Methods.From 442 lateral cerical radiographs, 40 with lordotic, 40 with straight or sigmoid, and 40 with kyphotic alignment were selected.

• 方法：本研究选择442例颈椎侧位片，其中挑选了40例颈椎前凸，40例曲度变直或成S型，40例曲度侧后凸。