For inclusion, at least one impingement sign needed to be positive, with in addition a second positive impingement test or a painful apprehension/positive relocation test. It is thought that patients with minor instability and secondary impingement will experience pain, but not apprehension with these tests.
Although not agreed on in literature, these tests are currently considered to be valuable in the clinical evaluation of symptoms associated with impingement.
Subjects were excluded if they had a history of dislocation of the shoulder, shoulder surgery, current symptoms related to the cervical spine, or documented structural injuries to the shoulder complex. All subjects gave their written informed consent to participate in the study. The study was approved by the ethics committee of Ghent University.