Effect of the Multicomponent Exercise Program MoveUS on the Kinematic Fatigue of People With Glenohumeral Instability: A Secondary Analysis From a Randomized Controlled Trial.

Small and underpowered for these outcomes: 47 people were recruited and 38 reached the 24-week follow-up, and the original trial was designed and powered around a different primary endpoint (the WOSI). Kinematic fatigue is described by the authors as an exploratory, performance-based construct rather than a validated measure of muscle fatigue, and there is no established minimal clinically important difference for it in this population, so it is unclear whether the delayed fatigue means anything patients would notice. Many outcomes and tasks were analysed with no correction for multiple comparisons, so some significant results may be chance findings. The sample was heterogeneous (traumatic and atraumatic instability, different jobs and sports) and the groups were not balanced at baseline, with a higher proportion of atraumatic cases in the standard care group, which the authors say may influence how people respond. Patients and treating therapists could not be blinded; only the assessor was. The usual care comparator was relatively low intensity, which the authors say may amplify the apparent effect of the experimental programme compared with a more intensive comparison. The single wrist-mounted sensor reflects the whole arm rather than the shoulder joint alone, and skin-mounted sensors can pick up artefacts such as sweat.

Government funded: a predoctoral grant from the Spanish Ministry of Universities (FPU21/06296), co-financed with FEDER funds through a University of Malaga research group grant (CTS-631), with open access costs paid by the University of Malaga. The authors declare no conflicts of interest, and no company selling the equipment or programme was involved.

Do not read this as proof that MoveUS improves shoulder function or reduces instability. What was measured was how long people could keep repeating a movement before their pace slowed, using a wrist sensor on an exploratory measure with no known threshold for clinical importance, in a small secondary analysis of a trial designed for a different question. Nothing here shows an effect on pain, recurrence or what patients can do in daily life.