Publications

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

Objective: This study aimed to evaluate sternocleidomastoid (SCM) muscle properties in infants with Congenital Muscular Torticollis (CMT) using myotonometry and determine its sensitivity to changes following physiotherapy.

Methods: Twenty-five infants (0-12 months) diagnosed with CMT participated in this study from May 2023 to February 2024. They underwent an 8-week physiotherapy program. Muscle tone, elasticity, and stiffness were measured using myotonometry, muscle strength by the Muscle Function Scale (MFS), and neck range of motion by an arthrodial protractor before and after treatment.

Results: The mean age was 4±1.56 months. Significant differences in SCM tone and stiffness between affected and intact sides were observed pre-treatment (p<0.05) but were not significant post-treatment (p>0.05). Intra-group improvements were significant for muscle tone (p=0.005), elasticity (p=0.009), stiffness (p=0.009), strength (p=0.006), and neck range of motion (p=0.021). Muscle tone decreased by 19.65%, muscle stiffness by 24.99%, and muscle elasticity improved by 9.42%. Passive lateral flexion increased by 59.09% and passive rotation by 25.40%.

Conclusions: SCM muscle properties differ between sides in individuals with CMT; however, myotonometry effectively detects improvements following physiotherapy, making it a valuable clinical evaluation tool. Nevertheless, the relatively small sample size should be taken into account when interpreting the findings.

Keywords: congenital muscular torticollis, muscle elasticity, muscle stiffness, muscle tone, physiotherapy

This study demonstrates that physiotherapy and rehabilitation programs positively influence the properties of the SCM muscle in infants with torticollis by reducing muscle tone and stiffness, increasing elasticity, and improving neck joint range of motion. Beyond highlighting these outcomes, the findings suggest important implications for clinical practice.

The ability of the myotonometer to detect changes in muscle biomechanics supports its potential use as an objective tool for monitoring treatment response, particularly in early intervention settings where accurate and quantifiable assessment methods are essential. Moreover, as this is the first study to apply the myotonometer to evaluate muscle elasticity in torticollis, it provides preliminary evidence for the device’s clinical utility and warrants further validation. Given its portability, ease of use, and cost-effectiveness, myotonometry represents a non-invasive and accessible alternative to imaging-based modalities for assessing muscle properties in both clinical and research settings. Future research should focus on the device’s role in guiding individualized therapy, compare muscle properties in infants with and without fibromatosis colli, and include larger sample sizes to strengthen generalizability and clinical relevance.