also: hinge · hinge back
Sealing the space a pulling lineman just left, usually by the tackle stepping down and turning back. The block that stops a pull from opening a hole in your own protection.
When a lineman pulls, he leaves a gap where he was standing. Hinging is one way to protect that space: the lineman next to the puller steps down and turns back, swinging like a gate on a hinge. The block keeps backside penetration from following the puller into the play.
hingedown block, seal and wall off