Peripheral Nerve Injuries - Upper Body

Review of Upper Quadrant Neuroanatomy Brachial Plexus - A network of nerves in the anterior shoulder that carries movement and sensory signals from the spinal cord at vertebral levels C5 - T1 to the arms and hands. ● From the vertebrae, the cords travel through the scalene triangle, under the clavicle, under the pectoralis minor, and into the arm

● Brachial plexus injuries typically stem from trauma to the neck and can cause pain, weakness and numbness in the arm and hand.Important to how we work through our clinical reasoning

Ulnar Nerve ● Innervates Flexor Carpi Ulnaris muscle, Flexor Digitorum Profundus (ulnar head)

Median Nerve ● Arises from vertebral levels C6-T1 via the brachial plexus ● Courses along the brachial artery, travels down anterior department of arm ● At level of elbow: Lies between humeral, superficial, and ulnar deep heads of pronator teres (big area of entrapment of median nerve) ● Enters anterior department of forearm into Flexor Digitorum Superficialis muscle ● At elbow and proximal aspect of forearm, innervates several muscles that are important for hand function/typing/occupational reasons (Pronator Teres, Flexor Carpi Radialis, Palmaris Longus, and Flexor Digitrum Superficialis) ● At the level of the humeral head of Pronator Teres, the anterior interosseous nerve splits off from the median nerve. Named as such as it travels along the anterior interosseous. Innervates deep muscles of the anterior forearm except ulnar half of FDP. ● Innervation:

○ Abductor Pollicis Brevis ○ Flexor carpi radialis ○ Flexor digitorum superficialis ○ Flexor pollicis brevis & longus ○ Lumbricals 1 & 2 ○ Opponens pollicis ○ Palmaris Longus ○ Pronator quadratus○ Pronator teres ○ Flexor digitorum profundus (radial half)

■ If you are trying to differentiate whether the issue is more myotomal

(relating to spinal root) vs distal nerve, assess finger flexion strength: ● Digits 2 and 3 flexion is caused by FDP innervated by MEDIAN N. ● Digits 4 and 5 flexion is caused by FDP innervated by ULNAR N.

THEREFORE ● Finger flexion weakness in Digits 2 & 3 = median n. dysfunction ● Finger flexion weakness in Digits 4 & 5 = ulnar n. dysfunction ● Finger flexion weakness in Digits 2-5 = dysfunction more

proximally, prior to split of median and ulnar nerves ● Popular areas of entrapment:

○ Pronator teres (elbow level) ○ Carpal tunnel (wrist level)

The “Carpal Tunnel” ● The median nerve can be entrapped in a lot of different places, but it is most commonly

entrapped in the “carpal tunnel” (wrist level) ● The carpal tunnel is formed where the flexor retinaculum spans from the scaphoid and

trapezium to the hamate and pisiform, deep and slightly distal to the palmar carpal ligament. This creates a canal that covers the flexor digitorum superficialis tendons, the flexor digitorum profundus tendons, the tendon of flexor pollicis longus, and the median nerve. These tendons in the carpal tunnel are covered by the ulnar and radial bursae (complex synovial coverings that protect the flexor tendons). The flexor digitorum superficialis and flexor digitorum profundus tendons are covered by the ulnar bursa, and the tendon of flexor pollicis longus is covered by the radial bursa.

● Deep to the FR is the FDS, FDP, FPL, FCR ● Superficial to the FR is the Ulnar nerve & artery, Palmaris longus, and anterior palmar

branch of median nerve

Radial Nerve ● Supplies the posterior portion of the upper limb ● Innervates the triceps brachii, brachialis, brachioradialis, and extensor carpi radialis

longus ● Dysfunction DIMINISHES ability to supinate, but since biceps brachii is the PRIMARY

muscle that supinates, person will still be able to supinate as long as biceps are intact

Arcade of Frohse ● The most superior part of the superficial layer of the supinator muscle ● A fibrous arch over the posterior interosseous nerve ● Sometimes called the supinator arch

SPECIFIC DIAGNOSES

1. Median nerve entrapment a. 4 possible sites of median nerve entrapment:

i. (1) Distal humerus by ligament of Struthers

ii. (2) Proximal elbow by bicipital aponeurosis iii. (3) Elbow between superficial and deep head of pronator teres muscle

