Leg Anatomy PDF

Leg Moore pp. 678-683, 746-763 John Gassler DPT DOSYS 702 Lecture 4, January 10, 2025 2  Learning Objectives - Leg At the end of this lecture the student will be able to: Describe the location of the cutaneous nerves and veins in the leg....

Leg Moore pp. 678-683, 746-763 John Gassler DPT DOSYS 702 Lecture 4, January 10, 2025 2  Learning Objectives - Leg At the end of this lecture the student will be able to: Describe the location of the cutaneous nerves and veins in the leg. Name and identify the important bony landmarks in the leg and ankle. Name and identify the muscles of the leg, their attachments, nerve supply, and actions. Describe the organization of the muscular compartments of the leg, the common function of the muscles in each compartment, and the nerve and arterial supply of each compartment. 3 3  Tibia and Fibula – Cross Section Interosseous Membrane Holds tibia and fibula together Provides surface for muscle attachment Separates anterior from posterior compartment Gilroy Fig 32.1D, p. 433 4 4  Tibia and Fibula - Distal (fibrous joint) Posterior malleolus Gilroy Fig 32.1A&B, p. 432 5 5  Foot Bones Regions Tarsal Bones Calcaneus (Clinical) Talus (Anatomical) Navicular Cuboid Medial cuneiform Intermediate cuneiform Lateral cuneiform Gilroy Fig 33.1, p. 452 6 6  Foot Bones Gilroy Fig 33.2C, p. 453 Gilroy Fig 33.2A, p. 452 7 7 Foot Bones - Lateral Gilroy Fig 33.2B, p. 452 8 8 Foot Bones - Medial Gilroy Fig 33.2D, p. 453 9 9  Leg Compartments Interosseous membrane Anterior Lateral Compartment Syndrome Posterior Intermuscular septa deep Crural fascia Crural fascia over the anterior tibia fuses with Posterior periosteum superficial 10 10  Leg Compartments Cross Section Anterior Lateral Deep Posterior Superficial Posterior 11 Gilroy Fig 35.2B, p. 501 11  Ankle Motions Occurs at talocrural joints Occurs at subtalar and talocalcaneonavicular joints 12 12  Anterior Leg Tibia is medial Anterior compartment lies lateral to shaft of tibia Tibia is subcutaneous (“shin”) Gilroy Fig 32.18A, p. 444 13 13 Anterior Leg Tibialis Anterior m. Extensor Hallucis Longus m. Extensor Digitorum Longus m. Fibularis Tertius m. Deep Fibular N. Gilroy Fi. 32.22B, p. 449 14 14  Anterior Leg Proximal Attachments Anterior tibia and fibula and interosseous membrane Gilroy Fig 32.19C, p. 445 15 15  EHL TA FT EDL 16 EDL 16  Anterior Leg mm. Distal Attachments/Actions Tibialis anterior – medial side of base of 1st metatarsal and medial cuneiform – dorsiflexion and inversion Tibialis Extensor hallucis longus – base of distal phalanx anterior of great toe - dorsiflexion, extension of great toe Extensor digitorum longus – dorsal digital expansions into bases of middle and distal phalanges of lateral 4 toes – dorsiflexion and eversion, extension of 4 small toes Fibularis tertius – base of 5th metatarsal bone – dorsiflexion, eversion 17 Gilroy Fig 32.22B, p. 449 17  Lateral Leg Both muscles originate from the shaft of the Fibularis Longus m. fibula Fibularis Brevis m. Superficial Fibular N. Both tendons pass posterior to the lateral malleolus on the lateral side of the ankle Gilroy Fig 32.21B, p. 448 18 18  Lateral Leg Fibularis Brevis m. Distal Attachment Attaches to tuberosity of the base of the 5th metatarsal bone Action – plantarflexion and eversion Gilroy Fig 32.21B, p. 448 19 19  Fibularis Longus m. Distal Attachment Passes under cuboid bone in groove Crosses plantar foot to attach to base of 1st metatarsal and medial cuneiform bones Action – plantarflexion and eversion 20 Gilroy Fig 32.21C, p. 448 20  Retinacula at the Ankle * * Gilroy Fig 33.18C, p. 467 21 21 FL FB FT 22 22 Posterior Leg mm. Superficial