Module 2A &2B Flashcards
What spinal nerve components contribute to the formation of the brachial plexus?
Ventral Primary Rami - C5-T1
What are the main reasons for entrapped in the IVF area?
disc herniation or degenerative processes related to arthritis
What significant risk to injury does the cervical spine have that is not an issue in the lumbar spine?
Spinal cord
What parts of the body do the muscular branches consist of?
Bones, tendons/ligaments, muscles, and vessels
- GSA axons: joint receptors (Pacinian corpuscles, Ruffini end organs, nociceptors); proprioceptors (muscle spindles and GTOs); other nociceptors
- GVA axons: primarily arising in vascular elements responding pressure
- GSE axons: innervating skeletal muscle cells
- Postganglionic GVE axons: sympathetic innervation of the vessels serving the muscles, bones, and surrounding soft tissues
What parts of the body do the cutaneous branch consist of?
Skin
GSA axons: high and low threshold fibers (mechanoreceptors, thermoreceptors, chemoreceptors, and nociceptors)
• GVA axons: primarily vascular pressure
• Postganglionic GVE axons: sympathetic innervation of the vessels, erector pili, and the sweat glands.
How do we sort the brachial plexus?
Hint: R, T, D, C, MB
Roots: C5-T1
Trunks: Upper, Middle, and Lower
Divisions: Anterior and Posterior
Cords: Lateral, Medial, and Posterior
Main Branches: Musculocutaneous, Axillary, Median, Ulnar, Radial
How do we evaluate integrity of spinal nerves?
MSR Tests
Muscle strength is accessed bilaterally, as are all of the tests.
Grading is somewhat subjective but meant to be evaluated WITHIN that patient, based on fitness, level of health, and degree to which pain affects the movement. Age and gender may play a role.
Reflexes are evaluated on a + scale, where ++ is normal.
What is the muscle test done to test C5? What is the peripheral route?
Deltoid muscle
Axillary nerve
What is the reflex test done to test C5? What is the peripheral route?
Biceps
Musculocutaneous
Where is the sensory test done for C5?
Toward the superior and lateral portion of the arm
What is the muscle test done to test C6? What is the peripheral route?
Biceps brachii and wrist extension
Musculocutaneous and posterior interosseous
What is the reflex test done to test C6? What is the peripheral route?
Brachioradialis
Radial nerve
Where is the sensory test done for C6?
Middle portion of the arm toward the side of the thumb
What is the muscle test done to test C7? What is the peripheral route?
Triceps brachii and wrist flexors
Radial and median
What is the reflex test done to test C7? What is the peripheral route?
Triceps
Radial
Where is the sensory test done for C7?
Middle 3 fingers
What is the muscle test done to test C8? What is the peripheral route?
Finger flexors
Median
Median (and ulnar)
What is the reflex test done to test C8? What is the peripheral route?
Finger flexor reflex
Median
Where is the sensory test done of C8?
Pinky finger
What is the muscle test done to test T1? What is the peripheral route?
Finger adductors and/or abductors
Ulnar
What is the reflex test done to test T1? What is the peripheral route?
NONE; trick question
Where is the sensory test done of T1?
Medial portion of the arm by the elbow
What is Thoracic Outlet Syndrome caused by? What area is this cause by?
caused by entrapment of all / some the contributing VPR of the brachial plexus as it enters the upper extremity.
3 main areas where these entrapments can occur: between the middle and anterior scalenes
under the clavicle and subclavius muscle
under the tendon of the pectoralis major
What are some causes of Scalenus Atticus Syndrome?
Strain types of injuries, as well as respiratory distress conditions such as: asthma, pheumonia, emphysema, COPD, and others.
What are some signs of Scalenus Atticus Syndrome? When do they often show up?
Transient signs of arm paresthesia and weakness in all areas of the arm, both sides of the hand.
These symptoms come and go with neck movements and breathing difficulty.
What is Adson’s Test used to? How is it performed on the patient?
Anterior Scalene Syndrome
Ask the patient to ipsilaterally rotate, contralaterally laterally flex, and extend his neck, while the radial pulse is palpated.
