The Effect of Changing Posture in Sitting on Selected Clinical Shoulder Tests

Background: Shoulder pain is the third most common musculoskeletal problem accounting almost 21% of all musculoskeletal complaints. Symptomatic Rotator cuff degenerative tears (RCDT) are mostly common above the age of 40. Deviations of posture in the upper quadrant such as, slouched posture and forward head position, have been linked repeatedly to rotator cuff diseases, altered scapular kinematics and changes in the acromiohumeral distance (AHD). No study yet examined the effect of changing posture in sitting on the output of shoulder clinical tests, in patients with RCDT. Objectives: The primary objective of the study is to examine the effect of changing posture in sitting on selected clinical shoulder tests in patients with rotator cuff degenerative tears (RCDT) Study design: A single blinded controlled clinical trial Methods: A total of 100 subjects (Patients referred to physiotherapy outpatient clinics of Clalit Healthcare Services in Holon and Hertzlyia) will be included in this study and divided into 2 groups: 50 subjects with shoulder pain who are diagnosed with RCDT by ultrasound and a control group of 50 volunteering subjects without any pain in the upper quadrant. All patients will be measured for their body weight and height and their hand dominance will be notified. Following reliability trials on the first 10 subjects, all subjects will be tested for pain provocation and level of pain (VAS) in both shoulders with 3 commonly used clinical shoulder tests for the diagnosis of rotator cuff diseases (Empty can - sensitivity=94%, specificity = 46% Neer test - sensitivity = 72%, specificity = 60%, and Hawkins-Kennedy test - sensitivity = 79%, specificity = 59% ) in 3 sitting postures; normal resting posture, slouched posture, and upright posture with scapular retraction as described by Kalra et al (2010). In addition, the rotator cuff muscle strength tests during shoulder abduction, internal rotation and external rotation will be measured for the 2 shoulders using a hand-held dynamometer.