Many people suffer from arthritis in their shoulder. Physical Therapy will help you strengthen the shoulder allowing you to move the shoulder without increased pain. Since arthritis is a degenerative condition, by actively strengthening the shoulder, you can slow the pace of the arthritis and build a strong shoulder to support your movements.
The swing for a golfer is perhaps the most crucial aspect to a low handicap. Everything about the swing must be correct from holding the club, to footing, and the swing. When you are standing there, and the swing is correct, the ball flies and nothing feels more fluent than that swing.