Movement Science Exam 2 Flashcards
What joints contribute to the shoulder complex?
AC - Acromioclavicular joint
SC - Sternoclavicular joint
GH - Glenohumeral joint
ST - Scapulothoracic joint
What bones contribute to the shoulder complex?
-Scapula
-Clavicle
-Humerus
-Sternum
Where does the scapula sit in resting position?
-Superior angle at T2
-Root at T3
-Inferior angle at T8
-Medial border rests 5-6cm from midline
-Sits approx 35 degrees anterior to the frontal plane
What nerves innervate the GH joint capsule?
C5-C6
What ligaments are involved with the GH joint?
-Coracohumeral
-Glenohumeral (3 divisions)
–Superior
–Middle
–inferior
The coracohumeral ligament limits what motions?
-External rotation and inferior translation
-Flexion and extension
The superior glenohumeral ligament limits what motions?
-Inferior translation
-External rotation at neutral position
The middle glenohumeral ligament limits what motions?
-External rotation at 0 and 45 degrees of abduction
The inferior glenohumeral ligament limits what motions?
-External rotation at 90 degrees of abduction
-Internal rotation at 90 degrees of abduction
What band of the glenohumeral ligament is the thickest?
The inferior band
What bursae are associated with the GH joint?
-Subscapular bursa
-Subacromial (subdeltoid) bursa
What classifications are involved with the GH joint?
-Diarthrosis
-Ball and Socket
-Triaxial
–3 degrees of freedom
—-Infinite planes of movements
A dislocation most commonly occurs how at the GH joint?
-Anteroinferiorly
What are some predisposing factors for GH joint dislocations?
-Loose capsule
-Small glenoid fossa
-No inferior musculature
-Labrum not providing sufficient enough lip
What injuries are associated with anterior dislocation of the GH joint?
-Bankart lesion
–tear capsule and labrum
-Hill-Sac’s lesion
–fracture portion of the humeral head
-SLAP lesion
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What types of stability does the GH joint have?
-Muscular
–Rotator cuff and deltoid
-Bony
-Ligamentous
-Cohesion
–Articular cartilage bein bathed in synovial fluid
-Intraarticular pressure (closed capsule)
What classifications are involved with the SC joint?
-Diarthrosis
-Saddle joint
-Biaxial (potentially triaxial)
-2 degrees of freedom (potentially 3)
What ligaments are associated with the SC joint?
-Anterior and posterior sternoclavicular
-Interclavicular
-Costoclavicular
What are the functions of the anterior and posterior sternoclavicular ligaments?
-Reinforce the capsule
-Prevent upward and lateral clavicle displacement
What is the function of the interclavicular ligament?
-Checks excessive upward glide of clavicle during depression
What is the function of the costoclavicular ligament?
-Site of fulcrum for elevation / depression and protraction / retraction
True or False: The SC joint has an articular cartilage disc?
True!
The disc helps to resist any force to dislocate the clavicle medially
What classifications are involved with the AC joint?
-Diarthrosis
What ligaments are associated with the AC joint?
-Coracoclavicular
–Trapezoid
–Conoid
What are the functions of the coracoclavicular ligaments?
-Prevent superior dislocation of clavicle
-Transmit forces from scapula to clavicle
-Produce and limit longitudinal rotation of the clavicle
What are some injuries associated with the AC joint?
-“Step-off” deformity
–Scap drifts down away from clavicle, so lateral end of clavicle appears elevated
Is the ST a true joint?
No, it is not a true physiologic joint. It is technically an extrinsic muscle of the shoulder
What are the scapula upward rotators (muscles)?
-Upper and lower traps
-Serratus anterior
What are the scapula downward rotators (muscles)?
-Rhomboid major and minor
-Pec minor
-Levator scapulae
What are the scapula retractors (muscles)?
-Rhomboid major and minor
-Middle and lower trap
What are the scapula protractors (muscles)?
-Pec minor
-Serratus anterior