This came from an NASM newsletter: "The efficiency of the kinetic chain also affects the ability to increase muscle size. For a muscle to grow, it must be stimulated. A joint that is dysfunctional due to muscle imbalances can inhibit the growth of muscles surrounding that joint (arthrokinetic inhibition)8, and the nervous system will only recruit the prime movers of a joint to the degree that the joint is stabilized9. So if muscle imbalances are present at a given joint, causing joint dysfunction, the nervous system will decrease activation to the muscles directly associated with that joint to protect it. Of course, if muscle fibers are not recruited as a result of this mechanism, they will not grow10. This is one reason for preparing the client's body through a properly structured flexibility and stability training program prior to progressing to hypertrophy training." What exactly do they mean by muscle imbalances, and is there any truth to this? Its funny, some of their info about hypertrophy is accurate and research-sound. Other parts (despite the official-looking footnoted sources) sound like the bodybuilding folklore we get from the magazines and our local gym heroes. I'm just wondering under which category the above quote falls.