The increase in the tension of the soft tissues around a nerve restricts the movement, affects the function of the nerve, and makes the nerve vulnerable to entrapment. Even a mild nerve compression can cause entrapment and lead to neuroinflammation. It is known that inflammatory mediators amplify axonal sensitivity. Although the spontaneous discharge potential of visceral afferents is quite low under normal conditions, neuroinflammation increases the excitability of these fibers. With this mechanism, hyperalgesia may develop in sensory fibers in neuroinflammation. This may cause pathologies in the organs innervated by the relevant nerve.

The fascia and muscles of the cervical region surround the vagus nerve. There are two main fascial compartments in the cervical region. The SCM and trapezius muscle fascias join to the most superficial fascia of the deep cervical fascia and they together form these compartments. These fasciae superiorly attach to the cranium and inferiorly to the pectoral region. The vagus nerve emerges from the jugular foramen together with the 9th and 11th cranial nerves. It then continues through the carotid sheath in the cervical region. The carotid sheath is in contact with the SCM muscle. For this reason, it can be thought that SCM muscle tension or thickness may affect the carotid sheath and thus the function of the vagus nerve passing through it.

In summary, deterioration in vagus nerve activity plays a role in pathologies of the organs innervated by the vagus. Although the relationship between vagal dysfunction and gastrointestinal system symptoms is clear, the mechanisms affecting vagus nerve function have not yet been clarified. It has been reported in the literature that some maneuvers from the cervical region are also effective on the vagus nerve. Also, according to investigators' clinical experience, gastrointestinal symptoms are frequently observed in patients with increased cervical soft tissue tension. However, there are not enough studies investigating whether the cervical region soft tissue tension can affect the gastrointestinal system via the vagus nerve. Therefore, this study was planned to examine the relationship of cervical soft tissue tension with vagus nerve function and gastrointestinal symptoms in asymptomatic individuals and individuals with neck pain.

Inclusion Criteria:

• Being 18-50 of age,
• Having less than 30 body mass index,
• Being a volunteer

Exclusion Criteria:

• Having any type of malign disease,
• Being diagnosed with a systemic disease (cardiologic, gastrointestinal, rheumatological, neurological, etc.),
• Having any type of surgery within the last 6 months,
• Being diagnosed with Whiplash syndrome
• Having an unhealed fracture
• Pregnancy
• Using prescribed medicine for the gastrointestinal system