TY - JOUR
T1 - Age-related changes in speed and accuracy during rapid targeted center of pressure movements near the posterior limit of the base of support
AU - Hernandez, Manuel E.
AU - Ashton-Miller, James A.
AU - Alexander, Neil B.
N1 - Funding Information:
The authors would like to acknowledge the support of National Institute on Aging (NIA) grant AG024824 (University of Michigan Claude D. Pepper Older Americans Independence Center), NIA grant F31AG024689 , the Office of Research and Development, Medical Service and Rehabilitation Research , the Development Service of the Department of Veterans Affairs , and the Dorothy and Herman Miller Fund for Mobility Research in Older Adults . Dr. Alexander is also a recipient of the K24 Mid-Career Investigator Award in Patient-Oriented Research AG109675 from NIA.
PY - 2012/11
Y1 - 2012/11
N2 - Background: Backward falls are often associated with injury, particularly among older women. An age-related increase occurs in center of pressure variability when standing and leaning. So, we hypothesized that, in comparison to young women, older women would display a disproportionate decrease of speed and accuracy in the primary center of pressure submovements as movement amplitude increases. Methods: Ground reaction forces were recorded from thirteen healthy young and twelve older women while performing rapid, targeted, center of pressure movements of small and large amplitude in upright stance. Measures included center of pressure speed, the number of center of pressure submovements, and the incidence rate of primary center of pressure submovements undershooting the target. Findings: In comparison to young women, older women used slower primary submovements, particularly as movement amplitude increased (P < 0.01). Even though older women achieved similar endpoint accuracy, they demonstrated a 2 to 5-fold increase in the incidence of primary submovement undershooting for large-amplitude movements (P < 0.01). Overall, posterior center of pressure movements of older women were 41% slower and exhibited 43% more secondary submovements than in young women (P < 0.01). Interpretations: We conclude that the increased primary submovement undershoots and secondary center of pressure submovements in the older women reflect the use of a conservative control strategy near the posterior limit of their base of support.
AB - Background: Backward falls are often associated with injury, particularly among older women. An age-related increase occurs in center of pressure variability when standing and leaning. So, we hypothesized that, in comparison to young women, older women would display a disproportionate decrease of speed and accuracy in the primary center of pressure submovements as movement amplitude increases. Methods: Ground reaction forces were recorded from thirteen healthy young and twelve older women while performing rapid, targeted, center of pressure movements of small and large amplitude in upright stance. Measures included center of pressure speed, the number of center of pressure submovements, and the incidence rate of primary center of pressure submovements undershooting the target. Findings: In comparison to young women, older women used slower primary submovements, particularly as movement amplitude increased (P < 0.01). Even though older women achieved similar endpoint accuracy, they demonstrated a 2 to 5-fold increase in the incidence of primary submovement undershooting for large-amplitude movements (P < 0.01). Overall, posterior center of pressure movements of older women were 41% slower and exhibited 43% more secondary submovements than in young women (P < 0.01). Interpretations: We conclude that the increased primary submovement undershoots and secondary center of pressure submovements in the older women reflect the use of a conservative control strategy near the posterior limit of their base of support.
KW - Aging
KW - Balance
KW - Center of pressure submovement
KW - Postural control
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U2 - 10.1016/j.clinbiomech.2012.06.007
DO - 10.1016/j.clinbiomech.2012.06.007
M3 - Article
C2 - 22770467
AN - SCOPUS:84866369575
VL - 27
SP - 910
EP - 916
JO - Clinical Biomechanics
JF - Clinical Biomechanics
SN - 0268-0033
IS - 9
ER -