I heard that based on kabbalah, one is never to raise his hands above his head except in prayer, such as when blessing al netilas yadyaim. May one be lenient in this inyan when performing exercises, or raising one’s hand in school, or when taking something off a high shelf?
The Ben Ish Chai over there says that it is only when raising one’s hand for no reason at all. If the person has a reason for what he is doing, i.e. he had to reach for something; to do exercise, stretch etc. it is permitted. As a side point this is only if someone is going to be makpid on ding kabalah things.
Ben Ish Chai Toldos 4, Zohar, In the beginning of Yisro