Document Detail


How do infants adapt to loading of the limb during the swing phase of stepping?
MedLine Citation:
PMID:  12611979     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Previous results from this laboratory have shown that human infants (<12 mo old) respond appropriately to transient changes in sensory input during stepping. We examined how infants adapted to a more enduring change in sensory input by applying load to one limb during stepping. A small weight (500-900 g) was strapped around the lower leg of infants aged 3-11 mo. Stepping with the weight on was recorded on the treadmill for a period of 0.5-3 min. The weight was then quickly detached during stepping, and the immediate response to unexpected loss of the weight recorded. Three-segment dynamic analysis of leg motion was used to estimate hip, knee, and ankle torques during swing in the sagittal plane. All infants adapted to the additional load on the leg by immediately increasing the generation of hip and knee flexor muscle torques. When the weight was removed, 7 of the 22 infants tested exhibited an after-effect (high stepping) in the first step after removal of the weight. The after-effect was manifested as an increase in toe trajectory height and hip flexion and coincided with higher hip flexor muscle torque in early swing. In an additional series of control experiments using seven infants, after-effects were shown to be unrelated to a sudden change in cutaneous input with removal of the weight. The presence of an after-effect indicates that some infants made an enduring adaptation to their stepping pattern that is revealed with the unexpected removal of the weight.
Authors:
Tania Lam; Claire Wolstenholme; Jaynie F Yang
Related Documents :
23393499 - A community based study of infant mortality in rural aligarh.
3758489 - Physical and behavioral sequelae of low birthweight in spiny mice (acomys cahirinus).
1430719 - Determinants of weight gain in pregnant adolescents.
20229329 - Is there a healthy foreign born effect for childhood obesity in the united states?
2007939 - Body composition, nutrition, and fluid balance during the first two weeks of life in pr...
23586439 - Specific-pathogen-free status is associated with lower infant mortality rate in rhesus ...
17876619 - Spinal epidural hematoma in an infant as the initial presentation of severe hemophilia.
1287559 - Docosahexaenoic acid status of term infants fed breast milk or infant formula containin...
25040899 - Tolerance to egg proteins in egg sensitized infants without previous consumption.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2002-12-11
Journal Detail:
Title:  Journal of neurophysiology     Volume:  89     ISSN:  0022-3077     ISO Abbreviation:  J. Neurophysiol.     Publication Date:  2003 Apr 
Date Detail:
Created Date:  2003-04-10     Completed Date:  2003-05-29     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0375404     Medline TA:  J Neurophysiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1920-8     Citation Subset:  IM    
Affiliation:
University Centre for Neuroscience and Department of Physical Therapy, University of Alberta, Edmonton, Alberta T6G 2G4, Canada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / physiology*
Biomechanics
Gait / physiology*
Hip Joint / physiology
Humans
Infant
Knee Joint / physiology
Leg / physiology*
Muscle, Skeletal / physiology
Torque
Walking / physiology
Weight-Bearing / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  An information theoretic approach to the contributions of the firing rates and the correlations betw...
Next Document:  PKA and PKC enhance excitatory synaptic transmission in human dentate gyrus.