longus; its anterior margin gives attachment to the plantar calcaneonavicular ligament, and its medial margin to a part of the deltoid ligament of the ankle-joint.

Describe the third layer of the foot muscles:

THIRD LAYER (short muscles of big and little toe) 1) flexor hallucis brevis - Muscular belly splits to blend medially with insertion of abductor hallucis (sharing medial sesamoid bone of great toe) and to blend laterally with insertion of adductor hallucis (sharing lateral sesamoid bone). 2) adductor hallucis - Consists of an oblique and a transverse head which merge to share lateral sesamoid bone of great toe with lateral tendon of flexor hallucis brevis. 3) flexor digiti minimi brevis

What is the calcaneocuboid joint? from wiki*

The calcaneocuboid articulation is the joint between the calcaneus and the cuboid bone. The ligaments connecting the calcaneus with the cuboid are five in number, viz., the articular capsule: --the dorsal calcaneocuboid ligament, --part of the bifurcated ligament, --the long plantar ligament, --and the plantar calcaneocuboid ligament. The calcaneocuboid joint is conventionally described as among the least mobile joints in the human foot. The articular surfaces of the two bones are relatively flat with some irregular undulations, which seem to suggest movement limited to a single rotation and some translation. However, the cuboid rotates as much as 25° about an oblique axis during inversion-eversion in a movement that could be called obvolution-involution. [2]

What type of joint is the ankle joint?

This is a hinge type synovial joint located between the inferior ends of the tibia and fibula and the talus. Most of the weight of the body is transmitted across the tibia while the fibula functions to stabilize the ankle joint.

Describe the Long plantar ligament:

This is the main support of the lateral longitudinal arch.

What makes up the medial part of the longitudinal arch?

This portion of the arch is higher and somewhat more important. It consists of: 1) calcaneus 2) talus (keystone of the arch) 3) navicular 4) three cuneiforms 5) medial three metatarsals

What makes up the lateral part of the longitudinal arch?*

This portion of the arch rests on the ground during standing. It consists of: 1) calcaneus 2) cuboid 3) lateral two metatarsals

What is the counterpart of the extensor digitorum brevis in the hand? ****

Trick question: this muscle has no counterpart in the upper member. Because the length from your forearm to your tips of fingers is small that muscle has the strength to extend the digits. However, because the Extensor digitorum longus starts at the knee it needs the smaller shorter extensor digitorum brevis to help it out in extending the toes.

What is the most likely end result of a forcible eversion injury to the the ankle? *

You are more likely to fracture the malleolus of the tibia than you are to tear the deltoid ligament.

What muscles act to evert the foot?

fibularis longus fibularis brevis fibularis tertius

What muscles act to invert the foot?

tibialis anterior tibialis posterior