The purpose of this study was to examine the combined effects of knee extension strength (KES), visual acuity (VA), and knee joint pain (KP) on gait in 212 older women. Including, walking speed, cadence, were selected as gait parameters. Knee extension strength was measured by isometric knee extension strength, while knee joint pain and decreased visual acuity were evaluated by subjective judgment. The combine effect of KP and KES factors was examined. Stance time was significantly longer in persons with both-KP than in persons with no KP. In addition, people with superior KES had significantly greater values in walking speed, cadence, and step length, and lower values in stance time and walking angle than those with inferior KES. Furthermore, double support time showed that persons with both-KP have significantly greater values than persons with no or one-KP in the inferior KES group. Also, persons with the inferior KES had significantly greater values in persons with both-KP. The combine effect of KES and VA factors was examined. There are significant differences between the superior and the inferior KES groups. In conclusion, the elderly with both the factors of decreasing KES and both-KP, as compared to the elderly with just one of those factors, have markedly different gait properties.
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