背景與目的: 雙重任務是同時執行兩項任務，與單一任務相比，雙重任務需要較多認知功能中的執行功能與注意力。而輕微認知受損介於正常認知老化和失智症之間，被認為是失智症的前驅期。對於輕微認知受損老年人而言，雙重任務對步態表現的影響程度大於健康老年人。根據研究指出，雙重任務訓練可以改善神經性疾病患者的雙重任務表現。然而雙重任務訓練是否可改善輕微認知受損老人雙重任務步態之表現則尚不清楚。因此本研究之目的為探討認知性及動作性雙重任務步態訓練對於輕微認知受損老人之雙重任務步態表現效果，並比較兩種訓練的效果是否有差異。
方法:本研究為單盲隨機對照試驗，包括治療前、治療後和一個月追蹤期評估研究。將符合標準的受試者隨機分配到三組中之一組，認知性雙重訓練組(N=9)、動作性雙重訓練組(N=8)、與常規物理治療組(N=10)。每次訓練45分鐘，每週3次，共8週。由Gait Up儀器測量一般行走和雙重任務行走表現，包括速度、步頻、步幅、步幅變異性、步幅時間、步幅時間變異性、及雙重任務效應。以路徑描繪測試（Trail Making Test, TMT）及數字廣度測試（Digit Span Test, DST）分別評估認知功能中之執行功能和注意力。基準值之類別資料使用卡方檢定分析，連續性資料以克瓦單因子等級變異數分析(Kruskal-Wallis one-way analysis of variance by ranks)比較組間差異。各評估數據資料使用魏克生符號等級檢定（Wilcoxon signed rank test），分別比較後測與前測、追蹤測量與前測的組內改變。使用克瓦單因子等級變異數分析(Kruskal-Wallis one-way analysis of variance by ranks) 及Dunn事後檢定，檢測治療介入後及1個月後追蹤之組間差異。統計顯著水準為p<0.05。
結果:結果顯示動作性雙重任務訓練可增加認知性及動作性雙重任務行走與一般行走之步幅，且此增加可維持至少一個月。而在動作性雙重任務治療後，動作性雙重任務行走步幅之增加較認知性雙重任務訓練具顯著差異，在1個月追蹤評估時，則較常規治療呈顯著差異；在1個月追蹤評估時，動作性雙重任務訓練亦可增加動作性雙重任務行走之步速，且此增加較對照組為明顯。在認知性雙重任務治療後，亦可增加認知性雙重任務行走步幅。而認知性及動作性雙重任務訓練均可增加一般行走之速度。另我們的結果亦顯示，動作性雙重任務行走訓練可增加執行功能，而常規物理治療則可增加注意力表現。
結論: 本研究結果顯示，針對輕微認知受損老人，動作性雙重任務訓練對不同雙重任務行走表現及一般行走表現皆有一些效果，而認知性雙重任務訓練對於在執行認知性雙重任務行走與一般行走時之表現有所改善，而動作性雙重任務訓練可改善執行功能，常規物理治療訓練可改善注意力。

