2Objectives Know the retinaculae around the ankle and their relations. Discuss the characteristic features of joints of foot.Explain the layers of foot with their contents.Identify the muscles present in the layers of foot with their actions.Understand the arches of foot.
4Extensor RetinaculaA thickening of deep fascia that keeps the long tendons around ankle joint in positionSuperior Extensor retinaculum :Attached to anterior borders of tibia & fibula above ankleInferior Extensor retinaculum:Y-shaped band located inferior to ankle
5the stem of the Y being attached laterally to the upper surface of the calcaneus,
6Structures Passing Deep to Extensor Retinacula From medial to lateral:1.Tom2.Has3.Very (vessels)4.Nice ( nerve)5.Dog &6.Pigeon
7Peroneal Retinacula Superior peroneal retinaculum Connects the lateral malleolus to calcaneum & holds the tendons of peroneus longus & brevisInferior peroneal retinaculumSynovial Sheaths of Peroneal Longus & Brevis:Tendons of peronei are surrounded by a single common tubular synovial sheath,deep to inferior peroneal retinaculum, they have separate sheaths
8Deep Fascia of Dorsum of Foot It is very thin, but just distal to ankle joint, it isthickened to form Inferior extensor retinaculum
10Extensor Digitorum Brevis OriginInsertionActionAnterior part of upper surface of the Calcaneum and from the Inferior extensor retinaculumBy four tendons into the proximal phalanx of big toe and long extensor tendons to second, third, and fourth toesExtend toes
11Insertion of Long Extensor Tendons The tendons of Extensor digitorum longus pass to the lateral four toes.Each tendon to the 2nd , 3rd & 4th toes is joined on its lateral side by a tendon of Extensor digitorum brevis.The extensor tendons form a Fascial Expansion (Extensor Expansion) on the dorsum of each toe.The expansion divides into (3) parts.Central part: inserted into the Base of Middle ph.Two Lateral parts: inserted into the Base of Distal ph.The (Extensor Expansion) receives insertion of :Interossei & Lumbrical muscles.
13Synovial Sheaths of Extensor Tendons on the Dorsum of Foot Tibialis anterior Extensor hallucis longus (Both have its own synovial sheath) Extensor digitorum longus & peroneus tertius : have a common sheath, it extends to the level of Base of 5th Metatarsal bone.
14Flexor RetinaculumExtends from the back of the medial malleolus to the medial side of calcaneum
15Structures passing posterior to medial malleolus, deep to flexor retinaculum Medial to lateralTibialis posterior tendonFlexor digitorum longus tendonPosterior tibial artery with venae comitantesTibial nerveFlexor hallucis longus tendon
16From anterior to posterior: 1.Tom2.Does a3.Very (vessels)4.Nice ( nerve)5.Hat
17Sole : DEEP FASCIAThe plantar aponeurosis is a triangular thickening of the deep fascia that protects the underlying nerves, blood vessels, and muscles.Its apex is attached to the medial and lateral tubercles of the calcaneum.The base of the aponeurosis divides into five slips that pass into the toes.
18MUSCLES OF THE SOLE OF THE FOOT The muscles of the sole are conveniently described in four layers from superficial to deep.
19First Layer Abductor hallucis, Flexor digitorum brevis, Abductor digiti minimi
23Function of small muscles of Foot Unlike the small muscles of the hand, the sole muscles have few delicate functions and are chiefly concerned with supporting the arches of the foot.Although their names would suggest control of individual toes, this function is rarely used in most people
24Arches of Foot Medial longitudinal arch Is formed of calcaneum, talus, navicular, 3 cuneiform bones, and first medial 3 metatarsal bones.Lateral longitudinal arch Is formed of calcaneum, cuboid & lateral 4th & 5th metatarsal bonesTransverse archLies at the level of tarso-metatarsal joints, formed of bases of metatarsal bones, cuboid & 3 cuneiform bones.
26Function of Arches of the Foot Weight bearingSupport walking & runningProvide potential space neurovascular bundle of the soleAct as shock absorberIn young child the foot appears to be flat because of presence of a large amount of subcutaneous fat on the sole of foot
27Fibrous Flexor Sheaths The inferior surface of each toe, from the head of the metatarsal bone to the base of the distal phalanx, is provided with a strong fibrous sheath, which is attached to the sides of the phalanges.The fibrous sheath, together with the inferior surfaces of the phalanges and the interphalangeal joints, forms a blind tunnel in which lie the flexor tendons of the toes.
28Synovial Flexor Sheaths The tendons of the flexor hallucis longus and the flexor digitorum longus are surrounded by synovial sheaths