From what I've gathered from the manga, The [Zoom Punch] involves a Hamon breathing technique that dislocates and stretches the joints to extend the arm and give it greater reach.
Because it's using The Ripple to dislocate the arm – that same Hamon energy dulls the pain caused by the move and naturally heals the dislocated arm as 'Zeppeli' later states in the manga that Hamon energy = life energy, and so its primary uses are to combat creatures such as Vampires or Zombies as well as "heal various wounds or ailments".
Because of this - I would naturally assume The Ripple would dull the pain from the recoil of the [Zoom Punch] and thus also keep the cells together in the arm and heal them.