A decrease in strength of the radial pulse is indicative of anterior scalene syndrome.
What is Costoclavicular Syndrome? What structures are involved?
This condition is caused by entrapment of the BP between the clavicle and the first rib. It can be related to clavicular fracture, subluxation / fixation of the clavicle, and spasming of the subclavius muscle
The subclavius muscle stabilizes the clavicle and is very important in stabilizing the shoulder.
How is the Costiclavicular Maneuver preformed?
The client must assume a position that further approximates these two structures. This is accomplished by asking your client to stick his chest out (pushing the rib cage and specifically the first rib anteriorly against the clavicle) and pull the shoulder girdle back and down (pulling the clavicle posteriorly and inferiorly against the first rib), similar to the military posture of attention. The patient may also be asked to look down (tuck the chin to the chest) or look away from the affected side as this further compresses the costoclavicular space.
What is Hyperabduction Syndrome? What are the area associated with this syndrome?
• The pectoralis minor entraps the BP as it passes between the coracoid process of the scapula and the attchments of the pectoralis minor on ribs 3-5.
• This muscle can be over-stretched in hyperabductions of the upper extremity (bringing the arm over and posterior to the head), wearing heavy backpacks or other things pulling the shoulder back
What is the Wright’s Test used for? How is the Wright’s test performed?
Wright’s test is used to evaluate pectoralis minor or hyperabduction syndrome.
The clients upper extremity is passively moved up and back, while the radial pulse is palpated. Decrease in strength of the radial pulse is positive for pectoralis minor syndrome. Taking a deep breath in causes a further contraction and hardening of the pectoralis minor while it is being pulled taut against the rib cage (as the pectoralis minor acts as an accessory inspiratory muscle).
What muscles are innervated by dorsal scapular nerve? What do these muscles do?
levator scapulae, rhomboideus minor, and rhomboideus major
These muscles elevate and retract the scapula
How is the Position of Attention performed? What areas are associated?
Dr places posterior hand on the elbow of the patient, anterior hand stabilizes the ipsilateral hip.
Pt is instructed to match the pressure of the dr’s hand which is pushing elbow anteriorly.
This simulates the “position of attention” or retraction of the scapula.
What is dorsal scapular nerve syndrome?
Trauma to the scalene muscles caused by violent stretching such as cervical hyperextension- hyperflexion as in whiplash dynamics:
- The entrapment is usually by the scalenus medius muscle.
Where does the suprascapular nerve arise from?
Anterior division C5-C6
Where does the supraspinatus nerve arise from?
C5
Where does the infraspinatus nerve arise from?
C6
Where does the nerve to the subclavius arise from?
C5-C6
What are the causes of suprascapular nerve entrapment?
- Paralabral ganglion cyst - pressing on the nerve.
- Thickening and/or bony ossification (bony change) of the overlying ligament (superior transverse scapular ligament - STSL).
How is damage causes to the suprascapular nerve?
- Entrapment of the nerve within the suprascapular notch
- A major or repetitive trauma
- Neuralgic amyotrophy (Parsonage-Turner Syndrome)
What is the lateral cord derived from? What are the 3 main branches?
Upper and middle trunk anterior division components (C5-C7)
the lateral pectoral nerve, the musculocutaneous nerve, and the branch contributing to the medial cord
What are the 3 cords of the plexus? What components are they made up of?
Lateral Cord: Anterior Divisions of C5-C7
Medial Cord: Anterior Divisions of C8-T1
Posterior Cord: Posterior Divisions of C5-T1
What are the branches of the lateral cord? What muscles do they attach to?
Lateral Pectoral Nerve (C5-C6)
- pectoralis major
Musculocutaneous Nerve (C5-C6)
- coracobrachialis
- brachialis
- biceps brachii
Contribution to the medial cord/median nerve
What are the muscular contribution of the Musculocutaneous Nerve?
Biceps brachii (C5-C6)
Brachialis (C5-C6)
Coracobrachialis (C5-C7)
What are the cutaneous contribution of the Musculocutaneous Nerve?
