A common mistake that can be made during workout sessions is focusing on just the “mirror muscles." These include the chest, biceps, triceps, shoulders and quadriceps and neglecting muscles that cannot be seen in the mirror such as lats, rear deltoids, hamstrings, and lower back. Making this mistake causes muscle imbalances and postural problems that make the simplest every day tasks more difficult.
Correct posture, full range of motion, and functional strength can only be maintained when muscles are in balance. When your strength training puts the emphasis on the muscles on the front side of your torso, those muscles will tend to get tighter and shorter over time, while the neglected opposing muscles in your back will get longer and weaker. Your shoulders will start rounding towards the front, your neck and head will start leaning forwards, and you may develop chronic neck and upper back pain. This postural problem can even lead to serious issues with pinched or entrapped nerves in your shoulders, or a propensity to injure your shoulder muscles, especially the rotator cuff which can lead to slouching.
These same principles apply to the lower body. The tendency of people who build mirror muscles only is to concentrate on squats to strengthen the quads and glutes and neglect their hamstrings. In fact, the majority of hamstring injuries result from imbalances caused by favoring quad exercises over hamstring stretches and exercises. The posterior chain, which includes the hamstrings, glutes, and back are critical. If your posterior chain is weak, you’ll never fully develop the “mirror muscles”. Exercises such as leg curls, deadlifts, and reverse lunges are excellent for the hamstrings.
If you are focusing just on your mirror muscles make a change today! When developing your routines make sure that the same amount of time is spent on the non-mirror muscles. Consult a fitness professional for assistance if needed. Working those muscles will do wonder for your aesthetic development, posture, and strength.