Background and purpose: Dual tasking is a performance when people execute two tasks simultaneously. Unlike single task, dual task condition requires more executive function and attentional resources. Mild cognitive impairment (MCI) is thought to be a transitional stage between normal cognitive aging and dementia, which considered to be a prodromal period of dementia. The magnitude of impact of dual task on gait performance is greater for the MCI elderly than for the healthy elderly. It is reported the dual task ability can be improved by dual task training in individuals with neurologic disorders. However, the effects of such training are not known in elderly with MCI. Therefore, the purpose of this study was to investigate the effects of cognitive and motor dual task gait training on dual task performance and to compare different types of dual task training in elderly with MCI.
Methods: This was a single blinded randomized controlled trial with pre-test, post-test, and one month follow-up study. Subjects meeting the criteria were randomly assigned to one of the three group, cognitive dual task training group (N=9), motor dual task training group (N=8) and conventional physical therapy group (N=10). The training was carried out for 45 minutes per session, 3 sessions per week for a total of 8 weeks. Gait performance was measured by Gait Up system, including speed, cadence, stride length, stride length variability, stride time, stride time variability, and dual-task cost-speed during single and dual task walking. The trail making test (TMT) and digit-span test were used to assess the executive function and attention respectively. The Kruskal-Wallis one-way analysis of variance by ranks and chi-square test were used for basic data analysis. All outcomes were analyzed by Wilcoxon signed-rank test for within group comparisons. The Kruskal-Wallis one-way analysis of variance by ranks was used for between-group comparisons with Dunn post hoc test for post-training and follow-up effects. The statistical significance was set at p<0.05.
Results: The results showed motor dual task training can improve stride length during both dual task walking and single walking, and such effects can be maintained at 1-month follow-up. The improvements in stride length during motor dual task walking were significantly more after motor dual task training than cognitive dual task training, and significantly more than conventional physical therapy training at 1-month follow-up. Also, the improvement in speed during motor dual task walking at 1-month follow-up was significantly more after motor dual task training than conventional physical therapy training. Cognitive dual task training can improve stride length during cognitive dual task walking. While both dual tasking training improved gait speed during single walking. In addition, motor dual task training improved executive function and conventional physical therapy training improved attention in MCI elderly.
Conclusions: According to our results, motor dual task training may improve both dual task gait performance and single walking performance. While cognitive dual task training improved cognitive dual task gait performance and single walking performance. Motor dual task training could improve executive function and conventional physical therapy training could improve attention in MCI elderly.

致謝..i
中文摘要..ii
英文摘要..iv
目錄..vi
表目錄..viii
圖目錄..ix
第一章 緒論....1
第一節 研究背景與動機..1
第二節 研究目的..1
第三節 研究假設 ..2
第四節 研究重要性..2
第二章 文獻回顧 ..3
第一節 雙重任務介紹..3
第二節 雙重任務與認知功能..3
第三節 輕微認知受損老年人雙重任務之表現..4
第四節 雙重任務步態訓練..5
第五節 總結..6
第三章 研究方法..7
第一節 研究設計..7
第二節 研究對象..7
第三節 研究流程..7
第四節 治療介入..7
第五節 結果評估..9
第六節 資料分析與處理..10
第四章 結果..12
第一節 受試者基本資料與前測值..12
第二節 認知性雙重任務步態表現..12
第三節 動作性雙重任務步態表現..13
第四節 一般步態表現..15
第五節 執行功能表現..15
第六節 注意力表現..16
第五章 討論..17
第一節 認知性雙重任務步態表現..17
第二節 動作性雙重任務步態表現..18
第三節 一般行走步態表現..18
第四節 認知功能..19
第五節 研究限制與未來建議..20
第六節 臨床應用..20
第六章 結論..20
參考文獻 ..22
附錄..36
附錄一、同意人體研究證明書..36
附錄二、認知性雙重任務組每週各次訓練內容..37
附錄三、動作性雙重任務組每週各次訓練內容..40
附錄四、對照組每週各次訓練內容.. 43
附錄五、路徑描繪測試量表..44
附錄六、數字廣度測試量表..46
表目錄
表一、受試者基本資料..26
表二、受試者在不同任務下步態表現之前測值..27
表三、受試者認知功能之前測值..28
表四、認知性雙重任務步態表現在不同組別之比較..29
表五、動作性雙重任務步態表現在不同組別之比較..30
表六、一般行走步態表現在不同組別之比較..31
表七、認知功能在不同組之結果..32
圖目錄
圖一、研究流程圖..33
圖二、受試者裝戴Gait up 儀器示意圖..34
圖三、認知性雙重任務步態表現-步幅之組間差異..34
圖四、動作性雙重任務步態表現-步幅之組間差異..35
圖五、動作性雙重任務步態表現-速度之組間差異 ..35

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