英语语法分析

Pain around and sometimes behind the kneecap.

膝盖周围疼痛，有时候在膝盖后面。

Roll the leg inward until the kneecap faces the other leg.

卷腿膝盖向内，直至面临另一方面，另一条腿。

Don't push your knee itself back, even though you are drawing your kneecap inward.

不要推你的膝关节自己回来，即使你正在拉你的膝盖向内。