The lower limb(1)

Muscles of lower limbThe muscles of lower limb are divided into: the muscles of hip, thigh, leg and foot.Muscles of hipanterior groupIliopsoas iliacus psoas major Psoas minor Tensor fasciae latae

Posterior groupGluteus maximus Gluteus medius Gluteus minimus Piriformis Obturator internus Quadratus femoris Obturator externus

Muscles of thigh

Anterior groupSartorius Quadricep Rectus femoris Vastus medialis Vastus lateralis Vastus intermedius

Medial group Pectineus Adductor longus Adductor brevis Adductor magnus Gracilis adduct thigh at hip joint

Posterior groupBiceps femoris Semitendinosus Semimembranosus flex the leg at knee joint extend the thigh at hip joint

Muscles of legAnterior groupTibialis anterior Extensor hallucis longus Extensor digitorum longus Peroneus tertius

Lateral groupPeroneus longus Peroneus brevis

plantarflex and evert the foot

Posterior group Superficial lager triceps surae Gastrocnemius Soleus Deep layer Popliteus Flexor digitorum longusFlexor hallucis longusTibialis posterior

Muscles of footMuscles on dorsum: extensor digitorum brevisMuscles in sole: medial, lateral and intermediate groups

Major muscles of lower limbIliopsoasOrigin: Psoas major: transverse processes and lateral surface of bodies of lumbar vertebraeIliacus: iliac fossaInsertion: lesser trochanter of femurAction: flexes thigh on trunkNerve supply: lumbar plexus

Gluteus maximusOrigin: gluteal surface of ilium and dorsal aspect of sacrumInsertion: gluteal tuberosity of femur and iliotibial tractAction: extends and laterally rotates thigh at hip joint; raises trunk when the lower limb is fixedNerve supply: inferior gluteal n.

Piriformis Origin: anterior surface of sacrumInsertion: greater trochanter of femurDivided the greater sciatic foramen into suprapiriform foramen and infrapiriform foramen Action: rotates thigh laterally at hip jointNerve supply: sacral plexus

SartoriusOrigin: anterior superior iliac spineInsertion: upper medial surface of tibiaAction: flexes hip and knee joints; rotates flexed knee mediallyNerve supply: femoral n.

Quadriceps femorisOrigin: Rectus femoris: anterior inferior iliac spineVastus medialis: medial lip of linea asperaVastus lateralis: lateral lip of linea asperaVastus intermedius: anterior surface of femurInsertion: tibial tuberosity via patellar ligamentAction: extends leg at knee joint; rectus femoris also flexes thigh at hip jointNerve supply: femoral n.

Tibialis anteriorOrigin: lateral surface of tibiaInsertion: medial cuneiform and base of 1st metatarsal Action: dorsiflexes and inverts footNerve supply: deep peroneal n.

Triceps suraeOrigin:Gastrocnemius: medial and lateral condyles of femurSoleus: soleal line of tibia and upper third of fibulaInsertion: calcaneum via tendo calcaneusAction: flexes knee joint and plantarflexes foot at ankle joint; steadies leg on foot during standing Nerve supply: tibial n.

Tibialis posteriorOrigin: posterior surface of tibia and ffibula and interosseous membraneInsertion: tuberosity of navicular, all cuniformsAction: plantarflexes and inverts footNerve supply: tibial n.

Arteries of lower limb Femoral a.Continuation of the external iliac a. Begins midpoint of inguinal ligamentPrincipal branch deep femeral a.: arises from the posterolateral surface of the femoral artery about 5 cm below the inguinal ligament. Distributed to all three muscle compartments by medial and lateral femoral circumflex and four perforating arteries of deep femoral a.

Popliteal a.Continuation of femoral a. at adductor hiatusDivided into anterior and posterior tibial arteries at lower border of poplitus Posterior tibial a.Passes downwars deep to gastrocnemius and soleus Passes behind medial mallealus by dividing into medial and lateral plantar arteriesBranches: peroneal a., medial and lateral plantar a,

Anterior tibial a. Descends on anterior surface of interosseous membraneIn front of ankle joint becomes dorsal a. of footDorsal a. of foot Passes forward between tendons of extensor longus and extensor digitorum longus to the proximal End of first intermetatarsal space

Obturator a.Branch of internal iliac a.Passes through the obturator foramen and enters medial compartment of thighsupplies obturator externus, pectineus, adductors of thigh, and gracilis

Veins of lower limb Deep veins: anterior and posterior tibial v. popliteal v. femoral v. external iliac v.Great saphenous v. Begins the medial end of dorsal venous arch of foodPasses anterior to the medial malleolus and ascends on the medial side of the leg, then passes behind the knee and curves forward around the medial side of the thigh Inclines anteriorly through the thigh to enter the femoral vein through the saphenous opening which lies about 3~4 cm below and lateral to the pubic tubercleTributaries: Superficial medial femoral v.Superficial lateral femoral v.External pudendal v.Superficial epigastric v.Superficial iliac circumflex v.

