Reliability of water volumetry and the figure of eight method on subjects with ankle joint swelling

Study Design: Single-group repeated measures with 2 raters. Objectives: To determine the interrater and intrarater reliability of water volumetry and the figure of eight method on subjects with ankle joint swel ling. Background: Measurements of ankle swelling are commonly performed to determ ine the nature and stage of injury and to monitor progress made during reha bilitation. Water volumetry and the figure of eight method are 2 techniques used to measure ankle swelling. Methods and Measures: Twenty-nine subjects with ankle swelling were measure d by 2 raters with the hypothesis that both measurement techniques would be reliable. Each rater performed 3 measurements of the swollen ankle using b oth measurement techniques during a single test session. The order of the r ater and of the measurement technique was randomized, and the raters were b linded to each other's measurements. Results: We found high interrater reliability for both the water volumetry (ICC [intraclass correlation coefficient] = 0.99) and figure of eight metho ds (ICC = 0.98). Additionally, intrarater reliability was high for both rat ers using both methods (ICCs = 0.98-0.99). Conclusions: Both methods are reliable measures of ankle swelling. The auth ors recommend the figure of eight method because of its ease of use, time e fficiency, and cost effectiveness. However, water volumetry may be more app ropriate when measuring diffuse lower-extremity swelling. Reliability of th ese 2 methods was established using subjects with foot or ankle pathology. Therefore, the results are applicable and generalizable to the clinical set ting.