Table 1.

Inclusion and exclusion criteria

All participants	Inclusion criteria: Male and female, Age 18 – 70 years, Able and willing to participate, No large radiological investigations or treatments in the past two years (effective dose > 10 mSv), Capable of giving informed consent, Not pregnant or likely to be pregnant, Willing for general practitioner to be informed about participation.
	Exclusion criteria: History of cervical spine surgery, Poor understanding of English, Current involvement as a subject in another research study.
Patients	Inclusion criteria: Mechanical neck pain (reproducible by neck movement/provocation tests) and no identifiable aetiology e.g. infection, inflammatory disease, Pain located within the area defined by the Neck Pain Task Force, Self-reported pain rating 3 or more on a 11-point numerical rating scale, Pain of at least 2 weeks duration, No contraindications to spinal manipulative therapy.
	Exclusion criteria: Non-mechanical neck pain, Depression history, Litigation/compensation pending, Manual therapy already received for this episode of neck pain, Primary complaint of arm pain, Traumatic onset of this neck pain episode, Central hypersensitivity as assessed by pressure algometry.
Healthy volunteers	Inclusion criteria: No activity-limiting neck pain lasting more than 24 hours in the last 12 months, No current neck pain, dizziness or vertigo (unsteadiness).
	Exclusion criteria: Cervical/thoracic spine manipulation in week prior to baseline imaging.