I can't figure out what's wrong with my arm. When I try to lift it up to comb my hair, I can only go so far and get stuck. It hurts like the dickens when I try to do that. But I can lie down on the bed holding on to my cane with both hands and the arm goes up all the way. Can you explain this to me?

You may have a condition referred to as pseudoparesis of elevation. Pseudo means like or similar to and paresis means paralysis. It seems like your arm is paralyzed in that it won't go through the motion you clearly have available. But there's no nerve damage or real paralysis going on.

Instead, it may be a case of a deficient rotator cuff and uneven pull of the muscles. The rotator cuff is a group of four muscles, tendons, and connective tissue that envelops the shoulder. The rotator cuff both moves and stabilizes the shoulder. Stabilizes means it holds the shoulder in the socket and prevents dislocations.

Without a properly functioning rotator cuff, when the deltoid muscle contracts, the necessary counter pull from the rotator cuff is missing. The patient ends up with pseudoparesis, which looks like an inability to lift the arm up overhead despite the fact that there is the necessary range-of-motion to do so.

It would be a good idea to see an orthopedic surgeon for an evaluation. There could be a simpler explanation. In any case, it's likely that there is a treatment that could help you and possibly prevent further problems from developing. Early intervention can sometimes prevent more invasive procedures. It may not be too late to try a conservative (nonoperative) treatment plan.