Using my CEx--Corrective Exercise Specialist-- certification allows me to design programs to fix muscular imbalances that gives you that lower or mid back ache or pain. Instead of trying to fix the symptoms, what I address are the root of what causes the symptoms. For example if someone has an ACL knee injury or strain then movement patterns are predictable. The person will have valgus knees (knees go inward) with some other movement compensations. These improper movement patterns cause strain in the knee joint which in turn cause wear and tear on the ligaments leading to injury. These problems are due to imbalances in the hip musculature or/and the ankle musculature. These would be the areas of correcting and preventing injury.
Through my experiences in this industry I have noticed that the majority of my clients have some kind of joint problem. Most are caused by sitting behind a desk all day at work or were past atheletes. The public's knowledge on how to make lower back, shoulder, or knee pains go away are unaccurate. Yes exercise does make you stronger and feel better but if you have a joint disfunction then your problems will get worse in the long run.