This still holds true but I belive this should be worded differently. My rewrite would say static arm vs dynamic arm. Static is how we basically use our arms in most of our daily activities. Brushing teeth, writing, drawing, eating etc. This only activates half of our arm and thus bigger muscles do not get involved. This is pretty much the definition how people get chicken arm in golf. When you have static arms your body stays still, so you can be accurate in whatever you are doing. Dynamic arms is something I would describe as using the whole arm, like in any other sport. Since our pecs/lats are connected in to our arm from the arm pit they automatically activate when you are using your whole arm. When the arm is connected your whole body reacts in the movement of the arms. Very clear examples of this is the windmill drill or freestyle swimming, heck any sport really.
Something how you can try it out yourself is to take a sideways stance and imitate a sidearm throw. Start with t-rexing or static arm, how you would write, eat etc. This moves only your forearm and wrist. Your body should be pretty still and only your arm moves. Then imitate the same move but think about using your whole arm. Your leading shoulder will turn and your hips start to work as well. It is impossible to throw well with an disconnected arm.
Something how you can try it out yourself is to take a sideways stance and imitate a sidearm throw. Start with t-rexing or static arm, how you would write, eat etc. This moves only your forearm and wrist. Your body should be pretty still and only your arm moves. Then imitate the same move but think about using your whole arm. Your leading shoulder will turn and your hips start to work as well. It is impossible to throw well with an disconnected arm.
