There are lots of patents for boxing gloves which contain an inflatable bladder…intended to protect the hand of the wearer and the body of the opponent.
Today’s invention however is a boxing glove with an inner liner that can be deflated.
The wearer would put the glove on and air would be removed from the liner, using a small suction pump, so that an initial fist shape could be supported by the tension in the inner skin as it ‘shrink-wraps’ the fist.
Making the liner long enough to include the wrist, would reinforce that joint too, so that traumatic bending and crushing of all the bones directly involved in punching would be avoided.
The normal boxing glove outer layer would be unaffected by this inner shrinkage.