A good indicator of joint health is mobility. Here is a simple exam you can do at home to see if your shoulder lacks normal range of motion which can be putting your shoulder at risk for injury or premature degeneration.
With your right arm, reach over your shoulder to try and touch the top part of your shoulder blade. With the opposite left arm, go behind your back and reach up towards the bottom of your shoulder blade (Picture A). Repeat again, but reversing the roles of your hands. Healthy range of motion should allow you to touch fingertips.
If you find that your two hands don’t touch (picture B), then you may need to spend some time working on shoulder mobility.
Here is a good stretch to help you work on shoulder mobility. Mimicking the test we just did, string a towel between your two hands. Alternate lifting upwards with your top hand (this will improve internal rotation of the bottom hand) and pushing down with the bottom hand (this will improve external rotation of the top hand). Alternate the hand positions and repeat.
Aim for 3 sets of 10 reps in each direction, and with each arm playing the role of the top and bottom hand.