Strength is the rawest form of power, and you possess it in some form. It is a very positive card if you are fighting illness or recovering from injury. As might be suspected, its influence over you, and the use you put it to, can trend towards light or dark. You likely trend towards facing your problems courageously, head-on, and conquering them through perseverance and will. However, with this ability to overcome life's obstacles, comes the responsibility to control yourself, and this card may be a warning to take command of your own actions or emotions before they damage you or the people you care about.
To get the full traditional meaning and interpreation of Strength, I suggest you visit Trusted Tarot and their Strength page.