This is a jutsu in which the user focuses precise chakra control into their hands or feet to enhance their strength. Tsunade created the concept of this jutsu to intimidate enemies and keep them at bay while she heals injured ninja. This jutsu is a very practical, offensive technique for medical ninja because it is very intimidating and very effective in eliminating enemies so the medical-nin can return to their primary task of healing the injured as soon as possible.
The training for this technique is arduous. Tsunade repeatedly came at Sakura with full power to help her learn. Naruto realizes that he should stop playing around when he sees Sakura perform Cherry Blossom Impact, because he realizes she could kill him. Another technique utilizing this is Tsunade's Painful Sky Leg.