Reliability of manual examination and frequency of symptomatic cervical motion segment dysfunction in cervicogenic headache.

This study investigated the reliability of manual examination procedures and the frequency that each or multiple segments in the upper cervical spine above the C4 vertebra were the dominant source of pain in subjects with cervicogenic headache (CGH). Eighty subjects were evaluated, 60 with CGH (39 females, mean age 33 years) and arbitrarily a further 20 asymptomatic subjects (13 females, mean age 34 years) included to reduce examiner bias, but subsequently omitted from data analysis. Two experienced physiotherapists examined on the same day each subject with standard manual examination procedures, independently rating each segment in the upper cervical spine above the C4 vertebra for involvement. Examiners were blind to each other's findings and the subject's clinical status. Standard and adjusted Kappa coefficients were calculated for each segment in symptomatic subjects only. Chi-squared analysis for goodness of fit was used to identify the segment that was most frequently determined the predominant symptomatic segment. Manual examination above the C4 vertebra showed good reliability. The C1/2 segment was most commonly symptomatic, with a positive finding at this segment in 63% of cases. The high frequency of C1/2 involvement in CGH highlights the importance of examination and treatment procedures for this motion segment.