Manual and instrument applied cervical manipulation for mechanical neck pain: a randomized controlled trial

Objective The purpose of this study was to compare the effects of 2 different cervical manipulation techniques for mechanical neck pain (MNP). Methods Participants with MNP of at least 1 month's duration (n = 65) were randomly allocated to 3 groups: (1) stretching (control), (2) stretching plus manually applied manipulation (MAM), and (3) stretching plus instrument-applied manipulation (IAM). MAM consisted of a single high-velocity, low-amplitude cervical chiropractic manipulation, whereas IAM involved the application of a single cervical manipulation using an (Activator IV) adjusting instrument. Preintervention and postintervention measurements were taken of all outcomes measures. Pain was the primary outcome and was measured using visual analogue scale and pressure pain thresholds. Secondary outcomes included cervical range of motion, hand grip-strength, and wrist blood pressure. Follow-up subjective pain scores were obtained via telephone text message 7 days postintervention. Results Subjective pain scores decreased at 7-day follow-up in the MAM group compared with control (P = 0.015). Cervical rotation bilaterally (ipsilateral: P = 0.002; contralateral: P = 0.015) and lateral flexion on the contralateral side to manipulation (P = 0.001) increased following MAM. Hand grip-strength on the contralateral side to manipulation (P = 0.013) increased following IAM. No moderate or severe adverse events were reported. Mild adverse events were reported on 6 occasions (control, 4; MAM, 1; IAM, 1). Conclusion This study demonstrates that a single cervical manipulation is capable of producing immediate and short-term benefits for MNP. The study also demonstrates that not all manipulative techniques have the same effect and that the differences may be mediated by neurological or biomechanical factors inherent to each technique.