Word for: sideways descent down a steep slope?

When descending a steep slope composed of dirt, gravel or slippery stone, one may at some point transition from a forward walk to a slower, more careful sideways one, using (say) the outside edge of the left foot and and inside edge of the right foot to dig into the ground and provide better purchase while descending.

Is there a word for this mode of locomotion, or one which could be considered to best describe it?

Usage ex: "He _____ down the slope, picking his way around crags and boulders."

Solution 1:

I think it is possible to use "sidle down" The Free Dictionary

sidle 1. to move sideways or obliquely.

And from snippet views in Google Books:

Being There: The Parables of Jesus in a Different Voice O'Malley, William J. · 2016. He hauled the mule's reins over her head and sidled down the rockfall through the bushes.

The Forgetting Tide Mike Hoinville · 2015 ... with a kind of side stepping motion as if he had skis on, he sidled down the very steep slope

People of the Bear Mother T. D. Austin · 2012 Then to my horror, as he sidled down the sloping boulder, the Grandfather slipped on a muddy patch of clay,

(NB The approved way of descending loose ground, e.g. scree, is to go down forwards - this lessens the chances of falling and of broken ankles.)