由于这样他不能长时间保持一个姿势，不久就会变换姿势。

For then he will not be able to hold any one position long, but will soon want to change it.

youdao

那时候他会一并克服苦受和不能保持一个姿势很长时间的烦恼以及觉得观智还不够清楚的想法。

Then he will overcome the painful feelings and the restlessness in being unable to remain long in one particular posture, and also the idea that his insight knowledge is not yet clear enough.

youdao

然后你就不能舒适地保持拇指朝下的姿势了，因为那样会造成肩部紧张。

Then you can't keep your thumb(s) down comfortably, it tenses up your shoulders. ) Q9 b.

youdao