Reliability of tensiomyography and myotonometry in detecting mechanical and contractile characteristics of the lumbar erector spinae in healthy volunteers
Authors: Christine Lohr, Klaus-Michael Braumann, Ruediger Reer, Jan Schroeder, Tobias Schmidt
Institution(s): Osteopathic Praxis, Hamburg, Germany; Osteopathie Schule Deutschland (OSD), Hamburg, Germany
Journal: European Journal of Applied Physiology - July 2018, Volume 118, Issue 7, Pages 1349–1359 (DOI: 10.1007/s00421-018-3867-2)
Field & Applications:
Purpose: Tensiomyography™ (TMG) and MyotonPRO® (MMT) are two non-invasive devices for monitoring muscle contractile and mechanical characteristics. This study aimed to evaluate the test–retest reliability of TMG and MMT parameters for measuring (TMG:) muscle displacement (Dm), contraction time (Tc), and velocity (Vc) and (MMT:) frequency (F), stiffness (S), and decrement (D) of the erector spinae muscles (ES) in healthy adults. A particular focus was set on the establishment of reliability measures for the previously barely evaluated secondary TMG parameter Vc.
Methods: Twenty-four subjects (13 female and 11 male, mean ± SD, 38.0 ± 12.0 years) were measured using TMG and MMT over 2 consecutive days. Absolute and relative reliability was calculated by standard error of measurement (SEM, SEM%), Minimum detectable change (MDC, MDC%), coefficient of variation (CV%) and intraclass correlation coefficient (ICC, 3.1) with a 95% confidence interval (CI).
Results: The ICCs for all variables and test–retest intervals ranged from 0.75 to 0.99 indicating a good to excellent relative reliability for both TMG and MMT, demonstrating the lowest values for TMG Tc and between-day MMT D (ICC < 0.90). Absolute reliability was suitable for all parameters (CV 2–8%) except for Dm (10–12%). Vc demonstrated to be the most reliable and repeatable TMG parameter (ICC > 0.95, CV < 8%).
Keywords: Paraspinal muscles, Mechanomyography, Repeatability, Muscle contraction.
The reliability for TMG Vc could be established successfully. Its further applicability needs to be confirmed in future studies. MMT was found to be more reliable on repeated testing than the two other TMG parameters Dm and Tc.