Exam 6 Flashcards
Rhomboid minor. O, I, I, A
- O: spinous processes of C6-C7 - I: medial border of scapula above scapular spine - I: dorsal scapular n - A: retract and elevate scapula
Muscles responsible for shoulder/scapula retraction
- Retraction: scapula moved posteriorly and medially, moving shoulder posteriorly – squeezing pencil between shoulder blades - Trapezius (primarily), rhomboids, lat dorsi
Actions of posterior forearm muscles?
- Most are extensors of wrist and/or digits - Brachioradialis is elbow flexor, can supinate too
What is a Colles fracture? How does it occur?
- Most common forearm fracture where person falls forward onto a extended hand to break fall. Results in distal ulnar fracture with distal fragment displaced dorsally accompanied by avulsion of the ulnar styloid. This is called a “dinner fork” deformity.
What is found in the suprascapular notch of the scapula?
- Suprascapular artery and nerve with superior transverse ligament of scapula covering the notch, artery is above, nerve is below
Subclavius. O, I, I, A
- O: junction of 1st rib and manubrium - I: inferior center of clavicle - I: nerve to subclavius - A: depresses clavicle
What muscle assists in function of lat dorsi?
- Teres major
Teres major. O, I, I, A
- O: posterior surface of inferior angle of scapula - I: medial lip of intertubercular groove of humerus - I: lower subscapular n - A: adduction and medial rotation of arm – assists lat dorsi
Draw the brachial plexus
see image
Biceps brachii. O, I, I, A
- O long head (lateral): supraglenoid tubercle of scapula - O short head (medial): tip of coracoid process - I: radial tuberosity, bicipital aponeurosis blends with antebrachial fascia and attaches to ulna - I: musculocutaneous n - A: supinates, flexes forearm; assists with flexion of shoulder/resists dislocation
What movements would you ask patient to do, to distinguish ulnar nerve damage at elbow?
Flex digits. Not the wrist.
What are the rotator cuff muscles? Innervation of these muscles?
- Mnemonic = SITS = supraspinatus, infraspinatus, teres minor, subscapularis - Supra/infraspinatus: suprascapular n - Teres minor: axillary n - Subscapularis: upper/lower subscapular n
What is the ulnar canal? Clinical implication
- Narrow passage between pisiform and hook of hamate (known as hamulus) through which ulnar nerve passes and compression can occur - Symptoms: a.) numbness and tingling medial 1.5 digits and/or b.) weakness in intrinsic hand muscles (hypothenar compartment and medial 2 lumbricals) - Known as handlebar neuropathy or ulnar canal syndrome. Note: superficial and deep branches come off after this area thus are implicated.
What are the most common glenohumeral joint dislocation given the anatomy?
- Anterior/inferior
Pectoralis minor. O, I, I, A
- O: ribs 3-5 - I: medial border of coracoid process of scapula - I: medial pectoral n - A: stabilizes scapula against thoracic cage, elevates rib cage when scapula fixed (accessory respiratory muscle)
Levator scapulae. O, I, I, A
- O: transverse processes of C1-4 - I: superior angle of scapula - I: dorsal scapular n - A: elevates scapula
Median nerve. Nerve root, motor to/sensory from?
- Nerve root: C6-T1 - Motor: motor to anterior forearm (except FCU & ½ FDP), thenar muscles, lateral 2 lumbricals - Sensory: cutaneous lateral palm, lateral 3 ½ digits including dorsal fingertips
Extensor digiti minimi. O, I, I, A
- O: lateral epicondyle - I: extensor expansion of digit 5 - I: deep branch of radial n - A: extends digit 5 at all joints (MCP, PIP, DIP), assist in wrist extension and adduction
Which cord of the brachial plexus is the largest?
- Posterior
Triceps reflex is testing what nerve root?
