Class 3 Flashcards
The ulnar nerve’s relationship to forearm muscles.
Under FCU and over FDP
Path of ulnar nerve
Inner/medial cord of brachial plexus
Posterior wall of axilla
Under pec minor (as do they all)
Coracobrachialis insertion
Medial triceps, posterior to medial epicondyle and Olecranon
Deep to FCU and above FDP
Over flex Ret and through Tunnel of Guyon (between hook of hamate and pisiform)
Ulnar claw hand
5 hyperextended at MCP and abducted at MCP an flexed at IP
Hypothenar mm wasting
Altered sensation in 5 and half of 4
Loss of lumbricals
Froment’s Sign
Results from ulnar nerve lesion
Adductor pollicis doesn’t work so can’t hold paper between thumb and index finger. Has to recruit FPL to flex DIP instead.
Tardy ulnar palsy
Common complication after elbow fracture.
Associated with callus or valgus deformity at elbow, which produce gradual stretching of nerve in ulnar groove.
Where can the ulnar nerve become compressed?
Cubital tunnel (ulnar collateral ligament + FCU) Between heads of FCU
What increased the chance of ulnar nerve compression?
Elbow Flexion
Valgus elbow
Thoracic outlet syndrome
Compression of brachial plexus from structures in thoracic outlet.
May also involve arteries and veins.
Thoracic outlet
Inter scalene triangle to inferior border of axilla.
Path of brachial plexus
Travels with subclavian artery
Btwn anterior and middle scalene
Then meets up with subclavian vein
Entire neurovascular bundle goes behind clavicle and under pec minor attachment and down arm.
Symptoms of TOS
Pain, numbness, weakness.
Tingling in arm, across upper thoracic area or over scapula
Trophic changes.
Causes of TOS
Cervical rib (C7) Anterior scalene syndrome Scalene triangle syndrome Costoclavicular syndrome Pec minor syndrome
Anterior scalene syndrome
TOS caused by brachial plexus being compressed between anterior and middle scalene
Scalene triangle syndrome
TOS caused by brachial plexus being caught in between anterior scalene (anterior), middle scalene (posterior) and R1 (inferior).
Costoclavicular syndrome
TOS caused by brachial plexus being compressed between clavicle and R1.
Pec Minor syndrome
TOS involving compression between the coracoid process and pec minor
Happens with hyperabduction with ER/extension
Lumbar plexus
Between heads of Psoas major, anterior to QL
Formed by anterior rami of spinal nerves L1-4
Supplies anterolateral abdominal wall, external genitals, part of lower limbs.
What nerves emerge from the lumbar plexus?
Iliohypogastric Ilioinguinal Genitofemoral Lateral cutaneous nerve of the thigh Femoral Obturator
Iliohypogastric nerve
L1
Anterior division of lumbar plexus
Ant-lat abdominal muscles
Skin of inferior abdomen and butt
Ilioinguinal nerve
L1
Anterior division of lumbar plexus
Ant-lateral muscles and skin of superior and medial thigh
Root of penis and scrotum
Labia majora and mons pubis
Genitofemoral nerve
L1-2
Anterior division of lumbar plexus
Cremaster muscle
Skin of middle anterior thigh
Scrotum and labia majora
Lateral cutaneous nerve of the thigh
L2-3
Posterior division of lumbar plexus
Skin of lateral, anterior and posterior thigh
Femoral nerve
Largest nerve in lumbar plexus
L2-4
Posterior division of lumbar plexus
Hip flexor muscles
Knee extensors
Skin of ant/med thigh and medial leg and foot
Obturator nerve
L2-4
Anterior division of lumbar plexus
Hip adductor muscles
Skin of medial thigh.
