Your ability to create power comes from your lower body. If you are lacking power in your golf swing, it could be from a faulty weight shift. Using only arms in your golf swing, restricts your power and causes a variety of mis-hits. Learning to shift your weight is key to adding power into your swing. Try this exercise is to help build a powerful weight shift.
Sit on an exercise ball and slide your back down the ball and you bend your knees and get into a squat position.
Cross your arms across your chest and you balance your weight evenly between both legs.
Roll your back up the ball so that your torso is flat like a table top.
Hold the position for a moment and return to the start position.
Repeat for 8 to 10 repetitions.