Shoulder Flashcards
scaption
elevation of the glenohumeral joint in the plane of the scapula
glenohumeral joint
a true synovial-lined diathrodial joint
glenoid fossa
flat, but made 50% deeper by a ring of fibrocartilage called the labrum
labrum
a ring of fibrocartilage that makes the glenoid fossa 50% deeper
forms part of the articular surface of the glenohumeral joint
attached to the margin of the glenoid cavity and the joint capsule and contributes to joint stability
scapula
the base of the glenohumeral joint
lies on the thoracic cage at 30 deg to the frontal plane, 3 deg superior to he transverse plane, and 20 deg forward in the sagittal plane
acromion morphology
flat
slightly convex
hooked (predisposes the shoulder to a rotator cuff injury)
coracoid process
acts as a lever for the pec major muscle to help stabilize the scapula
coracobrachialis and short head of the biceps originate here
greater tuberosity
attachment for supraspinatus, infraspinatus, and teres minor
lesser tuberosity
attachment for subscapularis
Z ligaments
aka glenohumeral ligaments
superior, middle, and inferior
Superior glenohumeral ligament
limits external rotation and inferior translation of the humeral head with the arm at the side
middle glemohumeral ligament
limits external rotation and anterior translaiton of the humeral head with the arm in 0 and 45 deg of abduction
inferior glenohumeral ligament
consists of an anterior band, posterior band, and axillary pouch with varying functions
coracohumeral ligament
consists of two bands that join near the acromion and prevents AC joint separation
Subacromial space
contains the long head of the biceps tendon, supraspinatus, and upper margins of subscapularis and infraspinatus, subdeltoid and subacromial bursae
narrowest between 60 and 120 deg of scaption
Impingement syndrome
pain in the subacromial space when the humerus is elevated or internally rotated
supraspinatus tendon and bursa become entrapped between the acromion and greater tuberosity
once the supraspinatus tendon is disrupted there will often be further impingement and irritation which can lead to biceps tendonitis and further rupture
thought to precipitate attritional changes in the rotator cuff leading to a tear
Clinical Findings of Impingement Syndrome
pain will often become worse at night as the subacromial bursa becomes hyperemic after use
subacromial bursa
one of the largest bursae in the body
provides two smooth serosal layers, one adhered to the overlying deltoid and the other to the rotator cuff beneath
Erb’s Palsy
aka erb-duchenne paralysis
upper brachial plexus injury from forceful depression of the shoulder
patient presents with internally rotated and adducted shoulder (waiter’s tip position)
biceps reflex is lost and there is muscle wasting; some elbow and hand motion may be present
Klumpke’s Palsy
aka Klumpke-Dejerine Paralysis
Lower brachial plexus injury from forceful pulling of the upper arm
impairment of wrist flexion and movements of the intrinsic muscles of the hand
Shoulder complex vascularization
thoracoacromial, suprahumeral, and subscapular arteries
Close packed position of the glenohumeral Joint
90 deg of abduction and full external rotation; or full abduction and external rotation
Open packed position of the glenohumeral joint
55 deg of semiabduction and 30 deg of horizontal adduction without internal or external rotation
acromioclavicular joint
diarthrodial joint formed by acromion and lateral end of the clavicle
serves as the main articulation suspending the upper extremity from the trunk and is the joint about which the scapula moves
coracoclavicular ligaments
conoid and trapezoid
mainly provide vertical stability, with control of superior and anterior translation as well as anterior axial rotation
AC joint innervation
suprascapular, lateral pectoral, and axillary nerves
AC joint blood supply
suprascapular and thoracoacromial arteries
Scapulothoracic joint
functionally a joint, but lacks characteristics of a true synovial joint
plays a significant role in all motions of the shoulder complex
sternoclavicular joint close packed position
maximum arm elevation and protraction
sternoclavicular joint open packed position
yet to be determined but likely when the arm is by the side
sternoclavicular joint ligaments
anterior and posterior sternoclavicular ligaments
interclavicular ligament
costoclavicular ligament
Tietze’s syndrome
aka costochondritis
etiology unknown, pain and swelling of one or more costocartilages, overlying skin is reddened, swelling may persist for months
scapular pivoters
trapezius, serratus anterior, levator scapulae, and rhomboids
humeral propellers
latissimus dorsi, pectoralis major and minor
humeral positioners
all three parts of deltoid
shouder protectors
rotator cuff muscles, biceps
scapulohumeral rhythm
the combination and synchronization of motions between the scapula and humerus during arm elevation
2:1 ratio between motion at GH joint and scapula, respectively
Frozen shoulder
adhesive capsulitis
inflammation of the synovial layers causing an outpouring of secretion exudate leading to formation of adhesions
no GH movement
progressive motion limitation and concomitant muscle atrophy
Herpes Zoster
aka shingles
chicken pox related, severe neuralgic pain, unilateral clear crops of vesicles along the course of a cutaneous nerve
Anterior GH dislocation
most common
95% recurrence after initial event
squaring off appearance of the shoulder
Sprengels Deformity
congenital, develops prior to the third month of skeletal development
partially undescended shoulder
2:1 female predominance
scapular winging
paralysis of serratus anterior due to long thoracic nerve damage
Scheuermann’s Disease
aka juvenile kyphosis
at least three continuous segments are wedges more than 5 deg
slight male predominance
etiology unknown
Scoliosis
60-80% women
lateral curvature of the thoracic spine with vertebral body rotation
Muscles prone to tightness
upper trap levator scapulae pec major and minor upper cervical extensors scm scalenes teres major and minor
Muscles prone to inactivity or lengthening
lower and middle trap rhomboids serratus anterior deep neck flexors subscapularis spuraspinatus infraspinatus
shoulder flexion
180 degrees
shoulder extension
60 degrees
shoulder abduction
180 degrees
shoulder adduction
50 degrees
shoulder external rotation
90 degrees
shoulder internal rotation
70 degrees
