Era P, Schroll M, Ytting H, Gause-Nilsson I, Heikkinen E, Steen B
Institute of Preventive Medicine, Kommunehospitalet, Copenhagen, Denmark.
J Gerontol A Biol Sci Med Sci. 1996 Mar;51(2):M53-63. doi: 10.1093/gerona/51a.2.m53.
There are no earlier cross-national comparative studies analyzing the functions of the posture control mechanisms and its sensory-motor correlates in elderly subjects. We investigated whether there are differences in balance between elderly subjects living in different geographical areas, and analyzed the sensory-motor associates of balance in men and women separately.
Using a force platform method, the functioning of the posture control system under three standardized conditions (normal standing, eyes open; normal standing, eyes closed; and tandem standing, eyes open) was studied among samples of 75-year-old residents in three Nordic localities, namely Glostrup in Denmark, Göteborg in Sweden, and Jyväskylä in Finland. The associations of the variables describing performance in each test with other sensory and motor functions were studied using correlation analyses and multivariate regression models.
Differences between the populations were observed in both tests with visual control, favoring the participants from Glostrup and Jyväskylä compared with those from Göteborg. However, only minor differences between the subjects from different localities were observed in the test performed with the eyes closed. In all localities there was a primary sex difference in favor of the women which, however, mainly disappeared when body height was taken into the analyses as a covariate. A good performance in the balance tests (body height-adjusted values) was associated with good visual acuity, low vibrotactile thresholds, and high psychomotor speed. Also, isometric muscle strength, especially hand grip and body extension, was positively associated with good performance in the balance tests. Among the women, a poorer balance was observed in women with a smaller body mass. The results of the multivariate analyses showed that among the men, the most important predictors of good performance in the balance tests were low vibrotactile threshold on the foot, high isometric hand grip strength, and low body stature. Among the women, the most important predictors were low body stature, high body mass, high isometric body extension strength, and high psychomotor speed. However, only a small proportion of the variance in balance (about 13% in the men and 11% in the women) could be explained by the help of these factors.
As the same procedure was applied to the analysis of postural balance, some differences between the populations living in different localities could be detected in some of the tests. The better performance of the women in the balance tests may partly be explained by anthropometric factors, especially differences in body height. There may also be differences in sensory-motor associates of balance in elderly men and women. On the basis of the associations observed, it is difficult to explain the differences in balance between the sexes or subjects living in different localities. Within the sexes, only a small proportion (10-13%) of the variation in balance during normal standing with eyes open could be explained by the factors included in the study.
目前尚无早期的跨国比较研究来分析老年受试者姿势控制机制的功能及其感觉运动相关性。我们调查了生活在不同地理区域的老年受试者在平衡能力上是否存在差异，并分别分析了男性和女性平衡能力的感觉运动关联因素。
采用测力平台法，在丹麦的格洛斯楚普、瑞典的哥德堡和芬兰的于韦斯屈莱这三个北欧地区，对75岁居民样本进行研究，观察他们在三种标准化条件下（睁眼正常站立、闭眼正常站立、睁眼串联站立）姿势控制系统的功能。使用相关分析和多元回归模型研究每个测试中描述表现的变量与其他感觉和运动功能之间的关联。
在两项有视觉控制的测试中观察到不同人群之间存在差异，与来自哥德堡的参与者相比，来自格洛斯楚普和于韦斯屈莱的参与者表现更优。然而，在闭眼测试中，不同地区受试者之间仅观察到微小差异。在所有地区，女性在平衡测试中表现更优，存在主要的性别差异，但在将身高作为协变量纳入分析后，这种差异基本消失。平衡测试中的良好表现（经身高调整后的值）与良好的视力、低振动触觉阈值和高精神运动速度相关。此外，等长肌力，尤其是握力和身体伸展力，与平衡测试中的良好表现呈正相关。在女性中，体重较小的女性平衡能力较差。多元分析结果表明男性中，平衡测试中良好表现的最重要预测因素是足部低振动触觉阈值、高握力和低身高。在女性中，最重要的预测因素是低身高、高体重、高身体伸展等长肌力和高精神运动速度。然而，这些因素仅能解释平衡能力差异中的一小部分（男性约13%，女性约11%）。
由于采用相同程序分析姿势平衡，在某些测试中可检测到不同地区人群之间存在一些差异。女性在平衡测试中的较好表现可能部分由人体测量因素解释，尤其是身高差异。老年男性和女性在平衡的感觉运动关联因素上也可能存在差异。基于观察到的关联，难以解释性别之间或不同地区受试者之间平衡能力的差异。在性别内部，睁眼正常站立时平衡能力变化中仅有一小部分（10 - 13%）可由本研究纳入的因素解释。
