1. Chapter 2 - Shoulder and Arm

2. Synergist Agonist: Antagonist:
muscle that causes specific movement or possibly several movements to occur through the process of its own contraction
Antagonist:
muscle that acts in opposition to the specific movement generated by the agonist and is responsible for returning a limb to its initial position.
Synergist
muscle which performs, or assists in performing, the same set of joint motions as the agonists

3. Topographical Views

4. Shoulder Complex comprised of 3 bones: Clavicle : “aka” collar bone;
acromioclavicular: joint laterally
sternoclavicular: joint medially (single attachment between the axial and appendicular skeleton)
Synovial joints
Scapula:
16 muscles attach to scapula
scapulothoracic joint is false joint
Along with clavicle important in stabilization and movement of the arm
Humerus:
Articulates with glenoid fossa to form glenohumeral joint
Synovial ball and socket joint.

5. Bones of the Shoulder and Arm

6. Bony Landmarks - Clavicle
CLAVICLE – convex medially, concave laterally

7. Bony Landmarks - Scapula, Anterior

8. Bony Landmarks - Scapula, Posterior

9. Bony Landmarks - Humerus, Anterior
Intertubercular groove is also known as the bicipital groove Radial fossa – where the head of radius hits the humerus Coronoid fossa – where the coronoid process of ulna hits the humerus Trochlea – medial condyle of humerus; on both anterior and posterior of humerus Capitulum – lateral condyle of humerus; only on anterior of humerus

10. Bony Landmarks - Humerus, Posterior
Olecranon fossa – where the olecranon process of ulna hits the humerus Trochlea - continues from anterior of humerus to posterior of humerus (Capitulum does not)

11. Bony Landmark Trails - 1 & 2

12. Bony Landmark Trails - 3 & 4

13. Trail 1 - Spine of Scapula, Medial Border
Spine of the Scapula
Superficial ridge
Oblique angle from acromion to the medial border
Attachment site for:
posterior deltoid
middle and lower trapezius
Separates the supraspinatus and infraspinatus fossa
Medial Border
Runs parallel to the vertebral column
Deep to the trapezius muscle
Attachment site for:
Rhomboids
Serratus anterior

14. Trail 1 - Lateral Border, Infraglenoid Tubercle
Extends superiorly and laterally from the inferior angle of the scapula towards the axilla (armpit)
Infraglenoid Tubercle
Located at the most superior aspect of the lateral border
Serves as attachment site of the long head of the triceps brachii

15. Trail 2 - Infraspinous Fossa, Supraspinous Fossa
Triangular area inferior to the spine of the scapula
Filled with infraspinatus muscle
Supraspinous Fossa
Deep depression superior to the spine of the scapula
Supraspinatus muscle attaches and lies in this fossa

16. Trail 2 - Subscapular Fossa
Located on the scapula’s anterior (underside) surface, against the rib cage
Attachment site for the subscapularis muscle Scapulothoracic joint – “pseudoarthrotic joint”; it moves like a joint, but it is attached to the thorax by muscle, so it is not a true joint between two bones (it is just suspended there)

17. Trail 1 - Inferior Angle, Superior Angle
Located at the inferior end of the medial border of the scapula
Superior Angle
Located at the superior end of the medial border of the scapula

18. Trail 3 - Acromion, Clavicle
Lateral aspect of the spine of the scapula Located at the top of the shoulder Articulates with the acromial end of the clavicle
Clavicle
S-shaped bone that is horizontally positioned across the upper thorax Lateral (acromial) end articulates with the acromion
relatively flat
Medial (sternal) end articulates with the sternum
rounded

19. Trail 3 - A/C Joint Acromioclavicular Joint (AC joint)
Synovial joint / diarthrosis
Articulation between the the acromion of the scapula and the (acromial end) of the clavicle. The lateral end of the clavicle is flat and sits slightly higher than the acromion

20. Trail 3 - S/C Joint Sternoclavicular Joint (SC joint)
Synovial joint / diarthrosis
Where the sternum articulates with the medial (sternal end) of the clavicle.
Contains a fibrous disk The medial end of the clavicle is rounded The S/C joint is the only bony attachment of the upper extremity to the axial skeleton

