Helbostad Jorunn L, Leirfall Sara, Moe-Nilssen Rolf, Sletvold Olav
Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway.
J Gerontol A Biol Sci Med Sci. 2007 Sep;62(9):1010-5. doi: 10.1093/gerona/62.9.1010.
Fatigue affects self-reported functioning in older persons. Balance and gait problems increase fall risk. The effect of physical fatigue in the elderly population in general, and on balance control during walking in particular is not well known. This study investigates how a repeated sit-to-stand task affects gait control in older persons.
Twenty-two persons (mean age 78 years) took part in a fatigue group (FG), and 22 persons (mean age 80 years) in a matched control group (CG). Participants walked back and forth on a walkway at different walking speeds. Gait data were adjusted for pretest-posttest differences in walking speed. The FG participants were physically fatigued by a repeated sit-to-stand task. Trunk data were obtained by a triaxial accelerometer and foot level data by an electronic walkway.
There were no group differences in preferred gait speed (p =.96) or in step length (p =.47) following the fatiguing task, but there were significant increases in step width (p =.023) and in mediolateral trunk acceleration amplitude (p =.038) in the FG group. Step-length variability (p =.004) and interstride trunk acceleration variability in the vertical direction (p =.002) increased, and tended to increase in the anteroposterior direction (p =.10) and to decrease in the mediolateral direction (p =.10) in the FG only.
Gait changes following a physical fatiguing task agree with changes previously found in older persons at risk of falling, suggesting that physical fatigue may represent a risk factor for falls in elderly persons.
疲劳会影响老年人自我报告的身体机能。平衡和步态问题会增加跌倒风险。一般老年人群体中身体疲劳的影响，尤其是对行走时平衡控制的影响尚不清楚。本研究调查重复坐立任务如何影响老年人的步态控制。
22名受试者（平均年龄78岁）参加疲劳组（FG），22名受试者（平均年龄80岁）参加匹配对照组（CG）。参与者在人行道上来回以不同步行速度行走。步态数据针对步行速度的测试前-测试后差异进行了调整。FG组参与者通过重复坐立任务产生身体疲劳。通过三轴加速度计获取躯干数据，通过电子人行道获取足部水平数据。
疲劳任务后，两组在偏好步态速度（p = 0.96）或步长（p = 0.47）方面无组间差异，但FG组的步宽（p = 0.023）和躯干中外侧加速度幅度（p = 0.038）显著增加。仅FG组的步长变异性（p = 0.004）和垂直方向的步间躯干加速度变异性（p = 0.002）增加，前后方向有增加趋势（p = 0.10），中外侧方向有减小趋势（p = 0.10）。
身体疲劳任务后的步态变化与先前在有跌倒风险的老年人中发现的变化一致，表明身体疲劳可能是老年人跌倒的一个风险因素。
