292. Bowing After Shemoneh Esrei

Tefillah u’Birkas Kohanim 5:11

One takes his leave from the left side first because, if we’re “facing” God, then our left is His right. This is what one would do when departing an earthly king: one would take his leave from the king’s right and then from his left. Therefore the Sages instituted that we withdraw from Shemoneh Esrei the same way that we withdraw from before a king.

Tefillah u’Birkas Kohanim 5:12

For all these bows, one must bend until the vertebrae in his spine protrude and he makes himself an arch. However, if bowing causes one pain so he just does his best and only bows a little, then he need not be concerned.