Shockwave added little to exercise for jumper's knee

Patellar tendinopathy, often called jumper's knee, causes chronic tendon pain that can dog athletes for months and interfere with training and competition. Progressive stretching and strengthening exercise is the standard treatment, but recovery is slow, so clinics frequently add radial pressure wave therapy — a shockwave-style device — in the hope of speeding things up. Whether that add-on actually delivers extra benefit beyond a supervised exercise programme has remained an open question. This trial set out to compare exercise plus radial pressure waves against exercise alone in physically active athletes.

Researchers ran an open-label randomised controlled trial at a university athletic training room in Chiba, Japan. Thirty-three athletes with chronic patellar tendon pain, averaging 20.3 years of age, were randomly assigned to radial pressure wave therapy plus exercise (17 athletes) or exercise alone (16 athletes). The treatment group received four weekly device sessions over a four-week period, while both groups performed daily lower-extremity stretching and strengthening exercises instructed by a physiotherapist. Symptoms were tracked with the Japanese version of the VISA-P questionnaire at baseline and at 4, 16 and 28 weeks after the intervention.

Both groups improved significantly over time. From similar baseline scores of 68.8 and 67.4, the pressure wave group climbed to 77.6 at four weeks, 82.5 at 16 weeks and 89.9 at 28 weeks, while the exercise-only group reached 72.7, 78.5 and 77.4 at the same time points. The treated group's advantage at 28 weeks was significant in unadjusted analyses, but disappeared once the analysis accounted for how long each athlete had been symptomatic. Participants receiving pressure wave therapy did, however, reach the threshold for clinically meaningful improvement earlier than controls.

Shockwave-style therapies are widely marketed for stubborn tendinopathies, yet trial evidence has been mixed, and this study adds a note of caution for the patellar tendon specifically. It suggests apparent device benefits can partly reflect differences in symptom duration between groups rather than the treatment itself. The trial was small and open-label, so a modest true effect — such as faster early improvement — cannot be ruled out. Larger trials that account for symptom duration from the outset are needed to settle whether the earlier gains are real and worth pursuing.

For an active person nursing a grumpy patellar tendon, the clearest signal here is that a consistent daily stretching and strengthening programme delivered clinically meaningful improvement on its own over 28 weeks. Adding radial pressure wave therapy did not produce a statistically significant extra benefit once symptom duration was taken into account, although treated athletes hit meaningful improvement sooner. This is a reason to see exercise as the foundation of tendinopathy care, with device add-ons as optional extras whose added value remains uncertain.