Table 1 Eligibility criteria

Inclusion:

▪ Patients with (local) shoulder pain in the presence of an atraumatic (ultrasonographically detected) partial thickness tear

▪ Clinical signs of ‘shoulder impingement’ (e.g. painful arc, positive impingement tests)

▪ Adults (≥ 18 years)

▪ No restrictions on sex

▪ Agreement on conservative treatment

▪ Ability to speak and comprehend the German language

▪ Agreement to participate (signed informed consent)

▪ Anticipated availability for follow-up (living in area of Hamburg)

▪ Agreement to physiotherapy in a collaborating practice

Exclusion:

▪ Presence of a full thickness tear at the affected shoulder

▪ Previous substantial shoulder trauma (e.g. shoulder dislocation, fractures)

▪ Previous surgery for the affected shoulder

▪ Previous surgery in the shoulder area that may be causal of or contributory to the current problem (e.g. surgery for breast cancer)

▪ Clinically relevant glenohumeral degeneration or disease (e.g. frozen shoulder)

▪ Current glenohumeral septic arthritis

▪ Clinically relevant acromioclavicular arthritis (e.g. local tenderness, positive provocation tests)

▪ Clinically relevant calcific tendinitis

▪ Ultrasonographic evidence of long head of biceps (LHB) tendon subluxation/ dislocation

▪ Referred pain from the cervical spine region

▪ Multisite musculoskeletal pain

▪ Systemic disorders, diseases or comorbidities as potential sources of (the current) shoulder pain (e.g. breast cancer, rheumatoid disease, inherited disorders (e.g. Marfan syndrome, Ehlers-Danlos syndrome)), or as impairing treatment (e.g. cancer, cardiac insufficiencies)

▪ Neurological disorders or deficits as potential sources of (the current) shoulder pain or impairing assessment and treatment (e.g. hemiplegic shoulder)

▪ Worker’s compensation claims

▪ Unwillingness or inability to give informed consent (e.g. cognitive or intellectual impairments)