Study design: Quasi-experimental.
Objectives: To explore for associations between demographic, patient history, and physical examination variables and short-term improvement in self-reported disability following dry needling therapy performed on individuals with low back pain (LBP).
Background: Dry needling is an intervention used with increasing frequency in patients with LBP; however, the characteristics of patients who are most likely to respond are not known.
Methods: Seventy-two volunteers with mechanical LBP participated in the study. Potential prognostic factors were collected from baseline questionnaires, patient history, and physical examination tests. Treatment consisted of dry needling to the lumbar multifidus muscles bilaterally, administered during a single treatment session. Improvement was based on percent change on the Oswestry Disability Index at 1 week. The univariate and multivariate associations between 33 potential prognostic factors and improved disability were assessed with correlation coefficients and multivariate linear regression.
Results: Increased LBP with the multifidus lift test (rpb = 0.31, P = .01) or during passive hip flexion performed with the patient supine (rpb = 0.23, P = .06), as well as positive beliefs about acupuncture/dry needling (rho = 0.22, P = .07), demonstrated univariate associations with Oswestry Disability Index improvement. Aggravation of LBP with standing (rpb = -0.27, P = .03), presence of leg pain (rpb = -0.29, P = .02), and any perception of hypermobility in the lumbar spine (rpb = -0.21, P = .09) were associated with less improvement. The multivariate model identified 2 predictors of improved disability with dry needling: pain with the multifidus lift test and no aggravation with standing (R(2) = 0.16, P = .01).
Conclusion: Increased LBP with the multifidus lift test was the strongest predictor of improved disability after dry needling, suggesting that the finding of pain during muscle contraction should be studied in future dry needling studies.
Level of evidence: Prognosis, level 1b.
Keywords: Oswestry; clinical prediction rule; lumbar spine; trigger point.