Shoulder proprioception in patients with subacromial impingement syndrome

BACKGROUND: Recently, proprioception deficits of the rotator cuff and the deltoid muscles have been suggested to play a pivotal role in the subacromial impingement syndrome (SIS). To date, there are no study has been found where the kinesthesia and joint position senses have been evaluated together in SIS. OBJECTIVE: To investigate the shoulder proprioception in patients with SIS. METHODS: Sixty-one patients with SIS and 30 healthy controls, aging between 25 and 65 years, were included in the study. Main outcome measure was proprioception, assessed with an isokinetic dynamometer. Kinesthesia, active and passive joint repositioning senses were tested at 0 degrees and 10 degrees external rotation. All tests were repeated 4 times and the mean of angular errors were obtained. RESULTS: The mean age was 49.14 +/- 10.27 and 48.80 +/- 11.09 years in patient group and in control group respectively. No significant difference was found between two groups in terms of age, gender and dominance. When involved and uninvolved shoulders of the patient group were compared, kinesthesia, active and passive joint position senses were significantly impaired in involved shoulders at all angles (P < 0.05). When involved shoulders of the patient group were compared to the control group, kinesthesia, active and passive joint position senses were significantly impaired in involved shoulders in patient group at all angles (P < 0.05) except active position sense at 0 degrees. When uninvolved shoulders of the patient group were compared to the control group, kinesthesia at 10 degrees was significantly impaired (P < 0.05). CONCLUSION: This study showed that shoulder proprioception was impaired in patients with SIS. This proprioceptive impairment was found not only in involved shoulders but also in uninvolved shoulders in patients with SIS.