It was his left side, less used and weaker, which was injured. Theoretically, the left side of our body represents our feminine aspects, the tendency to be creative, to be intuitive, and to simply just be. The right side represents our masculine aspects, the tendency to be aggressive, the tendency to be logical, and the tendency to do. The characteristics which we display often can be related to the dominance of one side over the other. And this dominance displays another aspect of ourselves which is not completely in balance.
Balance is equilibrium.
It is the attainment of a state in which opposing energies are present in equal strength. It is not necessary to be still to be balanced. Think of the magician who balances spinning plates on top of sticks. As long as they are spinning at the appropriate rate, they remain balanced. When they slow down, they become unbalanced, and fall.