Kuznetsov Nikita A, Riley Michael A
Department of Biology, Northeastern University, Boston, MA 02115, USA.
Department of Psychology, University of Cincinnati, Cincinnati, OH USA; Center for Cognition, Action, & Perception, University of Cincinnati, Cincinnati, OH USA.
Gait Posture. 2015 Sep;42(3):275-9. doi: 10.1016/j.gaitpost.2015.05.022. Epub 2015 Jun 11.
This study tested the hypothesis that age-related postural control deficits are more clearly detected from force plate recordings when using postural control tasks with an explicitly defined goal as opposed to the frequently used quiet stance task. Eighteen older adults (over 65) and seventeen younger adults (under 30) stood on a force plate with visual feedback (VFB) of the center of pressure (COP) and without such visual feedback with eyes open (NVFB). In the VFB condition, online visual feedback about the COP was provided and participants maintained that feedback on a stationary visual target for 80s. We hypothesized that age-related difference in COP variability (standard deviation of COP position and average absolute maximum COP velocity; AAMV) would be more pronounced in the VFB than in the NVFB condition. In addition, we hypothesized that Berg balance scale (BBS) scores for older adults would correlate more strongly with the COP measures in the VFB condition than in the NVFB condition. Results showed that VFB enhanced age-related differences only for AAMV in anterior-posterior direction. Both age groups decreased postural sway when using VFB. Older adults increased AAMV with VFB while young adults did not, indicating that the task modified their postural control strategy stronger than in younger adults. BBS scores were correlated with the AAMV in both feedback conditions, while COP position variability was more clearly correlated with BBS in the VFB condition. These results suggest that the quiet stance task is sufficient to index balance function if velocity-based COP variables are utilized in the analysis.
与常用的安静站立任务相比，当使用具有明确界定目标的姿势控制任务时，从测力板记录中能更清晰地检测到与年龄相关的姿势控制缺陷。18名老年人（65岁以上）和17名年轻人（30岁以下）站在一个测力板上，分别在有压力中心（COP）视觉反馈（VFB）和无此类视觉反馈且睁眼（NVFB）的情况下进行测试。在VFB条件下，提供关于COP的在线视觉反馈，参与者需在一个固定视觉目标上保持该反馈80秒。我们假设，与年龄相关的COP变异性（COP位置标准差和平均绝对最大COP速度；AAMV）差异在VFB条件下比在NVFB条件下更明显。此外，我们假设老年人的伯格平衡量表（BBS）得分在VFB条件下与COP测量值的相关性比在NVFB条件下更强。结果表明，VFB仅在前后方向上增强了与年龄相关的AAMV差异。两个年龄组在使用VFB时姿势摆动都减少了。老年人在VFB时AAMV增加，而年轻人则没有，这表明该任务对他们姿势控制策略的改变比对年轻人更强。在两种反馈条件下，BBS得分均与AAMV相关，而在VFB条件下，COP位置变异性与BBS的相关性更明显。这些结果表明，如果在分析中使用基于速度的COP变量，安静站立任务足以作为平衡功能的指标。
