hi friend
are you concerned with motor control dysfunction of shoulder.i mean weakness of /muscle imbalance between core muscles and superficial muscles.in shoulder rotator cuff is considered to be the core muscle by its concavity compression action.if rotator cuff is weak,the superficial muscles like pectorals and lattisimus will overact and cause shoulder instability
the are articles by the name of shoulder instability in journal section of this site
also check articles by mary magarey in manual therapy journal 2003
in new zealand journal of physiotherapy there is an article on multidirectional instability
please check these