School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
Institute of Environment, Health and Societies, Brunel University London, UK.
Age Ageing. 2019 Nov 1;48(6):811-816. doi: 10.1093/ageing/afz113.
This study evaluated the effect of attentional focus instructions on movement efficiency during a level-ground walking task in older adults with and without a history of falls.
One hundred and thirty-four community-dwelling older adults were categorised into older fallers (OF) (n = 37) and older non-fallers (ONF) (n = 97). Each participant was instructed to walk at a self-selected pace along a 6 m walkway under three attentional focus conditions (i.e. internal, goal-directed and control) for a total of nine trials. Average muscle activity indices of lower limb co-contractions were measured using surface electromyography.
Both shank and thigh muscle co-contractions were higher in OF than in ONF in all three conditions. OF also demonstrated higher shank muscle co-contraction under the internal relative to the goal-directed condition, with no such change observed in ONF.
Despite no significant between-group differences in functional balance and balance confidence, relative walking inefficiencies were observed in OF compared with ONF. This finding demonstrates the debilitating consequences of falling that can occur with relative independence from various physiological or psychological factors that are commonly associated with falling and used to rationalise behavioural change. We also provide evidence that OF are more susceptible to conditions that provoke them to allocate attention internally. Therefore, in clinical contexts (e.g. gait rehabilitation), verbal instructions that refer to body movements (internal focus) might serve to compromise movement efficiency in older adults with a history of falls. Such changes will, theoretically, lessen the ability to react efficiently to changing environments experienced in daily life.
本研究评估了在有和没有跌倒史的老年人进行平地行走任务时,注意力集中指导对运动效率的影响。
134 名居住在社区的老年人被分为老年跌倒者(OF)(n = 37)和老年非跌倒者(ONF)(n = 97)。每个参与者被要求在三种注意力集中条件(即内部、目标导向和控制)下以自我选择的速度沿着 6 米的走道走 9 次。使用表面肌电图测量下肢协同收缩的平均肌肉活动指数。
在所有三种条件下,OF 的小腿和大腿肌肉协同收缩都高于 ONF。OF 在内部条件下相对于目标导向条件下也表现出更高的小腿肌肉协同收缩,而 ONF 则没有这种变化。
尽管在功能平衡和平衡信心方面没有显著的组间差异,但与 ONF 相比,OF 的相对步行效率较低。这一发现表明,跌倒会对老年人造成致残后果,而这些后果可能与跌倒相关的各种生理或心理因素相对独立,这些因素通常与跌倒有关,并被用来合理化行为改变。我们还提供了证据表明,OF 更容易受到引起他们内部注意的条件的影响。因此,在临床环境中(例如步态康复),提到身体运动(内部焦点)的口头指导可能会降低有跌倒史的老年人的运动效率。从理论上讲,这些变化将降低他们在日常生活中应对不断变化的环境的有效能力。