One day, your shoulder feels fine. The next day, the pain is as sharp as anything you've ever felt—a twisting, shooting pain that seems to have come from nowhere. Yes, you played softball over the weekend, but it's hard to equate a couple of hard throws from right field with the intense pain that you feel in your shoulder.

So you call your doctor, who asks you what you did over the weekend. You explain your symptoms, giving your doctor a good idea of where to look. The pain is almost certainly bursitis, tendinopathy, or both—two of the most common joint problems affecting people age 35 years and older. One study, in fact, says two-thirds of men who complain of muscle problems are suffering from one of the two.

The Difference Between Tendinopathy and Bursitis

It's important to keep in mind is that tendinopathy and bursitis are different, although people tend to associate them as one. What they have in common is that they both cause pain, often in the same areas, like in the rotator cuff of the shoulder. But they are not the same condition.

In tendinopathy, the tendons—tissues that attach muscles to bone—become injured. Tendinopathy may include:

  • Tendinitis—an inflammation of the tendon. (Although this term is used often, most cases of tendinopathy are not associated with significant inflammation.)
  • Tendinosis—microtears (tiny breaks) in the tendon tissue with no significant inflammation.

In bursitis, the bursae—fluid filled sacs that help the muscles and tendons glide smoothly over other underlying bones—become inflamed.

Tendinopathy is almost always caused by overuse or misuse of the tendons, as in tennis elbow or sore knees or feet among serious runners. The pain of bursitis, on the other hand, may be due to overuse, but may also be a reflection of underlying arthritis (or even gout).

Any physically active person is susceptible to bursitis or tendinopathy. The tendons and bursae may become irritated either from constant use or from unaccustomed demands of being a “weekend warrior.” The more active you are, the more likely you are to get tendinopathy. Bursitis may occur with activity, or it may come on without known provocation. Each case is different, and there seems to be no correlation with a family history of bursitis or tendinopathy.

That's one of the differences between these two conditions and arthritis, in which heredity does seem to play a role. Arthritis affects a different part of the musculoskeletal system by causing a swelling in the lining of the joints.

Listening to Your Body's Signals

Since physical activity is one cause of bursitis and tendinopathy, the best way to avoid the inflammation and pain is to avoid doing more than you can. Pain is a communication tool; it's the way your brain tells your body to change the way you exercise.

Consider your sore shoulder. Baseball fans will recognize your symptoms as the dreaded rotator cuff injury so common to pitchers. One reason pitchers are susceptible is because pitching—especially throwing so hard and throwing curve balls—is a very unnatural action.

Tendinopathy and bursitis are as painful as they are inevitable—especially for those who believe they should play through pain and that soreness is just an excuse to work harder. But techniques as simple as an effective warmup and sound mechanics, whether you're swinging a tennis racquet or throwing a softball, can help you avoid a painful morning after.

How to Avoid Pain and How to Treat It

You can avoid the pain in one of two ways. First, warm up before you start throwing. It sounds too simple to be effective, but life usually works out that way, doesn't it? If you make sure your tendons are loose, they are less likely to become inflamed. Second, be sure that your muscles are strong before you use them fully. Weight training, perhaps under the guidance of a personal trainer, can help you achieve appropriate levels of strength for the activities you wish to do. Working at full strength may help you reduce your risk for either tendinopathy or bursitis.

If you do inflame the tendons or the bursae despite warming up, the best approach is to rest. This gives the body a chance to heal itself; any nonsteroidal anti-inflammatory drug (NSAID), like ibuprofen, helps, as does icing the affected area. Then, look at how you can change the way you throw to prevent the problem from happening again., helps, as does icing the affected area.

Keep in mind that anti-inflammatory drugs can cause ulcers, stomach, or bowel bleeding, and other serious complications if taken frequently over long periods of time. If tendinopathy doesn’t improve within a few weeks, you should see your doctor. Topical NSAIDs are effective in reducing acute pain from bursitis or tendinopathy and also avoid the risk of gastrointestinal adverse effects.

Cortisone can be injected into bursae and around tendons, which will reduce the inflammation.Cortisone injection is more effective than NSAIDs in relieving acute pain. But this treatment is not going to eliminate the mechanical problem that caused the inflammation in the first place. While cortisone injections are frequently used for troubling and prolonged symptoms, there is at best limited evidence that they provide lasting relief or are more effective than injection with numbing medications alone.

Braces such as the tennis elbow bands can protect your tendons during physical activity. Once the acute pain has subsided, eccentric strength training is especially effective in treating tendonitis.

That approach is the key to a successful rehabilitation. That is, to look at the biomechanical aspects: Is the bursitis or tendinopathy caused by a training error? Can you change the way you do something? The key is to find out why the muscles aren't strong enough or why they are too inflexible.

Once that's under control, doctors say, you can throw as hard as you want from right field and remain pain free.