Theeffectivenessofradialshockwavetherapyonmyofascialpainsyndrome:atwo-armed,randomizeddouble-blindplacebo-controlledtrial

Myofascial pain syndrome (MPS) is an extremely common musculoskeletal condition, with lifetime prevalence estimates ranging from 30% to 93% among people experiencing musculoskeletal pain. It is characterized by painful myofascial trigger points—hyperirritable, palpable nodules within skeletal muscle fibers—that cause localized pain, muscle tenderness, referred pain, and can significantly impact quality of life, work productivity, and mental health. Despite its prevalence, there is no gold standard treatment for MPS, and responses to various interventions vary considerably. Radial shockwave therapy (RSWT) has become one of the most frequently used treatments for MPS and is even recommended by NICE for certain tendinopathy conditions.

However, the evidence supporting its short-term effectiveness has been limited by poor methodological quality in previous studies, with small sample sizes, heterogeneous protocols, and a lack of proper placebo-controlled trials. This study was designed to address these gaps by conducting a rigorous, double-blind, placebo-controlled trial to determine whether RSWT truly provides benefits beyond placebo for patients with MPS in the neck and upper back.

The researchers conducted a two-armed, randomized, double-blind, placebo-controlled trial at an outpatient physical rehabilitation department in a tertiary hospital in Saudi Arabia. They recruited 70 adults aged 18 years or older who had MPS affecting the neck and/or upper back, with palpable tenderness and trigger points in these areas. Participants were randomly assigned to either the intervention group or the control group in a 1:1 ratio using computer-generated randomization with concealed allocation in sealed opaque envelopes.

The intervention group received six weekly sessions of genuine radial shockwave therapy using a Storz Medical device set to 1.5 bars (0.068 mJ/mm²), 2000 pulses, at 15 Hz frequency with a D20 transmitter headpiece. The control group received an identical treatment regimen except their device was set to 0.3 bar (0.01 mJ/mm²)—a non-therapeutic, no-energy shock that produced sound but delivered no meaningful therapeutic dose. Both groups also received standard physical therapy stretches and exercises, including therapeutic home exercises (Quadruped Cat/Camel, wall arm slide, push-up variations, neck rotation stretch, and horizontal shoulder adduction stretch), performed 10–15 repetitions, 2 sets, 3–4 times per week.

Importantly, both participants and outcome assessors were blinded to group allocation. Outcomes were measured at baseline, 4 weeks, 8 weeks, and 12 weeks using the numeric pain score (NPS, 0–10 scale), neck disability index (NDI, 0–50 scale), pressure pain threshold (PPT, measured with a digital algometer), and SF-12 quality of life scores (physical and mental components). The analysis was conducted on an intention-to-treat basis, with last observation carried forward for the 20 participants (29%) lost to follow-up.

The study found that both groups improved significantly over time, but there was no statistically significant difference between the genuine shockwave and placebo groups at any time point. For the primary outcome of pain (NPS), the placebo group improved by 2.4 points from baseline to 4 weeks (p = 0.000), 2.6 points by 8 weeks (p = 0.000), and 3.6 points by 12 weeks (p = 0.000). The shockwave group improved by 1.9 points at 4 weeks (p = 0.000), 2.1 points at 8 weeks (p = 0.000), and 2.3 points at 12 weeks (p = 0.000). The between-group comparison showed no significant difference at 4 or 8 weeks, with only a marginal difference at 12 weeks (p = 0.047) that was not considered clinically meaningful.

For pressure pain threshold, both groups showed statistically significant improvements at all time points (placebo: −0.48, −0.51, −0.66 kg/cm²; shockwave: −0.5, −0.5, −0.6 kg/cm²; all p < 0.05), but again with no significant between-group differences. For neck disability, the placebo group improved significantly at all time points (6.47, 6.13, 8.22 points; p < 0.05), while the shockwave group improved significantly only at 4 weeks (5.56 points, p = 0.010) but not at 8 or 12 weeks. Quality of life measured by SF-12 showed no significant changes in the shockwave group, while the placebo group actually showed significant improvement in physical scores at 8 weeks (p = 0.01) and 12 weeks (p = 0.02).

No serious adverse events were reported, with only two participants in the shockwave group experiencing temporary pain sensitivity. The dropout rate was comparable between groups.

This carefully designed trial provides strong evidence that radial shockwave therapy, at the parameters tested, does not offer meaningful benefits beyond placebo for patients with myofascial pain syndrome in the neck and upper back. Both groups improved substantially, suggesting that the therapeutic home exercises, standard physical therapy care, natural history of the condition, and placebo effects likely account for the improvements seen. The authors note that cultural factors may have influenced outcomes, as patients in Saudi Arabia and similar regions often have strong positive expectations for technological treatments like shockwave therapy, potentially enhancing placebo responses.

An important caveat is that the placebo device may not have been completely inert—the 0.3 bar (0.01 mJ/mm²) dose, while considered subtherapeutic, might still have produced some physiological effects. The authors acknowledge this limitation and suggest future research should explore optimal placebo parameters.

For clinicians, this study suggests that RSWT should not be prioritized as a standalone or primary treatment for MPS. Instead, the emphasis should be on evidence-based standard care including therapeutic exercises, education, and active rehabilitation strategies. The authors recommend using RSWT only as an adjunct to standard care, given that both groups improved and the treatment is safe. For patients, this means that expensive shockwave therapy sessions may not be necessary, and that consistent engagement with home exercises and physical therapy may provide equivalent benefits at lower cost.

Healthcare systems and insurers may want to reconsider coverage policies for RSWT in MPS given these findings.