Consensus for the measurement of the camptocormia angle in the standing patient

INTRODUCTION: Camptocormia is characterized by a pathological forward flexion of the trunk, which is reversible when lying and worsened by standing and walking. So far there is no consensus on how to measure the angle of flexion, and studies therefore give differing results. Harmonization is needed for both research and clinical practice. Orthopedic measures are not useful for this purpose. METHODS: Two expert raters independently analyzed the photographs of 39 Parkinson patients with camptocormia while standing. They used four different methods to determine the camptocormia angle. The results were compared statistically. An international Consensus Group reviewed the results and drafted recommendations. RESULTS: The four methods yielded camptocormia angles that differed by up to 50% in the same patient. Inter-rater reliability and test-retest reliability also differed, but were satisfactory to excellent. CONCLUSION: This Consensus Group concluded that two of the methods qualified as reliable measures of the trunk angles in standing patients based on their clinimetric properties. They propose that the 'total camptocomia angle' be the angle between the line from the lateral malleolus to the L5 spinous process and the line between the L5 spinous process and the spinous process of C7. They also propose that the 'upper camptocormia angle' be the angle of the lines between the vertebral fulcrum to the spinous processes of L5 and C7, respectively. An app is provided on the web for these measurements (http://www.neurologie.uni-kiel.de/de/axial-posturale-stoerungen/camptoapp).