Mandibular stretching and 4-4-8 breathing for autonomic nervous system activity

Investigation of the Effects of Mandibular Stretching Exercise and 4-4-8 Breathing Exercise on Autonomic Nervous System Activity, Muscle Tone, and Psychological State: A Randomized Controlled Trial

This will test whether jaw-stretching and 4-4-8 breathing change nervous system activity, muscle tension, and psychological state in healthy university students.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 52 (estimated)
• Ages: 18 Years to 30 Years
• Sex: All
• Sponsor: Necmettin Erbakan University (Academic / other)
• Locations: 1 site (Konya, Konya)
• Trial ID: NCT07472010 on ClinicalTrials.gov

What this trial studies

This randomized controlled trial will enroll healthy university students aged 18–30 and randomly assign them to intervention groups involving mandibular stretching, 4-4-8 breathing, or the study protocol's comparison condition. Baseline and post-intervention measurements of autonomic nervous system parameters, muscle tone, and psychological status will be collected. The interventions are non-invasive and performed by participants according to standardized instructions over the intervention period. Study outcomes aim to determine whether these simple exercises produce measurable physiological or psychological changes.

Who should consider this trial

Good fit: Healthy university students aged 18–30 who can perform the jaw stretching and 4-4-8 breathing exercises and have no neurological, musculoskeletal, or respiratory disorders or medications affecting the autonomic nervous system.

Not a fit: People with jaw, neck, or respiratory disorders, neurological disease, or those taking medications that affect autonomic function are unlikely to benefit and are excluded from participation.

Why it matters

Potential benefit: If successful, these simple, low-cost exercises could offer a non-drug way to improve autonomic balance, reduce muscle tension, and support psychological well-being in young adults.

How similar studies have performed: Prior small studies suggest breathing techniques can alter autonomic markers like heart rate variability, but the combined or comparative effects with mandibular stretching remain largely untested.

Eligibility criteria

Inclusion Criteria:

* Inclusion Criteria:
* Healthy university students
* Age between 18 and 30 years
* Voluntary participation in the study
* Ability to understand and perform mandibular stretching exercise and 4-4-8 breathing exercise

Exclusion Criteria:

* History of neurological disorders
* Musculoskeletal disorders affecting the jaw, neck, or respiratory system
* Respiratory diseases
* Use of medications that may affect the autonomic nervous system
* Inability to perform the exercises required in the study

Where this trial is running

Konya, Konya

• Necmettin Erbakan University — Konya, Konya, Turkey (Türkiye) (Recruiting)

Study contacts

• Principal investigator: Neslihan Altuntaş YILMAZ, PhD — Necmettin Erbakan University
• Study coordinator: Mehin Mammadzada, MSc Student

Conditions Muscle Tone; Psychological State; Autonomic Nervous System; Mandibular Stretching Exercise; 4-4-8 Breathing Exercise; Breathing Techniques