Group Gastrocnemius m. Soleus m. Plantaris m. Tibial N. Gilroy Fig 32.20A, p. 446 23 23  Gastrocnemius m. Medial and lateral heads Origin: medial and lateral femoral condyles posteriorly Combine to form Achilles tendon Insertion: posterior calcaneus Action: Plantarflexion; 20 – knee flexion Tibial N. Branch to each head 24 Gilroy Fig 32.23B, p. 450 24 Gastrocnemius m. Plantaris m. Prox. Attachment Same origin and insertion as lateral head of gastrocnemius Gilroy Fig 32.23B, p. 450 25 See Netter Plate 479 25  Plantaris m. Soleus m. Sole – from L. solea (sandal) Action: plantarflexion Origin: proximal tibia Innervation: tibial n. and fibula Insertion: posterior calcaneus Gilroy Fig 32.20B, p. 446 26 26 Tendocalcaneal bursa Lies between calcaneus and tendo-Achilles 27 Moore, fig. 7.102, p. 819 27 Deep Posterior Leg mm. Popliteus Flexor digitorum longus Tibialis posterior Flexor hallucis longus Flexor hallucis longus Flexor digitorum longus 28 Gilroy Fig 32.24B, p. 451 28  Deep Posterior Leg mm. Popliteus functions to unlock the knee joint when in full extension If foot is on ground, popliteus laterally rotates the femur on the tibia Popliteus m. O: Posterior tibia Flexor hallucis I: lateral epicondyle Flexor longus on femur digitorum longus Innervation: tibial n. Gilroy Fig 32.24B, p. 451 29 Medial condyle of femur is larger than lateral condyle. When extending the leg at the knee joint, as the joint comes into full extension, the lateral condyles cannot move any more, but the medial condyles can continue to move. This causes the femur to medially rotate on the tibia if there is weight bearing through the knee joint. If the foot is off the ground, the tibia will rotate laterally on the femur. When the fully-extended knee joint is locked in this position, the knee joint needs to be “unlocked” prior to flexion motion. If the foot is off the ground, the popliteus will medially rotate the tibia on the femur If there is weight bearing through the knee joint, the femur will laterally rotate on the tibia. 29 Deep Posterior Leg mm. Tibialis Posterior m. Flexor Digitorum Longus m. Flexor Hallucis Longus m. Origin: Posterior tibia, fibula, interosseous membrane Innervation: Tibial nerve 30 Gilroy Fig 32.20C, p. 447 30  Deep Posterior Leg mm. Distal Attachments/Actions The tendons of all three deep posterior leg muscles pass to the medial side of the ankle Insertions/Actions Tibialis posterior: navicular tuberosity, adjacent structures/Inversion Flexor digitorum longus: distal phalanges of small toes/small toe flexion Flexor hallucis longus: distal phalanx of great toe/great toe flexion Gilroy Fig 32.20A, p. 447 31 31  Tibialis Posterior m. Distal Attachment Tuberosity of navicular Medial cuneiform 32 Gilroy Fig 33.13A, p. 462 32  Tarsal Tunnel Formed by flexor retinaculum attaching between medial malleolus and calcaneus Gray’s Fig 6.105, p. 646 33 33 Tom Dick AN’ Harry and vein 34 34 Flexor Retinaculum Gilroy Fig 28.18B, p. 439 35 35  Deep Posterior Leg mm. Passage at ankle Gilroy Fig 28.14A, p. 435 36 36 Popliteal Region Posterior Leg Neurovascular Moore Fig 7.52B &7.54 37 37  Tibial Nerve L4,5,S1,2,3 Passes into posterior leg between the two heads of gastrocnemius Passes under tendinous arch of soleus Travels between superficial and deep posterior muscle groups Travels to medial side of ankle and passes deep to flexor retinaculum Gilroy Fig 34.36B, p. 494 38 38  Sural Nerve Medial sural cutaneous branch of Medial sural Sural cutaneous br. tibial n. communicating br. Travels into posterior leg between two heads of gastrocnemius Receives sural communicating branch from common fibular n. Combine to form