The effects of blurred vision on the mechanics of landing during stepping down by the elderly

NoVisual impairment is an important risk factor for falls. However, relatively little is known about how visual impairment affects stair or step negotiation. The aim of the present study was to determine the effects of blurred vision on the mechanics of landing during stepping down by the elderly. Twelve elderly subjects (72.3±4.7 year) stepped down from three levels (7.2 cm, 14.4 cm and 21.6 cm). Step execution time, ankle and knee joint angular displacements at the instance of ground contact, and vertical landing stiffness and the amount of bodyweight supported by the contralateral (support) limb during the initial contact period were recorded. Measurements were repeated with vision blurred by light scattering lenses. With blurred vision, step execution time increased (P<0.05), knee flexion and ankle plantar-flexion increased (P<0.05), vertical stiffness decreased (P<0.01), and the amount of bodyweight being supported by the contralateral leg increased (P