entrapment nerve pain
- Entrapment neuropathy is caused by physical
compression or irritation of major nerve trunks or
peripheral nerves, producing distant nerve pain symptoms. Certain sites
in the body are more likely to produce nerve entrapment
because of anatomical vulnerability (design fault). In
some cases compression of blood vessels may also occur
producing signs of poor circulation.
- Symptoms in the arms can be produced by the nerve
compression at the following sites:-
- Neck - Thoracic
- Shoulder -
- Elbow - Ulnar
Neuritis, Median Neuritis, Radial Neuritis.
- Wrist - Carpal
Tunnel Syndrome, Ulnar Neuritis.
- Symptoms in the legs can be produced by nerve
compression at the following sites:-
- Buttock - Piriformis Syndrome
- Hip -
- Lower Leg -
- Foot - Mortons'
Neuroma, Tarsal Tunnel Syndrome, Medial Plantar
Neuritis, Deep Peroneal Neuritis.
- Treatment consists of joint and muscle mobilization
(reducing muscle spasm and tissue swelling, increasing
the amount of physical space for the pinched nerve),
injections (reducing nerve inflammation), and surgical
decompression (enlarging the available space for the
pinched nerve when conservative treatments have
Thoracic Outlet Syndrome
is caused by compression
of the brachial plexus (main nerve bundle to the arm)
and brachial vessels (artery and vein) in the root of
the neck. It can produce a mixture of symptoms in the
arm and shoulder including pain, pins and needles,
numbness, weakness, and circulation changes (changes
in color or temperature and swelling).
- Compression can occur in three separate
Syndrome occurs when the space between
the collar bone (clavicle) and first rib is
narrowed. This can be due to a congenital
abnormality, or due to poor posture with
rounded shoulders e.g. large breasts with a
pressure from bra straps.
- Cervical Rib
Syndrome occurs when there is an extra
rib or unyielding fibrous band. The brachial
plexus then has to pass over this extra
structure causing nerve and vessel compression
when the arm and shoulder are placed in certain
positions. Symptoms most often occur down the
inner arm to the little finger due to
compression of the lower parts of the
- Scalenus Anterior
Syndrome (much rarer) occurs when the
brachial plexus and vessels are trapped between
the anterior and middle scalene muscles
(similar to piriformis syndrome in the
- In slim patients the cervical rib can be
felt just above the collar bone.
- Some patients have symptoms when the armed
is pulled downwards, and others when the arm is
elevated. Relief of the symptoms occurs when
the arm is moved in the opposite
- Adson's Test is used to look for suspected
compression. The patient looks to the affected
side taking a deep breath. The examiner lifts
the arm to 90 degrees, and notes whether the
radial pulse disappears. However, the test must
be interpreted with caution as there are many
false positives, as the radial pulse may
disappear in normal people as the head of the
humerus (upper arm bone) compresses the
brachial vessels when the arm is taken beyond
- Bruit - performing the tests above may
cause compression of the subclavian artery,
producing a bruit (murmur) audible with the
- X-rays of the chest and neck may reveal a
bony cervical rib but not a tight fibrous
- MRI scanning may reveal soft
tissue anatomical abnormalities.
- Subclavian angiography (dye test) may
confirm subclavian vessel compression.
- EMG (Electro-myography) studies may confirm
nerve dysfunction due to nerve
- Ultrasound Dopler studies may reveal
- The Edgelow Proctocol is an exercise and
posture modification/awareness approach
to reducing compression on the nerves and
- Exercises to stretch the scalene muscles
and related tight tissues can relief scalene
- Spinal Manipulation to the
lower neck and upper thoracic spine, and
attention to posture can increase the space
between the clavicle and the 1st rib in
costo/cervical syndrome. Breast reduction and a
properly fitting bra is advised for some women
with over/large breasts.
- Surgery is sometimes required to remove a
cervical rib, part of the 1st rib, or rarely
the lower part of the scalene muscles.
is caused by compression of the suprascapular nerve
at the back of the shoulder.
