Objective: The aim of this study was to investigate the clinical effects of low-level laser therapy (LLLT) in patients with acute low back pain (LBP) with radiculopathy.
Background Data: Acute LBP with radiculopathy is associated with pain and disability and the important pathogenic role of inflammation. LLLT has shown significant anti-inflammatory effects in many studies.
Materials and Methods: A randomized, double-blind, placebo-controlled trial was performed on 546 patients. Group A (182 patients) was treated with nimesulide 200 mg/day and additionally with active LLLT; group B (182 patients) was treated only with nimesulide; and group C (182 patients) was treated with nimesulide and placebo LLLT. LLLT was applied behind the involved spine segment using a stationary skin-contact method. Patients were treated 5 times weekly, for a total of 15 treatments, with the following parameters: wavelength 904 nm; frequency 5000 Hz; 100-mW average diode power; power density of 20 mW/cm(2) and dose of 3 J/cm(2); treatment time 150 sec at whole doses of 12 J/cm(2). The outcomes were pain intensity measured with a visual analog scale (VAS); lumbar movement, with a modified Schober test; pain disability, with Oswestry disability score; and quality of life, with a 12-item short-form health survey questionnaire (SF-12). Subjects were evaluated before and after treatment. Statistical analyses were done with SPSS 11.5.
Results: Statistically significant differences were found in all outcomes measured (p < 0.001), but were larger in group A than in B (p < 0.0005) and C (p < 0.0005). The results in group C were better than in group B (p < 0.0005).
Conclusions: The results of this study show better improvement in acute LBP treated with LLLT used as additional therapy.
It has been suggested that laser therapy may act by stimulating ligament repair (Reddy et al 1998), by anti-inflammatory effects (Sakurai et al 2000, Bjordal and Baxter 2006), and/or by reducing interstitial swelling by stimulating the motoricity of lymphatics (Carati et al 2003, Kaviani et al 2006). There is also in vivo and in vitro evidence that 830 nm laser inhibits AÃ¤ and C fibre transmission (Tsuchiya et al 1993, Tsuchiya et al 1994). It is possible that laser-induced neural blockade may then lead to long-term altered nociception, analogous to the prolonged analgesia seen in some patients with local anaesthetics (Arner et al 1990). The repeated application of laser may reduce tonic peripheral nociceptive afferent input to the dorsal horn and facilitate reorganisation of synaptic connections in the central nervous system producing pain modulation (Coderre et al 1993, Mense 1993).
Low level laser therapy may also be an effective adjunctive or alternative treatment for chronic low back pain with avoidance of systemic drug use (Basford et al 1999, Gur et al 2003). Because of the significant placebo response rate in clinical trials, non pharmacologic treatments require careful investigation to ascertain effectiveness. However, even though laser therapy is available in many clinics, it has not yet received FDA approval and the efficacy of laser therapy is controversial. Limitations of previous human studies and the application of an inadequate dose in our own previous studies lead us to choose a higher dose. In addition, we were interested in laser therapy as an adjuvant therapy to a conventional modality. The specific research questions for this study were:
1. In chronic low back pain, is low level laser therapy more effective than placebo-laser therapy plus exercise at decreasing pain, increasing lumbar range of motion, and reducing disability? 2. In chronic low back pain, is low level laser therapy plus exercise more effective than placebo-laser therapy plus exercise at decreasing pain, increasing lumbar range of motion, and reducing disability?