EXSC305 Ch.5 Test With
Complete Solution
Acromioclavicular Joint - ANSWER -clavicle is connected to scapula at distal end via AC
joint
-small, gliding joint
has a fibrocatilaginous disc
reinforced with a dense capsule and set of AC joint ligaments lying above and below the
joint
shoulder complex is made up of - ANSWER -sternoclavicular joint(SA)
-acromioclavicular joint (AC)
-scapulothoracic joint
-glenohumeral
sternoclavicular joint - ANSWER -clavicle joined to manubrium of sternum and is the only
point of skeletal attachment of the upper extremity to trunk
-Large end of clavicle articulates with small surface of sternum.
-gliding joint
-has a fibrocartilaginous disc
SC joint movements - ANSWER 3 degrees of freedom: eleveation and depression,
protraction and retraction, posterior and anterior roation
scapulothoracic joint - ANSWER 3 degrees of freedom: protraction and retraction,
upward and downward rotation, and elevation and depression
glenohumeral joint - ANSWER -shoulder joint
-motions at shoulder joint represented by arm movements
-offers the greatest ROM and movemnt potention of any joint in the body
-ball and socket joint w/ head of humerus fitting into the glenoid fossa of scapula
size difference between humeral head and glenoid fossa - ANSWER one of the reasons
the shoulder joint has extreme mobility
, 25%- 30% - ANSWER percentage of humeral head in contact with glenoid fossa at any
given time
ligamentous and muscular structures - ANSWER since there is minimal contact between
glenoid fossa and head of the humerus, should relys of ________________ for stability
Glenohumeral: static stabilizers - ANSWER articular surface, glenoid labrum, joint
capsule, ligaments
Glenoihumeral: dynamic stabilizers - ANSWER support of the shoulder joint occur s in
primarily in the midrange of motion and is provided by the muscles as they contract in a
coordinated pattern to compress the humeral head in the glenoid cavity
glenoid labrum - ANSWER a rim of fibrocartilage that deepend the shoulder joint cavity
5-9mm and increases the contact area of the head of humerus and glenoid fossa to 75%
joint capsule - ANSWER has approximately twice the volume of the humeral head,
allowing the arm to be raised through a considerable ROM. tightens in carious extreme
positions and is loose in the midrange of motion
ligaments - ANSWER caracohumeral ligament and 3 glenohumeral ligaments
subacromial bursa - ANSWER a bursa is a fluid filled sac found around strategic sites
around the synovial joint that reduces friction in the joint
arm movements - ANSWER 180 degress of flexion
60 degrees of extension
180 degrees of abduction
90 degrees of internal rotation
90 degrees of external rotation
135 degrees of horizontal adduction
45 degrees of horizontal abduction
shoulder flexion and shoulder abduction - ANSWER -deltoid generates ~50% of the
muscular force for elevation of arm
-when the arm elevates, the rotator cuff also plays important role because the deltoid
cannot flex or abduct the arm w/o stabilization of the humeral head.
-shoulder girdle must protract, elevate, and rotate upward with posterior clavicular
rotation to maintain the glenoid fossa in optimal position
rotator cuff - ANSWER teres minor, subscapularis, infrasprinatus, supraspinatus
shoulder extension and shoulder adduction - ANSWER -arm is slowly lowered muscles
Complete Solution
Acromioclavicular Joint - ANSWER -clavicle is connected to scapula at distal end via AC
joint
-small, gliding joint
has a fibrocatilaginous disc
reinforced with a dense capsule and set of AC joint ligaments lying above and below the
joint
shoulder complex is made up of - ANSWER -sternoclavicular joint(SA)
-acromioclavicular joint (AC)
-scapulothoracic joint
-glenohumeral
sternoclavicular joint - ANSWER -clavicle joined to manubrium of sternum and is the only
point of skeletal attachment of the upper extremity to trunk
-Large end of clavicle articulates with small surface of sternum.
-gliding joint
-has a fibrocartilaginous disc
SC joint movements - ANSWER 3 degrees of freedom: eleveation and depression,
protraction and retraction, posterior and anterior roation
scapulothoracic joint - ANSWER 3 degrees of freedom: protraction and retraction,
upward and downward rotation, and elevation and depression
glenohumeral joint - ANSWER -shoulder joint
-motions at shoulder joint represented by arm movements
-offers the greatest ROM and movemnt potention of any joint in the body
-ball and socket joint w/ head of humerus fitting into the glenoid fossa of scapula
size difference between humeral head and glenoid fossa - ANSWER one of the reasons
the shoulder joint has extreme mobility
, 25%- 30% - ANSWER percentage of humeral head in contact with glenoid fossa at any
given time
ligamentous and muscular structures - ANSWER since there is minimal contact between
glenoid fossa and head of the humerus, should relys of ________________ for stability
Glenohumeral: static stabilizers - ANSWER articular surface, glenoid labrum, joint
capsule, ligaments
Glenoihumeral: dynamic stabilizers - ANSWER support of the shoulder joint occur s in
primarily in the midrange of motion and is provided by the muscles as they contract in a
coordinated pattern to compress the humeral head in the glenoid cavity
glenoid labrum - ANSWER a rim of fibrocartilage that deepend the shoulder joint cavity
5-9mm and increases the contact area of the head of humerus and glenoid fossa to 75%
joint capsule - ANSWER has approximately twice the volume of the humeral head,
allowing the arm to be raised through a considerable ROM. tightens in carious extreme
positions and is loose in the midrange of motion
ligaments - ANSWER caracohumeral ligament and 3 glenohumeral ligaments
subacromial bursa - ANSWER a bursa is a fluid filled sac found around strategic sites
around the synovial joint that reduces friction in the joint
arm movements - ANSWER 180 degress of flexion
60 degrees of extension
180 degrees of abduction
90 degrees of internal rotation
90 degrees of external rotation
135 degrees of horizontal adduction
45 degrees of horizontal abduction
shoulder flexion and shoulder abduction - ANSWER -deltoid generates ~50% of the
muscular force for elevation of arm
-when the arm elevates, the rotator cuff also plays important role because the deltoid
cannot flex or abduct the arm w/o stabilization of the humeral head.
-shoulder girdle must protract, elevate, and rotate upward with posterior clavicular
rotation to maintain the glenoid fossa in optimal position
rotator cuff - ANSWER teres minor, subscapularis, infrasprinatus, supraspinatus
shoulder extension and shoulder adduction - ANSWER -arm is slowly lowered muscles