- The suprascapular nerve is a branch of the
brachial plexus (C5+C6). It returns sensory
information from the shoulder joint, and
carries motor signals to the infraspinatus and
- The nerve is liable to injury as it travels
through the suprascapular notch where in
travels between the tough transverse ligament
above and the bony groove of the scapula
- Injury may occur as the result of overuse
of the arm or excessive traction.
- Neuralgic pain often radiates to the C5 and
C6 dermatomes i.e. to the point of the shoulder
and down to the outside aspect of the
- In some cases the radiation of pain is
- Direct pressure over the nerve in the notch
with the examining finger can reproduce the
local and referred pain down the arm.
- Prolonged entrapment of the nerve leads to
visible wasting of the supraspinatus and
- EMG can help to confirm the diagnosis.
- Rest can help reduce tissue swelling in the
notch in the initial phases.
- Suprascapular nerve block with local
anaesthetic and steroid can also help reduce
swelling and pain.
- Surgery is needded in resistant cases to
release the transverse ligament.
Ulnar Neuritis at
the elbow is caused by compression or irritation of
the ulnar nerve as it runs behind the elbow joint.
- The nerve runs just inside the tip of the
elbow (where your funny bone is) lying in a
groove called the cubital canal and covered by
the arcuate ligament.
- Most cases of compression occur at the
level of this ligament, but can also occur
between the two heads of flexor carpi ulnaris
muscle just below the elbow joint.
- Direct blow to the elbow.
- Fractures of the elbow joint.
- Repetitive injuries like flexing the elbow
(overuse) or leaning on it.
- Arthritis (eg rheumatoid) leading to joint
- Pain and tingling in the elbow and down the
inside of the forearm to the little finger and
half the ring finger (ulnar nerve territory).
Clinical numbness on sensory testing.
- Pressure on the ulnar nerve in the groove
or tapping it (positive Tinel's sign), may
reproduce symptoms down the forearm and into
the little finger.
- Clumsiness of the hand due to weakness of
the muscles supplied by the ulnar
- Clinical weakness on testing.
- EMG help to differentiate between ulnar
neuritis and other causes of C8 and T1 nerve
irritation (cervical disc lesion, thoracic
- Avoid local repetitive trauma - consider
using protective elbow pads.
- Avoid or reduce elbow flexion.
- Injections of steroid may help either in
the ulnar groove or between the two heads of
flexor carpi ulnaris.
- Surgery - moving the nerve out of the
groove and into the front part of the elbow
joint may help.
Median Neuritis at the
elbow is much less common than ulnar neuritis.
- The median nerve crosses in front of the
lower humerus (arm bone) to the front of the
elbow joint, and then passes between the two
heads of pronator teres to reach the
- Some people have an anatomical abnormality
at the elbow
consisting of a spur called the Supracondylar
Process, which forms a tunnel at the inside
edge of the humerus bone covered by the
Ligament of Struthers. The median nerve can be
compressed in this tunnel.
- In others the nerve is compressed between
the two heads of pronator teres muscle below
the level of the elbow joint.
- Sensory symptoms involve the outer three
and a half fingers. Clinical numbness on
- Weakness in the hand and forearm depends
upon which level at which the compression
occurs and may involve forearm pronation, wrist
flexion, and opposition of the thumb.
- If the pronator teres is the problem, then
the symptoms will be aggravated by pronation of
the forearm (elbow straight, palm down).
- Surgical decompression may be helpful.
Radial Neuritis at the
elbow is much less common than ulnar neuritis.
- The radial nerve at the elbow divides into
- The sensory
(superficial) branch supplies the outer
forearm, base of the thumb, and back of the
- The motor
(deep) branch supplies the extensor muscles of
the forearm, and is known as the posterior
interosseus nerve. It pierces the supinator
muscle before entering the forearm.
