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Completed

NCT Number: NCT06230692

Diaphragm Structure and Function 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.

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Key information

Conditions

Respiratory Muscle Training Behavior Motor Activity

Age range

6 year–12 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Maryland, Baltimore

Baltimore, Maryland, 21201, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

POWERbreathe Plus IMT

Device

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.

Primary outcomes

  1. Percent completion

    Time frame: 6 weeks

    Percentage of enrolled participants who complete the 6-week inspiratory muscle training protocol

  2. Adherence to treatment protocol

    Time frame: 6 weeks

    Number of sets and repetitions of training breaths completed during the 6-week inspiratory muscle training protocol

Secondary outcomes

  1. Maximal inspiratory pressure (measured in cm H2O)

    Time frame: 6 weeks

    Maximal pressure generated during an inspiratory maneuver, representing inspiratory muscle strength

  2. Diaphragm thickness (measured in mm)

    Time frame: 6 weeks

    Thickness of the diaphragm muscle measured by noninvasive ultrasound imaging

  3. Exercise ventilation

    Time frame: 6 weeks

    Ratio of ventilation to carbon dioxide production (VE/VCO2) during steady-state walking, representing ventilatory drive during exercise

Other outcomes

  1. 6-minute walk test distance (measured in m)

    Time frame: 6 weeks

    Maximal distance walked in 6 minutes

Sponsors and collaborators

Lead sponsor

University of Maryland, Baltimore

Other

Registry information

Official study title

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

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Jan 30, 2024
Registry last updated
Mar 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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