Tetanus is characterized by powerful violent muscle spasms summed up by trismus, or lockjaw, Risus sardonicus, a persistent grin, and opisthotonos, a highly arched back with patient resting on his head and heels.

破伤风的典型强有力的肌肉痉挛，记住典型三联：关紧闭、苦笑面容、角反张，即背部高耸，患者仅以头脚着地的体态。