- C7
Muscles responsible for shoulder/scapula elevation
- Trapezius (primarily), levator scapulae, rhomboids
Extensor carpi ulnaris. O, I, I, A
- O: lateral epicondyle - I: base of MC V - I: deep branch of radial n - A: extends / adducts wrist (ulnar deviation)
How to tell the difference clinically between a clavicle fracture and a dislocation (eg. AC joint)?
- Dislocation: weight of upper limb on affected side is pulling arm down and shoulder shows bony promimence. - Fracture: swelling, patient is holding arm up
Describe the superficial veins of the arm
- cephalic vein (lateral arm) to axillary vein via deltopectoral groove - communication between cephalic and basilic in cubital fossa = medial cubital vein - basilic vein to axillary vein through basilic hiatus
Pronator quadratus. O, I, I, A
- O: distal ulnar shaft - I: distal radial shaft - I: anterior interosseous n (branch off median n) - A: pronation
Damage to the axilla / midshaft humerus results in what? What nerve is damaged?
- This is aka Saturday night/Honeymoon/Crutch palsy Symptoms? - Damage to radial nerve Symptoms: a.) Weakness in triceps possible b.) Loss of all muscles in posterior compartment of forearm = inability to extend, tonus of flexors c.) Sensory loss to dorsum hand between MC I and II
Flexor pollicis longus. O, I, I, A
- O: radial shaft, interosseous membrane - I: base of distal phalanx of pollex - I: anterior interosseous n (branch off median n) - A: flex 1st wrist, CMC, MCP and IP joints
What is the lateral thoracic artery a branch of?
- Branch of thoracoacromial or subscapular artery
What is the nerve of the posterior compartment of the arm? Action produced by these muscles? Muscles?
- Nerve: radial nerve - Action: extension at elbow - Muscles: triceps brachii, anconeus
What is anterior interosseous syndrome? Symptoms? What is damaged?
- Aka Kiloh-Nevin syndrome - Damage to anterior interosseous nerve usually d/t trauma. Loss of FPL and lateral half of FDP resulting in inability to make OK sign with thumb and index finger. No sensory deficits result.
What muscle does the musculocutaneous nerve pierce through? What does this nerve become and when?
- Pierces coracobrachialis muscle - Becomes lateral antebrachial cutaneous nerve to supply sensory to lateral forearm
What is the nerve of the posterior compartment of the forearm? Action produced by these muscles? Approximate origin of most muscles?
- Nerve: radial nerve - Action: extensors and supinators of forearm and hand - Muscles: brachioradialis, ECRL, ECRB, ECU, ED, EDM, supinator, ABLE muscles (apL, epB, epL, Ei) - Approximate origin: common extensor tendon from lateral epicondyle/supracondylar ridge (for superficial group)
When landing on hand, which forearm bone is more likely to be fractured?
- Radius, which is in contact with carpals and transmits most of weight. Ulnar mostly dislocates
Brachioradialis reflex is testing what nerve root?
- C6
Extensor carpi radialis longus. O, I, I, A
- O: lateral supracondylar ridge of humerus - I: base of MC II (who cares) - I: radial n - A: extends / abducts wrist (radial deviation)
Flexor digitorum profundus. O, I, I, A
- O: ulnar shaft, interosseous membrane - I: base of distal phalanges 2-5 - I: medial half (digits 4/5) by ulnar n; lateral half (digits 2/3) by anterior interosseous n (branch off median n) - A: flex wrist, MCP, PIP, DIP
Muscles responsible for shoulder/scapula superior rotation
- Superior rotation is lateral rotation of scapula - Trapezius and serratus anterior
Pronator syndrome. What does this look like? What nerve is damaged? Where?
- Compression of median n b/w humeral and ulnar heads of pronator teres d/t muscle hypertrophy (or trauma) - Pain in proximal forearm, weakness in flexing fingers and wrist, decreased sensation in lateral palm and fingers
Lateral head of the FDP is what muscle?
- Flexor indicis
What is Volkman’s ischemic contracture?
