1What 4 interrelated joints comprise the shoulder complex?
Sternoclavicular, acromioclavicular, glenohumeral, and scapulothoracic joints
2Which joint of the shoulder complex is not a true joint?
The scapulothoracic (ST) joint
3Which joint acts as a strut holding the scapula at approximately the same distance from the trunk?
Sternoclavicular (SC) joint
4Which joint firmly attaches the scapula to the clavicle?
Acromioclavicular (AC) joint
5What type of joint is the sternoclavicular joint?
Saddle joint
6What is the shape of the medial end of the clavicle along its longitudinal diameter?
Convex
7What is the shape of the medial end of the clavicle along its transverse diameter?
Concave
8How many degrees of freedom does the SC joint have?
3 degrees of freedom
9What SC joint motions occur in the frontal plane?
Elevation and depression
10What SC joint motions occur in the horizontal plane?
Protraction and retraction
11What SC joint motion occurs around the longitudinal axis?
Axial/longitudinal rotation
12How many degrees of elevation occur at the SC joint?
30–45 degrees
13How many degrees of depression occur at the SC joint?
10 degrees
14What arthrokinematic motion occurs during SC joint elevation?
Convex clavicular surface rolls superiorly and slides inferiorly
15What arthrokinematic motion occurs during SC joint depression?
Convex clavicular surface rolls inferiorly and slides superiorly
16Which ligament is taut during SC joint elevation?
Costoclavicular ligament (CCL)
17Which ligaments are taut during SC joint depression?
Superior sternoclavicular ligament and interclavicular ligament (ICL)
18What arthrokinematic motion occurs during SC joint retraction?
Concave clavicular surface rolls and slides posteriorly
19What arthrokinematic motion occurs during SC joint protraction?
Concave clavicular surface rolls and slides anteriorly
20Which structures check SC joint retraction?
Anterior bundle of costoclavicular ligament and anterior capsule
21Which structures check SC joint protraction?
Posterior bundle of costoclavicular ligament and posterior capsule
22How many degrees of protraction and retraction occur at the SC joint?
~15 degrees in each direction
23How many degrees does the clavicle rotate posteriorly around its longitudinal axis during overhead reach?
~20–35 degrees
24Can clavicular posterior rotation occur with the arm resting at the side?
No, it is mechanically linked to arm flexion or abduction
25What type of joint is the acromioclavicular joint?
Plane or gliding synovial joint
26What cartilage lines the articular surfaces of the AC joint?
Fibrocartilage
27How many degrees of freedom does the AC joint permit?
3 degrees of freedom
28How many degrees of upward rotation occur at the AC joint during overhead arm elevation?
~30 degrees
29What are the rotational adjustment motions of the AC joint?
Anterior/posterior tilting and internal/external rotation
30What is the resting position of the scapula relative to the ribs?
Between the 2nd and 7th ribs
31How far lateral to the spine is the resting scapula located?
~6 cm
32What is the resting anterior tilt of the scapula?
10 degrees
33What is the resting upward rotation of the scapula?
5–10 degrees
34What is the resting internal rotation of the scapula?
30–40 degrees
35What combined joint motions produce scapulothoracic elevation?
SC elevation plus AC downward rotation
36What combined joint motions produce scapulothoracic protraction?
SC protraction plus AC internal rotation
37What combined joint motions produce scapulothoracic upward rotation?
SC elevation plus AC upward rotation
38Why is upward rotation of the scapula critical for overhead reach?
It maximizes upward reach, preserves abductor length-tension, and preserves subacromial space volume
39What proportion of the humeral head is covered by the glenoid fossa articular surface?
~1/3
40How much larger is the humeral head surface than the glenoid fossa longitudinally?
~1.9 times
41How much larger is the humeral head surface than the glenoid fossa transversely?
~2.3 times
42In which directions does most glenohumeral instability occur?
Anteriorly and inferiorly
43What is a subluxation of the GH joint?
