I use to use my hands a lot when I talked because for some reason I was able to keep a rhythm and stay fluent. However, a professor of mine who also stutters told me that hand motions is a secondary behavior and secondary behaviors are only temporary solutions. I tried speaking without hand movement and I stutter more than I ever did. I told him why is it bad if normal people still use their hands to talk, he then said that it really depends on the person and if it helps you then keep using it lol. I use my hands still but not often as I use to lol.