Immediate effects of 90 degree versus 45 degree inversion on cerebral hemodynamics and HRV in yoga practitioners: A randomized controlled trial
Overview
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Tarun Kumar S
- Enrollment
- 30
- Locations
- 1
- Primary Endpoint
- Change in cerebral haemodynamics (blood flow velocity in the middle cerebral artery measured by transcranial Doppler).
Overview
Brief Summary
This randomized controlled trial aims to compare the immediate physiological effects of two inversion angles, 90 degrees and 45 degrees, on cerebral hemodynamics and heart rate variability (HRV) in healthy yoga practitioners. The study is based on traditional yogic texts, which describe spontaneous activation of Jalandhara Bandha (throat lock) during deeper inversions that may influence cerebral autoregulation.
During 90-degree inversion (Sarvangasana), Jalandhara Bandha activation mechanically influences the carotid sinus. The carotid sinus baroreceptors act as sensors responding to the stretch in the carotid artery when the mean arterial pressure increases. Type 1 (dynamic) baroreceptors have large myelinated A-fibers, while Type 2 (tonic) have small A and unmyelinated C-fibers. When arterial pressure rises, these receptors in the carotid sinus and aortic arch send afferent signals via the glossopharyngeal nerve to the nucleus tractus solitarius (NTS) in the brainstem. This activation enhances parasympathetic tone and suppresses sympathetic activity, leading to reflex bradycardia and systemic vasodilatation.
Thirty yoga practitioners aged 18 to 35 years with a Minimum of 1 year of regular yoga practice, familiarity with inversion postures like sarvangasana and vipareeta karani. will be randomized equally into two groups. Group A will perform a 90-degree inversion posture (Sarvangasana type), and Group B will perform a 45-degree inversion posture (Vipareeta Karani Mudra).
Cerebral blood flow velocity will be measured using transcranial Doppler, and HRV parameters will be assessed using ECG at three time points – before, during, and immediately after the posture. Data will be analyzed using repeated measures ANOVA to compare within and between-group changes over time.
The study seeks to understand how inversion angle and Jalandhara Bandha activation influence cerebral autoregulation and autonomic modulation through carotid baroreceptor mechanisms in yoga practitioners.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Masking
- None
Eligibility Criteria
- Ages
- 18.00 Year(s) to 35.00 Year(s) (—)
- Sex
- All
Inclusion Criteria
- •Healthy yoga practitioners aged 18 to 30 years.
- •Minimum of 1 year of regular yoga practice, familiarity with inversion postures like sarvangasana and vipareeta karani mudra.
- •Ability to perform inversion postures safely under supervision.
- •Willing to participate and provide an informed consent form.
Exclusion Criteria
- •History of cardiovascular, neurological, and psychiatric disorders.
- •Recent history of cervical spine, neck, and back injuries.
- •Vertigo, severe migraine, and neurological disorders affecting balance.
- •Pregnancy and lactation.
- •Any contraindications to yoga inversions, as determined by clinical assessment.
Outcomes
Primary Outcomes
Change in cerebral haemodynamics (blood flow velocity in the middle cerebral artery measured by transcranial Doppler).
Time Frame: Assessed before, during, and immediately after a single session of the assigned inversion posture. | Baseline (Pre): before the inversion posture (resting supine position) | During: while maintaining the inversion posture (at 1–2 minutes) | Post: immediately after completion of the posture (within 1 minute of returning to supine)
Secondary Outcomes
- Change in heart rate variability (HRV) — time-domain (SDNN, RMSSD) and frequency-domain (LF, HF, LF/HF ratio) parameters.
Investigators
Tarun Kumar S
S-VYASA University