Having a mobile shoulder is a key part of any golf swing. Without the appropriate amount of mobility in the shoulders, a golfer will have to modify a golf swing or will almost always demonstrate a loss in the important posture that is needed to keep a golf swing efficient and consistent. Everyone who golfs knows that poor posture and inconsistency lead to loss in distance and an inevitable chasing of the golf ball around the course keeping you proficient in your ability to count in the 90s and 100s.
Achieving and maintaining good shoulder mobility will allow a golfer to keep a good swing path and be able to set the golf club in a better position at the different phases of the golf swing. Two important shoulder motions that a golfer needs are shoulder external rotation and horizontal adduction.
Shoulder external rotation can be improved by lying on your back and taking the head of a golf club in the hand of the shoulder being stretched and with the arm close to the side of the body. The non-stretching arm uses the golf club to push the hand of the shoulder being stretched down toward the floor trying to touch the back of the hand on the floor.
Shoulder horizontal adduction can be improved by moving the arm being stretched across the front of the body and pulling it further toward the chest with the non-stretching arm.
Stretches can be held for 45 sec and repeated 1-2 times. Stretches should be light to moderate in intensity. If pain is noted, then seek the appropriate medical professional. A physical therapist who understands the body mechanics of a golf swing can help you with that. Stretches can be performed on a daily basis and can also be done as part of a warm up for a round of golf.
Stretching the shoulders for these motions regularly will not only help with general shoulder function, but will also help keep a better posture during a golf swing leading to a more efficient and consistent swing. It is a lot less work and a lot more fun counting scores in the 60s, 70s, and 80s.