Upper Limb II Flashcards
Brachial plexus
All of the nerves that innervate the upper limb originate from here, a somatic plexus formed by the anterior rami of C5 to C8 and most of the anterior ramus of T1, originates in the neck, passes laterally and inferiorly over rib 1, enters the axilla and associates with the axillary artery
Brachial plexus parts
Roots, trunks, divisions, cords, terminal branches
Brachial plexus roots
Posterior rami, anterior rami from C5-T1
Brachial plexus trunks
Upper trunk (C5-C6), middle trunk (C7), lower trunk (C8-T1)
Brachial plexus cords
Lateral cord (C5-C7), posterior cord (C5-T1), medial cord (C8-T1)
Brachial plexus terminal branches
Axillary nerve (C5-C8), musculocutaneous (C5-C7), ulnar nerve (C8-T1), radial nerve (C5-T1), median nerve (C5-T1), provide motor innervation to muscles of the upper limb and sensory innervation to specific regions of the skin
Completely severed nerve
Function of nerve proximal to injury is normal, function of the nerve distal to the injury is lost, results in loss of muscle function and regions of numbness on the skin
Musculocutaneous nerve
Terminal branch of the lateral cord, enters the anterior compartment of the arm and runs between the brachialis and biceps brachii
Median nerve
Terminal branch of both lateral and medial cords in the axilla, runs distally with the brachial artery and medial aspect of the arm, crosses anterior to the elbow joint and enters forearm, gives off a deep branch in the upper part of the forearm (anterior interosseous nerve) and continues into the hand through the carpal tunnel
Ulnar nerve
Terminal branch of the medical cord, runs distally with the brachial artery and median nerve in the medial aspect of the arm, passes posterior to the medial epicondyle and enters the forearm, travels down the lateral aspect of the forearm close to the ulna, divides into a superficial and deep branch at the wrist
Axillary nerve
Terminal branch of the posterior cord, exits through the posterior wall of the axilla, passes posterior to the surgical neck of the humerus
Radial nerve
Terminal branch of the posterior cord, passes out of the axilla into the posterior compartment of the arm along the posterior aspect of the shaft of the humerus, enters forearm posterior to the lateral epicondyle of the humerus, travels to the posterior aspect of the hand, gives off a deep branch in the forearm (posterior interosseous nerve)
Loss of nerve to a muscle
Results in atrophy disuse of that muscle
Movement accomplished by 2+ muscles innervated by different nerves with single nerve damage
Results in weakness of the movement
Movement accomplished by muscles innervated by the same nerve with single nerve damage
Results in complete loss of movement
Loss of muscle function
Results in the opposite function/motion being dominant
Nerve injury associated with motor deficit and…
Sensory loss
Axillary nerve injuries
Anterior dislocation of the humerus, fracture of the surgical neck of the humerus
Axillary nerve lesion deficit
Weakness in abduction of the arm, sensory loss on lateral shoulder and upper arm
Radial nerve injury
Midshaft fractures of the humerus
Radial nerve lesion deficit
Loss of wrist and digit extension, weakness of supination, “wrist drop”, sensory loss on posterior arm and forearm and dorsum of hand
Median nerve injuries
Fractures of the elbow and distal humerus or within the carpal tunnel (carpal tunnel syndrome)
Median nerve lesion deficit - humerus fracture
Weakened wrist flexion, hand deviates to ulnar side when wrist is flexed, loss of index and middle finger flexion at MP, DIP, and PIP joints, weakness of thumb abduction, loss of thumb opposition and loss of thumb flexion, loss of pronation, cannot make a fist, sensory loss on palmar and dorsal aspects of index, middle, and half of ring fingers and palmar aspect of thumb
Median nerve lesion deficit - carpal tunnel syndrome
Weakness of thumb abduction and flexion, loss of thumb opposition (atrophy of thenar pad), sensory loss on palmar and dorsal aspects of index, middle, and half of ring fingers and palmar aspect of thumb
Deep branch of the median nerve injury
Anterior interosseous syndrome
Deep branch of the median nerve lesion deficit
Weakness of thumb flexion, loss of flexion of the DIP joint of the index and middle fingers, weakness of pronation, can’t make the “OK” sign, no sensory loss associated
