Fonte: Robert E. Sallis, MD. Kaiser Permanente, Fontana, California, Stati Uniti
L’esame della spalla continua controllando la forza dei muscoli della cuffia dei rotatori e dei tendini bicipiti. I muscoli della cuffia dei rotatori (supraspinatus, infraspinatus, teres minor e subscapularis) agiscono come compressori, tenendo la testa omerale in posizione contro la glenoide. Lesioni e degenerazione dei tendini della cuffia dei rotatori sono le fonti più comuni di dolore alla spalla.
Il test di forza del muscolo rotatore viene eseguito testando i movimenti contro la resistenza applicata dall’esaminatore. Il dolore con questi movimenti resistiti suggerisce tendinite; debolezza suggerisce una lacerazione della cuffia dei rotatori. La forza testata è seguita da test per la sindrome da impingement, l’instabilità della spalla e la lesione del labbro. È importante testare entrambe le spalle e confrontare tra i lati. La spalla opposta dovrebbe essere usata come standard per valutare la spalla infortunata, a condizione che non sia stata ferita.
The clinical evaluation of the shoulder begins with inspection, palpation, and testing range of motion, followed by strength testing of the rotator cuff and biceps muscles. While assessing the strength of the rotator cuff muscles, it is essential to differentiate true muscle weakness from a painful inhibition of strength that can be seen with severe tendonitis. The next part of the exam is the assessment for signs of impingement, using the Neer's, Hawkins, and crossover tests. Pain or lack of motion with these maneuvers suggests impingement of the rotator cuff tendons in the subacromial space. Stability of the shoulder is then evaluated using the anterior and posterior drawer tests, the sulcus sign, and the relocation test. Finally, the labrum is evaluated for injury using the clunk test, labrum grind test, and O'Brien's test.
Examination of the shoulder includes simple but sensitive tests, which help a clinician, reach a diagnosis.
In shoulder exam part one, we covered inspection, palpation, and testing the range of motion. This video will focus on the maneuvers evaluating muscle strength and a few special tests for specific shoulder injuries and diseases.
The strength of the rotator cuff muscle is assessed by testing movement against resistance provided by the examiner. Pain with these resisted motions suggests tendonitis, whereas weakness suggests a tear. On the other hand, the special tests are performed to reproduce the symptoms of impingement syndrome, shoulder instability, or labrum injury.
First, lets review the strength tests, which involve a series of resisted motions. Remember, it is important to compare one side to the other in assessing pain or weakness. These maneuvers assess the muscles of the rotator cuff, and then the biceps and the triceps.
Start by testing the infraspinatus and teres minor muscles by examining external rotation motion against resistance. With elbows bent to 90°, ask the patient to push both hands away from the midline while you try to push them inwards. Next, assess the subscapularis muscle by doing to opposite and testing internal rotation against resistance. The following maneuver evaluates the supraspinatus muscle (2.4.1). This is the “empty-can test”. Have the patient raise both the arms to their sides and about 30° forward with their thumbs down. Then instruct them to hold this position, while you are attempting to push their arms down.
The following two tests evaluate the biceps muscle. For the first test called the Speeds Test, have the patient raise both arms in front to 90° with their palms up and elbows bent to 15° flexion. Ask them to hold this position while you attempt to push the arms down. Next, for the Yergason’s Test, ask the patient to bend their elbow to 90° and hold while you attempt to pull their arm down, at the same time trying to twist it into pronation. Finally, test the triceps. Request the patient to bend the elbow forward to 90° and then ask them to push against your hand in an attempt straighten the arm.
After the muscle strength tests, the next group of maneuvers is performed to elicit the pain associated with the impingement syndrome, which is a painful condition caused by inflammation and degeneration of rotator cuff tendons when they are impinged, or trapped, in the subacromial space.
Start with eliciting the Neer’s impingement sign. Passively raise the patient’s affected arm in front of them and overhead. This test is considered positive if pain is reproduced at maximal forward flexion. For the next test called the Hawkins’ impingement sign. Raise the patient’s arm forward to 90° with the elbow bent to 90°, and passively rotate the shoulder externally and internally. Finally, perform the crossover test. Raise the patient’s arm forward to 90° and move it across the body towards the opposite shoulder. Repeat the same maneuver on the other side and note if the patient feels any pain over the acromioclavicular joint.
The next group of maneuvers assess for glenohumeral joint instability, which refers to the inability of maintaining the humeral head centered inside the glenoid fossa.
The first set of maneuvers in this group is called the Apprehension Tests done in both the anterior and posterior direction. Position the arm in 90° abduction position and elbow bent to 90° and apply an anterior force to the posterior aspect of the shoulder. Next, ask the patient to lie down, and in the same arm position apply a posterior force on the anterior aspect of the shoulder. These tests are considered positive only when they provoke an unpleasant sensation of the shoulder coming out of joint. Simple pain with these tests may be from rotator cuff or labrum injury, rather than instability.
For the subsequent test, called the Relocation Test, passively rotate the patient’s shoulder externally until discomfort is noted. Then apply downward pressure to the anterior humeral head. This should relieve the shoulder discomfort in patients with anterior instability. Next, request the patient to stand up. With their arms hanging at the sides, grasp the patient’s arm just above their elbow and pull it downward. This would cause formation of a prominent sulcus between the acromion and the humeral head in a patient with inferior instability.
Now lets review the final group of tests called the labrum tests. These maneuvers are performed to diagnose the injury of the cartilage rim that surrounds the glenoid fossa called the glenoid labrum.
Start with the “Clunk test”. In seated position, passively rotate the patient’s shoulder through a full range of motion. A prominent “clunk” or a “pop” may indicate labrum tear. For the next test, have the patient bend their elbow to 90° and raise their shoulder on the side to 90°. Then grasp the upper arm and compress their humeral head is into the glenoid cavity, while rotating the humerus internally and externally. This maneuver is called the Labrum Grind Test, and it induces significant pain or “clunking” in patients with a labrum injury.
Finally, perform the “O’Brien’s test” for SLAP, that is superior labrum, anterior and posterior labral injury. Ask the patient to forward flex both arms to 90° with 10° horizontal adduction and elbows extended. Instruct them to rotate their arms so their thumbs are pointing up. Then apply a downward force on both arms. Repeat the same maneuver in thumbs down position. Increased pain in the thumbs down position, compared to the thumbs up, is suggestive of SLAP injury. Note that this maneuver will also aggravate acromioclavicular joint pain. This test concludes the shoulder examination. Remember, that systematic evaluation of a patient with shoulder pain should also include the neck exam.
You’ve just watched JoVE’s video demonstrating a part of the shoulder examination. In our first video on this topic, we reviewed how to perform inspection and palpation of the shoulder and how to evaluate range of motion. The current video demonstrated how to test the shoulder muscles strength, and how to perform special tests for the impingement syndrome, shoulder instability, and labrum injury. As always, thanks for watching!
