Reliability of lower extremity girth measurements after anterior cruciate ligament reconstruction

The purpose of this study was to determine the intra- and inter-rater reliability of lower extremity girth measurements in patients recovering from anterior cruciate ligament (ACL) reconstructive surgery. Nine subjects, within several months of their surgery, volunteered. Circumferential measurements were taken of the involved and uninvolved legs at the following locations: 15 cm inferior to the joint line; 5, 10 and 15 cm superior to the joint line; at the joint line; and at mid-thigh. All subjects were supine with the knee in extension whilst a specially designed device, formulated to make circumferential measurements at locations around the knee, was applied to the extremity. Three physical therapists each repeated all measurements on two occasions, in random order, during the same test session. Intra-tester intraclass correlation (ICCs) calculated showed high coefficients (0.82-1.0) for both the involved and uninvolved sides for all locations of the measurement. Inter-tester ICCs ranged from 0.72 to 0.97. The measurements established sufficiently high reliability to justify their use both within and between examiners for subjects recovering from surgery of the ACL.