Publications
Acute Myotonometric Changes in the Masseter and Upper Trapezius Muscles After Upper Body Quarter Stretching and Coordination Exercises or Chewing
Authors: Marsa Magdic 1, Milos Kalc 2, Matjaz Vogrin 1, 3
Affiliations:
- Institute of Sports Medicine, Faculty of Medicine, University of Maribor, 2000 Maribor, Slovenia
- Institute for Kinesiology Research, Science and Research Centre Koper, 6000 Koper, Slovenia
- Department of Orthopaedics, University Medical Centre Maribor, 2000 Maribor, Slovenia
Journal: Applied Sciences - January 2025, Volume 15, Issue 1, Article no. 344 (DOI: 10.3390/app15010344)
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Field & Applications:
- Medical
- Treatment evaluation
- Musculoskeletal disorder
- Temporomandibular disorder
- Orofacial muscles
- Muscle development / Performance
Pathologies in neck and masticatory muscles affect muscle tone and biomechanical and viscoelastic properties, necessitating precise assessment for treatment.
This study evaluated the impact of two guided interventions – relaxing exercises targeting the neck and masticatory muscles (“Exercise”) and heavy chewing using six chewing gums (“Chewing”) – on the masseter and upper trapezius muscles. Twelve participants (aged 19-40 years) underwent myotonometric assessment pre- and post-intervention, measuring tone, stiffness, decrement, relaxation time, and creep.
The results showed significant changes in the masseter muscle after exercise, with increased stiffness (14.46%, p < 0.001) and tone (7.03%, p < 0.001) but decreased creep (-9.71%, p < 0.001) and relaxation time (-11.36%, p < 0.001). Conversely, chewing decreased stiffness (-8.82%, p < 0.001) and tone (-5.53%, p < 0.001), while it increased creep (9.68%, p < 0.001) and relaxation time (9.98%, p < 0.001). In the trapezius muscles, tone decreased after both interventions (Exercise: -7.65%, p < 0.001; Chewing: -1.06%, p = 0.003), while relaxation increased (Exercise: 1.78%, p < 0.001; Chewing: 2.82%, p < 0.001).
These findings reveal the distinct effects of exercise and chewing on muscle properties, emphasising the complexity of their therapeutic potential and the need for further investigation.
Figure 1. Study design and methodology overview. (a) Study design. (b) Position of the MyotonPRO probe on the masseter muscle. (c) Position of the MyotonPRO probe on the upper trapezius muscle. (d) MyotonPRO probe. (e) MyotonPRO parameters.
Keywords: exercise, mastication, muscle tonus, relaxation techniques, relaxation therapy, temporomandibular joint disorders, masseter muscle, trapezius muscle, bruxism, intervention studies
In conclusion, this study examined the effects of a guided exercise intervention and heavy chewing on the masseter and upper trapezius muscles. The results, which did not align with our hypotheses, highlight a complex relationship exists between these interventions and muscle properties. These findings emphasise the need for further research to better understand the therapeutic potential of exercise interventions for TMDs and shoulder-neck dysfunctions.