Reliability of the Ely's test for assessing rectus femoris muscle flexibility and joint range of motion

Rehabilitative protocols and orthopadic research are significantly influenced by the ability to perform reliable measures of specific physical attributes or functions. The hypothesis was that the Ely's test for evaluating rectus femoris flexibility and joint range of motion (ROM) is a reliable clinical tool. Participants (n = 54) were between the ages of 18 and 45, and had no history of trauma. Three clinicians with orthopedic expertise assessed quadriceps flexibility and joint ROM using pass/fail and goniometer scoring systems. A retest session was completed 7 to 10 days later. Statistically, Kappa values for pass/fail scoring (intrarater $\bar {X}=0.52$, interrater $\bar {X}=0.46$) and ICC values (intrarater $\bar {X}=0.69$, interrater $\bar {X}=0.66$) for goniometer data both indicated that the Ely's test demonstrated only moderate levels of intra‐ and interrater reliability. Measurement error values (SEM = 4°, ME = 4°, and CV = 3%) and Bland and Altman plots (with 95% Limits of Agreement) further demonstrated the degree of intrarater variance for each examiner when executing the Ely's test in a clinical setting. Results call into question the statistical reliability of the Ely's test, and provide clinicians with important information regarding the reliability limits of the Ely's test when used to clinically evaluate flexibility and joint ROM in a physically active population. More research is required to determine the variables that may confound statistical reliability of this orthopedic technique that is commonly used in a clinical setting to assess function about the thigh region. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:793–799, 2008