It is the area that sustains most pressure when using the palm of the hand for support, such as in handstand.
en.wikipedia.org The components of a freestyle vaulting routine "may" include mounts and dismounts, handstands, kneeling and standing and aerial moves such jumps, leaps and tumbling skills.
en.wikipedia.org In solo handbalancing, a single artist performs handstands, one-hand stands, planches and other equilbristic maneuvers, usually on top of pommels, blocks or other apparatuses.
en.wikipedia.org For a true handstand, the exercise is performed free-standing, held in the air.
en.wikipedia.org In the beginner version, the jumper does a handstand, comes down and then pulls the rope under.
en.wikipedia.org