Does shockwave therapy lead to better pain and function than sham over 12 weeks in people with insertional Achilles tendinopathy? A randomised controlled trial

Key Points

1. Shockwave therapy when added to exercise and education was no better than sham treatment in patients with insertional Achilles tendinopathy.
2. Both groups showed similar improvements in pain and function over 12 weeks, suggesting any benefits may be due to exercise, education, or placebo effects.

BACKGROUND & OBJECTIVE

Insertional achilles tendinopathy can be more challenging to treat than midportion tendinopathy. Exercise is the recommended first-line treatment, but some patients don't respond well. Shockwave therapy is commonly used as an adjunct treatment however evidence for its effectiveness is limited.

This study examined whether adding radial extracorporeal shockwave therapy to exercise and education would improve outcomes in patients with insertional Achilles tendinopathy compared to a sham treatment.

Shockwave therapy is commonly used as an adjunct treatment for Achilles Tendinopathy however evidence for its effectiveness is limited.

While shockwave therapy appears safe, the evidence in this study doesn't support its use as a treatment for insertional Achilles tendinopathy.

METHODS

• 76 participants with insertional Achilles tendinopathy were randomly divided into two groups who received either:

  1. three sessions of shockwave therapy plus exercise and education;
  2. three sessions of sham shockwave therapy plus exercise and education.

• The exercise program included calf raises with bent and straight knees, performed every second day. Participants could continue walking, running and sports if pain was below 4/10 (see Video 1).

• The primary outcome was pain and function as measured by the VISA-A questionnaire. Secondary outcomes included worst pain in last 24 hours, physical activity levels, quality of life and psychological measures (kinesiophobia, catastrophizing, self-efficacy).

• Measurements were taken at baseline, six weeks, and 12 weeks.

CALF RAISE EXERCISES

RESULTS

• Both groups improved over time, with VISA-A scores increasing from around 47 at baseline to 61 at 12 weeks. But there were no significant differences between groups at either six or 12 weeks for any of the outcomes.

• No serious adverse events occurred in either group. Minor adverse events (temporary pain increases) were slightly more common in the shockwave group between 6-12 weeks.

• Exercise adherence was similar between groups at six weeks but slightly higher in the shockwave group at 12 weeks (67% vs 49%).

LIMITATIONS

• The sham treatment still caused some pain (though less than real shockwave), which could have triggered pain-modulating effects.

• The physiotherapists delivering the shockwave/sham treatments weren't blinded (i.e. they knew which treatment they were providing.)

• The exact energy dose delivered to the tendon insertion is uncertain, though it was likely in the high-intensity range.

• Only 14% of eligible patients enrolled, which may limit generalizability.

CLINICAL IMPLICATIONS

Achilles tendinopathy is a common overuse condition that accounts for up to 9% of all running injuries (1). The condition can manifest in two locations - at the midportion of the tendon or at the insertion into the calcaneus. Insertional tendinopathy can be more challenging to manage due to several factors, including poorer blood supply at the insertion and mechanical compression of the tendon against bone during ankle movement (2,3).

This study found no benefit from adding shockwave therapy to exercise and education for insertional Achilles tendinopathy. This shows that the improvements seen in both groups were caused by one or more of the following: placebo effects, natural history, or the exercise and education program.

While shockwave therapy appears safe, with only minor adverse events reported, the evidence in this study doesn't support its use as a treatment for insertional Achilles tendinopathy. Clinicians should focus on delivering quality exercise programs and education. Furthermore, patients that seek out radial extracorporeal shockwave therapy should be educated that any benefit is likely due to the placebo effect. This placebo effect is also influenced by the patient-clinician interaction, the clinician’s personality and contextual factors such as the clinician’s reputation and the patient’s prior experience of treatment.

+STUDY REFERENCE

Alsulaimani B, Perraton L, Vallance P, Powers T, Malliaras P (2024) Does shockwave therapy lead to better pain and function than sham over 12 weeks in people with insertional Achilles tendinopathy? A randomised controlled trial. Clinical Rehabilitation.

SUPPORTING REFERENCE

1. Li H-Y and Hua Y-H. Achilles tendinopathy: current concepts about the basic science and clinical treatments. BioMed Res Int 2016; 2016.
2. Malliaras P. Physiotherapy management of Achilles tendinopathy. J Physiother 2022; 68: 221–237.
3. Benjamin M, Kaiser E and Milz S. Structure-function relationships in tendons: a review. J Anat 2008; 212: 211–228.