Manckoundia Patrick, Mourey France, Pfitzenmeyer Pierre, Van Hoecke Jacques, Pérennou Dominic
INSERM/ERIT-M 0207 Motricité-Plasticité, Université de Bourgogne, Dijon, France.
Clin Neurophysiol. 2007 Apr;118(4):786-93. doi: 10.1016/j.clinph.2006.11.274. Epub 2007 Feb 20.
We hypothesised that backward disequilibrium (BD), defined by a posterior position of the centre of mass with respect to the base of support, could be caused by a backward tilt in the perception of verticality.
The relationship between BD, the perception of verticality, and the history of falls in 25 subjects aged 84.5+/-7.4 years was analysed. An original ordinal scale, the BD scale (BDS), was used to quantify BD. Postural (PV) and haptic verticals (HV) were measured in sagittal plane.
BDS scores closely correlated with the number of falls (r = 0.81, p =10(-5)). The more the PV was tilted backward, the greater the BDS scores (r = -0.95, p<10(-6)), with a huge backward tilt of about 15 degrees in 4 subjects with severe BD. In these subjects, the tilt in perception of verticality was transmodal since a severe backward HV tilt was also found.
This transmodality suggested high-order cognitive disruption in the construction of the subjective vertical used in postural control by subjects showing BD, which confirmed our hypothesis.
This study clearly shows that perception and action with respect to gravity are closely related and brings a new insight about fall mechanisms in the elderly.
我们假设，由质心相对于支撑面的后位所定义的向后失衡（BD）可能是由垂直感的向后倾斜引起的。
分析了25名年龄在84.5±7.4岁的受试者的BD、垂直感与跌倒史之间的关系。使用一种原始的序数量表，即BD量表（BDS）来量化BD。在矢状面测量姿势垂直（PV）和触觉垂直（HV）。
BDS评分与跌倒次数密切相关（r = 0.81，p = 10⁻⁵）。PV向后倾斜得越多，BDS评分越高（r = -0.95，p < 10⁻⁶），在4名患有严重BD的受试者中，存在约15度的巨大向后倾斜。在这些受试者中，垂直感的倾斜是跨模态的，因为还发现了严重的向后HV倾斜。
这种跨模态表明，表现出BD的受试者在姿势控制中使用的主观垂直构建中存在高阶认知障碍，这证实了我们的假设。
这项研究清楚地表明，关于重力的感知和行动密切相关，并为老年人跌倒机制带来了新的见解。
