It will help the stroke if you can make you bodylift and drop, it is called undulation.
如果你能使你的身体上来下去的话，将有助于你的划动。
2
Two legs to continue into the bodylift on state body gravity fall, stand on his head on his shoulders, legs, two feet as far as possible unbend wearing tight slippers.
两腿继续上举成身体倒立状态，身体重心落在肩上，两腿尽可能伸直，两脚穿紧拖鞋。
3
As you become more proficient and comfortable in the pose, learn to lift and lighten the body by actively grounding the crown of the head onto the floor.