Table 2.

Physical pathology leading to exclusion

	Treatment group	Healthy controls
Inclusion	● Chronic (> 6 months, < 5) neck problems ● WAD grades II-III [59] verified by clinical examination ● Average neck pain ≥ 2/10 on the Visual Analogue Scale (VAS) [60] last week prior to examination ● ≥20% neck disability on the Neck Disability Index (NDI) [41] ● of working age (18– 63 years) ● within daily reach of a computer/tablet/smartphone and Internet ● shown to have exhibited neck symptoms within the first week following the injury (i.e., neck pain, neck stiffness, or cervical radiculopathy) ● righthanded in addition to experiencing either equal-sided or dominant right-sided pain	● age and gender matched ● healthy individuals ● without neck pain or disability (VAS < 10 mm, NDI < 5%) ● without known diseases
Exclusion	● exhibiting signs of head injury* at the time of WAD injury ● previous fractures or dislocation of the cervical spine ● considerable degree of known/suspected physical pathology** ● severe neck problems within their medical history which resulted in sick leave for more than a month in the year before the current whiplash injury ● generalized or more overwhelming pain occurring elsewhere in the body presently ● other illness/injury that may prevent full participation from being feasible ● lack of ability to either understand or write Swedish ● increased risk of bleeding ● severe obesity (body mass index; BMI > 35) ● contraindications of MRI [48]	● earlier neck injury ● recurrent neck pain ● earlier treatment for neck pain ● increased risk of bleeding ● BMI > 35 ● contraindications of MRI [48]

*Signs of head injury: amnesia before or after injury, loss of consciousness, altered mental status (e.g., confusion, disorientation), focal neurological changes (changes in perceptions of smell and taste)

**known or suspected physical pathology included: myelopathy, spinal tumours, spinal infection, ongoing malignancy, cervical spine surgery