The point of greatest stress on a muscle is always at the point where the limb in use is perpendicular to the force, so spending time at the stretch and contraction are not necessarily helpful, though a full range of motion is always necessary. Learn why!
this is good stuff. i tend to think whenever i'm too strict, i'm not getting as good a workout. Seems like the big guys at the gym are'nt strict lifters, and a little cheat movement seems to work for them.