The favorite muscle groups worked in nearly every gym in America are the ones we can see in the mirror. The biceps, pecs, abs and quads. This, along with the fact that we spend nearly every waking hour working our extremities in front of our body, only leads to bad posture and premature joint wear. These muscles are in fact typically too tight and strong for the muscles in the back of our bodies to work against to help us maintain an upright and erect posture with properly aligned joints, protected from disease.
Focus more on stretching the muscles in front of the body and perform twice as many pulling type exercises as you do pushing exercises. Pulling against resistance works the neglected muscles in the back of the joints whereas pushing works the muscles in front of the body. This is the way to create a more balanced workout and body structure.