Abstract text (incl. figure legends and references)

Objective: To assess if subjects who develop headache shortly after a whiplash injury show less range of motion on the flexion-rotation test (FRT) than those who do not develop headache

Methods: A case-control study was conducted on patients between 18-65 years old diagnosed with whiplash associated disorders (WAD) grade II according to the Quebec Task Force. Patients were excluded if they had previous headache prior to the whiplash injury, were evaluated more than 30 days after the whiplash injury and/or who had a serious disease or congenital condition. Range of motion (º) on the FRT was evaluated bilaterally in consecutively recruited patients. The evaluator was blinded to the headache status.

Results: 41 patients were included in this study, 22 and 19 with and without headache, respectively. Baseline differences between groups were found only in relation to sex; there were more women in the group with headache (73.7% vs 50% in the non-headache group). Statistical analysis revealed that range of motion (º) on the FRT was significantly reduced in patients with headache on both the left (mean±SD: 28,98±7,76 vs 35,29±4,92; p=0,002) and right side (29,73±7,7 vs 36,84±4,05; p<0,001) when compared to the non-headache group.

Conclusion:

A decreased range of motion was observed on the FRT in patients who have developed headache shortly after a whiplash injury when compared to those patients who did not develop headache. These findings suggest that the upper cervical structures may be involved in the presence of headache in patients with acute WAD.