Effectiveness of Electrical Dry Needling for Lower Extremity Pain Disorders

Abstract

Study Design: Randomized, single-blinded, multi-center, parallel-group trial. Background: Manual therapy, exercise and acupuncture have been found to be moderately effective for knee osteoathrtitis (OA) when applied in isolation. No study has previously investigated the effectiveness of the combination of electrical dry needling in addition to manual therapy and exercise in patients with knee OA. Similarly, the isolated application of electrical dry needling, manual therapy, exercise, and ultrasound has been found to be effective for plantar fasciitis (PF). However, no study has investigated the combined effect of these interventions in patients with PF. Objectives: 1, To compare the effects of adding electrical dry needling into a manual therapy and exercise program on pain, stiffness, function, and disability in individuals with painful knee OA; 2, To compare the effects of adding electrical dry needling into a program of manual therapy, exercise and ultrasound on pain, function and related-disability in individuals with PF. Methods: For study 1, two hundred and forty-two participants (n=242) with painful knee OA were randomized to receive electrical dry needling, manual therapy and exercise (dry needling group, n=121) or manual therapy and exercise (non-dry needling group, n=121). The primary outcome was the related-disability as assessed by the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index at 3 months. Secondary outcomes were knee pain intensity as measured by the Numeric Pain Rating Scale (NPRS), WOMAC subscales (pain: WOMAC-P; stiffness: WOMAC-S; and physical function: WOMAC-PF) medication intake, and the Global Rating of Change (GROC). The treatment period was 6 weeks with follow-up assessments at 2 weeks, 6 weeks, and 3 months after the first treatment session. Both groups received between 8-10 sessions of manual therapy (passive joint mobilizations and muscle stretching) and exercise (riding a stationary bicycle, range of motion and strengthening exercises to the lower extremity). In addition, the dry needling group also received electrical dry needling using a standardized 9-point protocol for 30 minutes on each treatment session. For study 2, 111 patients with PF were randomized to receive electrical dry needling, manual therapy, exercise and ultrasound (n=58) or manual therapy, exercise and ultrasound (n=53). The primary outcome was first-step pain in the morning as measured by the Numeric Pain Rating Scale (NPRS). Secondary outcomes included resting foot pain (NPRS), pain during activity (NPRS), the Lower Extremity Functional Scale (LEFS), the Foot Functional Index (FFI), medication intake, and the Global Rating of Change (GROC). The treatment period was 4 weeks with follow-up assessments at 1 week, 4 weeks, and 3 months after the first treatment session. Both groups received 6 sessions of impairment-based manual therapy directed to the lower limb, self-stretching of the plantar fascia and the Achilles tendon, strengthening exercises for the intrinsic muscles of the foot, and therapeutic ultrasound. In addition, the dry needling group also recieved 6 sessions of electrical dry needling using a standardized 8-point protocol for 20 minutes. The primary aims were examined with a 2-way mixed-model ANCOVA with group as the between-subjects variable and time as the within-subjects variable after adjusting for baseline outcomes. Results: For study 1, the analysis revealed that individuals receiving the combination of electrical dry needling, manual therapy and exercise experienced significantly greater improvements in related-disability (WOMAC: F=35.504; P<0.001) than those receiving manual therapy and exercise alone at 6 weeks and 3 months. The dry needling group also experienced greater improvements in all the secondary outcomes (knee pain intensity: F=29.094, P<0.001; WOMAC-P: F=30.13, P<0.001; WOMAC-S: F=39.665, P<0.001, WOMAC-PF: F=30.114; P<0.001). In addition, patients receiving electrical dry needling were 1.7 times more likely to have completely stopped taking medication for their pain at 3 months than individuals receiving manual therapy and exercise (OR: 1.6; 95%CI: 1.24-2.01; P=0.001). Based on the cutoff score of +5 on the GROC, significantly (X2=14.887; P<0.001) more patients (n= 91, 75%) within the electrical dry needling group achieved a successful outcome compared to the manual therapy and exercise group (n=22, 18%) at 3 months follow-up. Effect sizes were large (SMD>0.82) for all outcome measures in favor of the electrical dry needling group at 3 months. For study 2, the 2X4 ANCOVA revealed that individuals with PF receiving the combination of electrical dry needling, manual therapy, exercise and ultrasound experienced significantly greater improvements in first-step morning pain (F=22.021; P<0.001), resting foot pain (F=23.931; P<0.001), pain during activity (F=7.629; P=0.007), LEFS (F=13.081; P<0.001), FFI Pain Subscale (F=13.547; P<0.001), FFI Disability Subscale (F=8.746; P=0.004), and FFI Total Score (F=10.65; P<0.001) than those who received manual therapy, exercise and ultrasound at 3 months No differences in FFI Activity Limitation Subscale (F=2.687; P=0.104) were observed. Patients in the electrical dry needling group were 1.2 times more likely than patients receiving manual therapy, exercise and ultrasound to have completely stopped taking medication for their pain at 3 months (OR: 1.22; 95%CI: 1.02-1.51; P=0.01). Based on the cutoff score of ≥+5 on the GROC, significantly (X2=45.582; P<0.001) more patients within the electrical dry needling group (n=45, 78%) achieved a successful outcome compared to the manual therapy, exercise and ultrasound group (n=11, 21%). Effect sizes were medium to large (0.53<SMD<0.85) at 3 months in favor of the electrical dry needling group. Conclusions: The inclusion of electrical dry needling into a manual therapy and exercise program was more effective for improving pain, function and related-disability than the application of manual therapy and exercise alone in individuals with painful knee OA at mid-term (3 months). Similarly, the inclusion of electrical dry needling into a program of manual therapy, exercise and ultrasound was more effective for improving pain, function and related-disability than the application of manual therapy, exercise and ultrasound alone in individuals with PF at mid-term (3 months).