Lower Limb

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Irfan Dotani

General Structures	Bones	List of Muscles	Joints and Ligaments	Arteries	Veins	Nerves
Hip	Ilium, Ischium, Pubic Bone, Acetabulum, Foramen obturatum	Piriformis, Superior gemellus, Inferior gemellus, Tensor fasciae latae, Sartorius, Gluteus medius, Gluteus minimus	Iliofemoral ligament, Pubofemoral ligament, Ischiofemoral ligament, Hip joint capsule	Gluteal artery, Pudendal artery, Perforating arteries, Femoral artery, Obturator artery	Great saphenous vein, Femoral vein	Saphenous nerve, Obturator nerve, Femoral nerve, Clunial nerve, Sciatic nerve, Cutaneous nerve, Gluteal nerve, Pudendal nerve
Knee	Femur, Tibia, Patella	Quadriceps femoris muscle, Hamstring, Gastrocnemius muscle, Vastus mediali, Vastus lateralis muscle, Popliteus muscle, Soleus muscle, Articularis genus muscle	Anterior cruciate ligament (ACL), Posterior cruciate ligament (PCL), Medial collateral ligament (MCL), Lateral collateral ligament (LCL), patellofemoral joint, tibiofemoral joint	Genicular artery, Popliteal artery, Tibial artery	Varicose veins, Femoral veins	Sciatic nerve, Tibial nerve, Peroneal nerve,
Ankle	Fibula, Tibula, Talus, Medial malleolus, Lateral malleolus	Anterior tibial, Posterior tibial, Peroneal tibial, Extensors, Flexors	Tibiofibular ligament, Deltoid ligament, Tibiofibular Syndesmosis joint, Motrise Joint, Plantar fascia	Anterior tibial artery, Peroneal (fibular) artery, Anterior medial malieolar artery, plantar artery, communicating branch	Popliteal vein, saphenous vein, femoral vein, Tributaries of LSV	Peroneal vein, Sural nerve, Tibial nerve, Fibular nerve
Thigh	Femur, Tibia, Fibula	Quadriceps femoris muscle, Hamstring, Biceps femoris muscle, Vastus medialis, Adductor longus muscle, Vastus lateralis muscle, Sartorius muscle, Semitendinosus muscle, Semimembranosus muscle, Gracilis muscle, Adductor magnus muscle, Pectineus muscle, Adductor brevis muscle, Illiopsoas, Illiacus muscle, Tensor fasciae latae muscle, External obturator muscle, Quadratus femoris muscle, Articularis genus muscle	Hip joint capsule, Iliofemoral ligament, Pubofemoral ligament, Ischiofemoral ligament	Gluteal artery, Pudendal artery, Perforating arteries, Femoral artery, Obturator artery\	Great saphenous vein, Femoral vein	Saphenous nerve, Obturator nerve, Femoral nerve, Clunial nerve, Sciatic nerve, Cutaneous nerve, Gluteal nerve, Pudendal nerve
Foot	Phalanges, Metatarsals, Cuneiform bones, Cuboid bone, Navicular bone	Abductor hallucis muscle, Extensor digitorum brevis muscle, Flexor digitorum brevis muscle, Tibialis anterior muscle, Extensor hallucis longus muscle, Flexor hallucis brevis muscle, Plantar interossei muscles, Quadratus plantae muscle, Abductor digiti minimi muscle of foot, Lumbricals of the hand, Dorsal interossei of the foot, Extensor hallucis brevis muscle	Inferior (Distal) Tibiofibular Joint, Talocalcaneal Joint, Talocalcaneonavicular Joint, Calcaneocuboid Joint, Naviculocuneiform Joint, Cuboideonavicular Joint, Intercuneiform And Cuneocuboid Joints, Tarsometatarsal Joints, Intermetatarsal Joints, Metatarsophalangeal Joints, Interphalangeal Joints, Cuboideonavicular ligament, Intercuneiform ligament, Metatarsal ligament	Dorsalis pedis artery, Posterior tibial artery, Anterior tibial artery, Arcuate artery of the foot, Medial plantar artery, Plantar arc, Deep plantar artery, Plantar metatarsal arteries, Medial tarsal arteries, Proper plantar digital arteries	Superficial dorsal vein, Lateral plantar vein, Saphenous vein, Posterior tibial vein	Lateral plantar nerve, Tibial nerve, Medial plantar nerve, Plantar digital nerves

