You might not be Atlas, but your shoulders still carry a lot of weight. If it weren't for them, you wouldn't be able to pitch a game-winning home run, shovel snow off your front walk, or even comb your hair.
The shoulders' ball-and-socket design gives you great range of motion, but at the expense of stability. The shoulder socket is shaped like a golf tee, fairly flat on top, so the ball of the upper arm bone can easily slip out of it. That instability is why the shoulder joint gets dislocated more often than any other joint in the body.
When you lift weights every day or pitch every weekend, you can put a lot of wear and tear on your shoulder muscles, tendons, and joints. This is especially true if your form or technique is incorrect. Repetitive stress can lead to tears and other injuries, which can take you off the playing field and leave you in serious pain.
Here's a guide to the most common shoulder injuries -- how to spot them, and what to do about them.
Rotator Cuff Injury
What it is: Your rotator cuff is the set of four muscles that sits around the ball of the shoulder joint and allows the shoulder to move.
How it can get injured: Sports that involve lifting your hands over your head -- like pitching in baseball, swimming the freestyle or butterfly stroke, serving in tennis, and weight lifting -- can cause the top part of the shoulder blade to pinch the rotator cuff muscles. This is called shoulder impingement.
Repetitive motion in sports can also overload the tendons of the rotator cuff. Those tendons can eventually swell and get inflamed -- a condition called tendinitis. If you ignore the pain and keep swinging that golf club or tennis racket, the tendon that connects the rotator cuff muscles to the ball part of the joint can eventually tear.
What you'll feel: Pain is the main symptom of a rotator cuff injury. The pain gets worse when you raise your arm, and you might hear a click or popping sound. Eventually, the shoulder will hurt even when you're not moving it. A rotator cuff injury can limit your shoulder movement and reduce your strength.