Cenciarini Massimo, Loughlin Patrick J, Sparto Patrick J, Redfern Mark S
Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:7006-9. doi: 10.1109/IEMBS.2009.5333838.
Older adults often exhibit increased co-contraction in response to a balance perturbation. This response is generally thought to enhance stability by increasing joint stiffness. We investigated the issue of increased stiffness in postural control by exposing seven older (75 +/- 5 y) and ten young (24 +/- 3 y) adults to pseudo-random medial-lateral (ML) floor tilts, and then fitting the measured ML body sway data to a previously-developed postural control model that includes stiffness and damping parameters. Significant increases were found in both parameters in the older adults compared to the young adults. This concurrent increase in stiffness and damping is more stabilizing than an increase in stiffness alone, which can lead to resonances.
老年人在面对平衡扰动时通常会表现出增强的共同收缩。这种反应通常被认为是通过增加关节刚度来提高稳定性。我们通过让7名老年人（75±5岁）和10名年轻人（24±3岁）接受伪随机的内侧-外侧（ML）地面倾斜，然后将测量到的ML身体摇摆数据拟合到一个先前开发的包括刚度和阻尼参数的姿势控制模型中，来研究姿势控制中刚度增加的问题。与年轻人相比，老年人的这两个参数均有显著增加。刚度和阻尼的同时增加比单独增加刚度更具稳定性，单独增加刚度可能会导致共振。
