INNERVATION OF LOWER LIMB

MARYAM JAMILAH BINTI ABDUL HAMID082013100002

IMS BANGALORE

OBJECTIVE Able to identify the origin, course and

termination of nerves. Able to annotate the nerves in the

diagram Able to describe muscles supplied by

the nerves

1) LUMBAR PLEXUS

A)ILIOHYPOGASTRIC NERVEOrigin: T12-L1Branch: Lateral and anterior cutaneousbranchesPath: Skin above the pubis Over the lateral side of the buttockModality: Motor and general sensory

B)ILIOINGUINAL NERVEOrigin: T12-L1-Accompanies the spermatic cord through

theinguinal canalBranch:  anterior scrotal or labial

branchesPath: skin of scrotum or labia majora adjacent part of thighModality: general sensory.

C)GENITOFEMORAL NERVEOrigin: L1-L2-Accompanies the spermatic cord through

theinguinal canalBranch:  genital and femoral branchesPath: skin of scrotum or labia majora cremaster muscle adjacent part of thigh & femoral triangleModality: general sensory and motor.

CI) GENITAL BRANCH passes through the deep inguinal ring

 and enters the inguinal canal. In men, the genital branch continues

down and supplies the scrotal skin. In women, the genital branch

accompanies the round ligament of uterus, terminating in the skin of the mons pubis and labia majora

CII) FEMORAL BRANCH The femoral branch passes underneath

the inguinal ligament Travelling adjacent to the external iliac

artery Supplying the skin of the upper, anterior

thigh.

D) LATERAL CUTANEOUS NERVE Origin: L2-L3Branch: Anterior and posterior branchPath/Supply: Anterolateral side of the thigh Anterior part of the gluteal region

DI)ANTERIOR BRANCHBecomes superficial about 10 cm below the inguinalLigament

Divides into branches-supply anterior and lateral parts of the thigh, as far as the knee.

Terminal:Meet anterior cutaneous branches of the femoral nerveand infrapatellar branch of the saphenous nerve toform peripatellar plexus.

DII)POSTERIOR BRANCHOrigin: Lateral cutaneous nerve

Branch: Filaments which pass backward across

the lateral and posterior surfaces of the thigh

-Supply: skin from the level of the greatertrochanter to the middle of the thigh

Path: Pierce into fascia lata

E) FEMORAL NERVEOrigin: L2,L3,L4

Emerges at lateral border of psoas major muscle in abdomen. Passes downwards between psoas major and iliacus muscles. Nerve enters the thigh behind inguinal ligament,lateral to femoral sheath as its formation is behind fascia iliaca.

Modality: general sensory and motor.

Path: enter femoral triangle by passing behind

inguinal ligament In thigh: in the groove between iliacus and

psoas major. NOT in the femoral sheath (located posterior

of the femoral sheath)Branch: Muscular, cutaneous, articular and

vascular

EI) MUSCULARAnterior Posterior

sartorius Rectus femoris, three vasti

(lateralis,intermedius and

medialis) & articularis genu

EII)CUTANEOUSAnterior Posterior

intermediate

Saphenous nervemedial

EIII)ARTICULAR Hip joint (nerve to rectus femoris) Knee joint (nerve to three vasti)

To the femoral artery and its branchesEIV)VASCULAR

F)OBTURATOR NERVEChief nerve of the medial compartment of the thigh

Origin: L2,L3,L4Supply: Adductor muscles of thighDivided into two; anterior and posterior

FI) ANTERIOR DIVISIONSupply:- Pectineus Adductor longus Gracilis Adductor brevis (ocassionally)

FII) POSTERIOR DIVISIONSupply:- Obturator externus Adductor magnus Adductor brevis (ocassionally)

G)ACCESSORY OBTURATOR NERVEOrigin: L3,L4

Descends along the medial border of psoas major, crosses the superior ramus of the pubis behind pectineus.

Termination: divides into 3 branches1) Supply the deep surface of pectineus2) Supply hip joint3) Communicates with the anterior

divison of obturator nerve

2)SACRAL PLEXUS

A) SUPERIOR GLUTEAL NERVEOrigin: L4,L5,S1Course: Enters gluteal region through greater

sciaticnotch above piriformis muscle.Runs between gluteus medius and gluteusminimus to end in tensor fascia lataeBranches: supplies gluteus

medius,gluteusminimus and tensor fasciae latae

B) INFERIOR GLUTEAL NERVE

Origin: L5,S1,S2

Course:

Enters the gluteal region through greater sciatic

notch below piriformis muscle

Branches:

A number of branches to gluteus maximus

muscle only

*Sole supply to the large antigravity, postural muscle with

red fibres,responsible for extending the hip joint

C)SCIATIC NERVE Thickest nerve in the bodyOrigin: (L4,L5,S1,S2,S3)

Tibial part: L4,L5,S1,S2,S3Common peroneal part: L4,L5,S1,S2

Course: Arises in pelvis. Gluteal region:

Passing through greater sciatic foramen below the piriformis to enter the gluteal region

(deep to gluteus maximus muscle.crosses superior gamellus,obturator internus,inferior gamellus,quadratus femoris to enter back of thigh)

Back of thigh Deep to long head of biceps femoris and superficial to

adductor magnusTermination: Divides into two terminal branches at the back

of the thighBranch:

Gluteal

region

Back of thigh;from tibial part From common peroneal part

Muscular

Nil Long head of biceps femoris, semitendinosus,semimembranos

us,ischial part of adductor magnus

Short head of bicep femoris

Articular

Nil Hip joint -

Terminal

Nil Tibial and common peroneal nerves

-

D) TIBIAL NERVEBack of the thighOrigin: L4,L5,S1,S2,S3Course: Long course. First in the popliteal fossa then back of legPopliteal fossa: Nerve descends vertically,superficial to popliteal

vessels.Back of leg:Posterior tibial vessels.superficial to tibialis posterior &deep to flexor digitorum longus. Deep to flexorretinaculum of ankle.

