At the top of the back swing you can see how the right arm has the elbow bent to 90 degrees and externally rotated (rotated away fro the body). Now many muscles are associated with restricting this arm position, namely the Chest muscles (Pectoralis Minor and Major) and some Shoulder muscles (Subscapularis and Teres Minor).
An easy test for how tight these are is the address posture shoulder rotation test.
Start by standing in a 5 iron address with both arms at shoulder height and elbows bent to 90 degrees (as shown). From here rotate the arms back, so the hands moves up and back. Now ideally we want the forearm to be inline with or past the spine angle. When testing note if you are cheating from arching your back too much. TPI have found that all professional golfers can get their forearm past the spine angle, so thats want we want t aim for…..
Now if you don’t quite have this yet, then try the two stretches below.
Pec Stretch – Hold for 30secs each side
Begin by kneeling on the floor on all fours with the hands under the shoulders and the knees under the hips.
Place one arm onto the Swiss ball/chair at 90º, ensuring that the shoulder is in contact with the ball, whilst maintaining your neutral posture on all fours.
From here slowly lower the shoulder of the arm on the ball to feel the stretch on the front of the shoulder/chest.
As the stretch eases off slowly try to drop lower.
T4 Wall Slide
Stand against a wall and move your feet about 1 feet away. Put your arms in the position as shown in picture A. From here push your lower back towards the wall.
Then to start the exercise inhale and then as your exhale raise your arms above your head as you squat down as far as you can comfortably. Keeping the low back
against the wall and arms pushed against the wall.
Perform 12 – 15 movements.