The Lower Limb

1. The Lower Limb Pelvis, Thigh, Leg and Foot

2. Innervation

3. “Lumbosacral plexus” Lumbar Plexus Arises from L1-L4 Lies within the psoas major muscle Mostly anterior structures Sacral Plexus Arises from spinal nerve L4-S4 Lies caudal to the lumbar plexus Mostly posterior structures Plexuses of the Lower Limb

4. Diaphragm and posterior abdominal wall: The psoas major and minor muscles, the quadratus lumborum muscle. The lumbar plexus and its related nerves.

5. Lumbosacral plexus Lumbar plexus (T12- L4): 1- Obturator nerve (L2-L3-L4) 2- Femoral nerve (L2-L3-L4) 3- Lumbosacral trunk (L4-L5) 7- subcostal nerve (T12) 8- iliohypogastric N. (T12-L1) 9- ilioinguinal N. (L1) 10- genitofamoral N. (L1-L2) 11- lateral cutaneous N. of the thigh (L2-L3)

6. Femoral nerve Cutaneous branches Thigh, leg, foot (e.g. saphenous nerve) Motor branches Anterior thigh muscles (e.g. quadriceps, sartorius, iliopsoas) Obturator nerve Sensory Skin medial thigh; hip, knee joints Motor Adductor muscles Lateral femoral cutaneous Sensory Skin lateral thigh Genitofemoral Sensory Skin scrotum, labia major, anterior thigh Motor Cremaster muscle Lumbar Plexus

7. Lumbosacral plexus Sacral plexus: Sciatic nerve (roots): L4 L5 S1 S2 S3 *Sciatic nerve is the thickest nerve of body. *It is composed of Common Peroneal and Tibial nerves. *Com. Peroneal: composed of dorsal rami Tibial: composed of ventral rami *L4+L5= Lumbosacral trunk 3- Lumbosacral trunk 4- Sciatic nerve 5- common peroneal N. 6- tibial N. 12- posterior femoral cutaneous nerve 13- pudendal nerve 14- superior gluteal nerve

8. Sciatic Motor: Hamstring Branches into: Tibial nerve Cutaneous Posterior leg and sole of foot Motor Posterior leg, foot Common fibular (peroneal) nerve Cutaneous Anterior and lateral leg, dorsum foot Motor Lateral compartment, tibialis anterior, toe extensors Superior gluteal nerve Motor Gluteus medius and minimus, tensor fasciae latae Sacral Plexus

9. Inferior gluteal nerve Motor Gluteus maximus Posterior femoral cutaneous nerve Sensory Inferior buttocks, posterior thigh, popliteal fossa Pudendal nerve Sensory External genitalia, anus Motor Muscles of perineum Sacral Plexus (continued)

10. Vasculature

11. Common iliac (from aorta) branches into: Internal iliac Supplies pelvic organs External iliac Supplies lower limb Arteries

12. Internal iliac branches into: Cranial and Caudal Gluteals (Superior and Inferior) Gluteals Internal Pudendal Perineum, external genitalia Obturator Adductor muscles Other branches supply rectum, bladder, uterus, vagina, male reproductive glands Arteries

13. External iliac becomes……. Femoral Once passes the inguinal ligament Lower limb Branches into Deep femoral Adductors, hamstrings, quadriceps Branches intoMedial/lateral femoral circumflex Head and neck of femur Femoral becomes…… Popliteal (continuation of femoral) Branches into: Geniculars Knee Splits into: Anterior Tibial Anterior leg muscles, further branches to feet Posterior Tibial Flexor muscles, plantar arch, branches to toes Arteries

14. Deep Veins: Mostly share names of arteries Ultimately empty into Inferior Vena Cava Plantar Tibial Fibular Popliteal Femoral External/internal iliac Common iliac Superficial Veins Dorsal venous arch (foot) Great saphenous (empties into femoral) Small saphenous (empties into popliteal) Veins

15. Lower limb: Muscles, Nerves and Vessels

16. Arteries to the pelvis The internal iliac artery and it’s branches

17. Arteries of the pelvis and the thigh 5- abdominal aorta 4- common iliac artery 1- internal iliac artery 15- external iliac artery 19- femoral artery 24- deep femoral artery 25- medial circumflex femoral artery 27- lateral circumflex femoral artery 30- terminal branches of deep femoral artery, the perforating arteries. 33- descending genicular artery

