Shoulder Impingement Syndrome Clinical Presentation

Age

See the list below:

• Patients younger than 40 years - Usually glenohumeral instability, and acromioclavicular joint disease/injury

• Patients older than 40 years - Consider glenohumeral impingement syndrome/rotator cuff disease and glenohumeral joint degenerative disease

Occupation

See the list below:

• Individuals at highest risk for shoulder impingement are laborers and those working in jobs that require repetitive overhead activity.

• Athletes (eg, swimming, throwing sports, tennis, volleyball)

Athletic activity

See the list below:

• Onset of symptoms in relation to specific phases of the athletic event performed

• Duration and frequency of play

• Duration and frequency of practice

• Level of play (eg, little league, high school, college, professional)

• Actual playing time (eg, starter, backup, bench player) and position played

• Lack of periodization in training - Athlete participating in same overhead sport year-round

Symptoms

See the list below:

• Onset: Sudden onset of sharp pain in the shoulder with tearing sensation is suggestive of a rotator cuff tear. Gradual increase in shoulder pain with overhead activities is suggestive of an impingement problem.

• Chronicity of symptoms

• Location: Pain usually is reported over the lateral, superior, anterior shoulder; occasionally refers to the deltoid region. Posterior shoulder capsule pain usually is consistent with anterior instability, causing posterior tightness.

• Setting during which symptoms arise (eg, pain during sleep, in various sleeping positions, at night, with activity, types of activities, while resting)

• Quality of pain (eg, sharp, dull, radiating, throbbing, burning, constant, intermittent, occasional)

• Quantity of pain (on a scale of 0-10, 10 being the worst)

• Alleviating factors (eg, change of position, medication, rest)

• Aggravating factors (eg, change of position, medication, increase in practice, increase in play, change in athletic gear/foot wear, change in position played)

• Functional symptoms - Patient changed mechanics (eg, throwing motion, swim stroke) to compensate for pain

• Associated manifestations (eg, possibly chest pain, dizziness, abdominal pain, shortness of breath)

• Provocative position: Pain with humerus in forward-flexed and internally rotated position suggests rotator cuff impingement. Pain with humerus in abducted and externally rotated position suggests anterior glenohumeral instability and laxity.

Other history

Inquire about previous or recent trauma, stiffness, numbness, paresthesias, clicking, weakness, crepitus of instability, and neck syndromes.

Inspection

See the list below:

• Men should have their shirts off and women should wear a tank top for the examination.

• Visualize entire shoulder girdle and scapular area. Inspect for scapular winging (long thoracic nerve palsy) by having the patient perform a wall push-up.

• Note muscle mass asymmetry/atrophy and bony asymmetry.

Active range of motion (AROM) is tested if possible. If not possible, passive range of motion (PROM) is performed, as follows:

• Forward flexion (average range is 150-180°)

• Abduction (average range is 150-180°)

• External rotation (average range with arm in adduction is 30-60°)

• External rotation (average range with arm in abduction is 70-90°)

• Internal rotation (average range, which is measured by how high the patient can reach around the back with the ipsilateral thumb [ie, ipsilateral hip, T12, L5], is above T8)

• Adduction (average range is 45°)

• Extension (average range is 45°)

Note the following:

• Stiffness with external/internal rotation is best tested with arm in 90° of abduction.

• External and internal rotation are best tested in the supine position with the scapulothoracic articulation stabilized.

• Most high-level pitchers have increased external rotation and decreased internal rotation in the pitching arm compared to the nonpitching arm. This may not be pathologic in the high-level athletic population.

• A painful arc of motion may be experienced with elevation above the shoulder level in patients with impingement.

Palpation

Palpate along the joints, noting the biceps tendons, supraspinatus and subscapularis tendons, and anterolateral corner of the acromion. Check for bony pain over anterior portion of acromion in region of potential os acromiale.

The entire shoulder girdle is palpated (noting tenderness, deformities, and atrophy) from acromioclavicular joint, clavicle, glenohumeral joint, scapula, scapulothoracic articulation, anterior/posterior shoulder capsule, supraspinous fossa, infraspinous fossa, and humerus (especially proximally).

Manual muscle testing

Concentrate on assessing the shoulder girdle muscles, especially external/internal rotation and abduction.

Supraspinatus may be isolated by having the patient rotate the upper extremity so that the thumbs are pointing toward the floor and apply resistance with the arms at 30° of forward flexion and 90° of abduction (called the supraspinatus isolation test or empty can test because the position assimilates emptying a can).

