There is swaddling, and then there is swaddling.  regular swaddling
recreates for the baby the conditions of the womb -- held firmly, not likely
to flail arms and legs about and trigger the startle (Moro) reflex, so can
be very comforting.  Overly-tight swaddling, or leaving babies tied up for
hours so they can't move *is* part of some traditional cultures -- I have a
newspaper article in my office from several years ago about Chinese rural
peasant farming families who leave their newborns "swaddled" in a sack of
sand in the house all day, with just their heads sticking out.  That way the
kids can't get into any trouble or come to any harm, and the sand absorbs
urine and feces.  They do show motor development delays . . . . .
Cradleboards and tightly-swaddled cribs/swings serve the same function,
keeping the child from moving around and hurting themselves.

Kathy D.