Manual therapy reduces pain, disability and oxidative stress in patients with chronic non-specific neck pain; a double-blind, randomized pilot study.

Objectives: Chronic nonspecific neck pain (CNNP) affects millions of people; nonetheless, several mechanistic details remain unknown. Oxidative stress (OS) is believed to be a contributing factor; however, its connection with manual therapy (MT), the current CNNP treatment, remains poorly investigated. Herein, the effects of low-velocity low-amplitude (LVLA) and high-velocity high-amplitude (HVLA) MT on pain relief, disability, and OS levels of CNNP patients are investigated.

Methods: The study follows a double-blind randomized pilot study design. OS is assessed using blood serum lipid hydroperoxides (LOOH). MT is assessed by using the Numeric Pain Rating Scale (NPRS) and the Neck Disability Index (NDI). Finally, the results are compared with those of patients receiving a sham intervention.

Results: Mixed ANOVA revealed that MT affects blood serum LOOH levels in CNNP patients. Pre-intervention, mean LOOH levels of CNNP patients (n = 11) were 3.3-fold higher compared to those of healthy individuals (n = 10; p-value < 0.001); whereas, following nine treatment sessions, a regression to healthy levels was documented. On the contrary, LOOH levels of patients following a sham intervention (n = 11), decreased by 0.7-fold during the first treatment session (p-value < 0.001), and remained unchanged even after the nine sessions (p-value > 0.99). Regarding NPRS, the MT group had a pre-intervention mean score of 4.91, which decreased to 1.36 after nine sessions (p-value < 0.001), whereas the sham group had a pre-intervention mean score of 5.27, which regressed to 4.64 post-intervention (p-value = 0.2208). Regarding NDI, the MT group had a pre-intervention mean score of 21.82, which decreased to 6.36 after nine sessions (p-value = 0.007). Conversely, the sham group had a pre-intervention mean score of 21.45, which increased to 25.09 post-intervention (p-value = 0.4392).

Discussion/conclusion: The results indicate that HVLA-LVLA MT causes significant decreases in pain and OS levels and improves function. Therefore, OS assessment in patients with CNNP could assist the evaluation of MT effectiveness in pain relief.