- Damage to brachial artery d/t supra-epicondylar fracture of trauma to cubital fossa results in ischemia to downstream muscles and tightness results
What travels in the radial groove?
- Radial nerve and profunda brachii artery
What nerve would likely be damaged if patient is able to flex, oppose and adduct thumb, but not extend it?
Radial nerve
Patient comes to office stating that he has carpal tunnel syndrome symptoms. He says that he has tingling sensations in his palm. What do you think?
- Sensation to palm is via the superficial branch of ulnar to medial side and the lateral side via palmar branch of median nerve - Carpal tunnel syndrome is compression of the medial nerve in the carpal tunnel. The palmar branch of medial has already come off proximal to the tunnel, so these symptoms are unlikely contributed to carpal tunnel syndrome.
Supinator. O, I, I, A
- O: lateral epicondyle of humerus, posterior olecranon process - I: proximo-lateral radius - I: deep branch of radial n - A: supinates forearm
Dorsal scapular artery is severed during a trauma. What nerve is likely affected? What muscle stops functioning if this is the case? What is the presentation?
- Dorsal scapular nerve - Rhomboids and levator scapulae - Elevation and retraction of the scapula are lost
Subscapularis. O, I, I, A
- O: subscapular fossa - I: lesser tubercle of humerus - I: upper and lower subscapular n - A: medial rotation, stabilization of glenohumeral joint
Describe levels of axillary lymph node drainage relevant to breast cancer staging. How does this affect prognosis?
- level 1: lateral to pec minor - ~65% five year survival - level 2: deep to pec minor - ~ 31% five year survival - level 3: medial to pec minor - ~ 0% five year survival
Pectoralis major. O, I, I, A
- O: clavicular head onto medial clavicle, sternocostal head onto anterior sternum - I: lateral intertubercular groove of humerus - I: lateral and medial pectoral n - A: adductor and medial rotator when fully activated, clavicular head flexes humerus, sternocostal extends from flexed position
Anatomical snuff box. Borders and contents?
- Borders a.) Tendons of APL and EPB – note these two run together, not both EPB and EPL b.) Tendon of EPL - Contents: radial artery - Sensory branch of radial nerve runs over this region
Extensor carpi radialis brevis. O, I, I, A
- O: lateral epicondyle - I: base of MC III (who cares) - I: deep branch of radial n - A: extends / abducts wrist (radial deviation)
Supraspinatus injury presents how?
- Patient unable to perform the initial 15-20 degrees of arm abduction. Deltoid muscle is the main abductor, but has no leverage when the arm is completely relaxed and at the side. These patients will attempt to swing arm out first.
What are axio-appendicular muscles attaching the upper limb to thorax?
- Anteriorly: pec major, pec minor, subclavius and serratus anterior - Posteriorly: trap, lat dorsi, lev scap, rhomboid major, rhomboid minor
What artery supplies blood to upper limb?
- Subclavian which changes its name to axillary (with 3 parts) in axilla and brachial in brachium (arm)
Infraspinatus. O, I, I, A
- O: infraspinous fossa of scapula - I: greater tubercle of humerus - I: suprascapular n - A: lateral rotation, stabilization of the glenohumeral joint
30 yo woman on hike falls on some sharp rocks, catching herself with her right hand, and resulting in deep lacerations of her medial palm and wrist. She bandages the wound and continues on. In week following, she begins to complain of numbness in palmar aspect of medial 1 ½ digits and general hand weakness. When asked to make a fist, flexion occurs at all IP joints; however, you notice clawing (extension at MCP and flexion at IP joints) of medial two digits of her right hand while at rest. She is unable to abduct her fingers against resistance or to hold a piece of paper bw thumb and lateral surface of index finger. a.) Why is flexion present at all IP joints? b.) Loss of which muscles are responsible for clawing of medial 2 digits? c.) What muscles are responsible for her inability to grip the paper between the thumb and lateral index finger? d.) What would be different if the injury were to occur at the elbow?
