Manual Therapy Dosage Factorial Study

This study will determine biological responses to different dosages of neck mobilization intervention in patients, providing opportunities to identify the optimal dosage, predictors of response, outcome measures as well as the longitudinal changes in biology.

Subjects with acute whiplash associated disorders (WAD) II and III with a symptom duration of less than 30 days (acute) or 30 to 90 days (subacute) will be randomly assigned to receive different doses of mobilization. The dosage treatment groups will differ in the number of sessions (1, 2 or 3 times per week) and the duration of treatment (duration of treatment intervention will be 3, 6, or 12 weeks). A zero treatment/week option is included to insure that the impact of any mobilization is included and because previous studies suggest a single mobilization may have a treatment effect.

All patient participants will receive a core standard treatment of education, advice to stay active, and neck/postural stretching and strengthening exercise. All patient participants will receive supervised exercise and advice for the full 12 weeks. All patients will be provided with an instructional CD and exercise brochure to reinforce the whole program.

Follow-up assessments will consist of quantitative sensory testing (vibration threshold; current perception threshold), the Neck Walk Index (NWI), the Upper Cyclical Reach and Grasp Task, muscle biology analyses (cytokine analyses), central breathing control tests (capnography), range of motion, head flexion endurance, and self-report symptoms and disability (Visual Analogue Scale; Neck Disability Index; Disabilities of the Arm, Shoulder, Hand; pain threshold and tolerance algometry; and perceived self-efficacy; SF-36).

Hypothesis: During recovery, patient are expected to transition from an acute painful state to one where they can resume normal activity and add intensive strengthening exercises.