18. Arteries of the leg 4-5: lateral and medial superior genicular aa. 6-7:lateral and medial inferior genicular aa. 8- medial (middle) genicular artery (piercing the oblique popliteal ligament to reach inside the knee joint). 1- Anterior tibial artery 2- posterior tibial artery 20- fibular artery 12- Dorsalis pedis artery

19. Arteries of the foot *When the Anterior tibial artery (1) passes Beneath the superior extensor retinaculum, It is called dorsal artery of the foot or Dorsalis Pedis artery (11). 12- shows where its pulsation can be felt. Ant. Tibial artery or Dorsalis pedis may give The lateral tarsal artery (13). Together, the lateral tarsal and dorsalis pedis Make the arcuate artery (14) giving rise to Metatarsal (15) and dorsal digital (16) arteries. *Dorsalis pedis gives a deep branch to join The plantar arch.

20. Arteries of the foot Posterior tibial artery(2) in the plantar region gives the medial (21) and lateral (23) Plantar arteries. Lateral plantar artery makes most part of the plantar arch (22) which give rise to plantar metatarsal arteries (24) and proper plantar digital arteries (25). The dorsal and plantar arches are connected via perforating branches. Pulsation of dorsalis pedis artery may be lost in some peripharal vascular diseases such as Burger’s disease or also in diabetes mellitus. Occlusion of blood vessels lead to gangrene. And even autoamputation of the first toe. Scars on the skin may develop.

21. Femoral hernia:

22. Subinguinal region 9- external pudendal vessels 10- superficial epigastric vessels 11- superficial circumflex iliac vessels

23. Anterior thigh region (deep) The femoral triangle Borders: Sartorius laterally Adductor longus, medially and also the floor Ilioinguinal ligament superiorly. Floor: iliopsoas m., pectineus m., and adductor longus. Content: A- lateral femoral cutaneous nerve B- Femoral nerve C- Structures inside the femoral sheath *Content of Femoral Ring: Femoral artery and genitofemoral N. (fem) Femoral vein Lymph nodes and areolar tissue (femoral Canal), the Rosenmuller node (they drain the Glans penis and clitoris) *Femoral hernia: painful, more in female, below and lateral to pubic tubercle.

24. Anterior thigh region (deep) Subsartorius (adductor, Hunter’s) canal: *Starts distal to femoral triangle. Content: Femoral artery and vein, saphenous nerve, nerve to Vastus medialis, small branches of Obturator nerve and great saphenous vein

25. Deep gluteal region: Greater sciatic foramen is divided by Piriformis muscle (2). Suprapiriformis hiatus: sup. Gluteal vessels (3, 4, 5) Infrapiriformis hiatus: Inferior Gluteal vessels (8,9) Internal pudendal artery and vein (10) Pudendal nerve (11) Posterior Cutaneous N. of the thigh (14) Sciatic nerve (15) Nerve to obturator internus (not shown) [18- inf. Clunial N., and 19- perineal N. are branches of posterior cutaneous N. of the thigh.] Int. pudendal artery, pudendal nerve and nerve to Obturator int. reenter the pelvis through lesser Sciatic foramen. Lesser Sciatic Foramen: Int. pudendal vessels. Pudendal nerve. Nerve to Obturator int. and tendon of Obturator internus.

26. Posterior femoral region Division of sciatic nerve Perforating vessels (artery and vein)

27. Popliteal region (superficial) 1- Greater saphenous vein (medially) 2- Saphenous nerve (medially) 3- Small saphenous vein 4- Medial sural cutaneous nerve 5- Branches of post. femoral cutaneous N.

28. Popliteal fossa: Diamond shape. Walls: Inferiorly: Gastrocnemius (medial and lateral heads) M. Superiorly: Semitendinosus and semimembranosus (medial) Biceps femoris (lateral) Its floor is composed of: Popliteal surface of femur, knee joint and upper Tibial bone, oblique popliteal ligament and Popliteal muscle with its covering fascia. Content of popliteal fossa: Popliteal artery Popliteal vein Tibial N. Common peroneal N. Genicular arteries and veins

