The effect of three different cooling gels on acute non-specific low back pain

Abstract

Background: Cryotherapy is often the first option in treating acute conditions and can be applied in various forms including ice packs and cooling gels. Cooling gels are easy to use and readily available making them popular with consumers. They can also contain additional ingredients which can assist with inflammation, making them ideal for musculoskeletal disorders. A cooling gel containing menthol and anti-inflammatory herbs is available in pharmacies nationwide in South Africa, but has not been clinically investigated. This gel is often used in the treatment of acute injuries such as low back pain but its effectiveness in treating this condition has not yet been verified. Objectives: To determine the effectiveness of a menthol cooling gel combined with anti-inflammatory herbs compared to a menthol gel and a placebo gel in the treatment of acute non-specific low back pain. Method: A double-blinded placebo controlled clinical trial (n = 60) was conducted. Each participant was randomly allocated into one of three treatment groups consisting of a minimum of 20 participants between the ages of 18 and 40 who met the study criteria. Informed consent was obtained from the participants prior to their participation in the study. At the initial consultation baseline measurements (pain rating, disability and pressure pain threshold) were taken and the respective treatments (menthol with anti-inflammatory herb, menthol or placebo gel) were administered. Participants were instructed on how to apply the gel at home and were requested to apply it three times a day for one week. Statistical analysis was performed using repeated measures ANOVA for inter- and intra-group analysis with one way ANOVA and chi square tests being used to compare baseline values. A p-value < 0.05 was considered to be statistically significant. The study received ethical clearance from the Durban University of Technology Institutional Research Ethics Committee (REC 81/13). Results: No significant differences were observed between the groups at baseline assessment, indicating that the groups were comparable. Participants were instructed on how to apply the gel at home and were requested to apply it three times a day for one week. Follow up appointments for data collection was scheduled at days three or four and six. No statistically significant differences were observed between the three groups over time for pain (p = 0.95), disability (p = 0.903) or pressure-pain threshold (p = 0.824), with all groups showing improvement. All three groups showed clinically significant changes in pain from moderate to mild over the duration of the study but no clinically significant changes were noted in terms of pressure-pain threshold and disability. Conclusion: The results indicate that irrespective of whether or not the gel contains active ingredients there was an improvement in acute low back pain. Further research needs to be conducted to determine if tissue depth and the concentration of the active ingredients such as menthol are factors affecting the efficacy of this gel.