Ulnar nerve injuries
Fractures of the medial epicondyle or compression of the nerve against the bone (tennis elbow) or with fractures or lacerations to the medial side of the wrist
Ulnar nerve laceration deficit - medial epicondyle fracture
Loss of abduction and adduction of fingers, loss of thumb adduction, loss of flexion of 4th and 5th digits at DIP joint, hand deviates to radial side when flexed, cannot make fist, sensory loss on medial side of hand and aspects of 4th and 5th digit
Ulnar nerve laceration deficit - wrist fracture
Loss of abduction and adduction of fingers, loss of thumb adduction, sensory loss on medial side of hand and aspects of 4th and 5th digit
Musculocutaneous nerve injury
Not common
Musculocutaneous nerve lesion deficit
Weakness of forearm flexion, weakness of hand supination, weakness of arm flexion, sensory loss on lateral forearm
Upper brachial plexus injuries
Birth injury or fall on the shoulder, separation of the head from the shoulder, Erb’s palsy
Upper brachial plexus lesion deficits
Affects musculocutaneous, axillary, and suprascapular nerves, arm hangs by the side and is adducted and medially rotated, forearm is extended and hand pronated, loss of abduction and lateral rotation of the arm, loss of flexion and supination of the forearm, loss of sensations over a small area over the lower part of shoulder
Lower brachial plexus injuries
Birth injury or sever abduction of the arm, Klumpke’s palsy
Lower brachial plexus lesion deficits
Affects ulnar and possibly median nerves, results in ulnar claw hand due to the unopposed action of the long flexors and extensors of the fingers (hyperextension of the MP joints and flexion at the IP joints), loss of function of the intrinsic muscles of the hand, loss of function of the ulnar flexors of wrist and fingers, loss of sensation over a small area along the ulnar border of the forearm and hand
Vascular supply to the upper limb
Originates from the subclavian artery in the root of the neck, continues posterior to the clavicle to enter the axilla (now called axillary artery), then branches off in the neck (thyrocervical trunk)
Axillary artery
Gives off 5 branches in the axilla: superior throacic, thoracoacromial, lateral thoracic, subscapular, anterior humeral circumflex, posterior hand circumflex, then becomes the brachial artery in teh arm
Brachial artery
One major branch, the deep brachial, which supplies the posterior compartment of the arm, splits into the radial and ulnar arteries anterior to the elbow
Radial and ulnar arteries
Run to the hand to anastomose with one another as teh superficial and deep palmar arches
Collateral branches around joints
Bypass any blockages of the main arteries to still get blood to the hand, also allow for planned ligation of the main artery at specific locations that would not result in serious consequences for the limb
Collateral circulation around the shoulder
Blockages of axillary artery proximal to the subscapular artery can be bypassed by anastomoses between branches of the thyrocervical trunk and the subscapular artery
Collateral circulation around the elbow
Blockages of the brachial artery distal to the origin of the superior and inferior ulnar collaterals may be bypassed by anastomoses between recurrent branches of the radial and ulnar arteries and the brachial and deep brachial arteries
Collateral circulation around the wrist
Blockages of either the radial or ulnar artery in the distal forearm may be bypassed by the anastomoses established between the two arteries through the superficial and deep palmar arches
Shoulder exam - inspection
Look for swelling, asymmetry, scars, ecchymosis, bruising, note posture and any deformities present (muscular atrophy, scapular winging, etc)
Shoulder exam - palpation
Palpate the sternoclavicular joint, clavicle, acromioclavicular joint, subacromial bursa, coracoid process, bicipital groove, greater tubercle, lesser tubercle, scapula (spine, medial and lateral borders)
Palpation of AC joint
Patient’s arm at his/her side, note swelling, pain and gapping, could indicate joint separation/pathology
Palpation of bicipital groove
Patient sitting, beginning with arm straight, actively flexes bicep muscle while examiner provides supination and external rotation, palpates groove for pain indicating pathology associated with long head of biceps tendon