21. Trail 3 - Coracoid Process, Deltoid Tuberosity
Anterior, beak-like projection of scapula Located inferior to the shaft of the clavicle
It can be located in the deltopectoral groove
Deltoid Tuberosity
Small, low bump
Located on the lateral side of the mid-humeral shaft
Serves as attachment site of the deltoid muscle fibers

22. Trail 4 - Greater Tubercle
Located inferior and lateral to the acromion on the proximal end of the humerus
Attachment site for 3 of the 4 rotator cuff muscles
Supraspinatus
Infraspinatus
Teres minor

23. Trail 4 - Intertubercular Groove and Lesser Tubercle
Lesser Tubercle and Intertubercular Groove
Lesser tubercle - smaller than and medial to the greater tubercle
Attachment site for subscapularis muscle Intertubercular groove (bicipital groove) - lies between the greater and lesser tubercles
Tendon of the long head of the biceps brachii muscle travels through here

24. Muscles of the Shoulder and Arm - Posterior

25. Muscles of the Shoulder and Arm - Lateral

26. Muscles of the Shoulder and Arm - Anterior

27. Deltoid - Palpate Deltoid Triangle shaped muscle
Composed of anterior, medial and posterior fibers.
All fibers abduct the humerus.

28. Deltoid - AOIN
Deltoid

29. Trail Guide: Deltoid

30. Trapezius - O and I Trapezius Divided into 3 groups:
Upper (descending) fibers
Middle fibers
Lower (ascending fibers)
Upper and lower fibers act as antagonists in elevation and depression respectively

31. Trapezius - AOIN
Trapezius
(CN XI) and C2, 3, 4

32. Trapezius - Palpate
Upper, Middle and Lower Fibers of the Trapezius

33. Trail Guide: Trapezius

34. Latissimus Dorsi - AOIN
Broadest muscle of the back
Intertubercular groove of the humerus

35. Latissimus Dorsi - O and I

36. Trail Guide: Latissimus Dorsi

37. Teres Major - AOIN Teres Major
Called the “lats little helper” because it is a synergist with the latissimus dorsi
Teres major and minor act antagonistically in medial and lateral rotation
Teres minor= laterally rotates
Teres major= medially rotates

38. Latissimus Dorsi and Teres Major - Palpate
Both are termed the handcuff muscles

39. Rotator Cuff Muscles Supraspinatus Infraspinatus Teres Minor
Subscapularis

40. Rotator Cuff Muscles - Supraspinatus AOIN

41. Rotator Cuff Muscles - Infraspinatus AOIN
Stabilize head of the humerus in glenoid cavity

42. Rotator Cuff Muscles - Teres Minor AOIN
Stabilize head of the humerus in glenoid cavity
Upper 2/3

43. Rotator Cuff Muscles - Subscapularis AOIN

44. Rotator Cuff Muscles - Palpate
Supraspinatus
Infraspinatus

45. Rotator Cuff Muscles - Palpate
Teres Minor
Subscapularis

46. Rotator Cuff Tendons - Anatomy and Palpate
Supraspinatus tendon
Infraspinatus Tendon
Teres Minor
Subscapularis

47. Rotator Cuff Tendons - Palpate
Supraspinatus Tendon
Medially rotate and extend arm(Handcuff position)
Just anterior and inferior to the acromion
Infraspinatus and Teres Minor Tendons
Flex shoulder to 90 degrees.
Deep to deltoid just inferior to the acromion

48. Rotator Cuff Tendons - Palpate
Subscapularis Tendon

49. Trail Guide: Rotator Cuff

50. Rotator Cuff Injuries
Supraspinatus is the strongest abductor of the shoulder
The major muscle that is usually involved is the supraspinatus muscle.
Rotator Cuff Tendonitis
Rotator Cuff Tears
Instability Impingement

51. Rotator Cuff Tendonitis
Also known as "bursitis" or "impingement syndrome"
Occurs when the rotator cuff gets irritated on the undersurface of the acromion.
Multiple causes(etiologies).
Some people are born with a "hooked" acromion that will predispose them
Rotator cuff weakness that causes the humerus to ride up and pinch the supraspinatus tendon
The bursa — a water-balloon type structure that acts as a cushion between the rotator cuff and acromion/humerus — gets inflamed.

