When exercising the muscles in one' s back, it is important, in order to maintain a healthy back, to exercise the muscles on opposite sides of the spine equally
After all, balanced muscle development is needed to maintain a healthy back, since the muscles on opposite sides of the spine must pull equally in opposing directions to keep the back in proper alignment and protect the spine
If the muscles on opposite sides of the spine are exercised unequally, one's back will be irreparably damaged.