輕度認知障礙高齡者在多重任務情境下步態啟動控制分析

Abstract

隨著老齡化人口增加，神經退化性疾病的發病人口也隨之增加，失智症是其中非常常見的一種。輕度認知障礙高齡者有更高風險罹患失智症，且其跌倒風險也更高。因此本研究將輕度認知障礙高齡者作為研究對象，採用運動生物力學分析手段，來釐請輕度認知障礙與無認知功能障礙高齡者在不同步態啟動情境下的生物力學表現，為未來高齡者輕度認知障礙與跌倒的診斷、預防和管理提供重要參考。本研究主要涉及三個實驗情境，分別為自發啟動、燈光誘發、多重任務啟動；在前兩個情境中，重點分析了有無輕度認知障礙及不同步態啟動速度（舒適或最快）要求對步態啟動的影響；最後一個情境，重點分析有無輕度認知障礙及不同認知任務（倒數、減一、語義連貫任務）對步態啟動的影響。本實驗採用橫斷面觀察性實驗設計，共招募了三十位實驗參與者（十一位輕度認知障高齡者，十九位健康高齡者），使用紅外動作捕捉系統、測力板，對步態啟動過程中動作完成時間、足底壓力中心及質心的移動長度及速度、平衡穩定性、一般步態表現進行分析，統計分析方法主要使用重複二因子變異數分析。結果顯示，自發啟動情境下，MCI與對照組的步態差異不明顯，但在信號燈誘發與多重任務情境中，MCI表現出更短的啟動時間、更長的壓力中心移動距離和更快的速度；步態啟動速度則對各情境下的生物力學參數有廣泛影響，而多重任務情境中語言流暢性任務的影響最為顯著。建議臨床介入時加入多重任務與較快步態啟動速度的訓練，防跌措施應降低時間壓力與認知負荷，未來研究可結合生理指標深入探討不同MCI亞型的步態表現差異。With the increasing aging population, the prevalence of neurodegenerative diseases has also risen, with dementia being one of the most common conditions. Older adults with mild cognitive impairment (MCI) are at a higher risk of developing dementia and experiencing falls. Therefore, this study focuses on older adults with MCI, employing biomechanical analysis methods to elucidate the biomechanical differences in gait initiation between individuals with MCI and cognitively healthy older adults under various gait initiation conditions. This research aims to provide important references for the diagnosis, prevention, and management of MCI and fall risks in older adults.The study primarily involves three experimental conditions: spontaneous gait initiation, cue-induced gait initiation, and dual-task gait initiation. In the first two conditions, the study examines the effects of MCI status and different gait initiation speeds (comfortable or maximum) on gait initiation performance. In the dual-task condition, the study focuses on the impact of MCI status and different cognitive tasks (countdown, subtraction, semantic fluency tasks) on gait initiation. Using a cross-sectional observational study design, 30 participants (11 older adults with MCI and 19 cognitively healthy older adults) were recruited. Gait initiation performance was analyzed using an infrared motion capture system and force plates, measuring parameters such as movement time, displacement and velocity of the center of pressure (COP) and center of mass (COM), balance stability, and general gait performance. Repeated two-way ANOVA was the primary statistical analysis method.The results indicate that under spontaneous gait initiation conditions, there are no significant differences in gait performance between MCI and control groups. However, in cue-induced and dual-task conditions, individuals with MCI exhibit shorter gait initiation times, longer COP displacement, and faster COP velocities. Gait initiation speed has a broad influence on biomechanical parameters across all conditions, while in dual-task conditions, semantic fluency tasks have the most pronounced impact. Clinical interventions should incorporate training that combines dual-task scenarios with faster gait initiation requirements. Fall prevention strategies should aim to reduce time pressure and cognitive load during gait initiation tasks. Future research could integrate physiological indicators, such as EEG and EMG, to explore gait initiation performance in different MCI subtypes across various environments.