The effects of dry needling on pain relief and functional balance in patients with sub-chronic low back pain

This randomized controlled trial investigated the immediate effects of dry needling in 25 patients with subacute low back pain, a condition that significantly affects quality of life and functional balance. Subacute low back pain, defined as pain persisting from 6 weeks to 3 months, frequently results in altered postural control and reduced body awareness. Dry needling is a therapeutic technique that uses solid filiform needles to treat myofascial trigger points and painful areas, providing pain relief through complex neurobiological mechanisms. In the protocol used, investigators inserted sterile disposable needles into the lumbar paravertebral muscles bilaterally at levels L2 to L5, positioned approximately 2 cm laterally to the spinous processes.

In addition, a third line of needles was inserted into the interspinous spaces from L1–L2 to L4–L5, affecting the supraspinous and interspinous ligaments. Deep insertion technique was used, reaching skin, muscle fascia, ligaments, and muscles, including the multifidus, longissimus lumborum, erector spinae, and iliocostalis lumborum. Results demonstrated significant improvements in two main measures. First, pain tolerance, measured by pressure algometry, increased significantly in the intervention group from 4.87 kg/cm² to 6.52 kg/cm² after treatment.

This increase in pressure tolerance suggests reduced central sensitization and possible release of myofascial trigger points in the lumbar region. Second, during functional balance assessment via mediolateral sway on force platforms, the treated group showed significant improvement in movement quality, with the percentage of signal at the dominant frequency increasing from 43.2% to 54.9%. This change indicates a more controlled and rhythmic movement pattern, suggesting better muscle coordination after treatment. The clinical implications of these findings, in the international context of the study, are relevant for physical therapists and physicians treating patients with low back pain.

Dry needling proved to be an effective intervention for immediate pain relief and improved motor control, and may be incorporated as an adjunctive treatment in conservative management of subacute low back pain. Improvement in functional balance is particularly important, as balance deficits are associated with increased fall risk and functional limitations in daily activities. However, the study has important limitations. The small sample size (n=25) limits generalization of the results.

The evaluation focused only on immediate effects, providing no information about durability of benefits. The absence of a sham-needling placebo group prevents conclusions about specific versus nonspecific effects of the intervention. In addition, balance evaluation considered only center of pressure and ground reaction force, without trunk kinematic analysis. Future research should investigate long-term effects, use larger samples, include adequate placebo groups, and assess specific functional activities of daily living for a better understanding of the full clinical impact of this promising intervention.