Shoulder Anatomy and Examination

By admin On Mar 2, 2024

Ovid: 5-Minute Orthopaedic Consult

Editors: Frassica, Frank J.; Sponseller, Paul D.; Wilckens, John H.

Title: 5-Minute Orthopaedic Consult, 2nd Edition

> Table of Contents > Shoulder Anatomy and Examination

Shoulder Anatomy and Examination

Constantine A. Demetracopoulos BS

Timothy S. Johnson MD

Basics

Description

Bones:
- Glenohumeral joint:
  - The humeral head articulates with the glenoid fossa of the scapula.
  - Stabilized by the glenohumeral ligaments (1) capsule and rotator cuff muscles
  - The labrum of the glenoid deepens the joint and enhances stability.
- AC joint:
  - The acromion process of the scapula articulates with the distal clavicle.
  - Suspends the arm and scapula
- Sternoclavicular joint:
  - The sternum articulates with the proximal end of clavicle.
  - Suspends the arm and scapula
- Scapulothoracic joint:
  - Consists of the body of the scapula and the muscles covering the posterior chest wall
  - Contributes to shoulder flexion and rotation
Muscles:
- The trapezius, levator, rhomboids, and serratus anterior stabilize the scapula to aid motion at the glenohumeral joint.
- Deltoid: Flexor, abductor, and extensor
- Rotator cuff:
  - Supraspinatus: Abductor and external rotator
  - Infraspinatus: External rotator
  - Teres minor: External rotator
  - Subscapularis: Internal rotator and adductor
- Pectoralis major: Adductor
- Coracobrachialis and biceps: Flexors
Nerves:
- Brachial plexus:
  - Passes through the axilla
  - Branches originate in the neck from C5–T1.
- Axillary nerve:
  - Innervates the deltoid
  - May be injured in anterior shoulder dislocations
- Musculocutaneous nerve: Innervates the biceps and coracobrachialis

Diagnosis

Signs and Symptoms

History

Thorough history of the mechanism of injury and the nature of pain

Physical Exam

Initial assessment:
- Assess the cervical spine and elbow.
- Perform a complete neurovascular examination of the extremities.
- Assess the contralateral shoulder for comparison.
Inspection:
- Expose both upper extremities from the shoulder girdle to the hand, inspecting for asymmetry, atrophy, and scapular winging.
Palpation:
- Palpate the sternoclavicular joint,
  clavicle, AC joint, coracoid, acromion, glenohumeral joint, bicipital
  groove, and the greater and lesser tuberosities of the humerus.
- Localize the pain.
ROM:
- Compare active and passive ROM.
  - Forward flexion: 180°
  - Extension: 50–60°
- Motion:
  - Assess in adduction and abduction.
  - Distinguish glenohumeral motion from combined glenohumeral and scapulothoracic motion (combined values).
  - External rotation: 80–90°
  - Internal rotation: 60–80°
  - Abduction: 160–180°

Tests

Biceps tendinitis:
- Pain to palpation in the bicipital groove, found anteriorly on the shoulder with the arm at 10° of internal rotation
- Yergason test:
  - Test resisted forearm supination with the elbow flexed at 90°.
  - Test is positive when pain is reproduced in the bicipital groove.
- Speed test:
  - With the elbow extended, the forearm
    supinated, and the shoulder flexed at 60°, ask the patient to resist
    additional forward flexion of shoulder.
  - The test is positive when pain is reproduced in the bicipital groove.
Subacromial bursitis:
- Presentation is very similar to that of rotator cuff tendinitis.
- Patient may present with subacromial crepitus.
Rotator cuff tear (2) (Fig. 1):
- Diffuse, dull, aching pain localized over the deltoid and upper arm
- Pain with overhead activities
- Tenderness to palpation over the greater tuberosity of the humerus
- Test individual rotator cuff muscles for weakness and or pain.
  - Supraspinatus: Test the patient’s
    strength in active arm elevation in the plane of the scapula with the
    patient’s thumb pointing down.
  - Infraspinatus and teres minor: Test the
    patient’s strength in active external rotation with the patient’s arm
    at the side and the elbow flexed at 90°.
  - Subscapularis (“belly press” test): Place
    both of the patient’s hands on his/her belly; have the patient press
    the belly inward while thrusting elbows forward; the test is positive
    if the elbow cannot be actively moved forward.
    