sural n. Sural n. Passes to lateral side of ankle posterior to lateral malleolus Commonly used for nerve grafts Gilroy Fig 34.36A, p. 494 39 39  Sural n. at Ankle Passes to lateral side of ankle posterior to lateral malleolus Innervates lateral side of foot Gilroy Fig 34.39, p. 496 40 40  Common Fibular n. L4,5,S1,2 Located along distal tendon of biceps femoris m. Wraps around head of fibula Enters fibularis longus m. Splits into superficial and deep branches Gilroy Fig 34.39, p. 496 41 41 Superficial Fibular n. Superficial L5,S1,S2 fibular n. Travels distally in lateral compartment and innervates both fibularis mm. Gilroy Fig 34.23, p. 484 42 42 Superficial Fibular n. L5,S1,S2 Becomes cutaneous Superficial fibular n. after innervating lateral compartment mm. Innervates skin on dorsum of foot Gilroy Fig 34.39, p. 496 43 43  Deep Fibular n. L4,5,S1 Travels across lateral compartment through intermuscular septum to anterior compartment Travels distally deep between tibialis anterior and extensor digitorum longus Innervates all anterior compartment mm. 44 Gilroy Fig 34.40B, p. 497 44 Deep Fibular n. L4,5, S1 Passes into foot under extensor retinaculum with anterior tibial a. 45 Gilroy Fig 34.40B, p. 497 45  Popliteal A. -anterior tibial a. (A) -posterior tibial a. (P) Popliteal a. -fibular a. (P) - perforating branches (L) Split into anterior and posterior tibial aa. A – anterior compartment P – posterior compartments Fibular a. L – lateral compartment Posterior Popliteal a. passes between heads of gastrocnemius tibial a. At distal border of popliteus, splits into anterior and posterior tibial aa. Posterior tibial a. passes under tendinous arch of soleus Fibular a. branches off laterally to flexor hallucis longus 46 46  Posterior Tibial A. Travels distally between superficial and deep posterior compartments Travels to medial side of ankle Passes into foot deep to flexor retinaculum and posterior to medial malleolus Fibular A. Travels distally on lateral side of posterior compartment between superficial and deep compartments Travels deep to flexor hallucis longus Gilroy Fig 34.36B, p. 494 47 47  Anterior Tibial Artery Passes into anterior compartment after popliteal a. splits Travels distally in anterior compartment between tibialis anterior and extensor digitorum longus Crosses into foot deep to extensor retinaculum Gilroy Fig 34.40B, p. 497 48 48  Anterior Tibial A. Becomes dorsalis pedis a. on dorsum of foot Clinically important site for palpating pulses in distal lower limb Gilroy Fig 34.40B, p. 497 49 49  Cutaneous Nn. And Vv. Of Leg Great saphenous v. Lesser Saphenous n. saphenous v. Sural n. Superficial fibular n. Gilroy Fig 34.26A & B, p. 486 50 50  Venous Return in the Lower Limb One-way valves in limb veins prevent backflow of blood when in anatomical position In the leg, muscle contraction pumps blood against gravity toward the heart Varicose Veins – swelling of veins 51 Moore Fig 1.26 51  Compartment Comparison Anterior Posterior (Both) Lateral Ant tibial artery Post tibial artery Perforating branches of fibular artery Deep fibular nerve Tibial nerve Sup. fibular nerve Dorsiflex Plantarflexion Plantarflexion Inversion – Tib. Ant. Inversion – Tib. Eversion Eversion – Ext. Digit. Post. Longus 52 52  Practice Question Q: A male patient presents to the emergency department with a laceration on the upper lateral aspect of his leg. Physical examination reveals that the superficial fibular nerve has been severed near its origin. Which motion would most likely be affected? A: Ankle eversion B: Ankle inversion C: Ankle dorsiflexion D: Medial rotation of the leg E: Lateral rotation of the leg 53 53