腹筋が進化しているらしい
https://i.imgur.com/0Q2FsG8.jpg
https://i.imgur.com/w34BAkP.jpg
https://i.imgur.com/vNeCFFE.jpg
https://i.imgur.com/3JoXVLZ.jpg
https://i.imgur.com/fq5jBNJ.jpg
https://i.imgur.com/K7XjrZC.jpg
https://i.imgur.com/NudgzX9.jpg