The One for All obtained from Deku does not exclusively contain the strength of All Might. If the previous owner made this muscle power his pillar, this does not apply to Deku. The protagonist of My Hero Academy In fact, he was in a special position where he inherited all the quirks of the previous owners.
Step by step he unlocked them all and came into contact with the residual will of the various owners of the One for All. During the brief time skip before the My Hero Academia war, the young hero was able to learn how to use quirks as well as leftovers, especially the first owner. The last unlined was that of the second owner, Transmission, who allows Deku to literally change gears or gear.
During the gear change, a Japanese onomatopoeia appears in the manga My Hero Academia, the meaning of which is of course not understood by everyone. Author Kohei Horikoshi reflects on this in a note inserted in Volume 37 of My Hero Academia, which has just been released in Japan. The "Kachak" that comes when Deku shifts gears is lo The same sound as when shifting gears in the car. In fact, the meaning of quirk is just that.
There have been several enthusiasts who have speculated about the sound and meaning of this deku power. But now there is also the certainty that the author gives. Surely, however, Midoriya will have to deal with the side effects of the last One for All quirk, which, especially during the last war, don't seem to be easy to endure in the long run.