Small saphenous v.Arises from the lateral part of the dorsal venous arch of footAscends behind lateral malleolus and then passes upward to the midline of the clft Pierces the deep fascia and enters the popliteal v.It drains the lateral side of the foot and ankle and the back of the leg.

Lymph nodes and vessels of lower limbPopliteal ln.Embedded in the fatty connective tissue of popliteal fossa Receive superficial lymphatic vessels from posterolateral part of calf, and from deep lymphatic vessels accompanying anterior and posterior tibial a.Efferents pass to the deep inguinal ln.

Superficial inguinal lymph nodesSuperior group: Lies just distal to the inguinal ligamentReceive lymph from anterior abdominal wall below umbilicus, gluteal region, perineal region, external genital organsInferior group: Lies vertical along the terminal great saphenous v.Receives all superficial lymphatics of lower limb, except for those from the posterolateral part of calf Efferent vessels drain into the deep inguinal ln. or external iliac ln.

Deep inguinal lymph nodesLie medial to the femoral v. Receive deep lymphatics of lower limb, perineal region, and efferent lymphatics from the superficial inguinal ln.Drain into the external iliac ln.

Nerves of lower limbFemoral n.: supplies anterior thigh muscles (quadriceps, sartorius and pectineus), hip and knee joint, and skin on anteromedial side of thigh, saphenous nerve is distributed to skin of medial side of leg and footObturator n.: enters thigh through obturator foramen; supplies medial group of muscles of thigh, obturator externus, and skin of medial side of thigh

Branches of sacral plexus Superior gluteal n. leaves pelvis through suprapiriform foramen and passes between gluteus medius and minimus to supplies these muscles and tensor fasciae lataeInferior gluteal n. leaves pelvis through infrapiriform foramenand supplies gluteus maximusPosterior femoral cutaneous: leaves pelvis through infrapiniform foramen,runs deep to gluteus maximus, and emerges from ite inferior border to supply skin of buttock and then surface skin over posterior of thigh and calf

Sciatic n. Leaves pelvis through infrapiriform foramen to enter gluteal region, runs inferiorly laterally deep to gluteus maximus, passing midway between the greater trochanter of femur and ischial tuberosity to back of thigh, lying deep to long head of biceps femoris, normally divided into tibial and common peroneal nerves just above popliteal fossaInnervates semitendinosus, semimembranosus and biceps femoris and has articular branches to hip and knee joints

Common peroneal n. passes over posterior aspect of head of fibula and then winds around neck of fibula, deep to peroneus longus, where it divides into deep and superficial peroneal nervesDeep peroneal n. descends on interosseous membrane and enters dorsum of foot; supplies anterior muscles of leg, and skin of first interdigital cleftSuperficial peroneal n. supplies peroneus longus and brevis and skin on anterior surface of leg and dorsum of foot

Tibial n. Runs inferiorly with posterior tibial vessels and terminates beneath flexor retinaculum by dividing into medial and lateral plantar nervesSupplies posterior muscles of leg and knee joint

Regional anatomy of the lower limb

Parts and regions of the lower limbGluteal regionbetween iliac crest superiorly and gluteal fold inferiorly Thighbetween hip and kneekneejoint between leg and thighLegbetween knee and footAnkleFoot

Surface anatomyGluteal region and thighanterior superior and inferior iliac spinestubercle of iliac crestischial tuberositygreater trochanter, pubic tubercle, pubic crest, superior border of pubic symphysisKneepatella ligament, tuberosity of tibia, medial and lateral condyles and epicondyles, tendon of biceps femoris, tendons of semitendinosus and semimembranosus, head of fibulaLeganterior border of tibia, neck of fibulaAnkle and footmedial and lateral malleolus, calcaneal tuberosity, tuberosity of navicular bone, and tuberosity of fifth metatarsal bone

Anterior and Medial Region of ThighSuperficial structuressuperficial fasciaSuperficial arteries: superficial epigastric a. superficial iliac circumflex a. external pudendal a.Superficial veinsgreat saphenous v.,superficial epigastric v.superficial iliac circumflex v.external pudendal v.superficial medial femoral v.superficial lateral femoral v.Superficial inguinal lymph nodes: superior group inferior group Cutaneous nerves:lateral femoral cutaneous n. anterior and medial cutaneous branches of femoral n.

Deep fascia fascia lata Iliotibial tract Saphenous hiatus falciform margin cribriform fascia

Lacuna musculorum Bounded by lateral portion of inguinal ligament anteriorly, ilium posterolaterally, iliopectinal arch mediallyContents: iliopsoas, femoral n. and lateral femoral cutaneous n.