Lower limb bony structures

	Parts	Function	Image
Hip	Ilium	The ilium forms the sacroiliac joint with the sacrum along its medial side and forms the superior end of the hip joint at the acetabulum. The sacroiliac joint is a planar joint that allows a slight degree of gliding between the pelvis and the spinal column. The hip joint is a ball-and-socket joint that permits the thigh to have a free range of motion.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Ischium	Forms the lower and back part of the hip bone.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Pubic Bone	The ventral and anterior of the three parts that come together to create the pelvic bone.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Acetabulum	A cup-shaped opening on each side of the pelvic girdle formed where the ischium, ilium, and pubis all meet, and into which the head of the femur inserts.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Foramen obturatum	The large opening created by the ischium and pubis bones of the pelvis through which nerves and blood vessels pass.	<figure-inline><figure-inline></figure-inline></figure-inline>

	Parts	Function	Image
Knee	Femur	Supports the weight of the body and allowing motion of the leg. The femur articulates proximally with the acetabulum of the pelvis forming the hip joint, and distally with the tibia and patella to form the knee joint.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Tibia	It forms the knee joint with the femur and the ankle joint with the fibula and tarsus.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Patella	The patella increases the leverage that the quadriceps tendon can exert on the femur by increasing the angle at which it acts. Also acts as protection for the muscles underneath the patella.	<figure-inline><figure-inline></figure-inline></figure-inline>

	Parts	Function	Image
Ankle	Fibula	Long, thin and lateral bone of the lower leg. It runs parallel to the tibia, or shin bone, and plays a significant role in stabilizing the ankle and supporting the muscles of the lower leg.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Tibula	Known as the shinbone and is the second largest bone in the body. Helps with weight-bearing and stabilization.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Talus	The talus bone forms the primary connection between the lower leg and foot and is vital for mobility. In fact, the structure of the talus bone is so unique it can form the connection between numerous other bones such as the tibia, fibula, calcaneus (heel) and navicular or tarsal bones found in the foot.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Medial malleolus	The medial malleolus is the prominence on the inner side of the ankle, formed by the lower end of the tibia.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Lateral malleolus	The lateral malleolus is the prominence on the outer side of the ankle, formed by the lower end of the tibia.	<figure-inline><figure-inline></figure-inline></figure-inline>

	Parts	Function	Image
Thigh	Femur	Supports the weight of the body and allowing motion of the leg. The femur articulates proximally with the acetabulum of the pelvis forming the hip joint, and distally with the tibia and patella to form the knee joint.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Tibia	It forms the knee joint with the femur and the ankle joint with the fibula and tarsus.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Fibula	Long, thin and lateral bone of the lower leg. It runs parallel to the tibia, or shin bone, and plays a significant role in stabilizing the ankle and supporting the muscles of the lower leg.	<figure-inline><figure-inline></figure-inline></figure-inline>

	Parts	Function	Image
Foot	Phalanges	The phalanges of the foot help us balance, walk, and run.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Metatarsals	Metatarsals are convex in shape (arch upward), are long bones, and give the foot its arch. They work with connective tissues, ligaments, and tendons to provide movement in the foot	<figure-inline><figure-inline></figure-inline></figure-inline>
	Cuneiform bones	This bone is cube-shaped and connects the foot and the ankle. It also provides stability to the foot.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Cuboid bone	The cuboid bone is one of the seven tarsal bones located on the lateral (outer) side of the foot. This bone is cube-shaped and connects the foot and the ankle. It also provides stability to the foot.	<figure-inline><figure-inline></figure-inline></figure-inline>
	Navicular bone	The navicular is a boat-shaped bone located in the top inner side of the foot, just above the transverse. It helps connect the talus, or anklebone, to the cuneiform bones of the foot	<figure-inline><figure-inline></figure-inline></figure-inline>

