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.

Quality assurance - "clalit" health services will provide ongoing auditing and monitoring of the study. data checks will be also examined by "clalit health services". the investigators are obliged to enter all the data into logs provided upfront by the organisation. All the data obtained will be stored in an original folder intended for inspection and all encounters with volunteers will be documented in the computerized medical file of the volunteers. Standard operating procedures will be followed by the regulations expected by "clalit" health services and the Israeli ministry of health. After the first 10 volunteers of the study a reliability and validity statistical analysis will be made to assess the sample size estimated. Missing, unavailable, "non-reported" or uninterpretable data will be excluded from the final analysis.Data will be analyzed using the Statistical Package for the Social Sciences Version 15 (SPSS Inc., Chicago, IL, USA). Results of measurements of each test will be analyzed for mean, standard deviation (SD) and range. Categorical variables will be described percentiles/median. Changes of variables in the same subject will be analyzed using a paired T test for continuous variables and Mann-Whitney test for categorical variables. In addition, the correlations between variables will be calculated using ICC. P values smaller than 0.05 (p<0.05) will be considered significant

Inclusion Criteria:

1. Patients aged over 40 years.
2. Patients with partial rotator cuff degenerative tears that were diagnosed by ultrasound.

Exclusion Criteria:

1. Recent trauma to the upper quadrant.
2. Patients with spondyloarthropaties and or rheumatological diseases
3. Any oncological disease.
4. Any surgery or fractures in the upper quadrant.
5. Systemic vascular pathology.

Patients aged over 40 years with partial rotator cuff degenerative tears that were diagnosed by ultrasound.