Postural threat influences postural strategy among healthy younger and older adults

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Polych, Melody A.
University of Lethbridge. Faculty of Arts and Science
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Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2003
The effects of postural threat on postural control among younger and older adults were examined. Fifteen younger (YA;8 females and 7 males; mean age 22.00 + 2.17 years) and fifteen older (OA; 10 females and 5 males; mean age 69.98 + 5.35 years) adults performed quiet standing and forward reaching under four conditions of postural threat. Postural threat was achieved by the manipulation of height (low(0.43m) and high (1.4m)) and stepping constraint (unconstrained (0.91m from the anterior edge of an elevating platform) or constrained (0m from the anterior edge of an elevating platform). Younger and older adults demonstrated conservative modifications to postural control that may reduce the likelihood of a fall in tenuous conditions. Interestingly, age-related differences emerged in the mechanism of achieving these accomodations to postural threat. Our findings indicate that older adults may adopt more proximal postural strategies under condtion of postural threat. The shift toward a more proximal postural strategies under conditions of postural threat. The shift toward a more proximal control of balance may reflect the age-related declines in the ability to control the movement of the trunk. Although these adaptations appear benefical to older adults, the possibility exists for detrimental consequences to postural recovery following a balance disturbance.
xi, 173 leaves : ill. ; 29 cm.
Dissertations, Academic , Posture -- Research , Equilibrium (Physiology) -- Research