Effectiveness of trigger point dry needling for plantar heel pain: a randomized controlled trial

BACKGROUND Plantar heel pain can be managed with dry needling of myofascial trigger points; however, there is only poor-quality evidence supporting its use. OBJECTIVE The purpose of this study was to evaluate the effectiveness of dry needling for plantar heel pain. DESIGN The study was a parallel-group, participant-blinded, randomized controlled trial. SETTING The study was conducted in a university health sciences clinic. PATIENTS Study participants were 84 patients with plantar heel pain of at least 1 month's duration. INTERVENTION Participants were randomly assigned to receive real or sham trigger point dry needling. The intervention consisted of 1 treatment per week for 6 weeks. Participants were followed for 12 weeks. MEASUREMENTS Primary outcome measures included first-step pain, as measured with a visual analog scale (VAS), and foot pain, as measured with the pain subscale of the Foot Health Status Questionnaire (FHSQ). The primary end point for predicting the effectiveness of dry needling for plantar heel pain was 6 weeks. RESULTS At the primary end point, significant effects favored real dry needling over sham dry needling for pain (adjusted mean difference: VAS first-step pain=-14.4 mm, 95% confidence interval [95% CI]=-23.5 to -5.2; FHSQ foot pain=10.0 points, 95% CI=1.0 to 19.1), although the between-group difference was lower than the minimal important difference. The number needed to treat at 6 weeks was 4 (95% CI=2 to 12). The frequency of minor transitory adverse events was significantly greater in the real dry needling group (70 real dry needling appointments [32%] compared with only 1 sham dry needling appointment [<1%]). LIMITATIONS It was not possible to blind the therapist. CONCLUSION Dry needling provided statistically significant reductions in plantar heel pain, but the magnitude of this effect should be considered against the frequency of minor transitory adverse events.