Muscles of the Shoulder, Arm & Elbow Dr Nick Renwick Arm & Elbow Flashcards
1
Q
What are the primary movements of the scapula?
A
Elevation, depression, protraction, retraction, upward rotation, and downward rotation.
2
Q
Which muscles are involved in scapular elevation?
A
Trapezius (upper fibers), levator scapulae.
3
Q
Which muscles are responsible for scapular depression?
A
Trapezius (lower fibers), pectoralis minor.
4
Q
What muscles contribute to scapular protraction?
A
Serratus anterior, pectoralis minor
5
Q
Which muscles perform scapular retraction?
A
Rhomboids, trapezius (middle fibers).
6
Q
What muscles are involved in upward rotation of the scapula?
A
Trapezius (upper and lower fibers), serratus anterior.
7
Q
What muscles perform downward rotation of the scapula?
A
Rhomboids, levator scapulae, pectoralis minor.
8
Q
What are the primary movements of the glenohumeral joint?
A
Flexion, extension, abduction, adduction, internal (medial) rotation, external (lateral) rotation, and circumduction.
9
Q
Which muscles are responsible for shoulder flexion?
A
Anterior deltoid, pectoralis major (clavicular head), biceps brachii, coracobrachialis.
10
Q
What muscles perform shoulder extension?
A
Posterior deltoid, latissimus dorsi, teres major, triceps brachii (long head).
11
Q
Which muscles contribute to shoulder abduction?
A
Supraspinatus (initial 15°), deltoid (after 15°).
12
Q
What muscles are responsible for shoulder adduction?
A
Pectoralis major, latissimus dorsi, teres major.
13
Q
Which muscles perform internal (medial) rotation of the shoulder?
A
Subscapularis, pectoralis major, latissimus dorsi, teres major, anterior deltoid.
14
Q
What muscles contribute to external (lateral) rotation of the shoulder?
A
Infraspinatus, teres minor, posterior deltoid.
15
Q
What are the main movements of the elbow joint?
A
Flexion and extension.
16
Q
Which muscles are responsible for elbow flexion?
A
Biceps brachii, brachialis, brachioradialis.
17
Q
What muscles perform elbow extension?
A
Triceps brachii, anconeus.
18
Q
What are the movements of the proximal radioulnar joint associated with the elbow?
A
Pronation and supination.
19
Q
Which muscles are responsible for forearm pronation?
A
Pronator teres, pronator quadratus.
20
Q
What muscles perform forearm supination?
A
Biceps brachii, supinator.
21
Q
What are the four muscles of the anterior axioappendicular group?
A
Pectoralis Major, Pectoralis Minor, Subclavius, Serratus Anterior.
22
Q
Which muscles are part of the posterior axioappendicular group?
A
Trapezius, Latissimus Dorsi, Levator Scapulae, Rhomboid Minor, Rhomboid Major.
23
Q
What muscles make up the rotator cuff?
A
Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
24
Q
Which two scapulohumeral muscles are not part of the rotator cuff?
A
Teres Major, Deltoid.
25
What are the muscles in the anterior compartment of the arm?
Biceps Brachii, Coracobrachialis, Brachialis.
26
Which muscles are found in the posterior compartment of the arm?
Triceps Brachii, Anconeus.
27
What are the origins of the pectoralis major muscle?
The medial half of the clavicle (clavicular head), sternum, superior six costal cartilages, and the aponeurosis of external oblique (sternocostal head)
28
Where does the pectoralis major insert?
Into the lateral lip of the intertubercular sulcus of the humerus.
29
What are the primary actions of the pectoralis major?
Adduction and medial rotation of the shoulder joint. The clavicular head alone flexes the shoulder joint, and the sternocostal head extends the flexed shoulder joint.
30
What nerves innervate the pectoralis major?
The lateral and medial pectoral nerves.
31
What is the origin of the pectoralis minor muscle?
The anterior surface of the 3rd to 5th ribs.
32
Where does the pectoralis minor insert?
Into the coracoid process of the scapula.
33
What is the primary action of the pectoralis minor?
It stabilizes the scapula by drawing it anteroinferiorly (forward and downward).
34
What nerve innervates the pectoralis minor?
The medial pectoral nerve.
35
What is the origin of the subclavius muscle?
The junction of the 1st rib and its costal cartilage.
36
Where does the subclavius insert?
Subclavian groove of the clavicle
37
What are the primary actions of the subclavius muscle?
It stabilizes and depresses the clavicle.
38
What nerve innervates the subclavius?
The nerve to subclavius.
39
What is the origin of the serratus anterior muscle?