Lacuna vasorum

Bounded by medial portion of inguinal ligament anteriorly, pectineal ligament posteromedially, lacunar ligament medially, and iliopectinal arch posterolaterallyContents: femoral sheath, femoral a. and v., genital branch of genitofemoral n. and lymphatic vessels, femoral ring

Femoral triangleThis triangle is bounded by: the inguinal ligament (base) superiorly; the medial border of sartorius laterally; the medial border of adductor longus medially. Inferiorly, the apex of the triangle is continuous with adductor canal.The anterior wall is fascia lataThe posterior wall consists of adductor longus, pectineus and iliopsoas , from medial to lateral side.

Contents of the femoral triangle1. The femoral artery and its branchesthe profunda femoris arteryThe lateral and medial circumflex arteriesThe deep external pudendal2. The femoral vein and its tributaries.3. Three or four deep inguinal lymph nodes lie along the medial side of the femoral vein. 4. The femoral nerve.5. The femoral canal.

Femoral sheath The femoral sheath is a a funnel- shaped sheath , derived from transversalis fascia anteriorly and iliac fascia posteriorly. It surroumds the femoral vessels and lymphatic about 2.5cm belower the inguinal ligamemt. Its lower end disappears at the lower margin of the saphenous opening where the sheath fuses with the adventitia of the vessels.

The femoral sheath is divided into three compartments by two fibrous septa. The femoral artery occupies the lateral compartment of the sheath. The femoral vein lies the middle compartment. The medial compartment is small, called the femoral canal.

The femoral canal It is about 1.3cm long , and its upper opening is called the femoral ring . The boundaries of the femoral ring are: the inguinal ligament, anteriorly; the lacunar ligament medially; the pecten of pubis, posteriorly; the femoral vein, laterally. covered by femoral septum superiorly. The canal contains a little loose fatty tissue, a small lymph node, and some lymph vessels.

Femoral hernia A femoral hernia is common in women than in men (possibly due to a wider pelvis and femoral canal ). If a loop of intestine is forced into the femoral ring, it expands to form a swelling in the upper part of the thigh.

Femoral nerveIt arises from the lumbar plexus in the abdomen, and enters the thigh posterior to the inguinal ligament and lateral to the femoral artery. It ends by dividing into a number of branches 2 cm below the inguinal ligament. Muscular branche to: pectineus, sartorius, quadriceps femoris

Cutaneous branches: (1) Anterior cutaneous nerves of the thigh (medial and lateral). (2) Saphenous nerve is the longest branch of the femoral nerve. It accompanies the femoral vessels in the adductor canal, then accompanies the great saphenous vein to the medial side of the leg and food.

Femoral arteryThis is the main artery of the lower limb and is directly continuous with the external iliac artery of the abdomen behind the inguinal ligament at the mid- inguinal point. It becomes the popliteal artery by passing through the adductor tendinous opening.

Profunda femoris which arises from the posterolateral surface of the femoral artery about 5 cm below the inguinal ligament. Lateral circumflex artery It arises from the profunda near its origin and runs laterally among the branches of the femoral nerve and then deep to rectus femoris. Here it divides into ascending, transverse, and descending branches. Medial circumflex artery arises either from the profunda near its origin or occasionally direct from the femoral artery.

Femoral veinThis is the direct continuation of the popliteal vein. It begins at the adductor tendinous opening and accompanies the femoral artery to the inguinal ligament behind which it becomes the external iliac vein. The femoral vein contains several valves.

The deep inguinal lymph nodesThree or four deep inguinal lymph nodes lie along the medial side of the femoral vein. Afferent lymph vessels reach them from the superficial inguinal and popliteal lymph nodes and from the deep structures of the limb. Efferent lymph vessels pass from the deep inguinal nodes along the femoral vessels to the external iliac nodes on the external iliac vessels in the abdomen.

Adductor canalExtends from apex of femoral triangle to adductor hiatusBounded by vastus medialis laterally, adductors longus and magmus posteriorly, and adductor lamina and sartorius anteriorlyContents saphenous nerve, femoral a., femoral v., lymphatic vessels, and loose connective tissue

Blood vessels and nerve of medial side of thigh Obturator a. : arises from internal iliac artery in the lesser pelvis, passes through the obturator canal where it divides into anterior and posterior branches. Obturator n.: arises from the lumbar plexus in the abdomen. It enters the thigh through the obturator canal where it divides into anterior and posterior branches. The anterior branch descends anterior to the adductor brevis. The posterior branch descends between adductors brevis and magnus supplying both.

Front of the leg and dorsum of the foot Superficial veinsThe dorsal venous arch lies on the distal parts of the bodies of the metatarsals. It drains the dorsum of the foot and toes.The small saphenous vein runs posteriorly, passing first inferior and then posterior to the lateral malleolus. It ascends to the popliteal fossa in the back of the leg.The great saphenous vein passes posterioriy on the medial side of the foot. It ascends anterior to the medial malleolus, then obliquely across the distal third of the medial surface of the tibia.

