Effects of Inspiratory Muscle Training on Stroke Rehabilitation Outcomes

Effect of Inspiratory Muscle Training on Respiratory Function, Diaphragm Thickness, Balance Control, Exercise Capacity and Quality of Life in People After Stroke: a Randomized Controlled Trial

This study is designed to explore the effects of a 4-week protocol of inspiratory muscle training (IMT) at 50% maximum inspiratory pressure (MIP) on respiratory function, diaphragm thickness, balance control, exercise capacity, and quality of life in people after stroke. To ascertain the effect of IMT on the relationship between diaphragm muscle contraction and activation of other trunk muscles, this study also explores whether any effect of the 4-week IMT protocol on balance control is associated with changes in the anticipatory posture adjustments (APAs) time - the onset time of postural muscles during a required task (e.g., the rapid shoulder flexion test).

Study Overview

• Status: Recruiting
• Conditions: Stroke
• Intervention / Treatment: Other: sham IMT; Other: Conventional treatment; Other: IMT-stable group (sitting on a stable surface); Other: IMT-unstable group (sitting on an unstable surface)

• Study Type: Interventional
• Enrollment (Estimated): 84
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Fang LIU; Phone Number: +86 13603049475; Email: s1350035@live.hkmu.edu.hk
• Study Contact Backup: Name: William Wai-nam Tsang; Phone Number: 085239708703; Email: wntsang@hkmu.edu.hk

Study Locations

• China
  • None Selected
    • Shenzhen, None Selected, China
      • Recruiting
      • Shenzhen Second People's Hospital
      • Contact: Fang LIU; Phone Number: +8613603049475; Email: s1350035@live.hkmu.edu.hk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 40 years and < 80 years;
• breathing spontaneously;
• clinically diagnosed with ischemic and/or haemorrhagic stroke;
• duration of stroke from onset falls within 1 month to 12 months after diagnosis;
• no thoracic or abdominal surgery within the last 6 months;
• able to understand and follow verbal instructions;
• no facial palsy, or mild facial palsy without limitation of labial occlusion;
• able to maintain a resting sitting posture without feet support for at least 30 seconds;
• no cognitive impairment (Montreal Cognitive Assessment (MoCA) score ≥ 26);
• able to independently walk at least 10 meters with or without an assistive device.

Exclusion Criteria:

• acute myocardial infarction or acute heart failure;
• acute pain in any part of the body;
• with respiratory illness or positive clinical signs of impaired respiratory function (such as shortness of breath, hypoxemia, chronic cough and sputum retention);
• with chronic cardiovascular dysfunction;
• Trunk Impairment Scale (TIS) score ≥ 20.
• patient with a nasal feeding tube, tracheal tube and/or any condition that prevents the measurement or the implementation of the study procedure.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Group A (sham IMT- stable group); conventional treatment + sham IMT	Other: sham IMT; with 10% maximum inspiratory pressure (MIP) as the training intensity, IMT will be conducted on a stable surface; Other: Conventional treatment; Participants in all groups will receive a standardised conventional rehabilitation protocol. It includes limb range of motion, muscle tone reduction, strengthening and endurance of limb muscles, transfer skills, task-directed movements, general gait training, and activities of daily living training.
Experimental: Group B (IMT-stable group); conventional treatment + target IMT while sitting on a stable surface	Other: Conventional treatment; Participants in all groups will receive a standardised conventional rehabilitation protocol. It includes limb range of motion, muscle tone reduction, strengthening and endurance of limb muscles, transfer skills, task-directed movements, general gait training, and activities of daily living training.; Other: IMT-stable group (sitting on a stable surface); 50% MIP as the training intensity, IMT will be conducted while sitting on a stable surface
Experimental: Group C (IMT-unstable group); conventional treatment + target IMT while sitting on an unstable surface	Other: Conventional treatment; Participants in all groups will receive a standardised conventional rehabilitation protocol. It includes limb range of motion, muscle tone reduction, strengthening and endurance of limb muscles, transfer skills, task-directed movements, general gait training, and activities of daily living training.; Other: IMT-unstable group (sitting on an unstable surface); 50% MIP as the training intensity, IMT will be conducted while sitting on an unstable surface

