Publications

Myoton Clarification Note: A Guide to Interpreting the Inverse Relationship Between Logarithmic Decrement and Tissue Elasticity

Background: Dehydration in children remains a common yet potentially life-threatening clinical challenge, particularly in primary care and emergency settings where rapid, objective, and non-invasive assessment tools are limited. Skin biomechanics may offer a new way of measuring hydration status.

Objective: To investigate the utility of a non-invasive skin biomechanical measurement device (MyotonPRO®) in differentiating hydration status in children aged 6 months to 6 years.

Methods: In this prospective case-control study conducted at Gaziantep University Hospital, 64 children were evaluated using the MyotonPRO® device at three anatomical sites: 1.5 cm above the umbilicus, and 4 cm above the wrist on the posterior surfaces of both arms. Dehydration was defined by serum osmolality ≥ 290 mOsm/kg or urine specific gravity > 1.025. Oscillation frequency, dynamic stiffness, and elasticity were measured and compared between dehydrated (n = 32) and non-dehydrated (n = 32) participants. Laboratory results and World Health Organization clinical dehydration scale findings were analysed and compared with the device measurements.

Results: Children in the dehydration group exhibited significantly lower oscillation frequency (18.75 ± 2.63 Hz vs. 20.64 ± 4.16 Hz; p = 0.034) and dynamic stiffness (430.06 ± 83.60 N/m vs. 499.78 ± 169.28 N/m; p = 0.042) in the right arm. Although similar results were observed in the left arm, there was no statistically significant difference. Biochemical markers such as creatinine, sodium, plasma osmolality, and urine specific gravity were significantly elevated in the dehydration group. Correlations were observed between MyotonPRO® parameters and serum creatinine, BUN, and albumin levels.

Conclusion: MyotonPRO® demonstrated significant differences in selected parameters (right arm oscillation frequency and stiffness), suggesting potential sensitivity to hydration status. However, its overall discriminative ability was limited. Therefore, MyotonPRO® may serve as a supportive, but not standalone, tool in clinical decision-making for monitoring hydration levels, particularly in primary care and emergency settings.

Keywords: pediatric dehydration, skin biomechanics, MyotonPRO, non-invasive assessment, primary care, fluid balance

This study is among the first to examine the use of a practical, non-invasive biomechanical device for evaluating pediatric dehydration. MyotonPRO measurements were feasible, rapid, painless, and sensitive to hydration-related changes in the selected parameters. Yet, because the discriminatory power was limited in this study, it cannot be accepted as an independent diagnostic tool at this stage. For now, the MyotonPRO® device should only be used as an adjunct to laboratory tests and clinical examinations. Nevertheless, the feasibility and sensitivity observed in this study highlight its promise and justify further evaluation in broader clinical contexts.