- Compression of the superficial branch may
cause pain and sensory symptoms in the forearm
to the base of the thumb. Numbness on clinical
- The deep branch can be injured by direct
blows to the forearm, and be compressed by an
acutely inflamed arthritic elbow joint, causing
pain and weakness of the wrist and
- Wasting of the extensor forearm muscles may
be found after prolonged or substantial injury,
causing weakness of wrist and finger
- Supinator Syndrome occurs when the radial
nerve is compressed by the supinator muscle
during repeated pronation/supination (twisting)
movements of the forearm.
- EMG is the investigation of choice.
- Rest in acute cases. Splints, physical
therapy, occupational therapy, and modification
of work place activities in chronic cases.
Carpal Tunnel Syndrome
is caused by compression of the median nerve at the
level of the wrist.
- The transverse carpal ligament forms the
roof of the carpal tunnel, through which pass
the flexor tendons and the median nerve.
- The median nerve supplies sensation to the
thumb, index, middle and half of the ring
finger, as well as the motor supply to muscles
of the hand.
Causes - Anything
that reduces the volume of the carpal tunnel can
cause median nerve compression:-
stress - either repetitive wrist
flexion or extension while gripping firmly,
may cause inflammation (tenosynovitis) of
the flexor tendon sheaths (outer tendon
arthritis patients are more prone to
tendon sheath inflammation especially when
using a cane.
- Colles fracture
- Subluxation of the Lunate bone
- Wrist ganglion formation (out-pouching
of the wrist joint capsule)
- Various metabolic conditions have been
associated with it - diabetes, gout,
- Pain, tingling, and numbness in the outer
three and a half fingers supplied by the nerve.
The pain is most often felt at night,
disturbing sleep, and is relieved by dangling
the arm out of bed. Some patients also describe
pain radiating up to the forearm, arm, shoulder
- Weakness / clumsiness of muscles in the
- Examination of the neck, shoulder, and
upper limb is necessary to exclude other causes
of nerve entrapment in the neck and upper
- The pain can be reproduced by pressing over
the carpal tunnel with the thumb for about 1
- Tapping over the nerve (Tinel's sign) can
also reproduce tingling of the affected
- Positive Phalen's Test - place both hands
together palm to palm, both wrists extended to
90 degrees, with the forearms horizontal, and
the hands close to the chest - the affected
hand will tingle after 1-2 minutes.
- Positive Reverse Phalen's Test - do the
same as above except with the hands back to
- EMG is the diagnostic test of choice.
- X-rays can help assess the degree of
osteoarthritis in the wrist.
- Laboratory studies to exclude metabolic
- Avoid repetitive activities and use of
- Avoid extremes of wrist flexion or
exentsion and use a splint especially at
- NSAIDs rarely help
- Injections around the nerve as it lies in
the carpal tunnel can be useful.
- Gentle manipulation and mobilization of the
wrist joint in osteoarthritis can be useful.
Particular attention should be paid to the
range of wrist extension and suppleness of the
- Surgery to
decompress the carpal tunnel by releasing the
transverse ligament, when conservative methods
have failed and there is definite weakness in
the hand - Before
Surgery - After
Ulnar Neuritis is caused
by compression of the ulnar nerve at the level of the
- The ulnar nerve travels with the ulnar
artery in the tunnel of Guyon, covered by the
transverse carpal ligament. At the level of the
wrist it divides into superficial sensory and
deep motor branches.
- The superficial sensory branch supplies the
skin over the hypothenar eminence (soft part of
the inside palm), the little finger, and half
of the ring finger.
- The motor branch supplies the muscles of
the hypothenar eminence and other muscles of
the fingers and thumb.
- Trauma - Colles fracture, flexor
tendonitis, acute blow to the open palm,
- Ganglion of the wrist joint may compress
the nerve in the tunnel.
- Pain, numbness and tingling in the ulnar
fingers when the superficial branch is
- Weakness of the hypothenar muscles,
interossei, and thumb adduction.
- Tinel's sign positive (tapping) and
symptoms also reproduced by firm pressure over
the nerve for 1-2 minutes.
- As for Carpal Tunnel Syndrome above.
