Publications

• Our results showed that MyotonPRO showed high reproducibility and reliability in the assessment of resting muscle tone in children with SMA.
• With an aim to observe peripheral changes easily, MyotonPRO can be an easy and quick assessment approach compared to EMG for quantifying skeletal muscle mechanical properties. This tool may help clinicians and researchers examine peripheral changes in the pathogenesis of SMA within the framework of skeletal muscle mechanical properties, to reach objective data on changes in skeletal muscle properties, and to observe changes in motor evaluation criteria.
• Myotonometer is simple to use and well tolerated by children, and also obtaining and interpreting data are quite easy to perform.

Background/Objectives: This study aimed to examine intra- and inter-rater reliability of a myotonometer (MyotonPRO) in measuring upper and lower extremity mechanical properties in children with spinal muscular atrophy types I and II.

Methods: Biceps brachii, triceps brachii, rectus femoris, and gastrocnemius muscle tone and stiffness in children (n = 21) were measured using the MyotonPRO device. Examiner 1 performed two sets of measurements in 60 min to determine intra-rater reliability. Examiner 2 performed measurements between Examiner 1’s sets. Intra-interclass correlation coefficient, minimal detectable change, and standard error of measurement values were calculated to assess intra- and inter-rater reliabilities in this cross-sectional study.

Results: The results showed excellent intra- and inter-rater reliability analyses for frequency and stiffness values except for the stiffness value of the gastrocnemius muscle, which presented good reliability (ICC = 0.71). Minimal detectable change values ranged from 0.59 to 1.98 Hz for muscle tone and 16.08 to 124.74 N/m for stiffness (for both intra- and inter-rater reliabilities).

Conclusions: Our findings indicate that MyotonPRO is a reliable tool for quantifying upper and lower extremity mechanical properties within one session in children with spinal muscular atrophy types I and II. Mechanical properties of the extremity muscle can be determined using this easily applied tool in future studies.

Keywords: muscle tone, myotonometry, muscle stiffness, reliability, spinal muscular atrophy

In conclusion, the results of this research show that MyotonPRO is a reliable device for clinicians to quantify the mechanical properties of upper and lower extremity muscle tone and stiffness in individuals with SMA Types I and II aged between 1 and 4 years old. Nevertheless, these study results are limited only to session repeatability, and day-to-day reliability still needs to be examined. The high reliability in the repeatability and reproducibility of MyotonPRO in this study will contribute to future studies.