Whichever approach you take, move the shinbone just enough to straighten the knee so that it no longer curves back, but not so much that the knee bends forward.

• 不管你用哪种方式，移动小腿骨恰到好处地伸直膝盖，不再让膝关节往后弯，但也不要太高以免膝关节向前弯。