(**most common site of entrapment of median nerve at elbow**) 1. Pronator teres syndrome - Syndrome that occurs when median

nerve is entrapped between superficial and deep heads of pronator teres muscle in forearm

a. Symptoms i. Mimics symptoms of carpal tunnel ii. Paraesthesia (altered sensation such as tingling or

“pins and needles”) iii. Pain in: polar axis of elbow, forearm, Digits 1,2,3 &

radial half of 4th b. Assessment:

i. If patient presents with traditional Carpal Tunnel Syndrome symptoms, it is extremely important to perform differential diagnosis to determine the site of the nerve entrapment.

ii. You can do this by performing a Tinel Sign over the wrist AND over the elbow and compare which elicits more severe symptoms. A positive Tinel sign over the elbow indicates Pronator Teres Syndrome as opposed to Carpal Tunnel Syndrome.

iii. Tinel Sign - Assessment for carpal tunnel syndrome in which clinician taps on the palm side of the wrist. If it elicits (causes) increased tingling/numbness over the median nerve distribution area (palm side of digits 1, 2, 3, and half of 4), that is a positive sign.

2. Anterior interosseous syndrome - indicated by more motor weakness versus altered sensation

iv. (4) Proximal forearm at edge of flexor digitorum superficialis b. If you suspect carpal tunnel syndrome, you must differentiate whether or not

median nerve entrapment is occurring cervically (at level of cervical spine), at

pronator teres (elbow), or carpal tunnel (wrist). Can differentiate by using EMG studies and compare results to normal nerve times.

2. Lateral epicondylitis or “Tennis elbow”

a. b. Characterized by:

i. Inflammation in the common extensor tendon (tendon origin of the extensor carpi radialis brevis muscle)

ii. The focal point of pain most likely near the lateral epicondyle of humerus c. Causes

i. Repetitive movement d. Treatment

i. Rest. Avoid activities that aggravate your elbow pain. ii. Pain relievers. Try over-the-counter pain relievers, such as ibuprofen

(Advil, Motrin IB) or naproxen (Aleve). iii. Ice. Apply ice or a cold pack for 15 minutes three to four times a day. iv. Technique. Make sure that you are using proper technique for your activities and avoiding repetitive wrist motions.

3. Medial epicondylitis of “Golfer’s elbow” a. Symptoms

i. Pain and tenderness usually felt on the inner side of the elbow. The pain sometimes extends along the inner side of your forearm and is typically exacerbated by certain movements.

ii. Stiffness - The elbow may feel stiff, and making a fist might hurt. iii. Weakness - You may have weakness in your hands and wrists.

iv. Numbness or tingling - These sensations might radiate into one or more fingers — usually the ring and little fingers.

b. Causes i. Damage to the muscles and tendons that control the wrist and fingers,

typically related to excess or repeated stress — especially forceful wrist and finger motions

ii. Improper lifting, throwing or hitting, as well as too little warmup or poor conditioning during racket sports, throwing sports, or weight training

iii. Forceful, repetitive occupational movements. These occur in fields such as construction, plumbing and carpentry

c. Prevention strategies: i. Strengthen your forearm muscles. Use light weights or squeeze a tennis

ball. Even simple exercises can help your muscles absorb the energy of sudden physical stress.

ii. Stretch before your activity. Walk or jog for a few minutes to warm up your muscles. Then do gentle stretches before you begin your game.

iii. Fix your form. Whatever your sport, ask an instructor to check your form to avoid overload on muscles.

iv. Use the right equipment. If you're using older golfing irons, consider upgrading to lighter graphite clubs. If you play tennis, make sure your racket fits you. A racket with a small grip or a heavy head may increase the risk of elbow problems.

v. Lift properly. When lifting anything — including free weights — keep your wrist rigid and stable to reduce the force to your elbow.

vi. Know when to rest. Try not to overuse your elbow. At the first sign of elbow pain, take a break.

d. Therapy Interventions: i. Rest. Put your golf game or other repetitive activities on hold until the pain is gone. If you return to activity too soon, you can worsen your condition. ii. Ice

the affected area. Apply ice packs to your elbow for 15 to 20 minutes at a time, three to four times a day for several days. To protect your skin, wrap the ice

packs in a thin towel. It might help to massage your inner elbow with ice for five minutes at a time, two to three times a day.

iii. Use a brace. Your doctor might recommend that you wear a counterforce brace to reduce tendon and muscle strain.

iv. Stretch and strengthen the affected area. Progressive loading of the tendon with specific strength training exercises has been shown to be

especially effective. v. Gradually return to your usual activities. When your pain is gone, practice

the arm motions of your sport or activity. Review your golf or tennis swing with an instructor to ensure that your technique is correct, and make adjustments if needed.

