ObjectivesTo assess the impact of low to moderate biomechanical stress on entheses in patients with psoriasis and psoriatic arthritis (PsA).MethodsWe conducted a prospective interventional study on a cohort of psoriasis and PsA patients who underwent a 60 min badminton training session. Pain assessment by Visual Analogue Scale (VAS), physical examination of 29 entheses (SPARCC, LEI, MASES) and bilateral ultrasound at the lateral humeral epicondyle, inferior patellar pole and Achilles tendon were performed before and after training. Ultrasound changes were assessed using the OMERACT scoring system. A follow-up assessment of pain and adverse events was performed at 1 week.ResultsSixteen patients were included (n=7 PsA; n=9 psoriasis) and 196 entheseal ultrasound scans were acquired. At baseline, median VAS pain (IQR) was 0.5 cm (0–2.3) and the total number of tender entheses was 12/464. Mean (min; max) Disease Activity Index for Psoriatic Arthritis was 6.1 (0.8; 19) and 5/7 PsA patients had an Minimal Disease Activity status. After training, no significant change in VAS pain (0.0 cm (0.0–2.0)) nor in tender entheses (13/464) emerged. Four patients (n=2 PsA, n=2 psoriasis) developed a grade-1 power Doppler-signal at six entheses, which, however, remained non-tender. At 1 week, median VAS pain remained stable (0.0 cm (0.0–3.0); p>0.05) and only one participant with active PsA at baseline reported increased arthralgias in three joints.ConclusionsLow to moderate physical strain, as in the context of leisure sport activity, seems well tolerated in psoriatic patients without increases in tenderness, pain and ultrasound-proven inflammation. Evidence-based recommendations for physical activity in PsA are direly needed and larger controlled studies should be conducted to define safe exercise thresholds.