How do you do a straight handstand without impinging?

I used to do handstands with a slightly arched back and slightly closed shoulder angle. No problem. Several months ago, I started trying to straighten my handstand out with stretching and just trying to open up the shoulders more and got injured after a few months of that. My rehab guy calls the position with the arm raised up high and palm facing away from the body an impingement position. He recommends raising the arm up with thumb pointing behind the body, which rotates the arm externally a little bit. This would be like doing a handstand on parallel bars.

My question is how do so many people seem to be able to do handstands with the fingers facing forward (and without looking like they are rotating their elbows outward)? The same applies to Coach Sommer's wall extensions with palms facing away. If this is healthy then maybe it's just a matter of gaining enough active flexibility before trying to do perfectly straight handstands?

Do you guys with perfectly straight handstands try to keep your arms rotated out enough so that it doesn't "lean" against the shoulder joint?

It may be the case that your scapula is not moving properly, so the rotator cuff is impinging on the acromion process. Also, the shape of your acromion determines how much room you have between the head of the humerus and the acromion process.

As you can here, the last acromion (type 3) is the most likley to cause impingement because it is hooked. Your acromion type cannot be changed.

Here is a short little article that gives some tips on how to reduce impingement.

http://www.elitefts.com/documents/impingement.htm

I'll summerize:

(1) Strengthen the rotator cuff.

(2) Stretch the downward scapular rotators, and strengthen the upward scapular rotators.

(3) Improve thoracic spine mobility.

A google search will lead you to a ton of exercises for improving these things.

I think you hit on something because my scapulae wing out a little bit (maybe from when I used to bench press).

My rehab guy has given me plenty of stabilization exercises, so I know what I need to do. I was just curious if most people with perfect handstands conciously thought about keeping the elbows rotated outward (like coach Sommer's recommendation for ring handstands and supports).

Maybe I should have put this thread in the joint preparation area.

Keeping the elbow rotated outward is important for all supports as it's better form. This is easier to do on rings and parallel bars and floor but more difficult on a single rail when in overgrip.