ROM test - forward flexion
Arm straight and brought upward through frontal plane, move as far as patient can go above head, 0 degrees is straight down at patient’s side, 180 degrees is straight up (160-180 is normal)
ROM test - abduction
Arm straight, hand palm up (arm supinated), 0 degrees is straight down at patient’s side, 180 is straight up (170-180 normal)
ROM test - external and internal rotation
Arm at side, elbow flexed at 90 degrees and held at waist, examiner externally or internally rotates arms, normal ER is 45 degrees, normal IR is 55 degrees
ROM test - Apley scratch test
External rotation and abduction, reach for upper scapula, compare bilaterally, internal rotation and adduction, reach for lower scapula, compare bilaterally
Strength tests - flexion and extension
Graded on 5 point scale (5 is ROM against gravity with full resistance by examiner, 1 is no joint motion) and whether pain is present
Strength tests - external and internal rotation
Sitting, arms at sides, elbows at 90 degrees, maintain elbow position at sides while external or internal rotation is attempted by patient against resistance, ER tests infraspinatus and teres minor, IR tests subscapularis
Strength test - empty can test
Patient sitting with arms straight out, elbows locked, thumbs down and arm at 30 degrees in scapular plane, patient should attempt to abduct arm against examiner’s resistance, tests supraspinatus
Strength test - lift off test
Patient rests dorsum of hand on back in lumbar area, attempts to push examiner’s hand away, tests subscapularis
Rotator cuff special test - drop arm test
Patient abducts arm then slowly lowers, may be able to lower arm slowly to 90 degrees (deltoid function), arm then drop to side if rotator cuff is injured, tests the supraspinatus muscle primarily
Rotator cuff special test - Neer’s sign
Patient seated with arm at side, palm down (pronated), examiner stabilizes scapular and raises the arm (between flexion and abduction), positive test will result in pain, impingement sign is elicited when the patient’s rotator cuff tendons are pinched under the coracoacromial arch
Rotator cuff special test - Hawkin’s test
Patient standing, examiner forward flexes shoulder to 90 degrees, then forcibly internally rotates the arm, positive test will result in pain in area of superior glenohumeral joint or AC joint, suggests subacromial impingement or rotator cuff tendonitis
Biceps tendon special test - Speed’s test
Forward flex shoulder against resistances while maintaining elbow in extension and forearm in supination, positive test results in tenderness of bicipital groove, indicating bicipital tendinitis
Labral tear special test - O’Brien’s active compression test
Patient standing, arm forward flexed 90 degrees, adducted 15-20 degrees, with elbow straight, full internal rotation so thumb is pointing down, examiner applies downward force on arm, patient resists, patient externally rotates arm so thumb points up, examiner applies downward force on arm, patient resists, positive test is pain or painful clicking elicited with thumb down that is decreased with thumb up
Labral tear special test - crank test
Shoulder elevated to 160 degrees in the scapular plane, a gentle axial load is applied through glenohumeral joint with one hand, while the other hand does IR and ER, positive test would be pain, catching or clicking in the shoulder
Glenohumeral joint stability test - sitting apprehension test
90 degrees of abduction, examiner applies slight anterior pressure to humerus and externally rotates arm, positive test would be patient expresses apprehension (thinks the shoulder will dislocate), indicates loose capsule and/or ligaments
Glenohumeral joint stability test - supine apprehension test
Patient in supine position with affected shoulder at edge of table, arm abducted 90 degrees, examiner externally rotates by pushing forearm posteriorly, positive test would be patient showing apprehension
Glenohumeral joint stability test - relocation test
Performed after positive result on anterior apprehension test, patient supine, examiner applies posterior force on proximal humerus while externally rotating patient’s arm, positive test would be patient expressing relief