L1
Iliohypogastric nerve
Ilioinguinal nerve
L1-L2
Genitofemoral nerve
L2-L3
Lateral cutaneous nerve of the thigh
L2-L4
Femoral nerve
Obturator nerve
Injury to femoral nerve
Can’t extend knee or flex hip
Wasting if quads
No sensation over ant/med thigh
Injury of obturator nerve
Paralysis of adductors
No sensation over medial thigh
Meralgia paresthetica
Entrapment of lateral cutaneous nerve near ASIS as nerve passes under inguinal ligament
Sensory alteration/burning pain in lateral thigh.
Sacral Plexus
L4-S4
Mostly anterior to sacrum
Supplies buttocks, perineum, lower limbs
Nerves of the sacral plexus
1 Superior gluteal 2 Inferior gluteal 3 Nerve to piriformis 4 Nerve to quadrator femoris & inf. gemellis 5 Nerve to obturator internus & sup. gemellis 6 Perforating cutaneous 7 Posterior cutaneous nerve of the thigh 8 Sciatic 9 Tibial 10 Common fibular 11 Pudendal
Superior gluteal nerve
L4-S1
Glute min, glute med, TFL
Inferior gluteal nerve
L5-S2
Glute max
Nerve to piriformis
S1-2
Piriformis
Nerve to quadrator femoris & inferior gemellis
L4-S1
Quadrator femoris
Inferior gemellis
Nerve to obturator internus & superior gemellis
L5-S2
Obturator internus
Superior gemellis
Perforating cutaneous nerve
S2-3
Skin of inferior and medial buttocks
Sciatic nerve
L4-S3
Largest and longest nerve in the body
Hamstrings, adductor Magnus
Bundle of tibial and common Fibular which split at knee
Tibial nerve
L4-S3
Branch of sciatic
Gastrocnemius, soleus, plantaris, popliteus, tib post, FDL and FHL
Branches into medial and lateral plantar at foot.
Medial plantar nerve
Branch of Tibial
Adductor hallucis, FDB, FHB, skin of medial plantar foot.
Lateral plantar nerve
Branch of tibial
Foot mm not served by medial plantar nerve
Common fibular nerve
L4-S2
Branch of sciatic.
Divides into superficial and deep fibular
Superficial fibular nerve
Branch of common fibular
Fib long, fib brev, and skin of distal anterior leg and foot dorsum.
Deep fibular nerve
Branch of common fibular
Tib ant, EHL, fib tertius, EDL, EDB and skin of toes 1 and 2.
Pudendal Nerve
S2-4
Muscles of perineum
Skin of penis, scrotum, clitoris, labia majora and minora, and vagina.
L4-S1
Superior gluteal
N to QF and Inf Gem
L4-S2
Common fibular
L4-S3
Sciatic nerve
Tibial nerve
L5-S2
Inferior gluteal
N to Ob Int and Sup Gem
S1-S2
Piriformis
S1-S3
Post Cut N of the Thigh
S2-S3
Perforating cutaneous nerve
S2-S4
Pudendal
Route of sciatic nerve
Sciatic foramen
Under (or through) piriformis
Between Ischial tuberosity and greater trochanter
Goes deep, follows adductor Magnus
Splits at popliteal fossa into tibial and common fibular
Route of tibial nerve
Goes between heads of gastrocs
Superficial between medial malleolus and Achilles.
Goes around malleolus and travels deep to flexor retinaculum
Divides into medial and lateral plantar nerves
Route of common fibular nerve
Travels around and below head of fibula
Splits into superficial and deep fibular nerves
Deep fib: deep to EDL and down to dorsum of foot
Superficial fib: down lateral leg to foot.
Tarsal Tunnel syndrome
Tibial nerve compressed as it passes through tarsal tunnel
Pain and paesthesia in sole of foot
Worse after long periods of standing or walking.
Night waking (like carpal tunnel)
Tarsal tunnel
Formed by medial malleolus, calcaneous, and talus on one side; deltoid ligament on the other.
Symptoms of sciatic nerve compression
Pain from buttocks and down lateral leg and foot
Foot drop. Paralysis of dorsiflexors and everters.
Nerve to the Piriformis
S1-S2
Piriformis
