Intrarater and Interrater Reliability of the Measurement of Leg Length

Abstract

The purposes of this study are to determine 1) the intrarater reliability of repeated leg length measurements with a tape measure and 2) the interrater reliability of leg length measurements with tape measure between two examiners. Thirty healthy subjects were measured their leg lengths in a blind method A pliable regular ruler covered with a blank sheet was used as a measurement tool. The leg length is measured from the anterior superior iliac spine to the medial malleolus. Both legs of each subject were evaluated 3 times by 2 physical therapists. Intraclass correlation coefficients (ICC) was used to analyze the data. The results of three separate trials showed that each physical therapist had significantly high intrarater reliability (ICC=.996-.998). Two examiners agreement was noted as well by highly significant intraclass correlation either in any separate trials (ICC=.975-.991) or in the mean values of the each three trials (ICC=.978-.993). These findings indicate that the leg length can be reliably measured with a tape measure from the anterior superior iliac spine to the medial malleolus in clinical use.