Pain is felt with tendonitis or partial injury to the supraspinatus tendon in the supraspinatus isolation test, but weakness also may be found accompanying partial-thickness or full-thickness disruption of the supraspinatus tendon.

Weakness also may be found with tendonitis, due to muscle inhibition from painful stimuli.

Special tests

Any test performed should compare both shoulders either to detect bilateral pathology or to establish a control for comparison with the affected shoulder.

• Neer test: Forcefully elevate an internally rotated arm in the scapular plane, causing the supraspinatus tendon to impinge against the anterior inferior acromion.

• Hawkins-Kennedy test: Forcefully internally rotate a 90° forwardly flexed arm, causing the supraspinatus tendon to impinge against the coracoacromial ligamentous arch. Note: Pain and a grimacing facial expression indicate impingement of the supraspinatus tendon, indicating a positive Neer/Hawkins impingement sign.

• Impingement test: Inject 10 mL of 1% lidocaine solution into the subacromial space. Repeat testing for an impingement sign. Elimination or significant reduction of pain constitutes a positive impingement test.

• Drop arm test: The patient places the arm in maximum elevation in the scapular plane and then lowers it slowly (the test can be repeated following subacromial injection of lidocaine). Sudden dropping of the arm suggests a rotator cuff tear.

• Supraspinatus isolation test/empty can test: The supraspinatus may be isolated by having the patient rotate the upper extremity so that the thumbs are pointing to the floor and apply resistance with the arms in 30° of forward flexion and 90° of abduction (assimilates emptying of a can). This test is positive when weakness is present (compared to the unaffected side), suggesting disruption of the supraspinatus tendon.

• A systematic review and meta-analysis used the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines, and 10 studies met the criteria to be included in the final analysis and review. The Hawkins-Kennedy test, Neer sign, and empty can test were determined to be best to negate the diagnosis of impingement. A negative Neer sign reduced the probability of subacromial impingement from 45% to 14%. The drop arm test and lift-off test were thought to be more useful for confirming the diagnosis of impingement if the test results were positive. ^[3]

Tests for instability

See the list below:

• Sulcus sign: Grasp the patient's elbow and apply inferior traction. Dimpling of the skin subjacent to the acromion (the sulcus sign) indicates inferior humeral translation, suggesting multidirectional instability.

• Apprehension test: Most effectively performed with the patient in the supine position stabilizing the scapula. Gently bring the affected arm into an abducted and externally rotated position. Patient apprehension and guarding by not allowing further motion by the examiner denotes a positive test that is consistent with anterior shoulder instability.

• Relocation test: Usually, this test is performed in conjunction with the apprehension test. After putting patient in an apprehensive position, apply a posteriorly directed pressure to the anterior proximal humerus, simulating a relocation of the glenohumeral joint that presumably was dislocated partially from the apprehension test. Posterior translation of the humeral head on the glenoid may be felt. A positive test may be noted when the patient becomes at ease with application of pressure on the anterior proximal humerus, suggesting anterior shoulder instability.

Other tests may be performed on the shoulder to rule out other pathology affecting the biceps tendon, glenoid labrum, cervical spine, sternoclavicular joint, acromioclavicular joint, and scapulothoracic joint. A survey of other joint ROM also should be performed to assess for generalized ligamentous laxity.

Neurovascular examination

To complete the shoulder examination, a full neurologic examination must be performed, along with assessment of all upper extremity vascular pulses.

Neurologic examination should include all neurologic segments from C5 through T1 myotomes (dermatomes with the corresponding stretch reflexes).

Primary impingement

See the list below:

• Increased subacromial loading

• Acromial morphology (A hooked acromion, presence of an os acromiale or osteophyte, and/or calcific deposits in the subacromial space make patients more predisposed for primary impingement.)

• Acromioclavicular arthrosis (inferior osteophytes)

• Coracoacromial ligament hypertrophy

• Coracoid impingement

• Subacromial bursal thickening and fibrosis

• Prominent humeral greater tuberosity

• Trauma (direct macrotrauma or repetitive microtrauma)

• Overhead activity (athletic and nonathletic)

Secondary impingement

See the list below:

• Rotator cuff overload/soft tissue imbalance

• Eccentric muscle overload

• Glenohumeral laxity/instability

• Long head of the biceps tendon laxity/weakness

• Glenoid labral lesions

• Muscle imbalance

• Scapular dyskinesia

• Posterior capsular tightness

• Trapezius paralysis