Purpose: To ascertain the ranges ofintervertebral motion of normal anddegenerative cervical vertebrae and evaluatethe relationship between the abnormality of thenormal cervical curvature and the pathogenesisof cervical spondylotic myelopathy (CSM).Methods: Flexion-extension latera view of thecervical spine was performed in 39 normalchildren of 13 and 14 year-old, 27 cases ofCSM, and 29 cases of normal adults to be usedas controls. The range of motion of the