4. DeQuervain’s tenosynovitis a. A painful condition affecting the tendons on the thumb side of your wrist. b. Symptoms:

i. Pain when you turn your wrist, grasp anything or make a fist. ii. Pain near the base of your thumb iii. Swelling near the base of your thumb iv. Difficulty moving your thumb and wrist when you're doing something that

involves grasping or pinching v. A "sticking" or "stop-and-go" sensation in your thumb when moving it vi. If the condition goes too long without treatment, the pain may spread further into your thumb, back into your forearm or both. Pinching, grasping and other movements

of your thumb and wrist aggravate the pain. c. Causes:

i. The exact cause is unknown ii. Exacerbated by repetitive hand or wrist movement — such as working in

the garden, playing golf or racket sports, or lifting your baby. (Repeatinga particular motion day after day may irritate the carpal tunnel, causing thickening and swelling that restricts their movement.)

iii. Direct injury to your wrist or tendon; scar tissue can restrict movement of the tendons

iv. Inflammatory arthritis, such as rheumatoid arthritis d. Diagnosis

i. Examine the hand - Does the patient report pain when pressure is applied to the thumb side of the wrist?

ii. Finkelstein test - Test in which you bend your thumb across the palm of your hand and bend your fingers down over your thumb. Then you bend your wrist toward your little finger. If this causes pain on the thumb side of your wrist, you likely have de Quervain's tenosynovitis.

iii. Imaging tests, such as X-rays, generally aren't needed to diagnose de

Quervain's tenosynovitis. e. Treatment

i. Medical doctor may: 1. Recommend using over-the-counter pain relievers, such as

ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve) to reduce pain & swelling

2. Recommend injections of corticosteroid medications into the tendon sheath to reduce swelling

ii. PT/OT treatment may include: 1. Use of a splint or brace such as a thumb spica splint to immobilize

the thumb and wrist and to help rest the irritated tendons

2. Avoiding repetitive thumb movements as much as possible 3. Avoiding pinching with your thumb when moving your wrist from

side to side 4. Applying ice to the affected area

5. Compensatory strategies such as modifying utensils & tools to reduce strain on wrist

6. Recommendation of ergonomic work setup to reduce strain on wrist

7. Suggestions on how to make adjustments to relieve stress on your wrists

8. Gentle exercises for the wrist, hand and arm to strengthen your muscles, reduce pain and limit tendon irritation.

9. Tendon gliding exercises

5. Saturday night palsy a. Radial nerve compression in the arm resulting from direct pressure against a firm

object

6. Carpal tunnel syndrome a. Entrapment or compression of the median nerve in the carpal tunnel b. Can cause numbness, tingling, pain, and weakness in the wrist & hand c. Often occurs as a result of repetitive motions like typing or writing d. The recurrent branch of the median nerve innervates the thenar compartment of

the hand, including flexor pollicis brevis, abductor pollicis brevis, and opponenspollicis. So, if the median nerve was compressed, all of these muscles might be affected.

e. The dorsal interossei, palmar interossei, and opponens digiti minimi are all muscles of the hand which are innervated by the deep branch of the ulnar nerve. f. Flexor pollicis longus is innervated by the median nerve, but it is a forearm muscle which is proximal to the carpal tunnel. Therefore, it would not be affected by compressing the median nerve in the carpal tunnel.

g. h. Treated with outpatient surgery to decompress the median nerve by cutting the

ligament at the bottom of the wrist to release pressure. Your hand and wrist may be bandaged for seven to 10 days. Often the bandage stays in place until you visit the clinic for removal of the stiches. You may or may not experience immediate relief, as the area will be sore following surgery. That will improve over time. Pain medication will be provided before you go home. It is recommended that you rest and elevate your hand and wrist, as well as limiting their use.

