Why can't i equip some armor?

[Ozz14]

I have the necessary experience, but when i scroll over it in my inventory it says in red "You cannot use this item!" and i spawn bare-chested. Why cant i use this armor and how do i remedy it?

[Tears of Destiny]

The requirements for armor are based on Strength not level.

difficulty: This is the minimum Strength that you must have in order to use this weapon, with the following exceptions: Bows use Power Draw, Throwing uses Power Throw, Shields use Shield Skill, Horses use Riding.