An ankle brace received by a footwear boot prevents extension or flexion of the foot while walking. The ankle brace includes a pair of side trusses joined at the top by a shin band and at the bottom by a metatarsal band. When placed on the boot the shin band extends over and across a lower front portion of the shin bone, the metatarsal band extends over the toes and lower foot, and the pair of trusses extend along the inside and outside in a parallel manner from the front of the foot to the ankle and up to the lower shin. A heel strap and heel cup attached to the pair of trusses extends around and receives the back of the boot, retaining the brace in place against the boot.