Lateral antebrachial cutaneous nerve - distribution to the lateral forearm, largely from C6. The C6 dermatologist continues down to the thumb and includes the web.
What are the neurological level indicators of the Musculocutaneous Nerve?
Biceps: C6
Biceps reflex: C5
Where is the lateral antebrachial cutaneous dermatome on the arm?
Lateral thumb side of the forearm
What are the branches of the medial cord?
Median nerve
Ulnar nerve
Medial cutaneous nerve of the arm
Medial cutaneous nerve of the forearm
Medial pectoral nerve
What are the segments of the medial pectoral nerve? What muscles does it innervate?
C8-T1
Lower fibers of the pectoralis major and pectoralis minor
What are the pectoralis minor trigger point pattern?
Associated with the muscles do mimic the C8 distribution in the hand, and can contribute to the diagnosis of hyperabduction syndrome (TOS)
What is the largest nerve in the upper extremity?
Median
What nerve innervates the flexors of the wrist and fingers as well as pronators of the forearm?
Median nerve
What are the muscular branches of the median nerve? What muscles are innervated?
Main muscular branch
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
Anterior interosseous nerve
- Flexor digitorum profoundus I & II
- Flexor policies longus
- Pronator Quadratus
Recurrent Branch of the Median nerve
- Abductor pollicis brevis
- Flexor pollicis brevis
- Oppoenens pollicis
- First lumbrical
- Second lumbrical
What is the orthopedic test for the median nerve?
Pinch test (OK sign)
Two muscle innervated by the AIN are necessary to make this sign: the flexor digitorum profundus, which flexes the DIP of the index finger, and the flexor pollicis longus, which flexes the DIP of the thumb.
What are the muscles of the thumb innervated by the recurrent branch (AKA Thenar branch) of the Median and the Palmar digital branch?
Thenar branch:
- Abductor pollicis brevis
- Flexor pollicis brevis: superficial head
- Opponents pollicis
Palmar digital branch
- Lumbricals I & II
What are the 2 heads of the flexor pollicis brevis? What nerve innervates them?
Superficial Head: median
Deep Head: Ulnar
What nerves innervates what lumbricals in the hand?
Lumbricals 1 and 2: Median nerve
Lumbricals 3 and 4: Ulnar nerve
What is the main “culprit” when it comes to carpal tunnel syndrome?
Transverse Carpal Ligament
Where is the digital cutaneous branch located?
Palm of the hand: Lumbricals 1 and 2 and half of 3
Back of the hand: top 2/3 of lumbrical 1 and 2 and thumb
Where is the palmar cutaneous branch located?
Lateral palm of the hand and thumb
What two muscles in the forearm does the ulnar nerve innervate?
Flexor carpi ulnaris
Flexor digitorum profundus
What are the muscular branches for the ulnar nerve?
- Flexor carpi ulnaris
- Flexor digitorum profundus
- Palmaris brevis
- Adductor pollicis
- Flexor pollicis brevis
- Opponens digiti minimi
- Abductor digiti minimi
- Flexor digiti minimi
-Lumbricals III and IV
- Palmar and Dorsal Interossei
Cutaneous branches
- digital/superficial
- palmar
- dorsal
What is the Tunnel of Guyon? What nerve runs through here and is a primary site for entrapment?
It is formed by a fascial ligament spanning the space between the pisiform and the hook of the hamate.
Ulnar nerve
What is the Froment’s Paper Test?
In this test you are specifically looking at the ability of the thumb to adduct, not the DIP to flex (as this is a function of the FPL– innervated by the… anterior interosseus nerve.
What are the muscles of the hand innervated by the ulnar nerve? What muscle is often tested?
Flexor digiti minimi, opponens digiti minimi, and abductor digiti minimi
Opponens digiti minimi
What nerve are the interossei innervated by? Which interossei are the aBductors and which are the aDductor?
Ulnar nerve
Dorsal interossei = aBductors
Palmar interossei = aDuctors
What are the cutaneous distribution of the ulnar nerve? Where are they located?
