http://jaoa.org/article.aspx?articleid=2093614 http://jaoa.org/article.aspx?articleid=2093614 J Am Osteopath Assoc. 2008 (Nov); 108 (11): 657-664 http://jaoa.org/article.aspx?articleid=2093614 http://jaoa.org/article.aspx?articleid=2093614 http://jaoa.org/article.aspx?articleid=2093614 This paper goes in depth on the topic J Am Osteopath Assoc. 2008 (Nov); 108 (11): 657-664