Patent ID: 7404256

Claim:
A method for measuring angles between body members, comprising the steps of: 1) providing a dual line protractor, wherein said dual line protractor comprises a protractor fixed to a central axis and having degree marks on its circumference, a first spool having a first retractable line rotatably mounted within a first housing on said central axis, and a second spool having a second retractable line rotatably mounted within a second housing on said central axis, wherein said first and second housings are rotatably mounted on said central axis so as to rotate relative to said protractor, and wherein said first and second lines are extendable from said first and second housings across said degree marks on said protractor; 2) attaching a tip of said first line to an anatomical landmark on a first body member, and attaching a tip of said second line to an anatomical landmark on a second body member; 3) placing said protractor on a joint between the first body member and the second body member; 4) measuring a first degree mark over which said first line extends on said protractor; 5) measuring a second degree mark over which said second line extends on said protractor, with the second body member at any desired position relative to the first body member; and 6) measuring an angle between the second body member and the first body member at the joint by calculating the difference in degrees between said first degree mark and said second degree mark.