Incomplete separation of articular surfaces, often with spontaneous alignment
44What is a dislocation of the GH joint?
Complete separation of articular surfaces without spontaneous alignment
45What provides dynamic stability to the GH joint?
The rotator cuff muscles
46What percentage of glenoid fossa depth is attributed to the glenoid labrum?
~50%
47What structures comprise the superior capsular structures (SCS)?
Superior capsular ligament, tendon of the supraspinatus, and coracohumeral ligament
48What motion tightens the anterior band of the inferior glenohumeral ligament?
90 degrees abduction combined with full external rotation
49What is the thickest and strongest part of the GH joint capsule?
Anterior band of the inferior glenohumeral ligament
50What motion tightens the posterior band of the inferior glenohumeral ligament?
90 degrees abduction combined with full internal rotation
51What motion tightens the middle glenohumeral ligament?
External rotation and anterior translation at 45–90 degrees of abduction
52What motion tightens the superior glenohumeral ligament?
External rotation and inferior/anterior translation of the humeral head
53Which rotator cuff muscle lies anterior to the GH joint capsule?
Subscapularis
54Which rotator cuff muscle is the thickest?
Subscapularis
55What two regions of the GH capsule are not covered by the rotator cuff?
Inferiorly and the rotator interval
56What structures reinforce the rotator interval?
Biceps long head tendon, coracohumeral ligament, and superior/middle GH ligaments
57What percentage of long head of biceps brachii tendon fibers arise from the superior labrum?
50%
58Where do the remaining 50% of the long head of biceps brachii tendon fibers arise?
Supraglenoid tubercle
59What is the normal angle of inclination of the humeral head with the humeral shaft?
~135 degrees
60How many degrees is the humeral head retroverted in the horizontal plane?
~30 degrees
61How much additional humeral retroversion do elite pitchers typically possess on their dominant side?
10–15 degrees
62What is the average upward inclination of the glenoid fossa relative to the horizontal axis?
~4 degrees
63What is the normal acromiohumeral distance (AHD) at 85 degrees of abduction?
~2.6 mm
64What is the normal acromiohumeral distance (AHD) at 20 degrees of abduction?
~7.5 mm
65What structures are compressed when the minimal AHD occurs between 35 and 70 degrees abduction?
Supraspinatus tendon against the greater tubercle
66What are the arthrokinematics of GH abduction?
Convex humeral head rolls superiorly and slides inferiorly
67What happens if the humeral head rolls superiorly without an inferior slide?
It contacts the coracoacromial arch in ~22 degrees of abduction after 10 mm of translation
68What are the arthrokinematics of GH external rotation in the anatomical position?
Humeral head rolls posteriorly and slides anteriorly
69What are the arthrokinematics of GH internal rotation in the anatomical position?
Humeral head rolls anteriorly and slides posteriorly
70What arthrokinematic motion predominates during GH internal and external rotation at 90 degrees abduction?
Spinning
71What is the ratio of GH abduction to scapulothoracic upward rotation in scapulohumeral rhythm?
2:1
72How many degrees of 180-degree shoulder abduction come from the GH joint?
120 degrees
73How many degrees of 180-degree shoulder abduction come from the scapulothoracic joint?
60 degrees
74During 180 degrees of shoulder abduction, how much scapular upward rotation comes from SC elevation?
~30 degrees
75How many degrees does the clavicle retract at the SC joint during full shoulder abduction?
15–20 degrees
76How many degrees does the scapula posteriorly tilt during full shoulder abduction?
~20 degrees
77How many degrees of external rotation occur at the GH joint during full shoulder abduction?
35–45 degrees
78What ligament pulls the clavicle into posterior rotation during scapular upward rotation?
Coracoclavicular (conoid) ligament
79What is the loose-packed position of the glenohumeral joint?
55 degrees abduction in scapular plane, neutral rotation
80What is the closed-packed position of the glenohumeral joint?
