Activation Patterns of Respiratory Muscles to Loaded Inspiratory Muscle Tests in Healthy Adults Under Different Posture

Study Overview
=================
Brief Summary
-----------------
Whether minimizing sternocleidomastoid (SCM) activation in supine position would increase diaphragm activation during loaded inspiratory muscle tests remains to be determined. Therefore, the purpose is to exam diaphragm and SCM activation during loaded inspiratory muscle tests in sitting and supine position in healthy adults.

Detailed Description
-----------------
Inspiratory muscle training usually performed in the upright sitting position. In healthy individuals, sternocleidomastoid (SCM) is rarely recruited during tidal breathing, but previous studies have demonstrated SCM activation during loaded inspiratory muscle tests in upright sitting position. Whether minimizing SCM activation in supine position would increase diaphragm activation during loaded inspiratory muscle tests remains to be determined. Therefore, the purpose is to exam diaphragm and SCM activation during loaded inspiratory muscle tests in sitting and supine position in healthy adults.

Official Title
-----------------
Activation Patterns of Respiratory Muscles to Loaded Inspiratory Muscle Tests in Healthy Adults Under Different Posture

Conditions
-----------------
Accessory Muscle

Intervention / Treatment
-----------------
* Other: Loaded inspiratory muscle test


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: age > 20 years old without exercise habit (any exercise that less than 3 days/week) can cooperate with the measurements of this study Exclusion Criteria: any clinical diagnosis that will influence the measurement, including any history of neuromyopathy angina, acute myocardial infarction in the previous one month pregnancy participated in inspiratory muscle training program in the previous three months any psychiatric or cognitive disorders, for example: Mini-Mental State Examination (MMSE) < 24, that will disturb the communication and cooperation of the study

Ages Eligible for Study
-----------------
Minimum Age: 20 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy adults<br>Healthy subjects without exercise habit that can cooperate with the measurements of this study, loaded inspiratory muscle test. | Other: Loaded inspiratory muscle test<br>* Loaded inspiratory muscle tests will be set at 30% of maximal inspiratory pressure in sitting and supine positions. The orders of the two loaded test conditions will be conducted in random order with at least 20 minute separation. This is an observational study. Subjects will perform only 15 breaths with each loaded test condition to exam the performance of their inspiratory muscles. Loaded inspiratory muscle test is not for training.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diaphragm and Sternocleidomastoid muscle activation | Root mean square values during different conditions | Through the completion of the loaded inspiratory muscle test condition; it would take about 3 minutes | 
| The mean median frequency of diaphragm and sternocleidomastoid muscle | The power spectrum is divided into two equal areas of the frequency value by median frequency to exam muscle fatigability | In one minute after the completion of the loaded inspiratory muscle test condition |