Differences in physical examination findings between those who present with or without headache soon after a whiplash injury: a cross-sectional study.

To determine differences in physical examination findings between people with acute whiplash-associated disorders (WAD) with and without headache. In this cross-sectional study, participants with acute WAD were evaluated to assess differences in the presence of physical impairments. The following were assessed: pain intensity on manual palpation the over spinous process of C1-C3, zygapophyseal joints of C0-C4, and trapezius, sternocleidomastoid, suboccipitalis, masseter and temporalis muscles; cervical range of motion (ROM); flexion-rotation test (FRT); forward head posture; cranio-cervical flexion test (CCFT); neck flexor and extensor endurance; pressure-pain thresholds (PPT) over neural structures and upper limb neural tests (ULNT) in addition to median UNLT + CCF. Correlation analyses were performed to assess the association between examination findings and headache intensity. Logistic regression and discriminant analyses were also performed. Forty-seven participants (26 men and 21 women; mean age = 38.9 years old) were included in the study. 60% of the participants presented with headache. Several examination findings were significantly different between groups. A group of examination findings composed of neck endurance, manual palpation over cervical and muscular structures, PPT, CCFT, ROM and FRT could discriminate between groups with a sensitivity of 86.7% and specificity of 90%. Several neuromusculoskeletal features are different between people with acute WAD with or without headache. A combination of features could distinguish between groups with high levels of sensitivity and specificity.