weeks). The good overall improvement after one year may
indicate that duration of symptoms may have had less influence
on outcome than the baseline SPADI score; however, further
research is needed to answer this question.
Strengths and limitations of the study. This study has sufficient
power because of the low dropout rate and a standard deviation
around the mean SPADI score below the standard deviation
used for power calculation. In addition to a sound statistical
analysis controlling for possible confounders, covariates and
time, further data about additional medication, diagnostics,
co-interventions and sick leave are given, enabling the reader
to draw a comprehensive picture of the patient group. Both
interventions are described in detail and can therefore be
reproduced easily.
For ethical and practical reasons it was not possible for us
to include a placebo group. We therefore could not analyze
the contribution of the natural course of the shoulder disorder
to the improvement. However, other studies found a significant
difference between exercise treatment and placebo or no
intervention. Due to the nature of our interventions and outcome
measures it was not possible to blind either therapists
or patients to the study protocol, but patients were kept naive
to group allocation. Since there was no difference between
groups, the influence of therapists’ beliefs about the applied
treatments or the longer contact times in the intervention group
seemed not to be relevant.