PT/OT Assessments ● Must assess where sensory symptoms are reported → Location of sensory

symptoms will match dermatomes of specific nerve ● If you are trying to differentiate whether the issue is more myotomal (relating to spinal

root) versus distal nerve, we can assess finger flexion strength ● Tinel Sign & Phalen Sign YouTube video ● Assess which digits display weakness:

○ Weakness in Digits 2 & 3 finger flexion = stemming from MEDIAN NERVE ○ Weakness in Digits 4 & 5 finger flexion = stemming from ULNAR NERVE ○ Weakness in ALL digits or digits 2-4 = stemming from NERVE ROOT

● Upper Limb Tension Tests (ULTT) (https://www.physio-pedia.com/Neurodynamic_Assessment)

○ Also known as Brachial Plexus Tension or Elvey Test ○ Designed to put stress on neurological structures of upper limb ○ The shoulder, elbow, forearm, wrist and fingers are kept in specific position to put

stress on particular nerve (nerve bias) and further modification in position of each joint is done as "sensitiser". The ULTT's are equivalent to the straight leg raise designed for the lumbar spine.

○ Purpose: ■ These tension tests are performed to check the peripheral nerve

compression or as a part of neurodynamic assessment . ■ The main reason for using a ULTT is to check cervical radiculopathy.

■ These tests are both diagnostic and therapeutic. ■ Once the diagnosis of cervical radiculopathy is made the tests are done to

mobilise the entrapped nerve. ○ Method

■ Each test is done on the normal/asymptomatic side first. Traditionally for the upper limb, the order of joint positioning is shoulder followed by

forearm, wrist, fingers, and lastly elbow. Each joint positioning component is added until the pain is provoked or symptoms are reproduced. To further sensitive the upper limb tests, side flexion of cervical spine can be added[4]. If pain is provoked in the very initial position, then there is no need to add further sensitisers.

■ If pain or sensations of tingling or numbness are experienced at any stage during movement into the test position or during addition of sensitisation manoeuvres, particularly reproduction of neck, shoulder or arm symptoms, the test is positive; this confirms a degree of mechanical interference affecting neural structures.

■ Upper Limb Tension Test 1 (ULTT1, Median nerve bias) 1. Shoulder girdle depression 2. Shoulder abduction 3. Shoulder external rotation 4. Forearm Supination5. Wrist and Finger extension 6. Elbow extension 7. Cervical side flexion

■ Upper Limb Tension Test 2A (ULTT2A, Median nerve bias) 1. Shoulder girdle depression 2. Elbow extension 3. Lateral rotation of the whole arm 4. Wrist, finger and thumb extension

■ Upper Limb Tension Test 2B (ULTT2B, Radial nerve bias) 1. Shoulder girdle depression 2. Elbow extension 3. Medial rotation of the whole arm 4. Wrist, finger and thumb flexion

■ Upper Limb Tension Test 3 (ULTT3, Ulnar nerve bias) 1. Shoulder girdle depression 2. Shoulder abduction 3. Shoulder external rotation 4. Wrist and Finger extension 5. Elbow flexion 6. Shoulder abduction

■ Musculocutaneous Nerve Tension Test (ULTT musculocutaneous) 1. Shoulder girdle depression 2. Elbow extension 3. Shoulder extension

4. Ulnar deviation of the wrist with thumb flexion 5. Either medial or lateral rotation of the arm could further sensitize

this nerve

● Fine Motor Coordination Tests

● DASH / QuickDASH ○ The Disabilities of the Arm, Shoulder and Hand (DASH) is a 30-item self-

report questionnaire that looks at the ability of a patient to perform certain upper extremity activities. Patients can rate difficulty and interference with daily life on a 5 point Likert scale.

○ The QuickDASH is an abbreviated version of the original DASH outcome measure (11 items compared to 30) that measures an individual’s ability to complete tasks, absorb forces, and severity of symptoms using a 5-point Likert scale from which the patient can select an appropriate number corresponding to his/her severity/function level

● Modified Ashworth Scale of Spasticity (Bohannon & Smith, 1987) ○ 0: “Slight increase in muscle tone with a “catch” when the limb is moved ○ 1: Slight increase in muscle tone, manifested by minimal resistance at the end of the ROM when the affected part is moved in flexion or extension ○ 1+: Light increase in muscle tone, manifested by catch, followed by minimal

resistance throughout the remainder (less than half) of the ROM ○ 2: More marked increase in muscle tone,but the limb is easily flexed ○ 3: Considerable increase in muscle tone ○ 4: Rigid in flexion or extension