Strength Imbalances and Injuries
It is important to have strength balanced throughout the body, but it is particularly important in opposing muscle groups. A muscle group that is over-developed relative to its opposing muscle group can cause joint pain, tight muscles, and muscle injuries. Some examples that I have had experience with are over-developed quadriceps, over-developed hamstrings, and under-developed lower abdominals.
The quadriceps were the first problem. I emphasized the quadriceps in weight lifting and running, and I didn’t know the importance of using the glutes and hamstrings. I think I had more groin and hamstring injuries due to this imbalance. Unfortunately, I over corrected this problem and made my hamstrings and glutes to strong relative to the quadriceps. This caused a knee-cap tracking problem. When the quadriceps are weak relative to the glutes and hamstrings, the knee-cap is pulled outward and causes a sharp pain when the knee is bent past about 45 degrees. The pain goes away once the quadriceps are strengthened enough to align the knee cap. Strengthening the quadriceps can take one or two months. Accomplishing this can be a little tricky since squats and most leg exercises could just maintain the imbalance by strengthening all of the muscles in the thigh evenly. The quadriceps have to be isolated in order to increase their strength relative to the hamstrings and glutes. The best way that I have found to isolate the quadriceps is to do the mi-range of a squat without weight and with the elbows or shoulders on the knees to support the upper body. By supporting the upper body, the glutes and hamstrings are passive since they don’t have to support the torso. Just do several inches of vertical motion with bent knees until the quads start to burn. The last strength imbalance was in the lower abdominal muscles. I think this resulted in lower back spasms. The lower abdominal muscles can be isolated by lying flat and lifting the pelvis upward. You have to hold on to something to keep the shoulders down. Lift and hold the pelvis off the ground for as long as possible, and do several sets.