Is the angular onset of pain during arm elevation associated to functioning in individuals with rotator cuff related shoulder pain?

BACKGROUND: Rotator cuff related shoulder pain (RCRSP) is the main diagnosis for shoulder pain. A painful arc during active arm elevation is a common finding in RCRSP. The angular onset of pain during arm elevation may play an important role on functioning of the upper extremities. OBJECTIVE: This study aimed to: 1) determine and characterize the association between the angular onset of pain during arm elevation and upper-limb self-reported functioning, 2) verify whether demographic and clinical characteristics contribute to this association, and 3) investigate whether these characteristics differ considering distinct ranges of angular onset of pain in individuals with RCRSP. METHODS: 252 individuals with RCRSP were divided in 3 groups based on the angular onset of pain during arm elevation in the sagittal plane: <60°, 60°-120°, and >120°. The Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire was used to assess functioning of the upper limbs. Demographic and clinical characteristics were selected for the multivariable analysis. RESULTS: Individuals with an angular onset of pain above 120° of arm elevation presented lower DASH score (lesser disability) than individuals with an angular onset of pain between 60°- 120°. Male sex, age, dominance of the side affected, duration of symptoms, and the angular onset of pain during arm elevation explained 31% of the DASH score variance. CONCLUSION: Individuals with RCRSP and angular onset of pain above 120° of arm elevation present better functioning than individuals with onset of pain between 60°-120°, and similar functioning as those with pain below 60°. Male sex, lower age, non-dominant side being affected and longer duration of symptoms are also associated to better functioning as assessed by the DASH questionnaire.