The Serola SI Belt is designed to hold the SIJ together so the likelihood of it opening beyond normal between treatments is greatly reduced. If the joint re-opens, the Serola SI Belt will minimize re-injury to the joint and its ligaments. During rehabilitation, the Serola SI Belt holds the sacrum to the ilia with the proper tension so that, during exercise, as you bring the ilia backward, it carries the sacrum with it. The ligaments are not stressed and the joint remains intact; this is critical to proper rehabilitation. Too much or too little tension will create muscular spasm and inhibition.