Topical Menthol Gel Versus a Placebo Gel on Postmanipulation Pain and Range of Motion in Patients With Mechanical Neck Pain

Abstract

Purpose: The purpose of this study is to determine whether patients with mechanical neck pain who received topical menthol gel application to their neck before cervical manipulation experienced a reduction in pain and an increase in neck range of motion following cervical manipulation. Methods: Patients (mean age, 35 years) with nonradicular mechanical neck pain were randomly assigned to a control (n = 31) or a treatment (n = 29) group. Five minutes before cervical manipulation, controls received topical placebo gel application to their neck, whereas the treatment received topical application of a mentholcontaining gel (Biofreeze ® ). Participants rated their neck pain on a 10-point scale before application of the get (Pre) and at 1 min (T1), 10 min (T2), 20 min (T3), and 30 min (T4) after cervical manipulation. Six measures of neck range of motion were assessed before the topical applications of gel and at T1 and T4. Repeatedmeasures ANCOVA was performed to compare the pain and neck range of motion following manipulation while controlling for premeasures. Results: There were no significant differences between the groups' pain or range of motion assessed at Pre. The treatment group reported significantly (P < .05) reduced pain at T2, T3, T4 compared to T1, while the control group did not experience significant change in their pain compared to T1. Neither study group rated a change in neck range of motion during the study. Conclusion: Topical menthol application before manipulation may reduce neck pain, but it has no measurable effect on neck range of motion following cervical manipulation among patients with mechanical neck pain.Keywords: Neck pain; manipulation; topical menthol Key Points After cervical manipulation, topical menthol (Biofreeze) applied to the neck reduced post-manipulation soreness in patients with mechanical neck pain, but it did not change the cervical range of motion.