Document Detail


The balance recovery mechanisms against unexpected forward perturbation.
MedLine Citation:
PMID:  19472056     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Falls are one of the main concerns of the elderly. Proper postural adjustments to maintain balance involve the activation of appropriate muscles to produce force and to relocate the center of body mass (CoM). In this study, biomechanical aspects of dynamic postural responses against forward perturbations were experimentally determined by simultaneous measurements of joint angles and EMG activations. Thirteen young and healthy volunteers took turns standing on a flat platform, and were directed to move in the forward direction by an AC servo-motor set at two different speeds (0.1 and 0.2 m/s). Joint motions were recorded, and they followed the sequence of ankle dorsiflexion, knee flexion, and then hip flexion during the later acceleration phase (AP) in order to maintain postural balance against forward perturbation. Tibialis anterior for the ankle dorsiflexion and biceps femoris for the knee flexion were activated during the second half of the AP as the primary muscles to recover balance. In addition, gastrocnemius, which was related to ankle plantarflexion, and rectus femoris, which was related to knee extension, were activated to maintain balance. Movements of the center of plantar pressure and ground reaction forces in fast-speed perturbation were significantly larger than those in slow-speed perturbation. As a result, the ankle strategy was used for slow-speed perturbation, but the mixed strategy consisting of both ankles and hip were used for fast-speed perturbation.
Authors:
Sungjae Hwang; Kisik Tae; Ryanghee Sohn; Jungyoon Kim; Jongsang Son; Youngho Kim
Related Documents :
16944106 - Representation of dynamic events triggered by motion lines and static human postures.
9247066 - Flexibility of anticipatory postural adjustments revealed by self-paced and reaction-ti...
16621566 - Modification of human postural responses to soleus muscle vibration by rotation of visu...
12967756 - The effects of visual input on postural control of the lumbar spine in unstable sitting.
10332626 - A marker-based measurement procedure for unconstrained wrist and elbow motions.
12700156 - Isolation of symbiotically expressed genes from the dinoflagellate symbiont of the soli...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-05-27
Journal Detail:
Title:  Annals of biomedical engineering     Volume:  37     ISSN:  1573-9686     ISO Abbreviation:  Ann Biomed Eng     Publication Date:  2009 Aug 
Date Detail:
Created Date:  2009-07-13     Completed Date:  2009-09-29     Revised Date:  2013-05-30    
Medline Journal Info:
Nlm Unique ID:  0361512     Medline TA:  Ann Biomed Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1629-37     Citation Subset:  IM    
Affiliation:
Department of Biomedical Engineering, Institute of Medical Engineering, College of Health Science, Yonsei University, 234 Maeji, Heungup, Wonju, Gangwon 220-710, South Korea.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Accidental Falls
Adult
Ankle / physiology
Female
Hip / physiology
Humans
Joints / physiology*
Male
Movement / physiology*
Muscle, Skeletal / physiology*
Postural Balance / physiology*
Posture / physiology*

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


Previous Document:  Hemodynamically driven stent strut design.
Next Document:  Functional consequences of HIV-associated neuropsychological impairment.