- See Piriformis Syndrome
is caused by compression of the lateral femoral
cutaneous nerve of thigh.
- The lateral femoral cutaneous nerve is a
branch of the lumbar plexus originating from
the 2nd and 3rd lumbar nerve roots.
- The nerve travels to the thigh by passing
under the inguinal ligament in its own tunnel.
At this point it sharply angulates and is
vulnerable to compression.
- It is purely a sensory nerve and
supplies an area of skin on the outside of the
mid to lower thigh.
- Direct injury in the groin (trauma and
- Increased abdominal girth associated with
obesity and pregnancy.
- Repetitive hip flexion.
- Pain, itching, tingling and numbness on the
outside part of the mid to lower thigh.
- Symptoms can be reproduced with direct
pressure with a finger over the inguinal
ligament, or by extending the hip joint
- EMG may be useful, but the diagnosis is
usually made clinically.
- Rest initially for acute symptoms (not for
the chronic condition)
- Weight loss, avoidance of tight clothing /
belts around the waist.
- Injections and repeated nerve blocks using
steroids in and around the nerve tunnel at the
level of the inguinal ligament.
- Surgery to decompress the nerve when all
- Compartment Syndromes
occur after acute or chronic swelling in any of the
four muscle compartments of the lower leg - anterior
(front), posterior (back), medial (inner), and lateral
- Each compartment is surrounded by tough fibrous
tissue called fascia which is relatively
- Acute compartment syndromes occur when there is a
sudden critical rise in pressure within the compartment
leading to loss of arterial blood flow, nerve damage
and muscle death (necrosis due to oxygen
- Chronic compartment syndromes occur due to smaller
rises in pressure which are sufficient to cause pain,
but which do not progress to the acute syage.
- The anterior compartment contains muscles
which pull the toes and foot upwards towards
you (tibialis anterior, extensor digitorum),
and the deep peroneal nerve (sensory nerve to
the skin between the first and second
- Unaccustomed running.
- Tibial / fibular fractures.
- Direct blow to the leg.
- Pain in the front of the shin after
exercise, which rapidly becomes severe.
- The pain is worsened by having the toes
pulled passively downwards, or by actively
bringing the foot upwards towards you.
- The skin at the front of the shin may be
red and hot.
- An acute anterior compartment syndrome is a
medical emergency. Unrelieved pressure in the
compartment causes necrosis of the muscles and
a permanent foot drop with numbness between the
first and second toes. Urgent surgical
fasciotomy is necessary to relieve the pressure
in the compartment.
- Patients with chronic anterior compartment
syndrome develop pain on exercise which causes
them to stop and rest. They are normal between
attacks. Exercise modification and sometimes
elective surgical fasciotomy are required.
- The medial compartment is deep in the leg
and contains muscles which move the foot and
the toes downwards away from you
(tibialis posterior, flexor hallucis longus,
flexor hallucis longus), and the posterior
tibial nerve (sensory to the sole of the
- Overuse especially in athletes after
running on a hard surface or a change in
- The medial compartment is the most commonly
affected. It presents as pain and tenderness at
the inside edge of the mid to lower shin bone
(tibia), and is often known as "Shin
- The pain starts at the beginning of a
running session, and becomes worse if the
exercise is continued.
- There is often warmth and redness over the
affected part of the leg.
- The symptoms may be reproduced on
examination by passively pushing the foot down
or actively raising it against resistance.
- Rest and strapping / taping to prevent
excessive plantar flexion.
- Stretching exercise for the medial
- Injections may be useful if a local trigger
point can be palpated (not usually in then
- Attention to running shoes and postural
problems in the foot.
- Surgery to release the tight fascial
- The lateral compartment contains muscles
which evert the ankle (turning your foot out),
and the lateral popliteal nerve.
- Acute unaccustomed exercise.
- Fairly rare syndrome, but may occur several
hours after exercise.
- May present with pain in the outside shin,
an inversion foot drop (foot turned in), and
distal sensory changes.
