Check out this journal article. It's all about how tefillin function in acupunctural terms. It compares the different minhagim of wrapping them and which points they impact. The points stimulated by our phylactaries* are the ones accupuncutral theory submits are relevant to clearing the mind and elevating the spirit. I wonder if there is something to this or whether the sheer number of points stimulated mean that someone could offer a compelling accupuncutral explanation for the random occurence. Does anyone know how common similar practices were among other semitic groups?
*phylactaries is a funny word. i often see it in museums. i wonder if anyone knows what phylacteries are that doesn't know the word tefillin.