Regarding the issue, here is a video of rehab specialist Rick Kaselj talking about how dumbell rows can hurt or mess your shoulders.http://www.youtube.com/watch?v=Q5BAx3B1PYs
For Andy, here are the cliffs notes:
- You want to prevent the muscles around the glenohumeral joint (shoulder joint) from turning off, aka leaving the arm hanging. This puts huge stress to the joint structures. Also you want to prevent anterior glide of the humerus. (Again, about the humerus kind of moving out from the glenoid fossa.
- Get some tightness and activate the scapular muscles and keep them stable. Don't leave the arm hanging at any time, the shoulder is a bit pulled back towards the whole movement. So you have to maintain some tension through whole ROM.