53. Rotator Cuff Tears
Occurs when tendonitis in the rotator cuff becomes chronic and it wears down one of the rotator cuff tendons (Supraspinatus tendon).
Tears can occur due to a traumatic event as a result of over tensioning the tendon or shoulder instability.
Can be a “pop” in the shoulder, usually with immediate pain (this is called an "acute rotator cuff tear").

54. Instability Impingement
Dislocations Head of the humerus completely pops out of the socket.
Initially most commonly due to significant trauma (although it can occur in some people without significant trauma)
In time it becomes easier and easier for the joint to dislocate.
Most shoulder dislocations are anterior.
Subluxations This is the feeling that the shoulder slips slightly out of socket, then immediately comes back in place.
Often happens without any major trauma. "loose-jointed".
Can occur in all directions "multidirectional instability".
Common in throwing athletes and swimmers

55. Acute rotator cuff tear Sudden tearing sensation followed by severe pain shooting from the upper shoulder area (both in front and in back) down the arm toward the elbow.
Decreased range of motion of the shoulder because of pain and muscle spasm. Acute pain from bleeding and muscle spasm: This may resolve in a few days. Large tears may cause the inability abduct the arm (raise it out to the side) due to significant pain and loss of muscle power.
Chronic rotator cuff tear Pain usually is worse at night and may interfere with sleep. Gradual weakness and decreased shoulder motion develop as the pain worsens. Decrease in the ability to abduct the arm.
Difficult to use the injured arm for activities that entail lifting the arm as high as or higher than the shoulder, to the front or side.
May develop “Frozen Shoulder”
Rotator cuff tendinitis More common in women years of age Deep ache in the shoulder also felt on the outside upper arm over the deltoid muscle Point tenderness may be appreciated over the area that is injured Pain comes on gradually and becomes worse with lifting the arm away from the body(abduction) or turning it inward (internal rotation) May lead to a chronic tear:
When a rotator cuff tendon becomes inflamed (tend=tendon +itis=inflammation), it runs the risk of losing its blood supply, causing some tendon fibers to die. This increases the risk that the tendon can fray and partially or completely tear.

56. Rhomboids - AOIN
Rhomboid Major and Minor

57. Rhomboids - Palpate
Rhomboids

58. Trail Guide: Rhomboids

59. Levator Scapula - Palpate
Located along lateral and posterior side of the neck
Inferior portion is deep to the upper trapezius
More superficial on the lateral side of the neck

60. Levator Scapula - AOIN
Levator Scapula
C3 and C4

61. Levator Scapula - O and I, Palpate

62. Trail Guide: Levator Scapulae

63. Serratus Anterior - Palpate
Lies along the posterior and lateral rib cage
Most of the muscle is deep to the scapula, latissimus dorsi or pectoralis major.
Superficial portion of the muscle lies inferior to the axilla
Works to abduct the scapula as an antagonist to the rhomboids

64. Serratus Anterior - AOIN
External surfaces of upper eight or nine ribs

65. Winging of the Scapula
Mostly due to a lesions of the long thoracic nerve (serratus anterior).
Rarely, but may also be due to spinal accessory nerve (trapezius) and dorsal scapular nerve (rhomboids).

66. Breast Tissue - Anatomy and Palpate
Composed of subcutaneous fat and supported by suspensory ligaments connecting skin with deep fascia anterior to the pectoralis major.
2/3 of the breast covers the pectoralis major.
The inferior and lateral aspects cover the serratus anterior muscle

67. Pectoralis Major - Palpate
Broad powerful muscle
Divided into 3 segments
Clavicular fibers
Sternal fibers
Costal fibers
The upper fibers and lower fibers act as antagonists to themselves
Upper fibers= flexion at the shoulder
Lower fibers=extension at the shoulder

68. Pectoralis Major - AOIN
Upper fibers: Lateral pectoral
Lower fibers: Lateral and medial pectoral

69. Trail Guide: Pectoralis Major

70. Pectoralis Minor - Palpate
Lies deep to the pectoralis major along the rib cage
Fibers run perpendicular to pectoralis major
Brachial plexus, axillary artery and vein cross underneath pectoralis minor