BRANCH:Popliteal fossa Back of leg

Muscular

Medial head of gastrocnemius,lateral head of

gastrocnemius,plantaris,soleus,popliteus

Soleus,flexor digitorum

longus,flexor hallucis

longus,tibialis posterior

Cutaneous &

vascular

Sural nerve Medial calcanean

branches & branch to

posterior tibial artery

Articular

Superior medial genicular,middle genicular,inferior medial genicular

Ankle joint

Terminal

- Medial plantar&lateral plantar nerves

E)COMMON PERONEAL NERVEOrigin: L4,L5,S1,S2-smaller terminal branch of sciatic nerve-back of the thighCourse: Lies in the upper lateral part of popliteal fossa,

along the medial border of biceps femoris muscle.Turns around lateral surface of fibula.Then,lies in the substance of peroneus longus muscleBranches: muscular (short head of biceps femoris),

cutaneous & vascular (lateral cutaneous nerve of calf & sural communicating), articular (superior lateral genicular, inferior lateral genicular, recurrent genicular)

Termination: Superficial peroneal & deep peroneal

EI)SUPERFICIAL PERONEAL Origin: Arises in the substance of peroneus

longus muscle,lateral to the neck of fibulaCourse: Descends in the lateral

compartment of leg deep to peroneus longus.Then lies between peroneus longus and peroneus brevis muscles and lastly between peronei and extensor digitorum longus. Pierce deep fascia in distal 1/3 of leg and descend to the dorsum

Branch: Supplies peroneus longus &peroneus brevis muscle. Cutaneous branch.

EII)DEEP PERONEAL Entire compartment of the leg & dorsum of

the foot.Course: lateral side of the neck of fibula under

cover of the upper fibres of peroneus longus.Enter anterior compartment of leg by pierce into intermuscular septum. Then pierce extensor digitorum longus & lie next to anterior tibial nerves.

Termination: dorsum of the foot by dividing into lateral and medial branches.

Muscular branches:-1)Anterior compartment of leg

a) Tibialis anteriorb) Extensor hallucis longusc) Extensor digitorum longusd) Peroneus tertius

Cutaneous branches:Lateral terminal branch end by forming thedorsal digital nerves for adjacent sides of the bigtoe and second toe.Articular branches:a) Ankle jointb) Tarsal jointc) Tarsometatarsal jointd) Metatarsophalangeal joint of big toe

EII)- LATERAL BRANCH Ends in pseudoganglion deep to the

extensor digitorum brevis. Branches again arise from the

pseudoganglion and supply the extensor digitorum brevis and the tarsal joints.

EII)-MEDIAL BRANCH Ends by supplying the skin adjoining the

first interdigital cleft & proximal joints of the big toe

F)PLANTAR NERVES Origin: termination of tibial nerve Begin deep to the flexor retinaculum Divided into two:-

Medial plantar nerveLateral plantar nerve

FI)MEDIAL PLANTAR NERVE• Larger terminal branch than lateral plantar nerve.• Lies between abductor hallucis & flexor digitorum

brevisBranch: MEDIAL PLANTAR NERVE

Muscular

Abductor hallucis; 1st layerFlexor digitorum brevis; 1st layerFirst lumbrical; 2nd layerFlexor hallucis brevis; 3rd layer

Cutaneous & vascular

Nail beds of medial 3.5 toes.Sympathetic branches to medial plantar artery

Articular Tarsometatarsal,metatarsophalangeal and interphalangeal joints of medial 2/3rd of foot

FII)LATERAL PLANTAR NERVE

Smaller than medial plantar nerve Runs obliquely between the first

and second layers of sole till the tuberosity of fifth metatarsal bone.

Then,divides into superficial and deep

Branch:

Trunk (S2,S3) Superficial branch Deep branchMuscula

rAbductor digiti minimi:1st layer

Flexor digitorum accessorius; 2nd layer

Flexor digiti minimi brevis: 3rd layer

3rd plantar interosseous: 4th layer

4th dorsal interosseous: 4th layer

1st & 2nd plantar interossei: 4th layer

1st ,2nd,3rd,dorsal interossei: 4th layer

2nd,3rd,4th lumbricals: 2nd layer

Addcutor hallucis: 3rd layer

Cutaneous &

vascular

- Nail beds of lateral 1.5 toes.Sympathetic branches to lateral plantar artery

-

Articular Tarsometatarsal Interphalangeal Metatarsophalangeal

CLINICAL ASPECTSSciatic nerve Foot drop Hamstring muscle affected Unable to do dorsiflexors and plantar flexors

of ankle joint & evertors of foot

REFERENCES 1) Chaurasia, B. (2013). Human anatomy

regional and applied dissection and clinical. (6 ed., Vol. 2). New Delhi: CBS Publishers & Distributors.

2) Cunningham Volume 1,Upper and Lower Limb. Oxford press.

3) http://medical-dictionary.thefreedictionary.com/femoral+nerve

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