The Impact of Diaphragmatic Breathing Instructions and Inspiratory Pressures on Diaphragm Contraction in Healthy Adults

Diaphragm Clinical Trial

Official title:

Diaphragmatic and Sternocleidomastoid Muscle Recruitment at Various Inspiratory Loads With and Without Breathing Instruction in Healthy Adults

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT06347549
• Other study ID #: HE-SF2024/09
• Status: Not yet recruiting
• Start date: April 15, 2024
• Est. completion date: April 15, 2026

Study information

• Verified date: March 2024
• Source: Hong Kong Metropolitan University
• Contact: Fang LIU
• Phone: +8613603049475
• Email: s1350035[@]live.hkmu.edu.hk
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

This is a cross-sectional obsessional study. This study aims (1) to investigate the relationship between sternocleidomastoid muscle recruitment and diaphragm thickness fraction during increasing inspiratory resistance in healthy adults; (2) to compare diaphragmatic and sternocleidomastoid muscle recruitment patterns with and without a standard diaphragmatic breathing instruction with increasing inspiratory resistance in healthy adults. Participants will be asked to breathe through a pressure threshold inspiratory loading device under different inspiratory resistances with and without a standard diaphragmatic breathing instruction. sternocleidomastoid muscle activity will be measured with surface electromyography, and diaphragm thickness will be assessed with ultrasonography.

Description:

Upon arrival at the laboratory, eligible participants will first perform a standard spirometry lung function test. The maximum inspiratory pressure (MIP) will be determined with a pressure threshold inspiratory loading device (POWERbreathe, K2). Each participant will then be instructed to use the device to perform, in random order, 10 breaths at an inspiratory intensity of 30%, 40%, 50%, 60%, 70%, and 80% MIP. A rest period of 15 minutes will be allowed between each inspiratory pressure set of 10 breaths. Simultaneous surface electromyographic (sEMG) recording of the right sternocleidomastoid muscle and ultrasound of right diaphragmatic thickness will be conducted during each breath. The entire recording procedure will be repeated on a separate day. During the repeat measurements, participants will be provided with specific breathing instruction to focus on the use of the diaphragm and to inhale air to the lower part of the chest. Practice trials will be conducted to ensure participant's understanding of diaphragmatic breathing.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 36
• Est. completion date: April 15, 2026
• Est. primary completion date: April 15, 2026
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• Participants =18 years of age with normal health

Exclusion Criteria:

• Pregnancy.
• Participants with known cardiovascular, pulmonary, musculoskeletal or psychiatric disorders.
• Participants with respiratory symptoms (from flu or other respiratory infection during the 2 weeks prior to measurements.

Related Conditions & MeSH terms

• Diaphragm
• Respiratory Aspiration

Intervention

Diagnostic Test:
• Various intensities of inspiratory muscle training
Each participant will be instructed to use a pressure threshold inspiratory loading device to perform, in random order, 10 breaths at an inspiratory intensity of 30%, 40%, 50%, 60%, 70%, and 80% of their maximum inspiratory pressure (MIP). A rest period of 15 minutes will be allowed between each inspiratory pressure set of 10 breaths. Simultaneous surface electromyographic (sEMG) recording of the right sternocleidomastoid muscle and ultrasound of right diaphragmatic thickness will be conducted during each breath. The entire recording procedure will be repeated on a separate day. During the repeat measurements, participants will be provided with specific breathing instruction to focus on the use of the diaphragm and to inhale air to the lower part of the chest.

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
Hong Kong Metropolitan University

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Diaphragmatic thickening fraction	Diaphragmatic thickening fraction is determined by "(thickness of the diaphragm at end inspiratory - thickness at end expiratory)/thickness at end expiratory". Diaphragmatic thickness will be measured by ultrasonography.	Through study completion, an average of 1 year
Secondary	Muscle activation of the sternocleidomastoid muscle	Surface electromyography will be used to measure accessory inspiratory muscle (sternocleidomastoid muscles) activity during each inspiratory muscle training intensity.	Through study completion, an average of 1 year
Secondary	Perceived Exertion Borg scale	This is a vertical scale quantified from 0 to 10, where 0 represents no symptoms, and 10 represents the maximum symptoms. The Borg score provides an individual measurement of the exercise intensity.	Through study completion, an average of 1 year