Knee range of motion: reliability and agreement of 3 measurement methods

We conducted a study to compare 3 methods of measuring knee range of motion: visual estimation by physicians, hand goniometry by physical therapists, and radiographic goniometry. We hypothesized that reliability would be high within and across all techniques. We found intrarater and interrater reliability to be satisfactory for visual estimation, hand goniometry, and radiographic goniometry. Interrater reliability across methods did not agree satisfactorily. Between-methods differences in estimating knee range of motion may result from variations in technique among physicians and physical therapists.