Lower limb muscles

	Muscle	Function	Insertion/Arise	Innervation	Blood supply	Image
Hip	Piriformis	Part of the lateral rotators of the hip, along with the quadratus femoris, gemellus inferior, gemellus superior, obturator externus, and obturator internus The piriformis laterally rotates the femur with hip extension and abducts the femur with hip flexion	Arise: The front of the sacrum by three fleshy digitations Attached to the portions of bone between the first, second, third, and fourth anterior sacral foramina, and to the grooves leading from the foramina A few fibers also arise from the margin of the greater sciatic foramen, and from the anterior surface of the sacrotuberous ligament. Insertion: The muscle passes out of the pelvis through the greater sciatic foramen, the upper part of which it fills It is inserted by a rounded tendon into the upper border of the greater trochanter behind, but often partly blended with, the common tendon of the obturator internus and superior and inferior gemellus muscles.	Piriformis nerve: Arise from posterior division of the ventral rami of the first and second sacral nerves	Branches of the internal iliac artery: Inferior gluteal Superior gluteal Internal pudendal arteries	<figure-inline></figure-inline>
	Superior gemellus	Help to steady the femoral head in the acetabulum. Help to laterally rotate the extended thigh and abduct the flexed thigh at the hip.	Insertion: Medial surface of greater trochanter of the femur, in common with obturator internus. Arise: The Gemellus inferior arises from the upper part of the tuberosity of the ischium, immediately below the groove for the Obturator internus tendon.	Innervation: Nerve to the obturator internus or nerve to quadratus femoris or both (L4-S1)	Arterial supply: Inferior gluteal artery	<figure-inline></figure-inline>
	Inferior gemellus	Help to laterally rotate the extended thigh and abduct the flexed thigh at the hip.	Insertion: Medial surface of greater trochanter of the femur, in common with obturator internus. Arise: Arises from the outer (gluteal) surface of the spine of the ischium, blends with the upper part of the tendon of the Obturator internus.	Innervation: Nerve to the quadratus femoris or nerve to the obturator internus or both (L4-S1).	Arterial supply: Inferior gluteal artery	<figure-inline></figure-inline>
	Tensor fasciae latae	Works in synergy with the gluteus medius and gluteus minimus muscles to abduct and medially rotate the femur. The TFL is a hip abductor muscle. Helps stabilize and steady the hip and knee joints by putting tension on the iliotibial band of the fascia.	Insertion: Iliotibial band Arise: Anterior superior iliac spine, outer lip of anterior iliac crest and fascia latae	Innervation: Superior gluteal nerve (L4, L5, S1)	Arterial supply: Superior gluteal and lateral circumflex femoral artery.	<figure-inline></figure-inline>
	Sartorius	Flexes and laterally rotates the hip joint and flexes the knee.	Insertion: Superior aspect of the medial surface of the tibial shaft near the tibial tuberosity. Arise: Anterior superior iliac spine.	Innervation: Femoral nerve	Arterial supply: Muscular branches of the femoral artery.	<figure-inline></figure-inline>
	Gluteus medius	Major abductor of the thigh; anterior fibers help to rotate hip medially; posterior fibers help to rotate hip laterally	Insertion: Lateral and superior surfaces of the greater trochanter. Arise: Dorsal ilium inferior to the iliac crest	Innervation: Superior gluteal nerve (L4, L5, S1)	Arterial supply: Superior gluteal artery	<figure-inline></figure-inline>
	Gluteus minimus	Abducts and medially rotates the hip joint.	Insertion: Interior surface of the greater trochanter. Arise: Dorsal ilium between inferior and anterior gluteal lines; also from the edge of the greater sciatic notch.	Innervation: Superior gluteal nerve (L4, L5, S1)	Arterial supply: Superior gluteal artery	<figure-inline></figure-inline>
	Gluteus maximus	Major extensor of hip joint, assists in laterally rotating the thigh; upper and middle third section of the muscle are abductors.	Insertion: Primarily in fascia lata at the iliotibial band; also into the gluteal tuberosity on the posterior femoral surface. Arise: Posterior aspect of dorsal ilium posterior to the posterior gluteal line, posterior superior iliac crest, a posterior inferior aspect of sacrum and coccyx, and sacrotuberous ligament.	Innervation: Inferior gluteal nerve (L5, S1, S2)	Arterial supply: Inferior and superior gluteal arteries and the first perforating branch of the profunda femoris artery.	<figure-inline></figure-inline>

	Muscle	Function	Insertion/Arise	Innervation	Blood supply	Image
Knee	Quadratus Femoris	Rotates the hip laterally; also helps adduct the hip.	Insertion: Quadrate tubercle and adjacent bone of intertrochanteric crest of the proximal posterior femur. Arise: Lateral margin of obturator ring above ischial tuberosity.	Innervation: Quadratus femoris branch of nerve to the quadratus femoris and inferior gemellus (L5, S1)	Arterial supply: Medial circumflex femoral artery, inferior gluteal artery, 1st - 4th perforating arteries, obturator artery, and some superior muscular branches of popliteal artery.	<figure-inline></figure-inline>
	Gastrocnemius muscle	Powerful plantar flexor of the ankle.	Insertion: The two heads unite into a broad aponeurosis which eventually unites with the deep tendon of the soleus to form the Achilles tendon, inserting on the middle 1/3 of the posterior calcaneal surface. Arise: Medial head from posterior nonarticular surface of medial femoral condyle; Lateral head from lateral surface of femoral lateral condyle.	Innervation: Tibial nerve (S1, S2)	Arterial supply: Each head supplied by a sural branch of the popliteal artery.	<figure-inline></figure-inline>
	Vastus medialis	Extends the knee.	Insertion: Medial base and the border of the patella; also forms the medial patellar retinaculum and medial side of quadriceps femoris tendon. Arise: Inferior portion of intertrochanteric line, spiral line, medial lip of linea aspera, superior part of medial supracondylar ridge of femur, and medial intermuscular septum.	Innervation: Muscular branches of femoral nerve.	Arterial supply: Femoral artery, profunda femoris artery, and superior medial genicular branch of popliteal artery.	<figure-inline></figure-inline>
	Vastus lateralis muscle	Extends the knee.	Insertion: Lateral base and the border of the patella; also forms the lateral patellar retinaculum and lateral side of quadriceps femoris tendon. Arise: Superior portion of the intertrochanteric line, anterior and inferior borders of the greater trochanter, superior portion of the lateral lip of linea aspera, and lateral portion of the gluteal tuberosity of femur.	Innervation: Muscular branches of the femoral nerve.	Arterial supply: Lateral circumflex femoral artery.	<figure-inline></figure-inline>
	Popliteus	Rotates knee medially and flexes the leg on the thigh.	Insertion: Posterior surface of the tibia in a fan-like fashion, just superior to the popliteal line. Arise: Anterior part of the popliteal groove on the lateral surface of the lateral femoral condyle.	Innervation: Tibial nerve (L4, L5, S1)	Arterial supply: Medial inferior genicular branch of the popliteal artery and muscular branch of the posterior tibial artery.	<figure-inline></figure-inline>
	Soleus	Powerful plantar flexor of the ankle.	Insertion: Eventually unites with the gastrocnemius aponeurosis to form the Achilles tendon, inserting on the middle 1/3 of the posterior calcaneal surface. Arise: Posterior aspect of the fibular head, upper 1/4 - 1/3 of the posterior surface of fibula, middle 1/3 of medial border of tibial shaft, and from the posterior surface of a tendinous arch spanning the two sites of bone origin.	Innervation: Tibial nerve (S1, S2)	Arterial supply: Posterior tibial, peroneal, and sural arteries.	<figure-inline></figure-inline>

