You get it from a house in Nimbasa City.
furret
Strength can be found in the Top Left Building in Nimbasa.
HM04-Strength
in nimbasa city in a house near the pokemon center.
In a house on the western side of Raimon City.
the house to the top left corner of the Pokemon center in nimbasa (middle city)
The HM Strength. It can be found in Nimbasa City, in one of the houses close to the Pokemon Center. Talk to everyone, and you'll get HM Strength! Hope this helped! :)
HM04 Strength is found in Nimbasa City in the top-left building.
You need to teach strangth to at least one of your pokemon. The pokemon that knows strength must be in your party if you need to use strength. Click on the rock and answer yes when it asks if you would like to move the rock. Then just walk into the rock and it will move
The rocks do not move until you have encountered Cobalion.
Strength
By using the HM Strength.