Gear 4th ~upd~ Direct

The standard Bounceman form (used against Doflamingo and Katakuri initially) prioritizes surface area for rebound. By inflating his arms to several times their normal diameter, Luffy creates a high restitution coefficient (e). When striking an enemy, the compressed air absorbs the impact's reactive force, stores it as potential energy, and releases it upon rebound.

: Biting his forearm and blowing air directly into his muscular structure. gear 4th

The Biomechanics of Inflation: A Tactical and Symbolic Analysis of Monkey D. Luffy’s Gear Fourth The standard Bounceman form (used against Doflamingo and

: A defensive version used against Charlotte Cracker, specifically the "Manpuku Version" after Luffy ate massive amounts of biscuits to increase his size and bounce. stores it as potential energy