In order for your middles to become more involved in your offense, they are going to have to work hard to transition to get off the net and make themselves more available. In the clip below former Georgia Tech Head Coach, and current Texas Associate Head Coach, Tonya Johnson explains the principles of spacing of the middle hitters. Coach Johnson explains why it is important to open a lane between the passer and the setter. She demonstrates her Spacing Drill to teach this concept.
For more information about the DVD that this clip came from click the link Using Middles Effectively in Your Offense
The YouTube video has sound, so please make sure that the sound is turned on and that you have access to the site (some schools block access to YouTube)