29. Posterior region of the leg 1- triceps surae m. 2- gastrocnemius 3- soleus 4- calcaneal tendon 5- saphenous nerve 6- great saphenous vein 7- small saphenous vein 9- medial sural nerve 10- communicating branch (lateral sural N.) 11- sural nerve 12- lateral dorsal cutaneous nerve 15- common peroneal nerve 16- posterior tibial artery 17- peroneal (fibular artery 18- popliteal artery 19- anterior tibial artery 20- perforating branch of fibular artery

30. Medial retromalleolar region: 1-2, the Flexor retinaculum 3- greater saphenous vein 5- saphenous nerve Structures passing beneath the Flexor retinaculum (from medial to lateral): Tibialis posterior tendon (7) Flexor digitorum longus (8) Posterior tibial artery and veins (10, 11) Tibial nerve (12) Flexor Hallucis longus (9)

31. Muscles of the dorsum of the foot: Tendon of the long extensors of the foot, lie superficial to these muscles and they form a dorsal aponeurosis into which the short Extensors of the digits, plantar and dorsal Interosseous muscles radiate. Extensor digitorum brevis (6): Origin: Calcaneus (7) Insertion: with 3 tendons to dorsal aponeurosis (8). Function: dorsiflexion of these digits Innervation: Deep peroneal nerve (S1-S2). Extensor Hallucis brevis (9): Origin: Calcaneus Insertion: Dorsal aponeurosis of 1st digit Function: Dorsiflexion of 1st digit Innervation: Deep peroneal nerve (S1-S2). 10- tibialis anterior tendon 11- Peroneus tertius

32. Muscles of the sole of the foot: 1- Plantar Aponeurosis Consist of longitudinal and transverse fibers. It maintains the longitudinal arch of the foot and protects the vessels and nerves there. 5- Abductor Hallucis: Origin: Tuber Calcanei (6), plantar aponeurosis (7). Insertion: medial sesomoid bone (8) and base of proximal phalanx of 1st toe (9). Innervation: Medial plantar Nerve (L5-S1). 10- Fexor Hallucis Brevis: Origin: medial cuneiform bone (11) It has 2 heads. A medial head (12) which extends to medial sesamoid bone (13) and Its lateral head (15) extend to lateral sesamoid bone (16) and inserted on proximal phalanx of 1st toe. Innervation: Medial Plantar Nerve (L5-S1).

33. Muscles of the sole of the foot: 11- Flexor digitorum Brevis: Origin: tuber calcanei Insertion: middle phalax of 2nd-4th digits Innervation: Medial Plantar N (L5-S1). 1- Lumbriclas (4 ones) Tiny muscles originating from tendon (2) of the flexor digitorum longus (medial side). Insertion: Dorsal aponeurosis of 2nd-5th digit. Function: plantar flexion of these digits Innervation: Medial Plantar N to 1, and Lat Plantar N to 2, 3 and 4 (S2 and S3) 3- Quadratus Plantae: Origin: by 2 heads from calcaneus Insertion: lateral border of the tendon of the Flexor digitorum longus. Innervation: Lateral Plantar N. (S1-S2).

34. Muscles of the sole of the foot: Plantar interossei MM (3), Blue They have single head, Number 7 Originate from medial side of 3rd-5th metatarsals bones. Insertion: medial side of 3rd-5th digits. Function: Adductors of the digits Innervation: Lateral Plantar N (S2-S3). Dorsal interossei MM (4), Red They have 2 heads Number 9 Originate from opposing surface of all metatarsals Insertion: to base of 2nd-4th digits Function: Abductors of the digits Innervation: Lateral Plantar N (S2-S3).

35. Muscles of the sole of the foot: 1- Adductor Hallucis: Has 2 heads: oblique head (3) and the transverse head (9). Innervation: Lateral Plantar N (S1-S2) 7- Long Plantar Ligament 12-Opponens digiti minimi, Innervation: Lat Plantar N (S1-S2) 15-16: Flexor Digiti Minimi: Innervation: Lateral Plantar N (S1-S2) 18- Abductor Digiti Minimi Origin: calcaneus(20) and 5th metatarsal (21) Insertion: Base of proximal phalanx of the 5th digit (22). Innervation: Lateral Plantar N (S1-S2). 23- Quadratus Plantae

36. Plantar region superficial: Plantar aponeurosis (1)

37. Plantar region deep: Lateral plantar nerve (13) and Medial plantar nerve (4), innervate the muscles and skin of the plantar side. Plantar arteries and veins (15,16, 3, 4) are involved in blood supply and venous drainage of the plantar region of the foot.