	Muscle	Function	Insertion/Arise	Innervation	Blood supply	Image
Ankle	Anterior tibial	Dorsiflexor of ankle and invertor of foot	Insertion: Medial and plantar surfaces of 1st cuneiform and on the base of the first metatarsal. Arise: Lateral condyle of tibia, proximal 1/2 - 2/3 or lateral surface of tibial shaft, interosseous membrane, and the deep surface of the fascia cruris.	Innervation: Deep peroneal nerve (L4, L5, S1)	Arterial supply: Anterior tibial artery	<figure-inline></figure-inline>
	Posterior tibial	Principal invertor of the foot; also adducts foot, plantar flexes ankle, and helps to supinate the foot.	Insertion: Splits into two slips after passing inferior to a plantar calcaneonavicular ligament; superficial slip inserts on the tuberosity of the navicular bone and sometimes medial cuneiform; deeper slip divides again into slips inserting on plantar surfaces of metatarsals 2 - 4 and second cuneiform. Arise: Posterior aspect of interosseous membrane, superior 2/3 of medial posterior surface of fibula, superior aspect of posterior surface of tibia, and from intermuscular septum between muscles of posterior compartment and deep transverse septum.	Innervation: Tibial nerve (L4, L5)	Arterial supply: Muscular branches of sural, peroneal and posterior tibial arteries.	<figure-inline></figure-inline>
	Extensor Digitorum Longus	Extend toes 2 - 5 and dorsiflexes ankle.	Insertion: Splits into 4 tendon slips after inferior extensor retinaculum, each of which inserts on the dorsum of middle and distal phalanges as part of extensor expansion complex. Arise: Lateral condyle of tibia, upper 2/3 - 3/4 of medial fibular shaft surface, upper part of interosseous membrane, fascia cruris, and anterior intermuscular septum.	Innervation: Deep peroneal nerve (L4, L5, S1)	Arterial supply: Anterior tibial artery	<figure-inline></figure-inline>
	Extensor Hallucis Longus	Extends great toe and dorsiflexes ankle.	Insertion: Base and dorsal center of distal phalanx of great toe. Arise: Anterior surface of the fibula and the adjacent interosseous membrane.	Innervation: Deep peroneal nerve (L4, L5, S1)	Arterial supply: Anterior tibial artery	<figure-inline></figure-inline>
	Flexor Digitorum Longus	Flexes toes 2 - 5; also helps in plantar flexion of the ankle.	Insertion: Splits into four slips after passing through the medial intermuscular septum of the plantar surface of the foot; these slips then insert on a plantar surface of bases of 2nd - 5th distal phalanges. Arise: Posterior surface of a tibia distal to the popliteal line.	Innervation: Tibial nerve (S2, S3)	Arterial supply: Muscular branch of the posterior tibial artery.	<figure-inline></figure-inline>
Flexor Hallucis Longus	Flexes great toe, helps to supinate ankle, and is a very weak plantar flexor of the ankle.	Insertion: Plantar surface of the base of distal phalanx of the great toe. Arise: Inferior 2/3 of the posterior surface of fibula, the lower part of the interosseous membrane.	Innervation: Tibial nerve (S2, S3)	Arterial supply: Muscular branch of peroneal and posterior tibial artery.	<figure-inline></figure-inline>

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