The overall frame for the trial is a main clinical effectiveness-part and an embedded mechanistic part. The clinical effectiveness-part will be reported in the main trial paper, and include the following outcomes: SPADI (primary outcome), Abduction strength, External rotation strength, Abduction ROM, Pain last week, QoL-index, QoL-VAS, Global impression of change and PASS. Missing outcome data will be imputed using multiple imputations based on the following variables: All previous scores in the relevant outcome, Age, Gender and Allocation.