This article says “…it is not entirely clear…”, yet the Dual Coding/Channel theory (see Paivio) explains why incorporating other senses (like movement) into learning not only makes it easier but allows for more neural links to be formed in the brain. Article is here: https://ww2.kqed.org/mindshift/2017/10/25/how-seeing-and-using-gestures-make-ideas-more-memorable/