After informed consent patients in age 18-63 years of age with WAD II-III with more than 6 months duration will be randomized to one out of the three alternatives of physiotherapy, treatment with medical exercise therapy with neck specific exercises (A),treatment with a behavioral approach combined with neck specific exercises (B), prescribed physical activity (C). Randomisation will be done by the central project leader. 200 patients will be included in the study. All physiotherapists engaged in the structured and well described treatment will be introduced in the program by the project leader. The measurements with good clinometric properties will be performed before treatment, after 12 weeks, 6, 12 and 24 months after inclusion into the study. Clinical measurements will be performed by a blinded investigator. Background data, disease-specific and generic data will be measured by self-evaluated answered questionnaires by the patients. Days of sick-leave will be collected from the Social Insurance Agency. Main outcomes of the measurements are pain intensity, neck specific disability and return to work. Cost-effectiveness will be calculated.