Proprioception of the Shoulder Joint in the Cases of Rotator Cuff Tears and Healthy Volunteers

Abstract

Proprioception was studied in rotator cuff tear and normal shoulder using active angle reproduction test. Subjects and methods: In cuff tear group(RCT), 33 cases (33 shoulders) were studied. They were 19 males and 14 females, their average age was 66.4 years.The average active elevation angle was 112.4° and the average external rotation angle was 51.4°. As a control group (C), 20 cases (20 shoulders) who had not had previous injury or disease in their shoulder were studied. Average elevation angle was 160.3° and average external rotation angle was 61.9°. The subjects were studied sitting on a chair and had a bandage put over their eyes. They rotate or elevate their shoulder to any angle. The difference absolute values between average of 3 times of reproduction of the angle and the target angle were studied. The target angles were 30° of internal rotation, 30° and 45° external rotation, 30°, 45° and 60° of elevation. In 30° of IR, error angle revealed 7.0° in RCT and 2.6° in C group (P<0.01). These were 4.6° and 2.5°(P<0.01) in 30° of ER, 3.6° and 2.5°(P=0.15) in 45° of ER. These were 4.0° and 2.1° in 30° of elevation (P<0.05), 4.1° and 1.9° in 45° of elevation (P<0.01), 4.8° and 2.4° in 60° of elevation(P<0.01). Proprioception of rotator cuff tear was lower than that of normal shoulder.