The AMA medical disability rating scale is a guideline used to rate the amount of disability an individual has usually in order to determine what their disability insurance payments will be. Impairment ratings are broken down into five different classes. Class 1 means no impairment and has a 0% rating. Class 2 is mild impairment and has between a 10%-20% rating. Class 3 is moderate impairment
. and has between 25%-50% rating. Class 4 is marked impairment and has a rating of 55%-75%. Class 5 is extreme impairment and has a rating of over 75%. You can find more information here: http://www.wcb.ns.ca/policymanual/334r.html
