Human Health Sciences, Graduate School of Medicine Kyoto University, 53, Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
Aging Clin Exp Res. 2012 Apr;24(2):157-61. doi: 10.3275/7716. Epub 2011 May 23.
Increased fear of falling is associated with greater muscular coactivation during standing postural control. Excessive muscular coactivation reduces the performance of agonist muscles. Although several recent studies have observed increased muscular coactivation during walking in older adults, little is known about the relationship between fear of falling and muscular coactivation during walking. The purpose of this study was to compare muscular coactivation during walking between older adults with fear of falling and older adults without fear of falling.
Thirty-eight healthy older adults (82.3 ± 6.8 years) participated in this study. Walking speed and step length were measured. Electromyography (EMG) data were collected from the tibialis anterior and soleus during walking to calculate the co-contraction index (CI). Subjects were divided into those with fear of falling and those without fear of falling, on the basis of a modified Falls Efficacy Scale (FES). Stepwise multiple regression analysis was used, with CI as the dependent variable, and fear of falling, experience of falling (during the past year), walking speed, step length, and age as independent variables.
Mean values of CI during walking, walking speed, and step length were 51.9 ± 11.7%, 0.90 ± 0.40 m/s, and 0.43±0.11 m, respectively. Eight subjects (21.1%) had fallen within the past year, and 19 subjects (50.0%) had fear of falling. All subjects without fear of falling had FES scores of 10 (maximum score). Subjects with fear of falling had a median FES score of 17 (interquartile range, 13 to 25). Stepwise multiple regression analysis revealed that fear of falling remained significantly associated with CI (p<0.01): CIs for subjects with fear and those without fear were 59.5 ± 12.2% and 46.7 ± 8.5%, respectively.
Individuals with a fear of falling have increased muscular co-activation at the ankle joint during walking, at least in a certain subgroup of older adults. Further research is needed to clarify negative and positive effects of muscular coactivation during walking in fearful subjects.
站立姿势控制时，恐惧跌倒会导致肌肉协同收缩增加。过度的肌肉协同收缩会降低主动肌的表现。尽管最近有几项研究观察到老年人在行走时肌肉协同收缩增加，但对于恐惧跌倒与行走时肌肉协同收缩之间的关系知之甚少。本研究旨在比较有恐惧跌倒和无恐惧跌倒的老年人在行走时的肌肉协同收缩。
38 名健康老年人（82.3±6.8 岁）参与了这项研究。测量了行走速度和步长。在行走过程中，从胫骨前肌和比目鱼肌采集肌电图（EMG）数据，以计算协同收缩指数（CI）。根据改良跌倒效能量表（FES），将受试者分为有恐惧跌倒和无恐惧跌倒的两组。采用逐步多元回归分析，以 CI 为因变量，恐惧跌倒、跌倒经历（过去 1 年）、行走速度、步长和年龄为自变量。
行走时 CI、行走速度和步长的平均值分别为 51.9±11.7%、0.90±0.40 m/s 和 0.43±0.11 m。8 名受试者（21.1%）在过去 1 年内跌倒，19 名受试者（50.0%）有恐惧跌倒。所有无恐惧跌倒的受试者 FES 评分为 10（满分）。有恐惧跌倒的受试者的 FES 评分中位数为 17（四分位距，13 至 25）。逐步多元回归分析显示，恐惧跌倒与 CI 显著相关（p<0.01）：有恐惧和无恐惧的受试者的 CI 分别为 59.5±12.2%和 46.7±8.5%。
有恐惧跌倒的个体在行走时踝关节的肌肉协同收缩增加，至少在某些老年人群中是这样。需要进一步研究来阐明在恐惧受试者中行走时肌肉协同收缩的负面影响和积极影响。