The anterior surfaces of ribs 1 to 8/9.
40
Where does the serratus anterior insert?
Into the medial border of the scapula.
41
What is the primary action of the serratus anterior?
It protracts the scapula and holds it against the thoracic wall.
42
What nerve innervates the serratus anterior?
The long thoracic nerve.
43
What is the origin of the trapezius muscle?
The superior nuchal line, external occipital protuberance, nuchal ligament, and the spinous processes of C7-T12.
44
Where does the trapezius insert?
Into the lateral third of the clavicle, acromion, and the spine of the scapula.
45
What are the primary actions of the trapezius?
Retraction of the scapula. The descending part elevates the scapula, and the ascending part depresses the scapula.
46
What is the innervation of the trapezius muscle?
The spinal accessory nerve (cranial nerve XI) and the C3 and C4 spinal nerves.
47
What is the origin of the latissimus dorsi muscle?
The spinous processes of T7-T12, thoracolumbar fascia, iliac crest, and the inferior 3-4 ribs.
48
Where does the latissimus dorsi insert?
Into the floor of the intertubercular sulcus of the humerus.
49
What are the primary actions of the latissimus dorsi?
It extends, adducts, and medially rotates the shoulder joint.
50
What nerve innervates the latissimus dorsi?
The thoracodorsal nerve.
51
What is the origin of the rhomboid minor muscle?
The nuchal ligament and spinous processes of C7-T1.
52
What is the origin of the rhomboid major muscle?
The nuchal ligament and spinous processes of C7-T1.
53
Where does the rhomboid minor insert?
Into the medial border of the scapula at the level of the spine of the scapula.
54
Where does the rhomboid major insert?
Into the medial border of the scapula at the level of the spine of the scapula.
55
What are the primary actions of the rhomboids?
Retraction and downward rotation of the scapula.
56
What nerve innervates the rhomboids?
The dorsal scapular nerve.
57
What is the origin of the levator scapulae muscle?
The transverse processes of C1-C4 vertebrae.
58
Where does the levator scapulae insert?
Into the medial border of the scapula, superior to the spine of the scapula.
59
What are the primary actions of the levator scapulae?
Elevation and downward rotation of the scapula.
60
What is the common action of all rotator cuff muscles?
They hold the humeral head in the glenoid cavity, providing stability to the shoulder joint.
61
What is the origin of the infraspinatus muscle?
The infraspinous fossa of the scapula.
62
Where does the infraspinatus muscle insert?
Into the greater tubercle of the humerus, at the middle facet.
63
What is the primary action of the infraspinatus muscle?
Lateral rotation of the shoulder joint.
64
What nerve innervates the infraspinatus?
The suprascapular nerve.
65
What is the origin of the supraspinatus muscle?
The supraspinous fossa of the scapula.
66
Where does the supraspinatus insert?
Into the greater tubercle of the humerus, at the superior facet.
67
What is the primary action of the supraspinatus muscle?
It initiates abduction of the shoulder joint (first 15 degrees of abduction).
68
What nerve innervates the supraspinatus?
The suprascapular nerve.
69
What is the origin of the subscapularis muscle?
The subscapular fossa of the scapula.
70
Where does the subscapularis insert?
Into the lesser tubercle of the humerus.
71
What is the primary action of the subscapularis muscle?
Medial rotation of the shoulder joint.
72
What nerves innervate the subscapularis muscle?
The upper and lower subscapular nerves.
73
What is the origin of the teres major muscle?
The inferior part of the lateral border of the scapula and the inferior angle.
74
Where does the teres major insert?
Into the medial lip of the intertubercular sulcus of the humerus.
75
What are the primary actions of the teres major muscle?
Adduction and medial rotation of the shoulder joint.
76
What nerve innervates the teres major muscle?
The lower subscapular nerve.
77
What is the origin of the teres minor muscle?
The middle part of the lateral border of the scapula.
78
Where does the teres minor insert?
Into the greater tubercle of the humerus, at the inferior facet.
79
What is the primary action of the teres minor muscle?
Lateral rotation of the shoulder joint.
80
What nerve innervates the teres minor muscle?
Axillary Nerve
81
What is the origin of the deltoid muscle?
The lateral third of the clavicle (anterior part), the acromion (middle part), and the spine of the scapula (posterior part).
82
Where does the deltoid muscle insert?
Into the deltoid tuberosity of the humerus.
83
What is the primary action of the deltoid muscle?
Abduction of the shoulder joint.
84
What nerve innervates the deltoid muscle?
The axillary nerve.
85
What are the specific actions of the anterior, middle, and posterior parts of the deltoid muscle?
