You can get the Strength HM from a blue-haired character in Nimbasa City in the building directly to the North of the Battle Institute.
furret
You get it from a house in Nimbasa City.
You get strength in Nimbasa City in the top left building.
Strength can be found in the Top Left Building in Nimbasa.
in nimbasa city in a house near the pokemon center.
in nimbasa at one of the buildings, you see an ace trainer. he will give you strength.
In Nimbasa City to the top left of the Pokemon Center there is a house with a blue haired kid in it. Talk to him for Strength.
HM04-Strength
If you want strength than white cool Pokemon than black
In the topmost floor of Mistralton cave (bring Pokemon that know Flash and Strength)
HM04 Strength is found in Nimbasa City in the top-left building.
teach it to a pokemon in ur party that it's compatible with. Then go back to ur pkmn party and select the pokemon (ie drilbur) and it should say strength