Publications

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

Background: Obstructive Sleep Apnea Syndrome (OSAS) is characterized by repetitive upper airway obstruction during sleep. The viscoelastic properties of accessory respiratory muscles may play a compensatory role in maintaining airway patency. This study aimed to investigate the association between OSAS risk and muscle biomechanics in industrial workers.

Methods: This cross-sectional study included 236 male industrial workers aged 18–55, categorized into low, moderate, and high OSAS risk groups using the STOP-BANG questionnaire. The viscoelastic properties (tone, stiffness, elasticity) of the genioglossus, sternocleidomastoid, and masseter muscles were assessed using the MyotonPRO device. Sociodemographic and occupational data were collected. Statistical analyses included Kruskal-Wallis and Spearman correlation tests and additionally, univariate and multivariate linear regression.

Results: A significant difference was found only in left genioglossus tone across STOP-BANG risk groups (p < 0.05). Age and BMI were moderately associated with increased muscle stiffness and reduced elasticity, particularly in the SCM and masseter muscles. In regression analyses, right SCM stiffness and BMI were significant in the univariate model; however, after adjusting for age, BMI, smoking and duration of employment, only right SCM stiffness remained an independent predictor of STOP-BANG score (β ≈ 0.01, p < 0.05).

Conclusions: Muscle viscoelastic properties are influenced not only by OSAS risk but also by age, BMI, occupational exposure, and smoking. Importantly, SCM stiffness may serve as a potential biomechanical marker associated with OSAS risk. Muscle biomechanics assessments could be used as a supportive, non-invasive screening tool in high-risk occupational populations.

Keywords: occupational health, obstructive sleep apnea, upper airway muscles, viscoelastic properties

This study provides preliminary evidence that the viscoelastic properties of upper airway-related muscles may vary according to OSAS risk levels in industrial workers. The significant difference detected particularly in the left Genioglossus muscle supports its critical role in maintaining airway patency. Although no significant group differences were found for other muscles (Sternocleidomastoid and Masseter), their relationships with individual factors such as age, body mass index, and duration of employment indicate that occupational and physiological influences affect their viscoelastic properties.

The significant positive correlations observed between duration of employment and muscle elasticity, especially in individuals with moderate and high OSAS risk, reflect the physiological imprint of prolonged occupational loading. These findings suggest that biomechanical muscle measurements could serve as early indicators of physiological strain within the industrial workforce.

Given that OSAS is known to increase attention deficits, daytime fatigue, and occupational accident risk, early identification of this disorder is critical for occupational health. In this context, the use of viscoelastic muscle measurements as a screening tool for individuals working in shift or physically demanding jobs may offer occupational physicians a practical and novel approach.

In conclusion, integrating non-invasive muscle biomechanics assessment methods into occupational health screening protocols could contribute to the early detection and prevention of work-related risks. Future multicenter, longitudinal studies will further clarify the diagnostic and predictive value of these biomechanical parameters.