IntegratingUltrasound-GuidedInjectionsandPeripheralMagneticStimulationinChronicMyofascial/LumbarPain

Myofascial pain syndrome (MPS) is an extremely common musculoskeletal condition, with prevalence estimates reaching up to 85% in patients presenting with musculoskeletal complaints. When chronic, MPS can lead to central sensitization, widespread pain syndromes, and significant functional impairment. The lumbar multifidus muscle, a key spinal stabilizer, is particularly vulnerable to atrophy and dysfunction in chronic low back pain. Conventional treatments including medications, physical therapy, and dry needling have limitations, driving interest in more targeted, technology-enhanced approaches.

This perspective article addresses the potential of combining two emerging modalities: ultrasound-guided injections (USGIs) and repetitive peripheral magnetic stimulation (rPMS).

The authors synthesized existing literature and presented their own preliminary clinical experience to propose an integrated treatment approach. They reviewed: (1) the pathophysiology of MPS, including the energy depletion model where chronic sarcomere contraction causes ischemia, hypoxia, and ATP depletion; (2) the mechanisms and clinical evidence for USGIs targeting the multifidus muscle, including dry needling, interfascial plane blocks, and fascial hydrodissection; (3) the principles of rPMS, including its electromagnetic induction mechanism, frequency-dependent effects, and comparison with TENS; and (4) their own pilot study combining multifidus USGIs with 12 sessions of rPMS in three patients with chronic low back pain. The USGI technique involved injecting a mixture of 5 mL 50% dextrose and 5 mL 1% lidocaine into the multifidus muscle using an in-plane, distal-to-proximal approach, followed by rPMS targeting the bilateral lumbosacral region.

The literature review revealed several key findings. For USGIs, a retrospective observational study of 90 participants with quadratus lumborum MPS found significant pain reduction at 72 hours (mean difference [MD]=3.085, 95% CI: 2.200–3.970, p<0.05), 1 month (MD=2.644, 95% CI: 1.667–3.621, p<0.05), 3 months (MD=2.017, 95% CI: 0.202–2.729, p<0.05), and 6 months (MD=1.339, 95% CI: 0.378–2.300, p<0.05) after injection with levobupivacaine and triamcinolone. Another study of 60 elderly patients with lumbar facet joint syndrome found that multifidus injection with 5% dextrose water reduced VAS scores from approximately 7.5 to around 1 after three injections. For rPMS, a meta-analysis of six RCTs with 139 participants found significant pain reduction (MD, −1.89; 95% CI, −3.32 to −0.47; p<0.05) and functional improvement (Oswestry Disability Index: MD, −8.39; 95% CI, −13.65 to −3.12; p<0.001).

Low-frequency rPMS (5 Hz) reduced soleus tendon reflex by 23.7% (p<0.001), while high-frequency rPMS improved FMA scores and muscle strength in stroke patients (p=0.012 to p=0.001). In the authors' pilot study of three patients, significant improvement in both pain (VAS) and disability (Oswestry Disability Index) was observed after 12 sessions of combined treatment.

The integration of USGIs with rPMS represents a promising multimodal strategy for managing chronic MPS and low back pain. USGIs provide precise, localized pain relief by disrupting pain generators, restoring perfusion, and breaking pathological reflex arcs, while rPMS offers non-invasive neuromuscular reconditioning through central and peripheral mechanisms. The dual approach addresses both nociceptive and neuromuscular components of chronic pain. For clinicians, this suggests a potential workflow where targeted injections are followed by rPMS sessions that can be administered by trained therapists.

However, the authors emphasize that USGI success depends on specialized training in ultrasound interpretation and injection techniques, and rPMS parameters require individual calibration. Future research needs include larger randomized controlled trials, standardized protocols, and investigation of whether the combination produces additive or synergistic effects. The approach may be particularly relevant for patients with multifidus dysfunction, a common but often underaddressed component of chronic low back pain.