Internal Rotation Resistance Test at Abduction and External Rotation

IRRT at maximal 90° abduction and maximal external rotation is performed with the shoulder at maximal 90° rotation and the elbow flexed to 90° (Fig. 2). The patient is then asked to resist the external rotation force applied perpendicular to the forearm by the investigator. The test is considered positive if the patient could not hold the position or if he or she showed weakness of resisted internal rotation compared with the other side. It should be noted the maximal 90° abduction and maximal external rotation is active range of motion. Passive motion may affect the result of the test because of severe pain.

The lift-off test is performed by placing the hand of the affected arm on the back (at the position of the midlumbar spine) and asking the patient to internally rotate the arm to lift the hand off the back \[9\]. The test is considered positive if the patient is unable to lift the arm posteriorly off the back or if he or she performs the lifting manoeuvre by extending the elbow or the shoulder. Weakness is also as a positive result.

The belly-press test is performed with the arm at the side and the elbow flexed to 90°, by having the patient press the palm into his or her abdomen by internally rotating the shoulder \[3, 5\]. The test is considered positive (1) if the patient shows a weakness in comparison with the opposite shoulder or (2) the patient pushes the hand against the belly by wrist flexion, despite instruction to the contrary.

IRLS test is evaluated with the affected arm of the patient was held by the examiner at maximum internal rotation \[10\]. The back of the hand is then passively lifted away from the body until almost full internal rotation is reached. Then, the patient is asked to actively maintain this position. The test is considered positive when the patient fails to maintain the position and the hand lagged.

The bear-hug test is performed with the palm of one side placed on the opposite shoulder and fingers extended and the elbow positioned anterior to the body \[3\]. The patient is then asked to hold that position when the examiner tried to pull the patient's hand from the shoulder with an external rotation force applied perpendicular to the forearm. The test is considered positive if the patient could not hold the hand against the shoulder or if he or she showed weakness compared with the other side.

IRRT at 0° abduction and 0° external rotation is performed with the arm at the side and the elbow flexed to 90° (Fig. 1). The patient is then asked to resist the external rotation force applied by the investigator. The test is considered positive if the patient could not hold the position at the side or if he or she showed weakness of resisted internal rotation compared with the other side. The test is negative if patients only complain of pain.

At the time of surgery, general anaesthesia was administered and the patient was placed in beach-chair position. A complete arthroscopic exploration of the glenohumeral joint and the subacromial space was performed through a standard posterior portal. The senior author performed a complete arthroscopic exploration. Arthroscopic evaluation of the rotator cuff was considered the gold standard for making the definitive diagnosis. Evaluation of the SSC was carried out with both a 30° arthroscope and a 70° arthroscope.