71. Pectoralis Minor - AOIN
Assist to elevate thorax during forced inhalation

72. Trail Guide: Pectoralis Minor

73. Pectoralis Minor Syndrome
Definition:
A form of Thoracic Outlet Snydrome (TOS) causing pain, numbness, tingling, and/or weakness in the arm and hand due to pressure against the nerves or blood vessels that supply the arm.
Causes:
tight muscles, ligaments, bands, or bony abnormalities in the thoracic outlet area of the body causing pressure on nerves (most common) or blood vessels.
Symptoms:
numbness and tingling in the fingers; pain in the neck, shoulder, and arm; headaches in the back of the head; weakness of the arm and dropping things from the hand; worsening of the symptoms when elevating the arm to do such things as comb or blow dry one's hair or drive a car; and coldness and color changes in the hand. Worse at night or when using the arm for overhead activities

74. Subclavius Subclavius (underneath clavicle)
Depress the clavicle and draw it anteriorly
Inferior surface of middle 1/3 of clavicle

75. Biceps Brachii - Palpate
Long head (lateral) and short head (medial)
Tendon of the long head passes through the intertubercular groove
Intertubercular groove helps stabilize the tendon

76. Biceps Brachii - AOIN
Biceps Brachii

77. Trail Guide: Biceps Brachii

78. Triceps Brachii - Palpate
Only muscle located on the posterior arm
Antagonist to the biceps brachii
Three heads:
Long head
Lateral head
Medial head

79. Triceps Brachii - AOIN
Triceps Brachii

80. Trail Guide: Triceps Brachii

81. Coracobrachialis
Coracobrachialis

82. Synergists - Shoulder, Flexion
Synergists – Muscles Working Together
Shoulder
(glenohumeral joint)

83. Synergists - Shoulder, Extension
(glenohumeral joint)

84. Synergists - Shoulder, Horizontal Abd. and Add.
(glenohumeral joint)

85. Synergists - Shoulder, Abduction
(glenohumeral joint)

86. Synergists - Shoulder, Adduction
(glenohumeral joint)

87. Synergists - Shoulder, Lateral and Medial Rotation
(glenohumeral joint)

88. Synergists - Scapula, Elevation and Depression
(scapulothoracic joint)

89. Synergists - Scapula, Adduction and Abduction
(scapulothoracic joint)

90. Synergists - Scapula, Upward and Downward Rotation
(scapulothoracic joint)

91. Other Structures - Axilla
Other Structures of the Shoulder and Arm
Axilla

92. Other Structures - Axilla
Other Structures of the Shoulder and Arm
Axilla
4 walls
Lateral wall= biceps brachii + coracobrachialis
Posterior wall= subscapularis + latissimus dorsi
Anterior wall= pectoralis major
Medial wall= rib cage and serratus anterior

93. Other Structures - Axilla
Other Structures of the Shoulder and Arm
Axilla

94. Sternoclavicular Joint

95. Ligaments of Shoulder and G/H Joint - Anterior
Ligaments of the Shoulder and Glenohumeral Joint

96. Ligaments of Shoulder and G/H Joint - Cross section
Ligaments of the Shoulder and Glenohumeral Joint

97. Glenohumeral Joint - Lateral

98. Glenohumeral Joint - Posterior

99. Coracoclavicular and Coracoacromial Ligaments
Coracoclavicular Ligament
Provide stability for the AC joint
Composed of trapezoid and conoid ligaments
Run from coracoid process of the scapula to the inferior surface of the clavicle
Coracoacromial Ligament
Attaches the scapula’s coracoid process to the acromion
Coracoacromial ligament + Acromion = Coracoacromial arch
Protects the rotator cuff tendons and subacromial bursa from direct trauma by the acromion

100. Subacromial Bursa Subacromial Bursa Aka “Subdeltoid bursa”
Fluid filled sac
Abduction of the arm compresses the bursa, therefore can indicate subacromial bursitis if painful abduction.

101. Axillary Lymph Nodes and Brachial Artery
Continuation of the axillary artery.
Branches at elbow into radial and ulnar arteries
Runs between the biceps brachii and triceps brachii muscles on the medial arm