Anterior part: Flexes and medially rotates the shoulder joint.
Middle part: Abducts the shoulder joint.
Posterior part: Extends and laterally rotates the shoulder joint.
86
What is the brachial fascia?
It is the deep fascia that encloses the muscles of the arm.
87
With which fascia is the brachial fascia continuous?
It is continuous with the deep fascia of the forearm.
88
What does the intermuscular septa of the brachial fascia divide the arm into?
It divides the arm into the anterior (flexor) compartment and the posterior (extensor) compartment.
89
What is the innervation of the anterior compartment of the arm?
The musculocutaneous nerve.
90
What is the innervation of the posterior compartment of the arm?
The radial nerve.
91
What is the innervation of the posterior compartment of the arm?
The radial nerve.
92
Why is the brachial fascia clinically important?
It is important for the spread of infection and haemorrhage within the arm.
93
What is the origin of the long head of the biceps brachii?
The supraglenoid tubercle of the scapula.
94
What is the origin of the short head of the biceps brachii?
The coracoid process of the scapula.
95
Where does the biceps brachii insert?
Into the radial tuberosity and the fascia of the forearm via the bicipital aponeurosis.
96
What are the actions of the biceps brachii at the shoulder joint?
Flexion of the shoulder joint.
97
What are the actions of the biceps brachii at the elbow joint?
Supinates the forearm, and when already supinated, it flexes the elbow joint.
98
What nerve innervates the biceps brachii?
The musculocutaneous nerve.
99
What is the origin of the coracobrachialis muscle?
The coracoid process of the scapula.
100
Where does the coracobrachialis insert?
Into the middle third of the medial humerus.
101
What are the primary actions of the coracobrachialis muscle?
Flexion and adduction of the shoulder joint.
102
What nerve innervates the coracobrachialis?
The musculocutaneous nerve.
103
What nerve innervates the coracobrachialis?
The musculocutaneous nerve.
104
What is the origin of the brachialis muscle?
The distal half of the anterior humerus.
105
Where does the brachialis insert?
Into the ulnar tuberosity and the coronoid process of the ulna.
106
What is the primary action of the brachialis muscle?
: Flexion of the elbow joint, regardless of whether the forearm is pronated or supinated
107
What nerve innervates the brachialis muscle?
The musculocutaneous nerve.
108
What is the origin of the long head of the triceps brachii?
The infraglenoid tubercle of the scapula.
109
Where does the lateral head of the triceps brachii originate?
The posterior humerus, superior to the radial groove
110
Where does the medial head of the triceps brachii originate?
The posterior humerus, inferior to the radial groove.
111
Where does the triceps brachii insert?
Into the olecranon process of the ulna.
112
What are the actions of the long head of the triceps brachii at the shoulder joint?
Extends the shoulder joint.
113
What is the primary action of the triceps brachii at the elbow joint?
Extension of the elbow joint.
114
What nerve innervates the triceps brachii?
The radial nerve.
115
What is the origin of the anconeus muscle?
The lateral epicondyle of the humerus.
116
Where does the anconeus insert?
Into the lateral olecranon and the proximal ulna.
117
What are the actions of the anconeus muscle?
It stabilizes the elbow joint and assists with elbow extension
118
What nerve innervates the anconeus muscle?
The radial nerve.
119
What are the primary muscle groups that act on the scapula?
Axioappendicular muscles
Scapulohumeral muscles
120
What structure is commonly involved in impingement in the rotator cuff?
The supraspinatus tendon is commonly impinged under the acromion process.
121
What are the primary causes of rotator cuff impingement?
Inflamed subacromial bursa
Swollen supraspinatus muscle/tendon
Subacromial bony spurs
122
What is a common symptom of rotator cuff impingement?
Pain during abduction of the shoulder, particularly in the mid-range.
123
What is tendinopathy in the context of the rotator cuff?
Tendinopathy refers to the disorganization of the normal tendon structure.
124
What are the common causes of rotator cuff tendinopathy?
Overuse
Age-related degeneration
Repeated trauma
Poor blood supply to the tendons
124
What are the types of rotator cuff tears?
Partial-thickness tears
Full-thickness tears
124
What are the main causes of rotator cuff tears?
Trauma
Degenerative changes (especially with age)
Overuse
125
In which population are rotator cuff tears most common?
Older adults are most commonly affected by rotator cuff tears due to degenerative changes.
126
What is the significance of rotator cuff injuries clinically?
Rotator cuff injuries can lead to weakness, pain, and reduced range of motion, significantly affecting shoulder function.
