Immediate clinical and neuromechanical effects of cervical spine manipulation compared to cervical spine mobilization among individuals with chronic neck pain: a randomized mechanistic cross-over trial.

The short version

This randomized mechanistic cross-over trial with 89 adults explored how two hands-on neck treatments differ right after they are delivered. Chronic neck pain, defined here as pain lasting at least 12 weeks, is one of the leading causes of disability worldwide. Spinal manipulation (SM) is a single quick, shallow thrust applied to a joint, and spinal mobilization (Smob) is a slower, repeated rocking pressure on the same area. Both are recommended in clinical guidelines, but they are often lumped together, so little was known about how their effects on pain, movement and muscle activity compare. Participants were aged 18 to 65, with an average of 35 years, and 65% were women. They were recruited in Zurich, Switzerland, and Trois-Rivieres, Canada. Each person attended two sessions three days apart, receiving SM in one and Smob in the other in random order. SM was one thrust to the most painful neck joint while lying face up, and Smob was 30 seconds of repeated pressure on the same level while lying face down. Pain was rated from 0 to 10, and neck movement, tenderness to pressure, grip strength and muscle electrical activity were measured before and after. Pain dropped by 0.79 points after SM and 0.37 points after Smob, a gap of 0.41 points (p = 0.002), which stayed below the 1.3 points considered clinically meaningful. Neck movement improved after both treatments, by about 4.6 degrees after SM and 3.7 degrees after Smob in bending forward and back, with no difference between them. Neck muscles responded more strongly during SM, with activity in the sternocleidomastoid about six times higher (0.144 versus 0.023). Tenderness and grip strength changed inconsistently, and the grip decrease of 1.13 kg was far under the 6 kg detectable change. Participants' own global impression of change favored SM (p < 0.001) but also stayed below the clinical threshold. Upper trapezius activity was likewise higher during SM (0.083 versus 0.024). No serious adverse events were reported. The authors state that statistically significant differences did not reach clinical significance, so the trial cannot support conclusions about which treatment works better in practice. Only immediate effects after one session were measured, many outcomes were tested, participants could tell the treatments apart, and baseline disability was mostly mild to moderate. Clinician training also differed between sites. The authors propose that future trials examine several sessions of each treatment, since a multi-session or combined approach may reach clinical relevance.

Key findings

• This trial of 89 adults with chronic neck pain (pain lasting at least 12 weeks) compared spinal manipulation (one quick thrust to a neck joint) with spinal mobilization (30 seconds of slower, repeated pressure) in a cross-over design, meaning every participant received both treatments three days apart.
• Pain fell by 0.79 points after manipulation and 0.37 points after mobilization on a 0 to 10 scale (p = 0.002 for the difference), but neither change reached the 1.3-point minimum considered clinically meaningful.
• Neck movement improved after both treatments by a similar amount (for example 4.6 vs 3.7 degrees in forward and backward bending), while neck muscle electrical activity (measured with electromyography, EMG) was clearly higher during manipulation than mobilization.
• Tenderness-to-pressure and grip-strength results were inconsistent or tiny, no serious adverse events occurred, and the authors describe the study as mechanistic, so they draw no conclusion about which treatment works better in clinical practice.

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