T3 - Neurology
Oct. 10, 2003
Dr. Laura McNeilly
** warning: notes may be contradictory with other neurology books
ex: Musculocutaneous N: C5-7, some people/books say C4, some say C8, it depends on the
person ie: Musculocutaneous Nerve: C5-C7 – sometimes someone may have it from C4 or to C8.
MARMU
Peripheral Nerve
Musculocutaneous C5 – 7
Motor
Coracobrachialis
Biceps brachii
Brachialis
Sensory
Skin of lat. Forearm, ant
and post.
Clinical Note
 Lat. To Axillary artery
Axillary C5 - 6
Deltoid
Teres Minor
Skin of lat. Arm, superior
1/2
Rarely injured
Radial C5 – T1
All MM of post arm and
forearm
Mainly post/central and
special area: ant/lat area
above elbow



Largest branch of the
BP
Most commonly injured
Travels in Radial
groove of Humerus
Median C5 – T1
All MM of ant forearm
except: FCU, and ulnar 1/2
of FDP
Skin of ant/lat hand first 3
1/2 digits

Commonly entrapped
at the wrist: CPS dt
RSI, pregnancy,
obesity
Ulnar C8 – T1
MM of ant/med forearm
and intrinsic MM of the
hand
Only in hand

Commonly damaged at
the med epicondyle,
aka funny bone
N/a
Supplies skin of med arm,
elbow to axilla
Brachial – upper arm
Medial Antebrachial
cutaneous C8 – T1
N/a
Supplies skin of med
forearm, wrist to elbow
Antebrachial – forearm
Dorsal scapular C4-5
Long thoracic C5-7
Subclavian C5-6
Suprascapular C5-6
Lateral pectoral C5-7
Medial pectoral C7-T1
Upper subscapular C5-7
Lower subscapular C5-7
Thoracodorsal C6-8
Motor only
 Minor branches of BP
Medial brachial cutaneous
C8 – T1
From superior trunk
“
“
from lateral cord
from medial cord
from posterior cord
“
“
“
“
Lumbar Plexus


Anterior rami of L2 – L4
Splits into anterior and posterior divisions
Anterior Division
 Gives rise to Obturator Nerve (L2 – L4)
Peripheral Nerve
Obturator
Motor
Medial thigh (adductors),
inc’l groin, anterior 1/2 of
Adductor Magnus
Sensory
Lower 1/2 of medial thigh
Clinical Note
Injured dt Pelvic fractures,
MVA, horseback riding
Peripheral Nerve
Femoral (L2 – 4)
Motor
MM of anterior thigh, inc’l
Sartorius and Pectineus
Sensory
Anterior thigh, knee cap,
medial lower leg and
medial foot.
Clinical Note
Exits pelvis via femoral
triangle.
Most commonly affected by
Diabetic neuropathy
Saphenous (branch of
Femoral N)
N/a
Supplies medial lower leg
Injured dt pelvic fractures,
compression (preg.,
obesity)
Nerve to Psoas (branch of
Femoral N)
Psoas
Iliacus
Quadratus Lumborum
N/a
Does not exit the pelvis,
rarely injured
Lateral Femoral cutaneous
(branch of Femoral N)
N/a
Skin of lateral superior
thigh
Meralgia Paresthetica –
painless loss of sensation
over lateral hip (preg.,
obesity)
Posterior Division
Sacral Plexus
 Anterior rami split into anterior and posterior divisions
 L4 – S2
Anterior Division
Peripheral Nerve
Sciatic L4 – S2
Motor
Sensory
Clinical Note
 Consists of Tibial and Common Peroneal N
 Exits the pelvis through the Greater sciatic foramen
 Impingement if travels through Piriformis
 Descends in posterior thigh deep to hamstrings
 Splits superior to Popliteal fossa into Tibial and Com. Peroneal
 Can be damaged dt compression (sitting on a hard surface)
 Impingement can also be at the vertebrae because of a sacral tilt
Tibial L4 – S2
All posterior thigh MM inc’l
posterior 1/2 of Adductor
Magnus, posterior lower leg
and Biceps Femoris, long
head.
Skin of posterior lower leg,
sole of foot and lateral foot
Commonly damaged while
passing around the medial
malleolus (ankle sprain),k
branches to Med & Lat
Plantar nerves
Posterior division
Peripheral Nerve
Common Peroneal L4 – S2
Motor
Splits to:
 Superficial peronial 
Peroneus L/B
 Deep peronial  rest
of MM of lower leg and
dorsum of foot
Sensory
Skin of anterior lower leg
and dorsum of foot
Clinical Note
Enters anterior
compartment by passing
over head of fibula.
Injured dt compression
where it passes over fibula,
by crossing leg, or tight
boots.
Gluteal L4 – S2
Splits to:
 Superior  Gl. Medius
and Minimus
 Inferior  Gl. Maximus
N/a
N/a