Palmar branch: palm below the pinky and half of the ring finger
Superficial branch: pinky and half of the ring finger
Dorsal branch: pinky and half of the ring finger and back of hand
What are the nerves of the posterior cord?
Upper and Lower Subscapular Nerves
Thoracodorsal Nerve
Axillary Nerve
Radial Nerve
What muscles are innervated by upper and lower subscapular nerve and thoracodorsal nerve?
upper subscapular nerve: subscapularis (C5-C6)
lower subscapular nerve: subscapularis (C5) and teres major (C6)
thoracodorsal nerve: latissimus dorsi
What is the purpose of the rotator cuff muscles?
Surrounds the head of the humerus providing for stabilization and fine movements of the humerus at the shoulder joint.
What are the muscles of the rotator cuff? What are their actions?
- supraspinous = abduction
- infraspinatus = lateral/ external rotation
- teres minor = lateral/ external rotation
- subscapularis = medial/ internal rotation
How do you test the latissimus dorsi?
• Can be done from several positions
• Supine; doctor braces opposite ASIS on top of patient hand
• Internally rotate and adduct arm, elbow straight
• Apply pressure against the patient’s effort to maintain that position.
What muscles are innervated by the Axillary nerve?
Teres minor
Deltoid
What is the significance of the quadrangular space?
Often the site of injury to the axillary nerve, is formed superiorly by the teres minor, medially by the long head of the triceps, inferiorly by the teres major, and laterally by the humerus and lateral head of the triceps.
What are some of the causes that could cause damage to the Axillary nerve? What are the symptoms?
Shoulder dislocation, scapular fracture, and other traumas to the area
Deltoid, teres minor, and the long head of the triceps
What is the cutaneous branch of the Axillary nerve?
Small portion of the skin under the shoulder
What are the muscles innervated in the antebrachium by the radial nerve?
Brachioradialis: C5, 6
Supinator: C6
Extensor carpi radialis longus: C6, 7
What are the muscles innervated in the antebrachium by the deep radial nerve (aka, the posterior Interosseus nerve)?
Extensor carpi radialis brevis: C6, 7
Extensor carpi ulnaris: C6, 7, 8
Extensor digitorum: (C6) C7 (C8)
Extensor digiti minimi: (C6) C7 (C8)
Extensor indicis: C7 (C8)
Extensor pollicis longus: C7, C8
Extensor pollicis brevis: C6, 7
Abductor pollicis longus: C6, 7
What are the cutaneous branches of the radial?
Lower lateral cutaneous nerve of arm: small portion of the lateral arm above the elbow
Posterior cutaneous nerve of arm: small portion of the posterior arm above the elbow
Posterior cutaneous nerve of forearm: posterior part of the forearm stops at the hand
Superficial branch: posterior part of hand thumb and fingers 1, 2, and half of 3
What is Upper Arm Radial Nerve Palsy: AKA “Saturday Night Palsy?” What are the common signs? What structures are involved?
• Compression of the radial nerve in the spiral groove of the humerus, or damage to the nerve in humeral fracture.
• Wrist drop is the most common sign of Radial Nerve Palsy
What is Radial Tunnel Syndrome (RTS): AKA Supinator Syndrome? What are the common signs? What structures are involved?
• Persistent pain around the lateral epicondyle, often misdiagnosed as lateral epicondylitis (“Tennis Elbow”).
• Pain may be dull and diffuse in the dorsal antebrachium, often due to repetitive pronation /
supination
• Nocturnal pain is common
• Pain, not weakness
What is Posterior Interosseus Nerve Syndrome (PINS)? What are the common signs? What structures are involved?
• Site of compression is at the Arcade of
Frohse, and weakness is the principle symptom
• Weakness of wrist, fingers, and thumb
extension; particularly the 3rd digit extension.
• No sensory changes, aching pain during
activity
What is Superficial Radial Nerve Compression? What are the common signs?
• Wartenberg’s Palsy
• The most common cause of superficial radial nerve palsy is wearing tight wrist bands.
