What is the explanation and rationale for using special maneuvers like Scarf, Yocum, Hawkin's Kennedy, Neer, Empty can, Lift Off, Yergason, and Speed's test in patients with shoulder pain or limited mobility, particularly those with a history of shoulder injuries or physically demanding occupations?

Shoulder Special Maneuvers: Explanation and Rationale

Impingement Tests

Neer Sign

This maneuver detects subacromial impingement by passively forcing the greater tuberosity against the anterior acromion. 1, 2

• The examiner stabilizes the scapula and passively flexes the arm forward overhead while internally rotating the humerus 2
• Pain reproduction indicates subacromial pathology (rotator cuff or bursal inflammation) 3, 4
• Demonstrates 75% sensitivity for subacromial impingement 4
• Highly reproducible with almost perfect agreement (Kappa 0.91-1.00) when standardized 2
• Most useful for identifying the painful arc between 60-120° of abduction/flexion, which is pathognomonic for subacromial pathology 3

Hawkins-Kennedy Test

This test compresses the supraspinatus tendon and subacromial bursa by internally rotating the humerus at 90° of forward flexion. 2, 4

• Position the shoulder at 90° forward flexion with elbow flexed to 90° 2
• Passively internally rotate the humerus, driving the greater tuberosity under the coracoacromial ligament 4
• Pain indicates subacromial impingement syndrome 5, 2
• Demonstrates 80% sensitivity for subacromial impingement, making it the most sensitive impingement test 4
• Exhibits almost perfect intra- and interexaminer reliability (Kappa 0.91-1.00) 2

Yocum Test

This maneuver isolates subacromial structures by having the patient actively compress the subacromial space. 5

• Patient places hand of affected side on opposite shoulder 5
• Patient actively elevates the elbow without elevating the shoulder 5
• Pain during elevation suggests subacromial impingement 5
• Sensitivity is satisfactory but specificity is poor for determining specific rotator cuff lesion location 5

Rotator Cuff Strength Tests

Empty Can Test (Jobe's Test)

This test specifically isolates the supraspinatus muscle by positioning the arm to minimize deltoid contribution. 1, 5

• Position arm at 90° abduction in the scapular plane (30° forward of coronal plane) 1
• Internally rotate the shoulder with thumb pointing downward (empty can position) 1
• Apply downward resistance while patient resists 5
• Pain indicates supraspinatus tendinitis; weakness or inability to maintain position suggests supraspinatus tear 5, 6
• Demonstrates 52.6% sensitivity and 82.4% specificity for full-thickness supraspinatus tears confirmed on arthroscopy 4
• Normal rotator cuff strength rules out full-thickness tear 3
• The severity of functional impairment does not correlate with tear size 5

Lift-Off Test (Gerber's Test)

This maneuver specifically tests subscapularis function by requiring internal rotation against resistance. 1, 5

• Patient places dorsum of hand against lower back at waist level 1
• Patient attempts to lift hand away from back against resistance 5
• Inability to lift hand off back indicates subscapularis rupture; pain without weakness suggests subscapularis tendinitis 5, 6
• This is the primary test for evaluating the subscapularis, the largest and strongest rotator cuff muscle 1

Biceps Tendon Tests

Yergason's Test

This test stresses the long head of biceps tendon in its groove and the transverse humeral ligament. 6

• Position elbow at 90° flexion with forearm pronated 6
• Patient attempts to supinate forearm and externally rotate shoulder against resistance 6
• Pain in the bicipital groove indicates biceps tendinopathy or instability 6
• Limited specificity for biceps pathology as it may also stress other anterior shoulder structures 7

Speed's Test (Palm-Up Test)

This maneuver isolates the long head of biceps by resisting forward flexion with the arm supinated. 5, 4

• Position arm at 90° forward flexion with elbow extended and forearm supinated 4
• Apply downward resistance while patient resists 5
• Pain in the bicipital groove indicates long head of biceps tendinopathy 5, 4
• Demonstrates 54% sensitivity and 81% specificity for biceps pathology 4
• More specific than Yergason's test for biceps tendon pathology 6

Scapular Stability Test

Scarf Test (Cross-Body Adduction Test)

This maneuver compresses the acromioclavicular joint by bringing the arm across the body. 4

• Passively adduct the arm horizontally across the chest toward the opposite shoulder 4
• Pain localized to the acromioclavicular joint indicates AC joint pathology 4
• Demonstrates 77% sensitivity and 79% specificity for acromioclavicular joint pathology 4
• Useful for differentiating AC joint pain from subacromial impingement 1

Critical Clinical Context

These tests have satisfactory sensitivity but generally poor specificity, particularly for determining the exact location and type of rotator cuff lesions. 5, 7

• The tests are highly reproducible when standardized but limited as structural discriminators 2
• They identify patients with subacromial pain and impingement phenomena but cannot definitively differentiate between specific pathologies 2
• Extreme diversity exists in test performance and interpretation across studies, which hinders evidence synthesis 7
• Normal rotator cuff strength on these tests effectively rules out full-thickness tears 3
• When clinical examination suggests referred pain, these shoulder tests are not indicated—imaging should target the suspected source instead 8