Diaphragm Pacing
Conditions
Keywords
breathing exercise, autonomic regulation, cognitive function, functional near-infrared spectroscopy
Brief summary
This study aims to investigate the effects of a combined thoracic expansion exercise (TEE) and slow diaphragmatic breathing (SDB) program on cognitive function, brain activation, psychological status, and head-shoulder posture in healthy young adults.
Interventions
OTHERthoracic expansion exercises and slow diaphragmatic breathing
4-week supervised training program, consisting of three 30-minute sessions per week. Thoracic expansion exercises consists of chest wall stretching and mobility drills. Followed by 15 minutes of progressive slow diaphragmatic breathing (4-s inhalation/6-s exhalation).
OTHERSham Block
During sham TEE, participants perform comfortable thoracic movements without foam rollers or specific breathing coordination. During sham SDB, they maintain a spontaneous, natural respiratory rhythm in relaxed postures. Crucially, the sham protocol lacks the rhythmic pacing (4:6s), diaphragmatic depth cues, and resistance-based progression required to trigger the neuro-cognitive "respiratory-brain" axis.
Sponsors
National Taiwan University Clinical Trial Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
1. age between 18 to 30 years with at least a high school education to ensure baseline cognitive task comprehension 2. the ability to adhere to verbal instructions 3. no regular participation in formal breathing exercise or mindfulness training within the past six months.
Exclusion criteria
1. a history of musculoskeletal, cardiovascular, or cerebrovascular diseases which may interfere this study 2. history of respiratory disease or recent respiratory infection 3. diabetes mellitus with neuropathy, peripheral neuropathy, or other neurological disorders 4. major surgery within the past six months 5. Current or past major psychiatric disorders or cognitive impairment 6. use of medications significantly affecting cerebral hemodynamics or autonomic function (e.g., beta-blockers, vasodilators) within the past 2 weeks 7. use of psychotropic medications or substances known to alter cerebral blood flow, neural activation, or autonomic regulation (e.g., antidepressants, antipsychotics, anxiolytics, stimulants, or sedative-hypnotics).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline in Working Memory | Baseline, Week 5 (post-intervention) | Assessed by the 2-back task. The outcome is calculated as the change in accuracy (percentage of correct responses) and reaction time. Accuracy range from 0% to 100%. Higher accuracy and lower reaction time indicate better working memory capacity. |
| Change from baseline in Inhibitory Control | Baseline, Week 5 (post-intervention) | Measured by the Stop-signal task (SST). The outcome is the change in Stop-Signal Reaction Time (SSRT) in milliseconds. SSRT values typically range from 100 to 500 milliseconds, with lower scores (faster reaction time) indicating better inhibitory control. |
| Change from baseline in Mental Set Shifting | Baseline, Week 5 (post-intervention) | Assessed using the Wisconsin Card Sorting Test (WCST). The outcome include the number of categories achieved, perseverative errors and set-loss errors. Higher number of categories achieved, lower perseverative errors and set-loss errors indicate better cognitive flexibility and set-shifting ability. |
| Change from baseline in Short-Term Memory | Baseline, Week 5 (post-intervention) | Assessed using the Corsi Block-Tapping Task. The outcome is Corsi span score. The Corsi span is defined as the longest sequence accurately reproduced by participants. Scores range from 0 to 9 blocks, with higher scores indicating better short-term memory capacity. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Heart Rate Variability (HRV) | Baseline and Week 5 (post-intervention) | HRV will be assessed as a non-invasive marker of autonomic nervous system (ANS) flexibility and neurovisceral integration, reflecting the dynamic regulation of the prefrontal-vagal pathway. Higher HRV serves as a physiological indicator of superior executive function and emotional regulation, whereas lower values are linked to autonomic dysregulation and cognitive fatigue. Data will be captured using a validated Polar H10 chest strap and the Elite HRV application for precise R-R interval detection. Outcome measurement include time-domain indices (SDNN, RMSSD), frequency-domain measures (HF, LF, and LF/HF ratio), and non-linear metrics (SD1, SD2). Increased RMSSD and HF power will be interpreted as enhanced parasympathetic modulation, providing the physiological foundation for improved attentional control and neural efficiency. |
| Change in Posture Alignment | Baseline and Week 5 (post-intervention) | 1. Craniovertebral angle (CVA) Measured from a lateral-view in a relaxed standing position. Participants look forward and maintain a comfortable stance during image acquisition. The CVA is the angle between a line connecting the tragus of the ear to the C7 spinous process and a horizontal line passing through C7. A Smaller angle indicates more severe forward head posture. 2. Acromion-to-table distance (ATD) While supine, the vertical distance between the posterior aspect of the acromion and the table surface is measured. A larger distance indicates increased rounded shoulder posture or thoracic kyphosis. |
| Change in Psychological status | Baseline and Week 5 (post-intervention) | The Traditional Chinese version of Depression Anxiety Stress Scales-21 (DASS-21) will be used to assess negative emotional states including depression, anxiety, and stress. DASS-21 contains 21 items, with 7 items assigned to each subscale. Participants rate their symptoms over the past week on a 4-point scale ranging from 0 ("did not apply to me at all") to 3 ("applied to me very much or most of the time") in each question. Subscale scores are obtained by summing the 7 items and multiply by two within each domain, with higher scores indicating greater severity of emotional distress. |
| Change in Brain Activation | Baseline and Week 5 (post-intervention) | Brain activation in the prefrontal cortex, primary motor cortex, supplementary motor area, and premotor cortex during tasks is assessed using functional near-infrared spectroscopy (fNIRS). The specific metric reported is the change in the concentration of oxygenated hemoglobin (HbO). Higher HbO values indicate increased regional cerebral blood flow and higher brain activation. |
Contacts
CONTACTYun Syuan Lin
PRINCIPAL_INVESTIGATORYan Ci Liu
School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University
Outcome results
None listed