Intra-rater reliability and agreement of various methods of measurement to assess dorsiflexion in the Weight Bearing Dorsiflexion Lunge Test (WBLT) among female athletes

Objectives: To examine the intra-observer reliability and agreement between five methods of measurement for dorsiflexion during Weight Bearing Dorsiflexion Lunge Test and to assess the degree of agreement between three methods in female athletes. Design: Repeated measurements study design. Setting: Volleyball club. Participants: Twenty-five volleyball players. Main outcome measurements: Dorsiflexion was evaluated using five methods: heel-wall distance, first toe-wall distance, inclinometer at tibia, inclinometer at Achilles tendon and the dorsiflexion angle obtained by a simple trigonometric function. For the statistical analysis, agreement was studied using the Bland-Altman method, the Standard Error of Measurement and the Minimum Detectable Change. Reliability analysis was performed using the Intraclass Correlation Coefficient. Results: Measurement methods using the inclinometer had more than 6 of measurement error. The angle calculated by trigonometric function had 3.28 error. The reliability of inclinometer based methods had ICC values < 0.90. Distance based methods and trigonometric angle measurement had an ICC values > 0.90. Concerning the agreement between methods, there was from 1.93 to 14.42 bias, and from 4.24 to 7.96 random error. Conclusion: To assess DF angle in WBLT, the angle calculated by a trigonometric function is the most repeatable method. The methods of measurement cannot be used interchangeably. (C) 2016 Elsevier Ltd. All rights reserved.