ObjectiveTo determine the potential differences in both scapular positioning and scapular movement between the symptomatic and asymptomatic contralateral shoulder, in patients with unilateral subacromial pain syndrome (SAPS), and when compared with participants free of shoulder pain.SettingThree different primary care centres.ParticipantsA sample of 73 patients with SAPS in their dominant arm was recruited, with a final sample size of 54 participants.Primary outcome measuresThe scapular upward rotation (SUR), the pectoralis minor and the levator scapulae muscles length tests were carried out.ResultsWhen symptomatic shoulders and controls were compared, an increased SUR at all positions (45°, 90° and 135°) was obtained in symptomatic shoulders (2/3,98/8,96°, respectively). These differences in SUR surpassed the minimal detectable change (MDC95) (0,91/1,55/2,83° at 45/90/135° of shoulder elevation). No differences were found in SUR between symptomatic and contralateral shoulders. No differences were found in either pectoralis minor or levator scapulae muscle length in all groups.ConclusionsSUR was greater in patients with chronic SAPS compared with controls at different angles of shoulder elevation.