## 4 Discussion
[61], who observed increased relaxation in the gastrocnemius muscles following ischemic compression on latent trigger points, commonly used for pain relief, inducing an improvement in range of motion and muscular relaxation. Moreover, MTrPs therapy of the trapezius muscle may prevent the development of dysfunction within the stomatognathic system, as the introduction of myofasical pain in the trapezius contributes to functional imbalances within the stomatognathic system [16]. The results of this study reveal that the type of physical activity significantly affects the muscle tone and the biomechanical and viscoelastic properties as measured by myotonometry. These findings highlight a complex interaction between the kind of exercise performed and its effects on muscle properties, demonstrating the importance of considering specific muscle groups and exercise types in such assessments. This study is not without its limitations. The sample size was small and comprised only healthy individuals, which may not be representative of the broader population, especially those with temporomandibular disorders (TMDs), who were not included in this study. The primary aim was to investigate the effects of guided exercise interventions designed to mobilise orofacial and neck muscles or the effects of heavy chewing in a healthy sample. However, this focus meant that only acute effects were studied, leaving long-term impacts unexplored. Moreover, the study could have benefited from multiple time points during the intervention to better capture the time course of changes in myotonometric parameters through more frequent assessments. The absence of randomization and the potential for carry-over effects between interventions, along with exclusion criteria that did not account for shoulder pathology or posture abnormalities, further limit the generalizability of our findings. Another notable limitation was the absence of a control condition without any intervention, which would have provided a clearer understanding of the distinct effects of each intervention. However, previous studies have demonstrated the high inter-visit reliability of the Myoton device, suggesting that no significant changes in myotonometric parameters would be expected after a period of rest. Nonetheless, we recommend that future research include a control condition to better differentiate these effects. Moreover, the masseter and upper trapezius muscles differ significantly in their inherent characteristics, which may influence the outcomes observed in this study. The masseter, predominantly influenced by genetic factors such as variations in the ACTN3 gene, exhibits structural and functional traits linked to craniofacial morphology [65]. In contrast, the upper trapezius, with its dual mesodermal origin and susceptibility to myofacial trigger points, reflects a more complex interplay of developmental and functional influences [66]. A further limitation of this study was that the presence of myofascal trigger points (MTrPs) was not assessed. This omission represents a drawback, as MTrPs in the upper trapezius and TMDs are known to be associated with alterations in the electromyographic activity patterns of masticatory muscles. Future research should include an evaluation of MTrPs to address this limitation [67]. Additionally, the study did not analyse the results based on sex. Myotonometry also has restrictions in its ability to measure muscles covered by thick subcutaneous fat (>20 mm) or tissues not categorised as soft biological tissue. Our study involved the repeated measurements of the masseter and upper trapezius muscles in subjects with a normal body mass index (BMI between 20 and 24). Moreover, when used according to instructions, the Myoton device does not require any additional assessments of subcutaneous fat and connective tissue with ultrasound. Finally, the sequential measurement of different muscles due to equipment constraints may have introduced additional variability.