Journal of the American Medical Association (JAMA)
http://jamanetwork.com/journals/jama/fullarticle/2499274
Canadian Family Physician
http://www.cfp.ca/content/60/6/505.short
British Journal of Sports Medicine
https://bjsm.bmj.com/content/49/2/88.short
Journal of the American Medical Association (JAMA)
http://jamanetwork.com/journals/jama/fullarticle/2593568