Prisoners were almost always transported on foot.  If speed was necessary, the prisoner generally was killed.  It the owner of the prisoner insisted, and a horse could be found, the prisoner rode.

In this case, however, he is afoot and bound in a time proven way.  His wrists are tied in front with a fresh cut staff passing between elbows and torso.|

His clothing has long since been distributed to his captors, and barefoot, he joins the procession to the victors village.

Should he find a breech in the security and decide to ‘make a break’, the staff across his back may make him think twice.

The staff accomplishes two things.  One, the pressure against his back is uncomfortable.  It always lets him know he is a captive.  Secondly, he can not run full out because the ends of the stick will catch in the brush and rocks and throw him down.   He must run sideways or very carefully choose his path.  His captors would choose a supple live branch, like a willow to bind him .  The staff bends but does not break, so it is always there. He is a prisoner of the willow.