Diaphragm
Conditions
Keywords
Diaphragmatic thickening fraction, Sternocleidomastoid muscles, Inspiratory pressures
Brief 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.
Detailed 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.
Interventions
DIAGNOSTIC_TESTVarious 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.
Sponsors
Hong Kong Metropolitan University
Study design
Observational model
CASE_CROSSOVER
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
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. * Participants can not cooperate the maximal inspiratory pressure measurement.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Diaphragmatic thickening fraction | Through study completion, an average of 1 year | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Muscle activation of the sternocleidomastoid muscle | Through study completion, an average of 1 year | Surface electromyography will be used to measure accessory inspiratory muscle (sternocleidomastoid muscles) activity during each inspiratory muscle training intensity. |
| Perceived Exertion Borg scale | Through study completion, an average of 1 year | 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. |
Countries
China
Outcome results
None listed