- numbness medial 1 ½ digits = ulnar n damage - general hand weakness = intrinsic hand loss = ulnar n damage - flexion at all IP joints = medial nerve function ok - clawing at rest medial two digits = loss of medial MCP flexors, medial IP extensors = medial lumbricals not function = ulnar n damage - loss of thumb to lateral surface index finger tension = loss of adductor pollicis = ulnar n damage - specifically here we have deep branch of ulnar n damage a.) FDS and FDP, median and ulnar intact b.) Lumbricals, clawing at 3/4 is ulnar n damage c.) Deep branch of ulnar innervating the adductor pollicis and 1st dorsal interosseous (wasting here too) d.) Ulnar n damage at elbow = complete loss of all muscles distally innervated by ulnar n = loss of FCU, medial half of FDP also affected in addition to above
What muscles are found in the superficial anterior compartment of the forearm?
- PT, FCR, FDS, FCU, palmaris longus
Teres minor. O, I, I, A
- O: lateral border of scapula - I: greater tubercle of humerus - I: axillary n - A: lateral rotation, stabilization of glenohumeral joint
Extensor indicis. O, I, I, A
- O: posterior ulna, interosseous membrane - I: extensor expansion of digit 2 - I: posterior interosseous n (of radial) - A: extends index finger at all joints, assists with wrist extension
14 yo girl slashed her right wrist with a razor blade. She was rushed to ED. After stopping bleeding, PEX revealed she could adduct, abduct and extend her thumb but was unable to oppose it. She had lost some fine control of the movements of her second and third digits and there was loss of sensation over her lateral three and a half digits. a.) Why can she adduct her thumb? b.) Why can’t she oppose her thumb? c.) Why can she abduct and extend her thumb? d.) What nerve is damaged? e.) Why are digits 2/3 affected?
- A.) Adduct thumb = adductor pollicis innervated by deep branch of ulnar - B.) opponens pollicis innervated by recurrent branch of median nerve, which is damaged - C.) Abduction of thumb by abductor digiti minimi brevis and longus. Longus (main abductor) is innervated by posterior interosseous branch of radial n, which is still in tact. Brevis (intrinsic thenar) nerve is innervated by recurrent branch of median, which is damaged. Extension of thumb by extensor pollicis brevis and extensor pollicis longus, which is innervated also by posterior interosseous of radial, which is not damaged. - D.) median (recurrent branch?) - E.) branch of median also innervates the lateral 2 lumbricals of digits 2/3
You ask patient to hold a flat piece of paper between their 2nd and 3rd digits. What muscles are you testing?
Plantar interosseous (PADS)
Radius landmarks
- Head and neck - Radial tuberosity - Shaft - Styloid process - Interosseous crest
If the axillary artery is accidentally ligated, how does the scapula get blood?
- Thyrocervical trunk – transverse cervical – dorsal scapular – thoracodorsal – subscapular – axillary
Describe the dermatome pattern of the upper limb. Correlate nerve roots with specific cutaneous regions.
- Pre-axial to post-axial sequence. Pre-axial is lateral side while post-axial is medial side. - C5: shoulder - C6: tip of thumb - C7: cannot test, too variable - C8: tip of fifth - T1: medial forearm at cubital region
What is the difference between a dermatome vs a peripheral nerve field vs a myotome?
- Dermatome is an area of skin innervated by a specific single nerve root - Peripheral nerve field is an area of skin composed of overlapping dermatomes with the supplying nerve made up of multiple roots - Myotome is the set of muscles innervated by a specific nerve root - When assessing for nerve root injuries, use myotomes and dermatomes. When assessing for specific nerves injuries distal to root, use peripheral nerve fields.
Extensor digitorum. O, I, I, A
- O: lateral epicondyle - I: extensor expansion of digits 2-5 - I: deep branch of radial n - A: extends digits 2-5 at all joints (MCP, PIP, DIP), assist in wrist extension
What are the superficial posterior compartment forearm muscles?
