My wife just had rotator cuff surgery. I’m typing this to you on my laptop from her room where she will be for a day or two before going home. Her roommate had the same surgery and is in some kind of device that moves her arm up and down and back and forth. She has a different surgeon than we do. Should I ask our doctor about using something like this for my wife?

What you are probably seeing is a device called continuous passive motion (CPM) machine. CPM is a way to keep the arm moving with gentle range-of-motion. The arm is placed in the device that is set to whatever motion is desired. It is motorized and repetitively moves the arm through the preset arc of motion. The idea is to keep adhesions (scar tissue) from forming.

In some cases, CPM has been helpful in reducing pain as well. Women seem to benefit more than men. And patients over 60 years old also seem to have a better result than younger patients. And with less pain, more motion is possible. The hope is that in the end, the patient will have a better result than if he or she just moved the arm manually.

But, in fact, studies show that CPM doesn’t really have a benefit in the long-run. It may reduce pain early on but when patients are compared 12 months later — those on CPM didn’t have any better overall strength, function, or motion than those patients who didn’t use CPM.

Given those results, it’s hard to justify the cost of the machine. Your wife will probably have just as good of results if the physical therapist works with her to move her arm. You (or a friend or other family member) can also learn how to do the passive motion exercises and help your wife with those.