Here is a really good article from Forbes, which outlines what really works, and how surgery for back pain, and procedures like spinal fusion, are not as effective for back pain as you might think.
http://www.forbes.com/forbes/2008/0421/088.html
And here is another interesting article on the negative effects of a tight back pack on adult health.
http://www.everydayhealth.com/publicsite/ShowArticle.aspx?IsP=news/614/news614220.xml&dp=2008/04/07&q1=&cen=&xid=nl_EverydayHealthHealthyLiving_20080408