- ECRB, ED, EDM, ECU, brachioradialis, anconeus
Lateral thoracic artery travels with what nerve? In relation to what muscle?
- Long thoracic nerve superficial to the serratus anterior
There is a blockage in the middle of the brachial artery. How could blood still get to the forearm and hand?
Collateral arteries of arm (duh!) Which? This might be good to draw out and tell exactly.
Joints of the hand. Name the joint, type, movement?
1.) Intercarpal joints: - Type: plane - Movement: sliding/translation 2.) Carpometacarpal joints (CMC): - Type: plan - Movement: sliding/translation 3.) Trapeziometacarpal joint: - Type: saddle - Movement: flexion, extension, abduction, adduction, opposition 4.) Metacarpophalangeal joints (MCP): - Type: condyloid - Movement: flexion, extension, abduction, adduction 5.) Interphalangeal joints (IP = PIP + DIP) – only IP for thumb - Type: hinge - Movement: flexion, extension
Brachialis. O, I, I, A
- O: ant humerus (distal half) - I: coronoid process and ulnar tuberosity of ulna - I: musculocutaneous and radial n - A: flexes forearm
19 yo male football player experienced lateral hyperflexion of his head and neck to right during tackle. Afterwards, he complained of numbness in his left upper limb. Palpation and radiographs confirmed that shoulder was not dislocated and no fractures were present in c-spine or pectoral girdle. 30 minutes later he began to experience severe burning pain in shoulder, lateral arm and forearm. Exam revealed he could not abduct or otherwise move the shoulder, nor could he flex at elbow. a.) What bests explains the pattern of burning/numbness? b.) What best explains the pattern of muscle dysfunction? c.) What is the level of the injury?
- A.) Dermatomal distribution. For peripheral nerve distribution, need to have damaged 3 nerves separately. - B.) No abduction at shoulder (C5), no flexion at elbow (C5) – myotomal pattern. - C.) C5 is definitely affected. Injuries such as this often also affect the C6 root or the upper trunk. If C6 injury, should see wrist flexion too. So this case isn’t Erb-Duchenne palsy. If it was, waiter tips presentation.
If recurrent branch of median nerve was damaged, what movements of hand would be impaired?
Opposition to 1st digit
What is the difference between the anatomical and surgical neck of the humerus?
- Surgical neck: thinnest part of humerus where injury is likely - Anatomical neck: bone epiphysis with primary ossification center
Supraspinatus. O, I, I, A
- O: supraspinous fossa of scapula - I: superior aspect of greater tubercle of humerus - I: suprascapular n - A: initiates abduction for first 15-20 degrees then deltoid takes over, stabilization of the glenohumeral joint
What is nursemaid’s elbow? How does this occur?
- Dislocation of radial head from annular ligament and away from humerus and ulna - Abrupt yanking of arm upwards
Describe blood supply to the hand. How to test for disruption in the supply?
- Blood supply to hand via radial and ulnar arteries via deep and superficial palmar arches 1.) Ulnar: a. Deep palmar branch of ulnar artery b. Superficial palmar arch i. Common palmar digital arteries (4) 1. Proper palmar digital arteries (8) – digits 2-4 ii. Proper palmar digital artery to 5th digit 2.) Radial: a. Superficial palmar branch of radial artery b. Deep palmar arch i. Palmar metacarpal arteries c. Princeps pollicis artery d. Radial indices artery (can originate from c.) - Test: Allen’s test = occlude both and release one to see
Humerus landmarks
- Head - Anatomical neck - Surgical neck - Greater tuberosity - Lesser tuberosity - Intertubercular groove/sulcus - Deltoid tuberosity - Radial groove - Coranoid fossa - Lateral/medial epicondyles - Capitulum - Trochlea - Olecranon fossa
Damage to forearm that causes inability to extend thumb and MCP joints is d/t trauma to what specific nerve?
- Deep branch of radial nerve