Medell J L, Alexander N B
Mobility Research Center, Division of Geriatric Medicine, The University of Michigan, Ann Arbor, USA.
J Gerontol A Biol Sci Med Sci. 2000 Aug;55(8):M429-33. doi: 10.1093/gerona/55.8.m429.
In older adults, clinical measures have been used to assess fall risk based on the ability to maintain stance or to complete a functional task. However, in an impending fall situation, a stepping response is often used when strategies to maintain stance are inadequate. We examined how maximal and rapid stepping performance might differ among healthy young, healthy older, and balance-impaired older adults, and how this stepping performance related to other measures of balance and fall risk.
Young (Y; n = 12; mean age, 21 years), unimpaired older (UO; n = 12; mean age, 69 years), and balance-impaired older women IO; n = 10; mean age, 77 years) were tested in their ability to take a maximal step (Maximum Step Length or MSL) and in their ability to take rapid steps in three directions (front, side, and back), termed the Rapid Step Test (RST). Time to complete the RST and stepping errors occurring during the RST were noted.
The IO group, compared with the Y and UO groups, demonstrated significantly poorer balance and higher fall risk, based on performance on tasks such as unipedal stance. Mean MSL was significantly higher (by 16%) in the Y than in the UO group and in the UO (by 30%) than in the IO group. Mean RST time was significantly faster in the Y group versus the UO group (by 24%) and in the UO group versus the IO group (by 15%). Mean RST errors tended to be higher in the UO than in the Y group, but were significantly higher only in the UO versus the IO group. Both MSL and RST time correlated strongly (0.5 to 0.8) with other measures of balance and fall risk including unipedal stance, tandem walk, leg strength, and the Activities-Specific Balance Confidence (ABC) scale.
We found substantial declines in the ability of both unimpaired and balance-impaired older adults to step maximally and to step rapidly. Stepping performance is closely related to other measures of balance and fall risk and might be considered in future studies as a predictor of falls and fall-related injuries.
在老年人中，临床测量方法已被用于根据维持站姿或完成功能性任务的能力来评估跌倒风险。然而，在即将跌倒的情况下，当维持站姿的策略不足时，通常会采用跨步反应。我们研究了健康年轻人、健康老年人和平衡受损老年人之间最大跨步和快速跨步表现可能存在的差异，以及这种跨步表现与其他平衡和跌倒风险测量指标之间的关系。
对年轻组（Y；n = 12；平均年龄21岁）、未受损老年组（UO；n = 12；平均年龄69岁）和平衡受损老年女性组（IO；n = 10；平均年龄77岁）进行测试，评估她们迈出最大步长（最大步长或MSL）的能力以及在三个方向（前、侧和后）快速跨步的能力，即快速跨步测试（RST）。记录完成RST的时间以及RST过程中出现的跨步误差。
基于单脚站立等任务的表现，与Y组和UO组相比，IO组表现出明显更差的平衡能力和更高的跌倒风险。Y组的平均MSL显著高于UO组（高16%），UO组的平均MSL显著高于IO组（高30%）。Y组的平均RST时间显著快于UO组（快24%），UO组的平均RST时间显著快于IO组（快15%）。UO组的平均RST误差往往高于Y组，但仅在UO组与IO组相比时显著更高。MSL和RST时间均与其他平衡和跌倒风险测量指标（包括单脚站立、串联行走、腿部力量和特定活动平衡信心（ABC）量表）密切相关（相关性为0.5至0.8）。
我们发现，未受损和平衡受损的老年人在最大跨步和快速跨步能力方面均有显著下降。跨步表现与其他平衡和跌倒风险测量指标密切相关，在未来研究中可能被视为跌倒及跌倒相关损伤的预测指标。
