"If you can't flex it then DON'T ISOLATE IT" You need to have control of your body if you are going to do isolation movements. If I asked you to flex your pecs this would be easy for most people. They can make their boobies bounce with pride. Now what if I asked you to do the same with your triceps, delts, hamstrings, lats? If you can't then why in the hell are you doing tight isolation bodybuilding cable work? Hum, never though of that one did you. Stick with the presses and rows and build muscle first. You can't flex bone.