This non-invasive system is activated by the cutaneous distribution of vagus nerve afferents via the external ear.

Manual therapy is effective in the treatment of musculoskeletal pain.

This non-invasive system is activated by the cutaneous distribution of vagus nerve afferents through the external ear. Somatosensory innervation is provided by the auricular branch.

Heart rate variability (HRV) is an indicator of the effects of these two components on the heart, reflecting the variations in the time intervals between heartbeats. High HRV generally indicates good autonomic balance and a healthy cardiovascular system, while low HRV can be a sign of stress, fatigue, or underlying health issues. When sympathetic nervous system activity increases, heart rate accelerates and HRV decreases; conversely, when parasympathetic nervous system activity increases, heart rate slows and HRV increases. Therefore, HRV is an important biomarker for assessing overall health status and developing stress management strategies.

The neck disability index is the most commonly used functional outcome tool for disabilities in the cervical region. This outcome assessment tool was created by modifying the Oswestry Disability Index and is highly reliable (Chad E. Cook, Amy E. Cook 2011).

Scoring is given for each question as A: 0 points, B: 1 point, C: 2 points, D: 3 points, E: 4 points, F: 5 points. The total score gives the test score. According to the test result 0-4=No disability 5-14= Mild disability 15-24= Moderate disability 25-34 = Severe disability

Range of motion is the ability of a joint to go through the full range of motion. The range of motion of a joint can be passive or active. Passive ROM - The maximum range of motion through which the joint can move with the aid of external force. Active ROM - the range of motion achieved by contracting and relaxing opposing muscles

The visual analogue scale (VAS) is a validated, subjective measure of acute and chronic pain. Scores are recorded by placing a handwritten mark on a 10 cm line representing the continuum between "no pain" and "worst pain"