Cutaneous nerves The upper two-thirds of the front of the leg is supllied by the saphenous nerve (L3,4) medially, and the lateral cutaneous nerve of the calf laterally. The lower third is supplied by the superficial peroneal and saphenous nerves. The dorsum of the foot is mainly supplied by the medial and intermediate cutaneous branches of the superficial peroneal nerve. However, the lateral margin is supplied by the sural nerve and the medial margin by the saphenous nerve proximally and the superficial peroneal distally. The first interdigital cleft and the skin immediately proximal to it are supplied by the deep peroneal nerve.

Deep fascia The deep fascia of the leg is very strong. Superior extensor retinaculum Inferior extensor retinaculum

Deep peroneal nerve It arises from the common peroneal nerve between the neck of the fibula and the peroneus longus muscle It descends in the anterior compartment of the leg with the anterior tibial vessels.It supplies all the muscles of the anterior compartment of the leg and extensor digitorum brevis. If the nerve is destroyed, dorsiflexion of the ankle and extension of the metatarsophalangeal joints is lost, and inversion is weakened the condition known as drop foot.

Anterior tibial artery It from the popliteai artery at the lower border of popliteus. It passes forwards above the interosseous membrane, and turns downwards on the anterior surface of that membrane with the deep peroneal nerve. It becomes the dorsalis pedis artery, midway between the malleoli.The anterior tibial veins are closely applied to the artery.

Dorsalis pedis artery It begins on the anterior surface of the ankle joint and runs with the deep peroneal nerve it divides into the arcuate artery and the first dorsal metatarsal artery at the proximal end of the first intermetatarsal space. On the dorsum of the foot it lies on the tarsal bones and is readily palpated against them between the tendons of extensor hallucis longus and extensor digitorum longus.

Dissetion

Superficial peroneal n. Deep peroneal n.

The gluteal region and back of thigh and leg

Cutaneous nervesMedial cluneal n.

suprapiriform forameninfrapiriform foramen

Structures passing suprapiriform foramenSuperior gluteal n., a., v. from lateral to medial sideStructures passing infrapiriform foramenSciatic n., posterior femoral cutaneous n., inferior gluteal n., a.,v., internal pudendal v., a., and pudendal n. from lateral to medial side

Pudendal nerve, internal pudendal artery These structures enter the gluteal region through the infrapiriform foramen. They then curve forwards to enter the perineum through the lesser sciatic foramen.

Sciatic nerve Course: It arises from the sacral plexus and passes through infrapiriform foramen into the gluteal region, deep to gluteus maximus, passing midway between the greater trochanter of femur and ischial tuberosity to back of thigh, the nerve lies deep to the long head of biceps on the posterior surface of adductor magnus. The sciatic nerve usually ends half-way down the back of the thigh by dividing into the common peroneal and tibial nerves. Distribution: semitendinosus, semimembranosus and biceps femoris and has articular branches to hip and knee joints

Relationship of sciatic n. to the piriformis

Boundaries of the popliteal fossa Diamond-shaped Upper lateral boundary: Biceps femoris Upper medial boundary: semimembranosus and semitendinosus Two lower boundaries are the heads of gastrocnemius Posterior wall: deep fascia Anterior wall: popliteal surface of the femur, the posterior capsule of the knee joint, and the fascia covering poplitells

Contents of the popliteal fossa Tibial and common peroneal nerves and their branchesPopliteal vein and its tributariesPopliteal artery and its branches Popliteal lympn nodesFatty tissue

Popliteal arteryIt begins at the adductor tendinous opening in. Here it is continuous with the femoral artery. It ends at the lower border of the popliteus muscle where it divides into anterior and posterior tibial arteries.Branches: 1. Superior, inferior, and middle genicular arteries 2. Muscular branches

Popliteal veinThis is formed by the junction of the anterior and posterior tibial veins near the lower border of the popliteus muscle. Popliteal lymph nodes There may be one or two nodes just under the deep fascia, close to the popliteal fossa vessels. They drain the deep tissues of the leg and foot and the knee joint. They also receive superficial lymph vessels from the lateral side of the foot, the heel, and the back of the calf. These drain along the line of the small saphenous vein.

The back of the legFind the small saphenous veinFind the Sural nerve and Peroneal communicating nerve

Find outGastrocnemius Soleus Plantaris Tibial nerve Popliteal artery and branches (Peroneal artery )Popliteus Flexor hallucis longus Flexor digitorum longus Tibialis posterior

Malleolar canalFormed by midial surface of calcaneus, flexor retinaculum and medial malleolusStructures passing Malleolar canalTibialis posterior Flexor digitirum longusPosterior tibial a. v. and n.Flexor hallucis longus