In today's generation it is common knowledge that the right side of the human brain controls the left side of the body and vice versa. This switch from right brain to left body is called in neuro- physiology, the decussation (crossing over - X) of the medullary pyramidal tract through the brain stem. Ariz”al says clearly that the right strap of tefillin head straps is shorter than the left strap. But look at your tefillin. On your chest the right strap is longer, the opposite of the Ari"zal's order. This is because the left and right straps on the head that originate from the bayit (with the parshiot inside) switch sides at the complicated knot behind your head. The switch occurs only in tefillin using the shita of German Ashkenazi Yekkies, a single knot. The double knot of the Russian style does not switch. The Tefillin shel Rosh knot is placed under the occipital process on the back of the skull at the exact same location where the brain stem switches sides. Everyone I've told this discovery to says that this is interesting, but no one has any suggestion of what to do with it. Hyam Yona Becker

In today's generation it is common knowledge that the right side of the human brain controls the left side of the body and vice versa. This switch from right brain to left body is called in neuro- physiology, the decussation (crossing over - X) of the medullary pyramidal tract through the brain stem. Ariz”al says clearly that the right strap of tefillin head straps is shorter than the left strap. But look at your tefillin. On your chest the right strap is longer, the opposite of the Ari"zal's order. This is because the left and right straps on the head that originate from the bayit (with the parshiot inside) switch sides at the complicated knot behind your head. The switch occurs only in tefillin using the shita of German Ashkenazi Yekkies, a single knot. The double knot of the Russian style does not switch. The Tefillin shel Rosh knot is placed under the occipital process on the back of the skull at the exact same location where the brain stem switches sides. Everyone I've told this discovery to says that this is interesting, but no one has any suggestion of what to do with it. Hyam Yona Becker

In today's generation it is common knowledge that the right side of the human brain controls the left side of the body and vice versa. This switch from right brain to left body is called in neuro- physiology, the decussation (crossing over - X) of the medullary pyramidal tract through the brain stem. Ariz”al says clearly that the right strap of tefillin head straps is shorter than the left strap. But look at your tefillin. On your chest the right strap is longer, the opposite of the Ari"zal's order. This is because the left and right straps on the head that originate from the bayit (with the parshiot inside) switch sides at the complicated knot behind your head. The switch occurs only in tefillin using the shita of German Ashkenazi Yekkies, a single knot. The double knot of the Russian style does not switch. The Tefillin shel Rosh knot is placed under the occipital process on the back of the skull at the exact same location where the brain stem switches sides. Everyone I've told this discovery to says that this is interesting, but no one has any suggestion of what to do with it. Hyam Yona Becker