Interrater and intrarater reliability of a handheld myotonometer in measuring mechanical properties of the iliotibial band

Objective: The aim of this study is to investigate the intra-rater and inter-rater reliability of the MyotonPRO device in measuring the mechanical properties of the iliotibial band in healthy individuals. Materials and Methods: Thirty-two healthy participants (20 males, 12 females) aged between 19 and 27 years were included in the study. The mechanical properties of the iliotibial band (tone, stiffness, elasticity) were measured using the MyotonPRO device (Mumeetria Ltd, Tallinn, Estonia). To determine the reliability of the device, measurements were performed by two independent researchers. After the initial measurements, a second round of measurements was repeated by the same two researchers after 48 hours. Results: The MyotonPRO provided very high intra- and inter-rater reliability in measuring the mechanical properties of the iliotibial band (intraclass correlation coefficients 2.1>0.81). The standard measurement error was calculated as 0.8 to 0.5 Hz for tone, 40.3 to 27.9 N/m for stiffness, and 0.1 log for elasticity for both raters. For inter-rater values, tone was 0.7 to 0.6 Hz, stiffness was 17.8 to 25.1 N/m, and elasticity was 0.04 to 0.1 log. The minimum detectable change for intra-rater measurements was found to be 2.3 to 1.5 Hz for tone, 111.7 to 77.3 N/m for stiffness, and 0.2 log for elasticity for both raters. For inter-rater measurements, tone was 1.9 to 1.6 Hz, stiffness was 49.4 to 69.6 N/m, and elasticity was 0.1 to 0.2 log. The coefficient of variation for all parameters was below 9.8%. Conclusion: The results indicate that the MyotonPRO device is a reliable tool for measuring the tone, stiffness, and elasticity of the iliotibial band in healthy individuals.