Diaphragm Structure and Function in Children

Understanding the Influence of Diaphragm Structure and Function on the Control of Breathing During Exercise in Children

The purpose of this research is to study the feasibility of a specific training program for the breathing muscles (inspiratory muscle training) and the effects on how breathing is regulated during exercise in typically developing children.

Study Overview

• Status: Completed
• Conditions: Respiratory Muscle Training
• Intervention / Treatment: Device: POWERbreathe Plus IMT

Detailed Description

During the first study visit, participants will undergo a series of pulmonary function and muscle performance tests followed by treadmill walking trials at different speeds with concurrent expired gas analysis via a face mask. The participants will then perform a training program for the breathing muscles at home for 6 weeks. The research team will follow up each week via telehealth visits to support training. After the 6-week training program, participants will return in-person for a follow-up visit and will undergo the same series of assessments as the first visit.

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • University of Maryland, Baltimore

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age range 6-12 years of age

Exclusion Criteria:

• History of neuromuscular, cardiac, or pulmonary disease
• Known intellectual or developmental problems that would preclude the ability to assent
• Ruptured eardrum
• Recent injury or condition (less than 6 months ago) that precludes strength testing or walking
• Recent (less than 2 weeks ago) or current respiratory or other type of illness

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Inspiratory Muscle Training (IMT); Participants will be asked to perform inspiratory muscle training (breathing exercise) 5 days per week for 6 weeks at home.

Device: POWERbreathe Plus IMT; Inspiratory muscle training will be performed using the POWERbreathe Plus IMT (POWERbreathe International Ltd., Warwickshire, UK), a commercially available inspiratory pressure threshold device. In this type of training, airflow is occluded until the generated inspiratory pressure reaches the predetermined threshold, which can be set at increments of 8 cm H2O. During the first week of training, the target intensity will be set at 50% of baseline maximal inspiratory pressure (MIP.) During the second week, the target intensity will be set at 60% of baseline MIP. Beginning at the third week and for the remainder of the training program, the target intensity will be set at 75% of the participant's baseline MIP. The target volume will be 5 sets of 6 breaths per day (total of 30 breaths per day), separated by 1-minute rest breaks between sets. The frequency of training will be 5 days per week, for a duration of 6 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent completion	Percentage of enrolled participants who complete the 6-week inspiratory muscle training protocol	6 weeks
Adherence to treatment protocol	Number of sets and repetitions of training breaths completed during the 6-week inspiratory muscle training protocol	6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal inspiratory pressure (measured in cm H2O)	Maximal pressure generated during an inspiratory maneuver, representing inspiratory muscle strength	6 weeks
Diaphragm thickness (measured in mm)	Thickness of the diaphragm muscle measured by noninvasive ultrasound imaging	6 weeks
Exercise ventilation	Ratio of ventilation to carbon dioxide production (VE/VCO2) during steady-state walking, representing ventilatory drive during exercise	6 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
6-minute walk test distance (measured in m)	Maximal distance walked in 6 minutes	6 weeks

Collaborators and Investigators

• Sponsor: University of Maryland, Baltimore
• Investigators: Principal Investigator: Simon Ho, University of Maryland, Baltimore

Study record dates

Study Major Dates

• Study Start (Actual): March 16, 2024
• Primary Completion (Actual): January 6, 2025
• Study Completion (Actual): January 6, 2025

Study Registration Dates

• First Submitted: January 19, 2024
• First Submitted That Met QC Criteria: January 19, 2024
• First Posted (Actual): January 30, 2024

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 25, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Exercise; Diaphragm; Control of Breathing
• Additional Relevant MeSH Terms: Behavior; Motor Activity
• Other Study ID Numbers: HP-00108839

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No