crabbing vs. spread-out

[EquesB@aol.com]

 I came into this thread a little late. Can you tell me if "crabbing" means a
horse that travels sideways, like dog-trotting?  My horse does this when his
hooves get long and I have to slow down my speed.  I try to not let that
happen as I was sure 50 miles of "crabbing" would bring in a sore back. How
does this term relate to the horse that trots placing the right rear far-out
to the right next to the right front and so on for the left rear out to the
side next to the left front?  ( Is this clear?) They kind of look as if they
are trotting with their legs spread? Any opinions on this? Jackie Baker.