Well I was geeking out tonight with Assessment Treatment of Imbalance: The Janda Approach by Page, Frank, and Lardner.  If you’re interested, they talk about shoulders and laxity, pages 206-207.  They recommend treatment similar to treating shoulder impingement on page 199-206.  You can get a PDF copy for $4.99 off Scribd.com.  That will give a sense for how some PTs will treat it.