Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA.
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL 32611, USA; Department of Sensorimotor Neuroscience, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, 734-8553 Japan.
Gait Posture. 2021 Mar;85:103-109. doi: 10.1016/j.gaitpost.2020.12.019. Epub 2020 Dec 26.
Postural control is impaired in older adults, as evidenced from greater variability of the center of pressure (COP) during postural tasks. Although COP variability associates with low-frequency COP oscillations (<1 Hz) in young adults, it remains unknown if the age-associated increase in COP variability relates to greater low-frequency COP oscillations.
Do low-frequency oscillations contribute to greater postural sway (center of pressure (COP) variability) in older adults when attempting to voluntarily maintain posture in a forward leaning position compared to young adults?
Seven young (25.7 ± 4.8) and seven older (71.0 ± 7.0) adults performed a postural lean forward task and attempted to match a COP target in the anterior-posterior direction as steady as possible. We quantified the COP variability as the standard deviation (SD) of COP displacements in the anterior-posterior and medial-lateral directions and quantified the frequency modulation of COP as the power in COP displacement spectra from 0-1 Hz.
We found that older adults had significantly greater anterior-posterior SD of COP (p = 0.027) and power below 0.5 Hz (p = 0.048) than young adults, but power from 0.5-1 Hz was similar (p = 0.083). In contrast, the medial-lateral SD of COP (p = 0.5) and power from 0-1 Hz (p = 0.228) was similar for the two age groups. For both the anterior-posterior and medial-lateral direction, the SD of COP was related to low frequency oscillations below 0.5 Hz.
For the first time, we show that the age-associated increase in postural variability relates to greater COP oscillations below 0.5 Hz.
姿势控制在老年人中受损，这表现在姿势任务中，压力中心（COP）的变异性更大。虽然 COP 变异性与年轻人的低频 COP 振荡（<1 Hz）相关，但尚不清楚与 COP 变异性相关的年龄相关增加是否与更大的低频 COP 振荡有关。
与年轻人相比，当老年人试图主动保持前倾姿势时，低频振荡是否会导致更大的姿势摆动（COPP 变异性），COPP 变异性是指 COP 位移的标准差（SD）。
七名年轻（25.7 ± 4.8）和七名年长（71.0 ± 7.0）成年人进行了姿势前倾任务，并试图尽可能稳定地在前-后方向上匹配 COP 目标。我们将 COP 变异性量化为前-后和内-外侧 COP 位移的标准差（SD），并将 COP 位移谱的频率调制量化为 0-1 Hz 范围内 COP 位移的功率。
我们发现，与年轻人相比，老年人的 COP 前-后 SD 明显更大（p = 0.027），0.5 Hz 以下的功率更大（p = 0.048），但 0.5-1 Hz 的功率相似（p = 0.083）。相比之下，两个年龄组的 COP 内-外侧 SD 和 0-1 Hz 的功率相似（p = 0.5）。对于前-后和内-外侧方向，COP 的 SD 与 0.5 Hz 以下的低频振荡相关。
这是首次表明，与年龄相关的姿势变异性增加与更大的 0.5 Hz 以下 COP 振荡有关。