- This is another medical emergency with
urgent surgery (fasciotomy) required to prevent
acute muscle necrosis and permanent nerve
- The posterior compartment contains powerful
muscles which move the foot downwards away from
you (plantar flexion) e.g. standing on tip toe.
The main muscles are soleus, gastrocnemius and
plantaris. They join together to form the
Achilles tendon which attaches to the back of
- Acute compartment syndrome can be caused by
- Chronic compartment syndrome can occur
after previous tibial fractures.
- Severe calf pain after exercise with
altered sensation in the sole of the foot, and
weakness of plantar flexion.
- Pain can be reproduced by stretching the
calf muscles during passive dorsiflexion, and
also during active plantar flexion.
- The acute syndrome requires urgent surgical
fasciotomy to prevent muscle necrosis and
permanent nerve damage.
Tarsal Tunnel Syndrome
is similar to Carpal Tunnel Syndrome in the wrist,
causing pain and numbness in the heel and toes.
- The posterior tibial nerve runs just behind
the inside ankle bone in a tunnel covered by
the flexor retinaculum.
- The tunnel also contains the tendons of
muscles tibialis posterior, flexor digitorum
longus and flexor hallucis longus.
- The posterior tibial nerve divides in the
tunnel to form the medial and lateral plantar
nerves. The medial nerve supplies the inside
heel skin and the inside three and a half toes.
The lateral nerve supplies the outside one and
a half toes.
- Tenosynovitis of the tendons in the tarsal
tunnel caused by overuse.
- Trauma - falls on to the feet from a
- Postural abnormalities of the foot e.g.
forefoot pronation (flat footed).
- Rheumatoid arthritis.
- Burning pain, tingling and numbness in the
sole of the foot and toes.
- May initially come on after prolonged
standing, but may be continuous in the later
- Sometimes pain radiates up the leg as well
as into the foot.
- There is tenderness over the tendons in the
tarsal tunnel with a positive Tinel's sign
- There may be clinical numbness in the sole
of the foot, and weakness of downward movements
of the toes.
- Correct any deformities in the foot with
- Injection of steroid into the tarsal tunnel
may be useful.
- Surgical decompression if all else
Medial Plantar Neuritis
- Anatomy - The
medial plantar nerve is a branch of the posterior
tibial nerve (see above). It may be trapped in the
abductor hallucis muscle to the big toe.
- Frequent causes include direct trauma, or a
badly fitting arch support.
- Symptoms are
similar to tarsal tunnel syndrome, except with
symptoms confined to the inner part of the sole of
- Treatment includes
orthotic assessment, LA/steroid injections, and
- Anatomy - The digital nerves
run between the long bones of the foot
(metatarsals) to supply the toes.
- They may become compressed at the level of the
head of the metatarsal bone as they travel in a
small canal. Swelling may develop and is called
- Symptoms include
burning pain and tingling in the forefoot with
shooting pain into the toes, usually made worse by
walking or walking in high heels (excessive toe
- A tender spot may be located on examination
between the heads of two adjacent metatarsal bones
which reproduces the pain in the foot and toes.
Grasping the forefoot and squeezing gently
compresses the nerve/neuroma between the metatarsal
heads reproducing symptoms in the toes.
- Treatment includes
orthotic support, avoidance of high heeled shoes,
LA/steroid injections, mobilization of the
metatarsal bones, and surgical decompression and
removal of the neuroma if necessary.
Deep Peroneal Neuritis
- Anatomy - The deep
peroneal nerve travels in the front of the ankle
and enters the top of the foot by passing under a
fibrous band called the extensor retinaculum. It
supplies sensation to an area of skin between the
first and second toes, and the extensor hallucis
longus muscle (moves big toe upwards).
- It may be injured after direct ankle trauma, or
by tightly fitting lace up shoes.
- Symptoms include
pain, 1st / 2nd toe numbness and tingling, and
weakness of big toe dorsiflexion.
- Treatment includes
avoiding pressure over the front of the ankle, and