Does shockwave therapy lead to better pain and function than sham over 12 weeks

Key points

1. 01No between-group difference in the primary pain and function score (VISA-A) at 6 weeks (difference 3, 95% CI -4.6 to 10.5) or 12 weeks (difference 4.6, 95% CI -2.5 to 11.6)
2. 02No significant between-group differences for any secondary outcome (pain, physical activity, kinesiophobia, catastrophising, self-efficacy, quality of life) at either timepoint
3. 03Both groups improved from baseline: mean VISA-A rose from approximately 47 to 61 points by 12 weeks, suggesting benefit from exercise, education, or natural history
4. 04No serious adverse events were reported in either group; non-serious adverse events were comparable early on but slightly higher in the shockwave group in the second six-week period
5. 05A consistent finding with the only other adequately powered sham-controlled trial (Mansur et al.), which also found no between-group differences

How it was conducted

Design

Two-armed, parallel-group, single-centre, superiority randomised controlled trial

Participants

76 adults (38 per group) with insertional Achilles tendinopathy confirmed by ultrasound, symptoms >3 months, aged 18 or older

Intervention

Three sessions of radial extracorporeal shockwave therapy (3000 shocks at 10 Hz, starting at 2 bar) or identical-appearing sham, plus exercise and education for all participants

Primary outcome

Victorian Institute of Sports Assessment - Achilles (VISA-A) questionnaire score at 12 weeks (minimal clinically important difference = 6.5 points)

Follow-up

Baseline, 6 weeks, and 12 weeks

Analysis

Intention-to-treat using repeated-measures linear mixed-effects model, adjusted for age, sex, BMI, and baseline scores

What they found

• Primary outcome (VISA-A) at 6 weeks: between-group difference 3 (95% CI -4.6 to 10.5, p = .44) - no significant difference
• Primary outcome (VISA-A) at 12 weeks: between-group difference 4.6 (95% CI -2.5 to 11.6, p = .20) - no significant difference
• Worst pain last 24 hours at 12 weeks: between-group difference -0.1 (95% CI -1.2 to 1, p = .87)
• Tampa Scale of Kinesiophobia at 12 weeks: between-group difference 0.6 (95% CI -6.8 to 8.1, p = .87)
• Pain Catastrophising Scale at 12 weeks: between-group difference 0.6 (95% CI -4.1 to 5.3, p = .80)
• EuroQol-5D-5L at 12 weeks: between-group difference 0.02 (95% CI -0.05 to 0.08, p = .56)
• Mean maximum pain during treatment was significantly higher in the shockwave group (7.6 SD 1.1) versus sham (3.8 SD 2.5) in session 1 (p < .001)
• Exercise adherence at 6 weeks: shockwave 68%, sham 65% (p = 1.00); at 12 weeks: shockwave 67%, sham 49% (p = .80)
• No serious adverse events in either group; non-serious adverse events in weeks 7-12 were higher in the shockwave group (39.5% vs 15.8%, p = .02)

Limitations

• Sham treatment still produced substantial pain (mean 3.8 out of 10 during session 1) because the applicator was pressed against the tender calcaneum, which may have triggered conditioned pain modulation and partially obscured any specific shockwave effect
• Physiotherapists delivering shockwave or sham were not masked to allocation, though scripted interactions were used to minimise bias
• The actual energy flux density delivered to the tendon insertion was uncertain, and the minimum effective dose for shockwave therapy is debated
• Follow-up was limited to 12 weeks, so longer-term differences between groups cannot be excluded

Why it matters

For patients

People with insertional Achilles tendinopathy should know that adding shockwave therapy to a supervised exercise and education program is unlikely to speed recovery compared to a convincing sham, so exercise-based care remains the primary approach.

For clinicians

Clinicians offering shockwave therapy for insertional Achilles tendinopathy should inform patients that any perceived benefit may reflect placebo mechanisms, and the current evidence does not support it as a specific adjunct to recommended exercise and education.

For readers

This well-powered, adequately blinded RCT aligns with the only other sham-controlled trial in this population, strengthening the conclusion that shockwave therapy lacks specific efficacy for insertional Achilles tendinopathy when added to modern exercise care.