Intratester and Intertester Reliability of Clinical Measures of Lower Extremity Anatomic Characteristics: Implications for Multicenter Studies

Abstract

Abstract:Objective: To determine whether multiple examiners could be trained to measure lower extremity anatomic characteristics with acceptable reliability and precision, both within (intratester) and between (intertester) testers. We also determined whether testers trained 18 months apart could perform these measurements with good agreement. Setting: University's Applied Neuromechanics Research Laboratory. Participants: Sixteen, healthy participants (7 men, 9 women). Assessment of Risk Factors: Six investigators measured 12 anatomic characteristics on the right lower extremity in the Fall of 2004. Four testers underwent training immediately preceding the study, and measured subjects on 2 separate days to examine intratester reliability. Two testers trained 18 months before the study (Spring 2002) measured each subject on day 1 to examine the consistency of intertester reliability when testers are trained at different times. Main Outcome Measurements: Knee laxity, genu recurvatum, quadriceps angle, tibial torsion, tibiofemoral angle, hamstring extensibility, pelvic angle, navicular drop, femur length, tibial length, and hip anteversion. Results: With few exceptions, all testers consistently measured each variable between test days (intraclass correlation coefficient>=0.80). Intraclass correlation coefficient values were lower for intertester reliability (0.48 to 0.97), and improved from day 1 to day 2. Intertester reliability was similar when comparing testers trained 18 months before those trained immediately before the study. Absolute measurement error varied considerably across individual testers. Conclusions: Multiple investigators can be trained at different times to measure anatomic characteristics with good to excellent intratester reliability. Intratester reliability did not always ensure acceptable intertester reliability or measurement precision, suggesting more training (or more experience) may be required to achieve acceptable measurement reliability and precision between multiple testers.Keywords: lower extremity alignment | risk factor assessment | posture | measurement stability Article:Little is known about the factors that predispose an individual to anterior cruciate ligament (ACL) injury.1,2 In part, this is because of the myriad of factors that have been proposed to explain the risk of ACL injury. Controlling and measuring multiple variables creates considerable challenges, as variables have the potential to interact with one another, and many of these variables are poorly defined or difficult to obtain reliably.3 Many of the potential risk factors cannot be measured after ACL disruption, because the injury modifies the risk factors, [4][5][6][7][8][9][10][11] and bilateral asymmetry cannot always be assumed. 12,13Because of these limitations, large prospective studies are recommended to identify ACL injury risk factors.14-17 However, prospective studies present their own challenges, as a large cohort of subjects is needed to yield sufficient ACL injuries. Uhorchak et al 16 prospectively fol...

Association Between Foot Type and Lower Extremity Injuries: Systematic Literature Review With Meta-analysis

“…The intrarater reliability of the navicular drop test was previously reported, with ICCs between 0.61 and 0.79, 68,73,86 whereas interrater reliability ranged from 0.46 to 0.83. 25,73,86,87 The validity agreement of the navicular drop test with values calculated from radiographs through radio-opaque markers affixed at the surface anatomical landmarks had good Pearson correlation coefficients (between 0.61 and 0.89). 37 As for relaxed calcaneal stance position, an earlier critical review of the literature concluded that this method was inherently unreliable and invalid.…”

Sex Differences and Representative Values for 6 Lower Extremity Alignment Measures

“…This method recently has been reported to have an intraclass correlation coefficient (ICC) of 0.91 to 0.97 for intratester reliability. 21 Tibial Varum. This measure was performed with the participant in a weight-bearing, double-limb stance.…”

“…This method of assessing Q angle has been reported to have an ICC of 0.89 to 0.98 for intratester reliability. 21 Genu Recurvatum. While standing, each participant was instructed to extend the knee as fully as possible.…”

“…This method has been reported to have an ICC of 0.88 to 0.97 for intrarater reliability. 21,26 Anterior Pelvic Tilt. Anterior pelvic tilt was measured using previously described methods.…”

“…17 In particular, the lower extremity alignments of navicular drop, tibial varum, Q angle, genu recurvatum, anterior pelvic tilt, and femoral anteversion are often implicated in both acute and chronic injuries and are commonly measured as part of a lower-quarter screening. 12,15,21 Clinicians often attempt to alter these alignments when they are considered excessive (malalignment). A visual inspection may reveal an obvious malalignment, but the lack of normative data in the literature regarding these measures makes it difficult to define a ''normal'' range.…”