Last week I told you about one of two things golfers must have to solve a painful shoulder. The first thing was to find out the strength of your shoulder. I explained that golfers need to generate about 14 lbs. of force up to 100 times in the course of a typical 18 hole round. And, that 14lbs., represented about 40% of normal strength.
The second thing to know is your shoulder ratio.
The rotation motions of the shoulder are referred to as internal and external rotation. To best understand these two motions, try this:
- Lie down on the floor on your back. Slide your right arm away from your body until it forms a 90 degree angle with your trunk.
- In this position, bend your elbow until it forms a 90 degree angle with the hand pointing up. You are now in what we call "neutral".
- From neutral, drop your hand back towards the ground. This motion is external rotation. When your hand hits the floor, you have moved through 90 degrees of motion.
- From neutral, drop your hand towards the ground. At some point in the motion, your shoulder will come up off the ground. This is the end of your internal rotation (see figure for example). Normal motion of internal rotation, from the neutral position, is 70-80 degrees. This gives your shoulder about 160 degrees of rotation movement (90 of external plus 70 of internal rotation).
The shoulder ratio is the amount of external rotation to internal rotation: 90 degrees of external rotation to 70 degrees of internal rotation giving you an ideal shoulder ratio of 1.3. Most golfers with shoulder pain have a shoulder ratio greater than 1.8 and often over 2.0 (a higher ratio means you have less internal rotation motion). I know - a lot of numbers - but hang in there. Here's why it matters. The golf swing takes less than 2 seconds - start to finish. In less than 2 seconds, your shoulder muscles have to figure out how when to contract, how hard, and for how long and this is influenced by how much motion you have in your shoulder. So, if you have a high shoulder ratio (or too little internal rotation motion), your muscles have less time to react. They have to work harder in a shorter period of time and your chance of injury then goes up.
To solve shoulder pain in golfers, you have to know at least shoulder strength and the shoulder ratio. These two numbers will help you understand why you hurt and what needs to change for you to play safely and pain-free.