sheet no.21

*Bones of the foot*

The foot consists of:

7 tarsal bones--->short bones
5 metatarsal bones--->long bones
14 phalanges--->long bones
.
♦Tarsal bones
1-Talus. (Bone of the ankle)
-It receives half of the person’s weight (for each talus) and divides it:
-->post. To calcaneus
-->ant. To head of metatarsals
-Position:
-superior To calcaneus

-part of calcaneus is post. And lat. To Talus.

-It is called the (key stone) of bones of the foot because of it's important position.

-If fractured flat foot resulted

-It articulates with:

Tibia ( inferior articular surface of it )

Medial malleolus ( of tibia )

Lateral malleolus ( of fibula )

To form ankle joint which is like a viseالملزمة))

That is why the ankle is very stable(balanced)

-It permits two types of movement.

Extension or dorsiflexion. (Toward your face).

Plantar flexion (standing on the tip of your toes).

2-Calcaneus bone (Heel bone)

-Position: below talus bone (part is lateral and posterior to it)
-Part of the weight transmitted through it to the ground i.e. it receives part of the weight (posterior part).
-largest in foot bones
Navicular bone
-small-boat shaped
- medial
-Receives part of the weight (anterior part)

4-Cuboid bone

-lateral
-articulates with calcaneus (posterior) and with 4th and 5th metatarsal bones (anterior).
-cuboidal-shaped
-ant. to Talus

5-cuniforms

-wedged bones
-They are 3 in number
-beside each other
-Named from medial to lateral:
( medial, inter medial and lateral)
or
(1st to 3rd)
-Articulates with navicular bone---> prox.
-articulates with bases 1st, 2nd and 3rd metatarsal bones respectively--->dist.


♦MetaTarsal bones

-5 in number.
-named from medial to lateral: 1st, 2nd, 3rd, 4th and 5th.
-bases are proximal.
-heads are distal.
- Bases of 1st, 2nd, and 3rd articulate with cuniform bones.
- Bases of 4th and 5th articulate with cuboid bone.
-In the foot there are two arches: (lateral and medial arches):-
1-lateral arch formed by calcaneus, cuboid, and (4th and 5th) metatarsal bones.
2- Medial arch formed by calcaneus, talus, cuniforms, navicular bone, (1-3) metatarsal bones.
-the medial arch is larger and stronger than lateral one.
- (If one of these bones of medial or lateral arch is fractured flat foot resulted).


♦Phalanges:

-2 for big toe
-3 for lat. 4 toes
-total=14

*The leg*

Covered by:

Skin.

Superficial fascia: contains:

A. small saphenus vein with sural nerve.
B. great saphenus vein with saphenus nerve.

3- Deep fascia: -extends from tibial condyles to both malleoli (lateral and medial malleoli).
- Thickened at the ankle (anterior), to form two retinaculums:-
1-superior extensor retinaculum.
2-inferior extensor retinaculum.
-it sends two intermuscular septi: (anterior and posterior) attached to fibula.
-these two intermuscular septi in addition to interosseus membrane and deep transverse fascia divide the leg into three compartments (anterior, posterior and lateral).
-The posterior compartment is subdivided into superficial and deep layers by deep transverse fascia with part of deep fascia.
-Each compartment has its own muscles, own action, own nerve supply, own arterial supply…
Muscles of the anterior compartment.

Consists of:

Tibialis Anterior muscle.
Extensor Hallucis Longus. (Of the big toe).
Extensor Digitorum Longus.
Peroneus Tertius.

(further details for theses muscles are in the HAND-OUT)

-N.B:

*Peroneus : fibula.
*Tertius : the third.
*Hallucis :of big toe
-all originate from fibula except tibialis ant. which originate from tibia.
-all innervated by deep peroneal nerve (branch from common peroneal nerve).
-all supplied by anterior tibial artery (branch from popletial artery).
-all extend the ankle (dorsiflex).

***(Tom Has Very Nice Doges and Pigs)***
T: tibialis, H: hallucis, V: ant. tibial vessels, N: deep peroneal nerve, D: extensor digitorum, P: peroneal tertius.

-N.B: dorsiflex=extension of ankle(up)
Plantarflex=flexion of ankle(down)
-N.B:standing on lat. Edge of foot is called inversion
-N.B: peroneus tertius is considered as a part of ext.digitorum longus.
-N.B: ant. Compartment is between 2 muscles and a tough fascia so it's painful when walking on leg for a long time.

To see more details see pages 410 and 426 Grant’s Atlas.

I’d like to dedicate this sheet to all my colleagues in medicine faculty especially to:
Medicine faculty:
(Osama a7mad 3abed 5aleel 3othman), a7mad abo 7alawe, 7amzeh jssar, m2moon, 5aled 7ajeer, mo2ayad kittaneh, yazeed eneef, a7mad shalabeh, abo 3eed, yazan 3toom, abo dieh, Sami 3abdeen, a7mad 3abed, a7mad el3eesa, rami salame, abo qamar, abo ed3aig, anas 3lean, a7mad 7nai6e, m7mmad sboo3.
Engineering faculty:
a7mad ya3’i, 3mar samreen, mohannad, a7mad jamal, malik abo 3’aneeme, , naser zeer, osama, abo sabreen (ABS), khoole, jihad, m7ammad 7osam, abo 7a6abe (abo 5ashabe). J

Special thanks for Dr. Maher Al-Hadidi