    Fig. 1. MRI image of a supraspinatus tendon tear.
- Neer sign:
  - Elevate the arm while stabilizing the scapula.
  - Positive sign: Pain at maximal elevation
- Hawkins test:
  - With the patient’s elbow flexed at 90°, forward flex the shoulder to 90° and internally rotate the humerus.
  - The test is positive if pain is reproduced on contact of the greater tuberosity with the acromion.
- Painful arc:
  - Active abduction in the coronal plane
  - The test is positive with pain at 60–100° of abduction.
  - Pain is common in tendinitis and small rotator cuff tears
- Drop-arm test:
  - Inability to hold arm up when passively positioned into an elevated position
  - Suggests a large tear
- Weakness, inability to elevate, and passive ROM that exceeds active ROM also suggest rotator cuff tear.
- Popeye sign:
  - The biceps resembles a “Popeye” muscle when resisted elbow flexion is tested.
  - Indicates a proximal rupture of the biceps tendon
  - Note: Also occurs with distal biceps tendon rupture
Shoulder instability (3):
- History of previous dislocations
- Patient complains of instability with or without pain.
- Anterior instability: Apprehension with 90/90 positioning (90° of abduction and 90° of external rotation)
- Posterior instability: Apprehension with humeral forward flexion in internal rotation
- Load and shift test:
  - With the humerus in a neutral position on the glenoid, axially load the humerus and shift the head anteriorly and posteriorly.
  - Excessive translation resulting in palpable subluxation and/or dislocation is a positive finding.
    
    Fig. 2. Radiograph of an AC joint separation.
- Sulcus sign:
  - With the affected elbow flexed, apply inferior traction to the arm and look for skin dimpling near the lateral acromion.
  - Dimpling indicates inferior instability.
AC joint arthritis/AC separation (4):
- Palpable point tenderness at the AC joint
- Palpable step-off at the AC joint in the presence of a separation (Fig. 2)
- Joint effusion may be present.
- Cross-body adduction test:
  - With the shoulder at 90° of flexion, passively adduct the arm.
  - The test is positive when pain is reproduced at the AC joint.
Labrum abnormality (Fig. 3):
- Patient describes pain as “deep” in the shoulder and occurring with overhead activities.
- Patient may have anterior or posterior joint line tenderness.
- Active compression test:
  - Position the affected arm as for the cross-body adduction test.
  - With the elbow extended, and the humerus internally rotated (thumb down), test resisted humeral elevation.
  - Positive test: Pain is elicited when in
    internal rotation but relieved when the test is repeated in external
    rotation (thumb up).
  - Pain localized deep in the shoulder is indicative of biceps or labral abnormality.
  - Pain at the top of the shoulder indicates AC abnormality.
  - Pain elsewhere is equivocal.
Glenohumeral joint arthritis:
- Start-up pain on initiation of activity
- Palpable joint-line tenderness
- Decreased active and passive ROM
- Active and passive ROM are equal.
- Pain at the extremes of motion in all planes
- Glenohumeral crepitus with motion
Adhesive capsulitis:
- Palpable joint line tenderness
- Severely decreased ROM
- Active and passive ROM are equal.
- Pain with motion in all planes
  
  Fig. 3. Arthroscopic image of a SLAP tear.

References

1. Curl LA, Warren RF. Glenohumeral joint stability. Selective cutting studies on the static capsular restraints. Clin Orthop Relat Res 1996;330:54–65.

2. Tennent
TD, Beach WR, Meyers JF. A review of the special tests associated with
shoulder examination. Part I: the rotator cuff tests. Am J Sports Med 2003;31:154–160.

3. Tennent
TD, Beach WR, Meyers JF. A review of the special tests associated with
shoulder examination. Part II: laxity, instability, and superior labral
anterior and posterior (SLAP) lesions. Am J Sports Med 2003;31:301–307.

4. Chronopoulos E, Kim TK, Park HB, et al. Diagnostic value of physical tests for isolated chronic AC lesions. Am J Sports Med 2004;32:655–661.

Additional Reading

Hoppenfeld S. Physical examination of the shoulder. In: Physical Examination of the Spine & Extremities. Norwalk, CT: Appleton & Lange, 1976:1–34.

Hoppenfeld S, deBoer P. The shoulder. In: Surgical Exposures in Orthopaedics: The Anatomical Approach, 3rd ed. Philadelphia: Lippincott, Williams & Wilkins, 2003:1–66.

Miscellaneous

FAQ

Q: What are the most common causes of atraumatic shoulder pain?

A: Rotator cuff disease, AC joint arthritis, cervical radiculopathy.

Q: What is the difference between a shoulder separation and a shoulder dislocation?

A: A shoulder separation is a dislocation of the AC joint. A shoulder dislocation is a dislocation of the glenohumeral joint.