Presentation on theme: "Leg Muscles. OBJECTIVES -Identify and name the contents of the muscular compartments of the leg. -Name the muscles causing plantar flexion, dorsiflexion,"— Presentation transcript:
OBJECTIVES -Identify and name the contents of the muscular compartments of the leg. -Name the muscles causing plantar flexion, dorsiflexion, eversion, inversion, flexion of digits and extension of digits. -Identify the neurovasculature behind the knee and in the leg
Tibia and fibula: -held together by an interosseuos membrane. -anterior border of tibia is subcutaneous from the tibial condyles to its distal end. [Shin] -only the distal ¼ of fibula is subcutaneous The distal ends are held together to form the proximal articular surface of ankle. Each ends subcutaneously as a Malleolus (medial – tibial and lateral - fibular). Proximal and distal tibio-fibular joints interosseous membrane Lateral malleolus Medial malleolus
Plantarflexion / dorsiflexion: (ankle jt) Flexion / extension:(digits) Inversion / eversion: Complex twisting movement at transverse tarsal and subtalar jts. [inter-tarsal joints]
The deep fascia surrounds the leg and attached to Anterior & Medial borders of Tibia. Three Intermuscular Septa Pass from the deep aspect of this fascia to be attached to : Anterior border of fibula (Anterior fascial septum) Posterior border of fibula (Posterior fascial septum) Transverse intermuscular septum Interosseous membrane: A thin & strong membrane, that binds the interosseous borders of tibia & fibula. It binds the two bones and provides attachment for muscles.
Together with the interosseus membrane, the septa divide the leg into (3) Compartments : 1-Anterior 2-Lateral (peroneal) 3-Posterior Each has its own Muscles, Blood and Nerve supply.
Anterior Compartment MUSCLESNERVE SUPPLY TIBIALIS ANTERIOR DEEP PERONEAL Extensor Digitorum Longus PERONEUS TERTIUS Extensor Hallucis LONGUS
Anterior compartment of leg: -tibialis anterior -extensor hallucis longus -extensor digitorum longus (fibularis tertius) All supplied by the deep fibular (peroneal) nerve. Hallux = big toe [hallucis] Tendons are bound down by extensor retinaculum as they cross the ankle jt. Function: -dorsiflexion (ankle) -extension (digits) -inversion tibialis anterior extensor digitorum longus extensor hallucis longus extensor retinaculum
extensor digitorum longus extensor hallucis longus Tibialis Anterior Deep dissection Anterior view: Note vulnerability of common fibular (peroneal) nerve as it winds around the neck of fibula. Superficial Fibular n. Common Fibular n. Deep Fibular n. DROP FOOT??????
Peroneus Longus Origin Insertion Action Lateral surface of shaft of fibula Base of first metatarsal and the medial cuneiform Plantar flexes foot at ankle joint; Everts foot at subtalar and transverse tarsal joints; Supports Lateral longitudinal & Transverse arches
Peroneus Brevis Insertion Action Origin Lateral surface of shaft of fibula Base of fifth metatarsal bone Plantar flexes foot at ankle joint; Everts foot at subtalar and transverse tarsal joint; Supports Lateral longitudinal arch of foot
Tendons of peronei are surrounded by a single common tubular synovial sheath, deep to inferior peroneal retinaculum, they have separate sheaths Tendons of peronei are surrounded by a single common tubular synovial sheath, deep to inferior peroneal retinaculum, they have separate sheaths Superior peroneal retinaculum Connects the lateral malleolus to calcaneum & holds the tendons of peroneus longus & brevis Inferior peroneal retinaculum Superior peroneal retinaculum Connects the lateral malleolus to calcaneum & holds the tendons of peroneus longus & brevis Inferior peroneal retinaculum
Diamond-shaped region Posterior to knee bounded: Sup.Medially: semimembranosus / semitendinosus Sup.Laterally: -biceps femoris Inferiorly: -medial & lateral heads of gastrocnemius.
Contents: 1. 1. Popliteal vessels 2. Small saphenous vein 3. Tibial nerve. 4. Common peroneal nerve. 5. Posterior cut. nerve of thigh. 6. Connective tissue & popliteal lymph nodes.
21 Contents: 1.Superficial group of muscles 2.Deep group of muscles 3.Posterior tibial artery 4.Tibial nerve The transverse intermuscular septum of the leg is a septum divides the muscles of the posterior compartment into superficial and deep groups.
25 MuscleOriginInsertionNerveAction Gastroc nemius Lateral head from lateral condyle of femur & medial head from above medial condyle Posterior surface of calcaneum via tendo calcaneus Tibial Plantar flexes foot at ankle joint; flexes knee joint Plantaris Lateral supracondylar ridge of femur Posterior surface of calcaneum Tibial Plantar flexes foot at ankle joint; flexes knee joint Soleus Shafts of tibia and fibula Posterior surface of calcaneum via tendo calcaneus TibialTogether with gastrocnemius and plantaris is powerful plantar flexor of ankle joint; provides main propulsive force in walking and running
Popliteus Lateral surface of lateral condyle of femur (Intracapsular) Post surface of shaft of tibia above soleal line Tibial Flexes leg at knee joint; Unlocks knee joint by lateral rotation of femur on tibia Flexor digitorum longus Posterior surface of shaft of tibia Bases of distal phalanges of lateral four toes Tibial Flexes distal phalanges of lateral four toes; plantar Flexes foot at ankle joint; Supports medial and lateral longitudinal arches Flexor hallucis longus Posterior surface of shaft of fibula Base of distal phalanx of big toe Tibial Flexes distal phalanx of big toe; plantar flexes foot at ankle joint; supports medial longitudinal arch Tibialis posterior Posterior surface of shafts of tibia and fibula and interosseous membrane Tuberosity of navicular bone and other neighboring bones. TibialPlantar flexes foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; supports medial longitudinal arch
Posterior (deep) compartment of leg: -Tibialis posterior -Flexor digitorum longus -Flexor hallucis longus Tendons are bound down by flexor retinaculum as they pass into foot behind the medial malleolus. Functions:-plantarflexion -flexion -inversion Innervated by Tibial nerve. flexor hallucis longus tibialis posterior flexor digitorum longus flexor retinaculum
Blood supply to the lower limb: Thigh: -Femoral artery and branches: (profunda, medial & lateral circumflex) Behind knee: -Popliteal artery Leg: -divides into anterior and posterior tibial arteries. to supply these compartments. The posterior tibial artery gives off the fibular (peroneal) artery to supply the lateral compartment. popliteal a. posterior tibial a. anterior tibial a. fibular artery
AnteriorPosterior Anterior, lateral, medial thigh ( lumbar plexus). - branches of femoral n. - lateral femoral cutaneous n.) Posterior thigh – from sacral plexus. Anteromedial leg – branch of femoral n. (Saphenous nerve). Posterolateral leg – from Sciatic n. (Sural nerve). Anterior leg: - From Sciatic n. (Superficial fibular n.) saphenous nerve Post. femoral cutaneous n. sural nerve Cutaneous innervation of thigh and Leg L4 S1
Great Saphenous vein: Drains into femoral vein in femoral triangle Small Saphenous vein: Drains into popliteal vein Superficial drainage of the lower limb FYI - varicose veins