Maximal voluntary isometric neck strength deficits in adults with whiplash-associated disorders and association with pain and fear of movement.

Study Design: Controlled laboratory study using a cross-sectional, repeated-measures design.

Objectives: To quantify maximal voluntary isometric neck forces in healthy subjects and individuals with whiplash-associated disorder (WAD), using an objective measurement system to evaluate the test-retest properties of these strength measurements and to assess the links between neck strength, pain, kinesiophobia, and catastrophizing in patients with WAD.

Background: The prognosis of WAD is difficult to predict due to a lack of objective measurement methods and to our limited understanding of the role of psychological factors in the development of chronic WAD symptoms.