Innervation Lower limb rotates 90 degrees medially Muscles on ventral side of developing long bone– Flexors, Adductors of LL

of Limbs ventral surface– posterior  anterior divisions of ventral rami of spinal nerves
preaxial border— medial. Muscles on dorsal side of developing long bone— Extensors, Abductors of LL
 posterior divisions of ventral rami of spinal nerves
Lumber Ventral rami of lumbar nerves join each other inside
Plexus Psoas Major muscle— Lumbar Plexus.
L1 - L4 Spinal
nerves L1
 Iliohypogastric
 Ilioinguinal

L1+L2– Genito-femoral

L2,L3,L4
 Obturator nerve (anterior division)
 Femoral (posterior division)

Femoral Nerve of anterior/ extensor compartment of thigh. Superficial group Complete section of femoral nerve
nerve  enters thigh at midpoint of inguinal ligament Muscular branches above level of its branches
L2,3, 4  pass distally for about 1 inch in femoral triangle—  to pectineus  Cutaneous loss of sensation
breaks up into several branches.  to sartorius medial, anterior— thigh, antero-medial
Cutaneous branches aspect of leg from knee to ankle
 Medial cutaneous N of thigh  Motor loss
Motor: muscles anterior thigh  intermediate cut. N of thigh. paralysis of quadriceps femoris– loss
 illiacus, pectineus, sartorius, quadriceps femoris. of extension of knee, impairment of hip
Deep group flexion
Sensory: skin on anterior thigh, medial leg.  1 Cutaneous: Saphenous nerve
 4 Muscular branches— to
Rectus femoris, vastus
medialis, lateralis, intermedius
Obturator Nerve of adductor compartment of the thigh Branches of obturator nerve Nerve injury
Nerve anterior divisions of anterior rami (L2-4)  trunk – to obturator externus Motor loss: marked weakness of
L2,3, 4 Accessory Obturator Nerve L3 & 4  anterior division adduction.
a. Muscular: pectineus a. Articular: hip joint Sensory loss: medial aspect of thigh.
b. Articular: hip joint b. Muscular: adductor longus, gracilis Hip joint diseases– disguise pain in
c. Communicating branch to anterior division of & pectineus knee [same nerve supply]
obturator nerve c. Cutaneous: subsartorial plexus
Motor: muscles of medial thigh – obturator externus,  posterior division
adductor longus, adductor brevis, adductor magnus, a. Muscular: adductor brevis &
gracilis. magnus
b. Articular: knee joint
Sensory: skin over medial thigh.

Sciatic Articular branches– hip joint divide within pelvis: Common

L4, L5, S1, S2, muscular branches– knee in thigh, muscles in leg and peroneal nerve (CPN) emerges
S3 foot through piriformis muscle.

Medial side Injection: upper & outer quadrant of

 Inferior gluteal nerve & vessels gluteal region - injure CPN >> foot
 Nerve to Obturator internus drop
 Internal pudendal vessels and nerve
COURSE & RELATIONS a. Sensory loss: Below knee
 leaves pelvis– greater sciatic foramen. except areas supplied by
 enters gluteal region below piriformis muscle. saphenous nerve,
 most lateral– structures emerging inferior to obturator nerve.
piriformis. b. Motor loss
 Tibial: plantar flexion impaired–
“shuffling gait”
 CPN: dorsiflexion impaired—
‘foot drop’, “high stepping gait”
*Sciatic nerve—
 penetrating injuries of gluteal region and thigh
 posterior dislocation of hip joint
 childbirth injury infant: traction on the legs
 injury to mother: compression by foetus or from forceps
Motor Common fibular portion
Tibial portion Motor: Short head of biceps femoris,
Motor: muscles in posterior compartment of thigh (exc. short head of biceps femoris), hamstring component of all muscles in anterior, lateral compartments of leg and extensor digitorum brevis.
adductor magnus Sensory: skin of lateral leg & dorsum of the foot.
all muscles in posterior compartment of leg and sole of the foot.
Sensory: skin of posterolateral leg, lateral foot & sole of the foot.
TIBIAL  Popliteus (Unlocking muscle)  Cutaneous
NERVE  Gastrocnemius, Soleus (main Plantar flexor of ankle)  Articular: Superior, Inferior & Middle 3 genicular branches medial side of knee
Long flexors– sole of foot (tiibialis posterior, flexor hallucis longus, flexor digitorum longus)  Terminal—Medial Plantar & Lateral Plantar

COMMON  Superficial branch— Fibularis longus and brevis Motor loss:

PERONEAL muscles 1. Loss of dorsiflexion (Deep peroneal nerve)
NERVE  Deep branch— 2. Loss of eversion (Superficial peroneal nerve)
1. Tibialis anterior, 3. Foot in planter flexed, inverted and adducted position
2. extensor digitorum longus,
3. extensor hallucis longus, Sensory loss: lower part of leg and dorsum of foot
4. peroneus tertius
Cutaneous
Nerves of
Lower Limb