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diaphragmatic thickness	The diaphragmatic thickness of both the left and right diaphragms will be measured by ultrasound. (Mindray M9, Shenzhen, China).	baseline, after 4 weeks of intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sitting Balance	A force plate will be used to measure changes in the center of pressure during the performance of various tasks in sitting positions.	baseline, after 4 weeks of intervention
Forced Vital Capacity (FVC)	Forced Vital Capacity (FVC) is a measurement used in pulmonary function tests to assess lung function. It refers to the total volume of air that a person can forcibly exhale from their lungs after taking the deepest breath possible. It will be measured using the spirometer.	baseline, after 4 weeks of intervention
Forced Expiratory Volume in one second (FEV1)	Forced Expiratory Volume in one second (FEV1) measures the volume of air a person can forcibly exhale in the first second of a forced breath. It will be measured using the spirometer.	baseline, after 4 weeks of intervention
Maximum Inspiratory Pressure (MIP)	Maximum Inspiratory Pressure (MIP) is a measure used in pulmonary function testing to assess the strength of the respiratory muscles, particularly the muscles used for inhalation. It will be measured using the spirometer.	baseline, after 4 weeks of intervention
Falls efficacy scale international	The Falls Efficacy Scale-International (FES-I) is a questionnaire measuring fear of falling in older adults. It has 16 items, scored from 1 to 4, with higher scores indicating greater fear. It's used in clinical settings to assess fall risk and tailor interventions.	baseline, after 4 weeks of intervention, 12-week follow-up after the end of intervention
6-Minute Walk Test	The 6-Minute Walk Test (6MWT) measures how far someone can walk in six minutes. It assesses exercise capacity and mobility.	baseline, after 4 weeks of intervention
Stroke Impact Scale	The Chinese version of the Stroke Impact Scale 3.0 (SIS) will be used to measure the quality of life. A higher overall score suggests better physical, emotional, and social functioning, while a lower score may indicate more significant impairment or limitations.	baseline, after 4 weeks of intervention, 12-week follow-up after the end of intervention
Anticipatory posture adjustments (APAs) time of trunk muscles	Participants will be requested to perform a rapid shoulder flexion test on the force plate. Surface electromyography (sEMG) (Noraxon USA, Inc., Scottsdale, AZ, USA) will be used to measure Anticipatory posture adjustments (APAs) time of trunk muscles.	baseline, after 4 weeks of intervention
Trunk Impairment Scale (TIS)	The TIS is a rating scale used to measure static sitting balance, dynamic sitting balance, and trunk coordination. The total TIS score ranges from 0 to 23 points, with a higher score indicating better trunk function.	baseline, after 4 weeks of intervention, 12-week follow-up after the end of intervention
Timed Up and Go Test (TUG)	TUG is a test to measure the time that a participant needs to stand up from a standard armchair, walk a short distance of about 3 meters, turn around, walk back to the chair, and sit down again.	baseline, after 4 weeks of intervention, 12-week follow-up after the end of intervention
Trunk muscle activity	Surface electromyography (sEMG) (Noraxon USA, Inc., Scottsdale, AZ, USA) will be used to measure the bilateral muscle activity of the erector spinae, rectus abdominis, external oblique muscle, internal oblique muscle, and transversus abdominis during sitting balance tests on the force plate.	baseline, after 4 weeks of intervention

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Berg Balance Scale (BBS)	The BBS measures balance and fall risk through 14 tasks scored from 0 to 4. The total score ranges from 0 to 56, with higher scores indicating better balance.	baseline, after 4 weeks of intervention
Timed Up and Go Test (TUG)	TUG is a test to measure the time that a participant needs to stand up from a standard armchair, walk a short distance of about 3 meters, turn around, walk back to the chair, and sit down again.	baseline, after 4 weeks of intervention
10-meter Walk Test	The 10-Meter Walk Test (10MWT) measures how quickly someone can walk a 10-meter distance. It's used to assess walking speed and mobility.	baseline, after 4 weeks of intervention
Falls efficacy scale international	The Falls Efficacy Scale-International (FES-I) is a questionnaire measuring fear of falling in older adults. It has 16 items, scored from 1 to 4, with higher scores indicating greater fear. It's used in clinical settings to assess fall risk and tailor interventions.	baseline, after 4 weeks of intervention, 12-week follow-up after the end of intervention
6-Minute Walk Test	The 6-Minute Walk Test (6MWT) measures how far someone can walk in six minutes. It assesses exercise capacity and mobility.	baseline, after 4 weeks of intervention
Stroke Impact Scale	The Chinese version of the Stroke Impact Scale 3.0 (SIS) will be used to measure the quality of life. A higher overall score suggests better physical, emotional, and social functioning, while a lower score may indicate more significant impairment or limitations.	baseline, after 4 weeks of intervention, 12-week follow-up after the end of intervention
Trunk muscle activity	Surface electromyography (sEMG) (Noraxon USA, Inc., Scottsdale, AZ, USA) will be used to measure the bilateral muscle activity of the erector spinae, rectus abdominis, external oblique muscle, internal oblique muscle, and transversus abdominis during sitting and standing balance tests.	baseline, after 4 weeks of intervention
Anticipatory posture adjustments (APAs) time of trunk muscles	Participants will be requested to perform a rapid shoulder flexion test on the force plate. Surface electromyography (sEMG) (Noraxon USA, Inc., Scottsdale, AZ, USA) will be used to measure Anticipatory posture adjustments (APAs) time of trunk muscles.	baseline, after 4 weeks of intervention
15-point rating scale	A 15-point rating scale will be used to rate the excise tolerance changes of the patients since the beginning of IMT intervention. The scale scores range from -7 ("a very great deal worse") to 0 ("about the same") to +7 ("a very great deal better"). Therapists and patients will be blinded to each other and rate the exercise tolerance change of the patient. The averaged rates of therapist and patient will be the final rate. Patients with an average rating of +3 ("somewhat better") or higher will be considered to have improvement. Patients with an average rating of +2 (a little bit better) to -2 (a little bit worse) will be considered to have remained stable. Patients with an average rating of -3 ("somewhat worse") or lower will be considered to have worsened.	baseline, after 4 weeks of intervention, 12-week follow-up after the end of intervention

Collaborators and Investigators

• Sponsor: Hong Kong Metropolitan University

Study record dates

Study Major Dates

• Study Start (Actual): February 21, 2025
• Primary Completion (Estimated): October 15, 2025
• Study Completion (Estimated): June 15, 2026

Study Registration Dates

• First Submitted: October 10, 2024
• First Submitted That Met QC Criteria: October 10, 2024
• First Posted (Actual): October 15, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 20, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: Stroke; Quality of life; Inspiratory muscle training; Balance control; Diaphragm; Exercise capacity; Anticipatory postural adjustment time
• 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: No.:HE-OT2023/13

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