Full abduction and external rotation
81What is the closed-packed position of the AC joint?
90 degrees of abduction
82What is the closed-packed position of the SC joint?
Full elevation and protraction
83What is the normal range of motion for GH external rotation at 90 degrees abduction?
90 degrees
84What is the normal range of motion for GH internal rotation?
70 degrees
85Which muscles act as upward rotators of the scapula?
Serratus anterior, upper trapezius, and lower trapezius
86Which muscle has the longest moment arm for scapular upward rotation?
Lower fibers of the serratus anterior
87Which muscles act as scapular elevators?
Upper trapezius, levator scapulae, and rhomboids
88Which muscles act as scapular depressors?
Lower trapezius, latissimus dorsi, pectoralis minor, and subclavius
89Which muscles act as scapular retractors?
Middle trapezius, rhomboids, and lower trapezius
90Which muscle is the primary scapular protractor?
Serratus anterior
91Which muscles act as downward rotators of the scapula?
Rhomboids, pectoralis minor, and latissimus dorsi
92Which nerve innervates the serratus anterior?
Long thoracic nerve
93What scapular deformity occurs when the serratus anterior is paralyzed or weak?
Scapular winging
94What is reverse scapulohumeral rhythm?
Exaggerated shoulder hiking where scapulothoracic motion exceeds GH motion
95Which muscles are external rotators of the shoulder?
Teres minor, infraspinatus, and posterior deltoid
96Which muscles are internal rotators of the shoulder?
Subscapularis, pectoralis major, latissimus dorsi, anterior deltoid, and teres major
97How much stronger are the internal rotators than the external rotators on average?
40–70% stronger
98Which muscle has the greatest moment arm for internal rotation at 30 degrees elevation?
Subscapularis
99Which muscle attaches to the upper facet of the greater tubercle of the humerus?
Supraspinatus
100Which muscle attaches to the middle facet of the greater tubercle of the humerus?
Infraspinatus
101Which muscle attaches to the lower facet of the greater tubercle of the humerus?
Teres minor
102Which muscle attaches to the lesser tubercle of the humerus?
Subscapularis
103What are the two parts of the coracoclavicular ligament?
Trapezoid ligament and conoid ligament
104What is the orientation of the conoid ligament?
Nearly vertical from coracoid base to conoid tubercle
105What is the orientation of the trapezoid ligament?
Extends superiorly and laterally from coracoid process to trapezoid line
106What nerve roots supply the axillary nerve?
107What nerve roots supply the suprascapular nerve?
108What nerve roots supply the dorsal scapular nerve?
109What nerve roots supply the long thoracic nerve?
110Which shoulder muscle group generates the highest peak isometric/isokinetic torque?
Extensors
111Which shoulder muscle group generates the lowest peak isometric/isokinetic torque?
External rotators
112What are the boundaries of the subacromial space?
Coracoacromial arch superiorly and humeral head inferiorly
113What is the average height of the subacromial space in adults at rest?
~1 cm (10 mm)
114What structures are contained within the subacromial space?
Subacromial bursa, supraspinatus tendon, long head of biceps tendon, and superior capsule
115Which ligament forms the coracoacromial arch with the acromion and coracoid process?
Coracoacromial ligament
116Where does the subclavius muscle insert?
Inferior surface of the middle third of the clavicle
117Where does the pectoralis minor insert?
Medial border of the coracoid process of the scapula
118Where does the coracobrachialis muscle insert?
Medial aspect of the middle shaft of the humerus
119Where does the teres major muscle insert?
Crest of the lesser tubercle of the humerus
120Where does the latissimus dorsi muscle insert?
Floor of the intertubercular groove of the humerus
121What muscle inserts onto the deltoid tuberosity of the humerus?
Deltoid
122What are the classic scapular positions seen in rounded shoulders posture?
Depression, downward rotation, protraction, internal rotation, and anterior tilt