The Effects of Inspiratory Pressures on Diaphragmatic Contraction in People After Stroke

The Effects of Different Inspiratory Pressures on the Diaphragmatic Thickness Fraction and Sternocleidomastoid Muscle Activation in People After Stroke

This is a cross-sectional study to determine the optimal inspiratory muscle training (IMT) intensity for stroke survivors. Participants will breathe through a pressure threshold inspiratory loading device with varying loads in random order. Each IMT intensity protocol consists of 10 breaths. During the test, accessory inspiratory muscle activity will be measured with surface electromyography (sEMG) and diaphragm thickness will be used to assessed with ultrasonography. Repeated-measures ANOVA will be used for statistical analysis to determine the most effective training intensity for future study.

Study Overview

• Status: Completed
• Conditions: Stroke
• Intervention / Treatment: Diagnostic test: Various intensities of inspiratory muscle training

• Study Type: Observational
• Enrollment (Actual): 36

Contacts and Locations

Study Locations

• China
  • None Selected
    • Shenzhen, None Selected, China
      • Shenzhen Second People's Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

People after stroke and healthy adults

Description

Recruitment of participants after a stroke:

The inclusion criteria are:

• clinical diagnosis of ischemic and/or hemorrhagic stroke.
• age ≥ 18 years.
• duration of stroke ranges from 1 month to 12 months after diagnosis.
• had no facial palsy, which could prevent proper labial occlusion.
• had not undergone thoracic or abdominal surgery.
• could understand and follow the verbal instruction.
• stable cardiac conditions.
• no previous history of respiratory problems.

The exclusion criteria are:

• acute myocardial infarction or acute heart failure.
• acute pain on chest or abdominal.
• with the clinical signs of significant pulmonary disease.
• consciousness impaired.
• patient with nasal feeding tube, tracheal tube and/or any condition, which prevent the measurement or training.

Recruitment of healthy participants:

The inclusion criteria are:

• age ≥ 18 years.
• had not undergone thoracic or abdominal surgery.
• no previous history of respiratory problems.

The exclusion criteria are:

• acute myocardial infarction or acute heart failure.
• acute pain in the chest or abdominal.
• with the clinical signs of significant pulmonary disease.
• unstable hypertension, arrhythmias, or unstable cardiovascular conditions, such as fluctuations in blood pressure and heart rate, indicate poor cardiac prognosis or the need for vasopressor medications.
• pregnant.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Stroke participants; People diagnosed with stroke and meeting all inclusion criteria will be included in this study.	Diagnostic test: Various intensities of inspiratory muscle training; Each participant will be asked to perform the lung function test to measure the maximal inspiratory pressure (MIP) after including the study. After the baseline measurement, all participants will be requested to use a nose clip to hold the nose and breathe with the mouth through a pressure threshold inspiratory loading device (POWERbreathe, KH2, England). The inspiratory pressure will be set at 30%, 40%, 50%, 60%, 70%, or 80% of their MIP, in random order. Each MIP intensity protocol consists of 10 breaths. Resting will be allowed between different protocols of contraction intensity (% MIP). During the test, sternocleidomastoid muscle activity will be measured with surface electromyography (sEMG) and diaphragm thickness will be used to assessed with ultrasonography.
Healthy participants; Healthy adults meeting all inclusion criteria will be included in this study.	Diagnostic test: Various intensities of inspiratory muscle training; Each participant will be asked to perform the lung function test to measure the maximal inspiratory pressure (MIP) after including the study. After the baseline measurement, all participants will be requested to use a nose clip to hold the nose and breathe with the mouth through a pressure threshold inspiratory loading device (POWERbreathe, KH2, England). The inspiratory pressure will be set at 30%, 40%, 50%, 60%, 70%, or 80% of their MIP, in random order. Each MIP intensity protocol consists of 10 breaths. Resting will be allowed between different protocols of contraction intensity (% MIP). During the test, sternocleidomastoid muscle activity will be measured with surface electromyography (sEMG) and diaphragm thickness will be used to assessed with ultrasonography.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Data will be measured at baseline and at the end of each inspiratory muscle training intensity protocol;

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 protocol.	Data will be measured at baseline and at the end of each inspiratory muscle training intensity protocol;
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.	Data will be measured at the end of each inspiratory muscle training intensity protocol;

Collaborators and Investigators

• Sponsor: Hong Kong Metropolitan University
• Collaborators: Shenzhen Second People's Hospital
• Investigators: Principal Investigator: Tsang William, Hong Kong Metropolitan University

Study record dates

Study Major Dates

• Study Start (Actual): March 2, 2024
• Primary Completion (Actual): August 17, 2024
• Study Completion (Actual): August 17, 2024

Study Registration Dates

• First Submitted: February 4, 2024
• First Submitted That Met QC Criteria: February 15, 2024
• First Posted (Actual): February 20, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 27, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Keywords: Stroke; Diaphragmatic thickening fraction; Sternocleidomastoid muscles; Inspiratory pressures
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Respiratory Tract Diseases; Respiration Disorders; Stroke; Respiratory Aspiration
• Other Study ID Numbers: REC Reference No.:HE-OT2023/13; Proj.Ref.No.: 2023/3007-R7052 (Other Grant/Funding Number: Research Donation Fund, Hong Kong Metropolitan University)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No