Background Patellar tendinopathy is a common and often difficult-to-treat knee injury in jumping athletes. Extracorporeal shockwave therapy (ESWT) appears to be a promising treatment but its effectiveness has not been studied in athletes who keep playing sports.

Objective To determine the effectiveness of ESWT in athletes with patellar tendinopathy with short duration of symptoms who are still in training and competition.

Design Multicenter two armed randomized controlled trial with blinded participants and outcome assessors.

Setting and participants Non-elite athletes aged 18–35. 57 volleyball, one handball and four basketball players with patellar tendinopathy (symptoms 3–12 months). Of these, 57 completed the study Intervention of three focused ESWT treatments (or placebo) at a weekly interval.

Main outcome measurements VISA-P score at 1, 12 and 22 weeks after the final treatment, when athletes were still in competition.

Results The mean VISA-P scores before and after treatment are summarized below. There was a significant effect for time (p<0.01) but no effect for treatment×time (p=0.82). One week after treatment more patients in the treatment group compared to patients in the placebo group evaluated the treatment as being beneficial (67% vs 37%, χ²=5.00 p=0.03).

Conclusions There was no effect of ESWT treatment protocol on the course of symptomatic patellar tendinopathy in jumping athletes who continued to train and compete.