Lower limb anatomy

Adductor brevis

Short adductor between two nerve divisions

Adductor longus

Superficial adductor at the femoral triangle

Adductor magnus

Broad hip adductor with a hamstring-like portion

Biceps femoris

Two-headed muscle along the outer posterior thigh

Extensor digitorum longus

Anterior leg muscle sending tendons to toes two through five

Extensor hallucis longus

Long extensor connecting the fibula to the great toe

Fibularis brevis

Shorter lateral leg muscle attaching to the fifth metatarsal

Fibularis longus

Lateral leg muscle whose tendon crosses beneath the foot

Fibularis tertius

Variable anterior-compartment muscle assisting foot eversion

Flexor digitorum longus

Long flexor reaching the tips of the four smaller toes

Flexor hallucis longus

Deep leg flexor carrying force to the great toe

Gastrocnemius

Two-headed calf muscle linking the knee and heel

Gluteus maximus

Large superficial muscle that drives hip extension

Gluteus medius

Broad lateral hip muscle supporting one-leg stance

Gluteus minimus

Deep gluteal muscle helping steady the hip joint

Gracilis

Slender medial-thigh muscle reaching the tibia

Iliacus

Broad iliac-fossa partner of psoas major

Inferior gemellus

Lower muscle bordering the obturator internus tendon

Obturator externus

Deep hip rotator arising outside the obturator membrane

Obturator internus

Pelvic-wall muscle with a tendon turning toward the hip

Pectineus

Short muscle bridging pubis and upper femur

Piriformis

Hip rotator marking routes through the greater sciatic foramen

Plantaris

Small calf muscle with a long, variable tendon

Popliteus

Deep knee muscle controlling rotation at the start of flexion

Psoas major

Spine-to-femur muscle contributing to hip flexion

Quadratus femoris

Short posterior hip muscle linking ischium and femur

Rectus femoris

Quadriceps muscle acting at both hip and knee

Sartorius

Long diagonal strap across the anterior thigh

Semimembranosus

Deep medial hamstring with an expanded proximal tendon

Semitendinosus

Medial hamstring ending in a long tibial tendon

Soleus

Deep calf muscle supporting standing and ankle push-off

Superior gemellus

Upper partner of the obturator internus tendon

Tensor fasciae latae

Lateral hip muscle that tensions the iliotibial tract

Tibialis anterior

Anterior leg muscle lifting and turning the foot inward

Tibialis posterior

Deep leg muscle helping support the medial foot arch

Vastus intermedius

Deep quadriceps component against the femur

Vastus lateralis

Large lateral contributor to knee extension

Vastus medialis

Medial quadriceps muscle supporting the extensor system

Bones

Calcaneus

Large tarsal bone forming the heel beneath the talus

Femur

Long thigh bone carrying load between hip and knee

Fibula

Slender lateral leg bone contributing to ankle stability

Hip bone (os coxae)

Fused ilium, ischium and pubis forming one side of the pelvis

Metatarsals

Five long bones connecting the tarsus with the toes

Patella

Sesamoid kneecap improving the quadriceps' mechanical advantage

Talus

Hindfoot bone linking the ankle with the foot below

Tibia

Main load-bearing bone on the medial side of the leg

Nerves

Common fibular (peroneal) nerve

Sciatic branch vulnerable where it curves around the fibular neck

Deep fibular (peroneal) nerve

Nerve for ankle dorsiflexion and the first dorsal toe web

Femoral nerve

Lumbar-plexus nerve supplying knee extension and anterior thigh sensation

Inferior gluteal nerve

Sacral-plexus motor route to gluteus maximus

Lateral femoral cutaneous nerve

Cutaneous nerve for the outer and front-outer thigh

Obturator nerve

Lumbar-plexus nerve serving most thigh adductors

Pudendal nerve

Somatic nerve carrying perineal sensation and sphincter control

Saphenous nerve

Femoral sensory branch extending along the medial leg

Sciatic nerve

Large sacral-plexus nerve containing tibial and fibular divisions

Superficial fibular (peroneal) nerve

Lateral-leg motor nerve continuing into dorsal foot skin branches

Superior gluteal nerve

Nerve to gluteus medius, gluteus minimus and tensor fasciae latae

Tibial nerve

Main nerve to posterior leg muscles and the plantar foot

Vessels

Anterior tibial artery

Arterial route through the front of the leg to the foot

Deep femoral (profunda femoris) artery

Deep arterial network supplying much of the thigh

Dorsalis pedis artery

Artery crossing the upper surface of the foot

External iliac artery

Main arterial route from the pelvis into the thigh

Femoral artery

Major arterial channel through the thigh toward the knee

Femoral vein

Deep venous return through the thigh

Great saphenous vein

Long superficial vein along the inner lower limb

Popliteal artery

Deep arterial supply behind the knee

Posterior tibial artery

Deep calf artery continuing into the sole

Small saphenous vein

Superficial venous route up the back of the calf

Organs

Deep inguinal lymph nodes

Deep groin nodes linking limb and pelvic lymph pathways

Popliteal lymph nodes

Lymph nodes accompanying the vessels behind the knee

Superficial inguinal lymph nodes

Subcutaneous groin nodes draining much of the lower body surface