- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Sex differences in voluntary activation of the diaphragm
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Sex differences in voluntary activation of the diaphragm Ramsook, Andrew Harry
Abstract
Purpose: Three studies were performed to examine how voluntary activation of the diaphragm changes after fatiguing tasks in young, healthy males and females. The change in diaphragm voluntary activation (D-VA) was also compared to the change in contractile function, assessed by the change in transdiaphragmatic twitch pressure (P¬DI,TW). Methods: Study 1 (Chapter 2) investigated the within- and between-session reliability of D-VA using cervical magnetic stimulation (CMS) to evoke twitches. Study 2 (Chapter 3) examined changes in D-VA after high intensity, whole-body exercise between sexes. Study 3 (Chapter 4) examined changes in D-VA after inspiratory pressure threshold loading (IPTL) between sexes. Conclusions: CMS can be used to reliably assess D-VA, measured via intraclass correlation coefficients (ICC) both within- (ICC: 0.76) and between-session (ICC: 0.88). After exercise, D-VA decreased in males and females. The decrease in D-VA was greater in males compared to females (87.4±10.8 vs 95.4±4.9%basline, respectively, p=0.036). The magnitude of the decrease in D-VA was less than the decrease in PDI,TW (Males: 70.3±12.4, Females: 85.2±16.7%baseline, p=0.024). After IPTL, both males and females showed a decrease in D-VA and PDI,TW. While males showed a greater decrease in PDI,TW (73.3±12.1 vs 87.1±15.0%baseline, respectively, p=0.016) compared to females, the decrease in D-VA was similar between sexes (88.2±10.5 vs 91.4±7.6%baseline, respectively, p=0.432). After IPTL, the decrease in PDI,TW correlated with the total respiratory work performed whereas the decrease in D-VA correlated with time until task failure. The magnitude of the decrease in PDI,TW was greater than the decrease in D-VA after IPTL. Collectively, the results of this thesis suggest that there are sex differences in the change in D-VA after exercise but not IPTL. This thesis provides a foundation for future work to investigate how diaphragm fatigability can affect exercise performance in humans.
Item Metadata
Title |
Sex differences in voluntary activation of the diaphragm
|
Creator | |
Supervisor | |
Publisher |
University of British Columbia
|
Date Issued |
2021
|
Description |
Purpose: Three studies were performed to examine how voluntary activation of the diaphragm changes after fatiguing tasks in young, healthy males and females. The change in diaphragm voluntary activation (D-VA) was also compared to the change in contractile function, assessed by the change in transdiaphragmatic twitch pressure (P¬DI,TW).
Methods: Study 1 (Chapter 2) investigated the within- and between-session reliability of D-VA using cervical magnetic stimulation (CMS) to evoke twitches. Study 2 (Chapter 3) examined changes in D-VA after high intensity, whole-body exercise between sexes. Study 3 (Chapter 4) examined changes in D-VA after inspiratory pressure threshold loading (IPTL) between sexes.
Conclusions: CMS can be used to reliably assess D-VA, measured via intraclass correlation coefficients (ICC) both within- (ICC: 0.76) and between-session (ICC: 0.88). After exercise, D-VA decreased in males and females. The decrease in D-VA was greater in males compared to females (87.4±10.8 vs 95.4±4.9%basline, respectively, p=0.036). The magnitude of the decrease in D-VA was less than the decrease in PDI,TW (Males: 70.3±12.4, Females: 85.2±16.7%baseline, p=0.024). After IPTL, both males and females showed a decrease in D-VA and PDI,TW. While males showed a greater decrease in PDI,TW (73.3±12.1 vs 87.1±15.0%baseline, respectively, p=0.016) compared to females, the decrease in D-VA was similar between sexes (88.2±10.5 vs 91.4±7.6%baseline, respectively, p=0.432). After IPTL, the decrease in PDI,TW correlated with the total respiratory work performed whereas the decrease in D-VA correlated with time until task failure. The magnitude of the decrease in PDI,TW was greater than the decrease in D-VA after IPTL. Collectively, the results of this thesis suggest that there are sex differences in the change in D-VA after exercise but not IPTL. This thesis provides a foundation for future work to investigate how diaphragm fatigability can affect exercise performance in humans.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2022-01-06
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
Attribution-NonCommercial-NoDerivatives 4.0 International
|
DOI |
10.14288/1.0406203
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Graduation Date |
2022-05
|
Campus | |
Scholarly Level |
Graduate
|
Rights URI | |
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International