HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 99/3/1224    most recent 00868.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Noah, J. A. Articles by Yang, J. F. Search for Related Content PubMed PubMed Citation Articles by Noah, J. A. Articles by Yang, J. F.

Breathing Frequency Changes at the Onset of Stepping in Human Infants

¹Department of Physical Therapy, ²Department of Speech Language Pathology and Audiology, and ³Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada

Submitted 3 August 2007; accepted in final form 23 December 2007

Breathing frequency increases at the onset of movement in a wide rage of mammals including adult humans. Moreover, the magnitude of increase in the rate of breathing appears related to the rate of the rhythmic movement. We determined whether human infants show the same type of response when supported to step on a treadmill. Twenty infants (ages 9.7 ± 1.2 mo) participated in trials consisting of sitting, stepping on the treadmill, followed by sitting again. Breathing frequency was recorded with a thermocouple, positioned under one naris and taped to a soother that the infant held in his/her mouth. A video camera, electrogoniometers, and force platforms under the treadmill belts recorded stepping movements. We found that the rate of breathing changed at the beginning of stepping. Most surprisingly, we found that when infants stepped at a frequency slower than their breathing frequency in sitting, the breathing frequency decreased. Average breathing frequency during stepping was positively correlated with stepping frequency. There was no evidence of entrainment between stepping and breathing. In conclusion, the rapid change in breathing frequency at the beginning of movement is functional in infants. The direction and magnitude of change in breathing is associated with the leg movements.