MyotonPRO as a new valid tool for measuring cervical muscle tension. A reliability study

Area of Science:

• Biomechanics
• Speech-Language Pathology
• Medical Device Technology

Background:

• Muscle tension dysphonia is a voice disorder often diagnosed subjectively.
• Objective biomechanical measurements of relevant muscles could aid diagnosis and treatment evaluation.
• Non-invasive methods are desirable for assessing cervicofacial muscle function.

Purpose of the Study:

• To assess the reliability of a handheld myotonometer for measuring biomechanical properties of cervicofacial muscles.
• To evaluate the potential of this method for diagnosing voice disorders, particularly muscle tension dysphonia.
• To determine inter- and intra-rater reliability of the myotonometer measurements.

Main Methods:

• A prospective pilot study involving 10 subjects.
• Measurements of frequency, stiffness, elasticity, relaxation time, and creep using a MyotonPRO handheld myotonometer.
• Inclusion of masseter, sternocleidomastoid, orbicularis oris, semispinalis capitis, suprahyoid, infrahyoid, and trapezius muscles.
• Inter- and intra-rater reliability assessed by two evaluators.

Main Results:

• Good to excellent inter-rater reliability was found for masseter, sternocleidomastoid, trapezius, and suprahyoid muscles.
• Good to excellent intra-rater reliability was observed for masseter, sternocleidomastoid, semispinalis capitis, and suprahyoid muscles.
• Lower reliability (ICC) was noted for stiffness and creep properties across several muscles.

Conclusions:

• Myotonometer measurement of mechanical properties in cervical and orofacial muscles is a reliable and reproducible technique.
• Further research is needed to link muscle properties to voice disorders and validate the tool for objective diagnosis and treatment monitoring.