學齡孩童於對稱與非對稱任務中雙手協調能力之探究

Abstract

前言：日常生活中包含許多以雙手為導向的對稱性與非對稱性任務，且各類任務皆可能以同時或順序方式執行。成功完成這些任務，需良好的雙手協調能力，此能力自嬰幼兒期即開始發展，並隨著年齡增長，在動作速度與準確性方面逐漸成熟。 然而，當此能力出現障礙時，可能導致動作的一致性、準確性、執行速度與雙手同步性下降，進而影響個體在自我照顧、學習與整體日常功能的表現。儘管雙手協調在發展與功能上皆扮演關鍵角色，過往研究多聚焦於單一類型的雙手活動，較少系統性探討學齡階段孩童在不同任務類型中的協調表現差異。此外，針對不同動作發展障礙類型之孩童，其在多樣化日常任務情境中的雙手協調模式，目前亦尚缺乏全面性的瞭解。 目的：本研究的目的為透過無標記身體姿勢追蹤方式（一）探討不同年齡發展階段的典型發展孩童（低年級與中高年級）於不同任務下（對稱同時、對稱順序、非對稱同時及非對稱順序）的雙手協調表現差異。（二）描述不同類型動作發展障礙孩童（單側損傷、雙側損傷、發展性協調障礙）在雙手任務中所展現的協調表現模式。 方法：本研究共納入包含23位低年級及17位中高年級之典型發展孩童以及8位動作發展障礙孩童（1位單側損傷、4位雙側損傷及3位發展性協調障礙）。雙手協調能力透過包含對稱及不對稱情境的日常生活導向任務（托盤抬舉、方塊收集、方塊串珠、水壺開啟）進行測試，測驗指標包含任務完成時間、目標同步性及動作重疊時間。針對第一個目的，使用共變數多變量分析（2 way MANCOVA）探討不同年齡組於各任務中雙手協調能力差異。針對第二個目的，使用描述性統計呈現不同種類型動作發展障礙孩童在不同任務中的雙手協調表現。 結果：共變數多變量分析結果顯示典型發展兒童在不同任務類型下展現出明顯的雙手協調表現差異，整體而言，同時性任務相較於順序性任務，呈現較高的雙手同步性與動作重疊程度，反映同時任務對雙側上肢同時參與的需求較高。此外，任務複雜度與雙手角色分工亦會影響協調表現。年齡發展方面，低年級組在總時間與動作重疊上與中高年級組相近，但在目標同步性表現較差，顯示其雙手時序控制能力尚未成熟。在動作發展障礙孩童中，發展性協調障礙組在多數任務中的表現大致與典型發展組相近，惟於較具挑戰性的任務（任務二至四）中，呈現出較大的雙手時間差異，且在最困難的串珠任務（任務三）中，完成時間明顯延長。單側損傷個案在執行順序性任務時，傾向採用較為同步的雙手代償策略，可能為了補償雙側功能的不對稱性。雙側損傷組同樣在串珠任務中花費較長的完成時間，在對稱性任務中，其雙手時間差異與典型發展組表現相近，惟於非對稱任務中（無論為同時或順序性任務）則展現出與典型發展組明顯不同的協調模式，顯示任務複雜性與雙手角色分配皆可能影響此類孩童的動作規劃與執行策略。整體而言，本研究顯示不同任務需求可突顯各類動作發展障礙孩童在雙手協調表現上的獨特模式。 結論：本研究運用無標記式的身體動作追蹤技術，探討不同發展階段之學齡孩童於多種任務情境下的雙手協調表現。結果顯示，在控制任務時間後，任務類型顯著影響雙手協調能力，尤其表現在目標同步性與動作重疊程度兩項指標上。年齡亦對協調表現具有顯著影響，低年級孩童表現出較差的目標同步性，反映出雙手協調能力隨發展階段逐漸成熟。於動作發展障礙孩童中，不同障礙型態亦呈現出與典型發展兒童相異之協調策略。整體而言，本研究強調應透過多元任務類型與多指標方式來全面評估孩童之雙手協調能力，其中目標同步性在區辨年齡與障礙類型上的敏感性尤為突出，可作為臨床辨識協調困難之重要參考指標。此外，針對不同障礙類型於不同任務下之協調表現進行比較，亦有助於治療師釐清協調困難樣貌，作為後續介入設計之依據。

Introduction: Daily life involves many types of bimanual activities, including both symmetrical and asymmetrical forms, and each task type can be executed either simultaneously or sequentially. These activities require the coordinated use of both upper limbs, involving precise temporal and spatial coupling, which is commonly referred to as bimanual coordination. This ability begins to emerge in early infancy and continues to mature throughout development, with progressive improvements in movement speed and accuracy. Deficits in bimanual coordination may result in reduced consistency, accuracy, speed, and synchrony between hands, ultimately impacting self-care, academic, and overall daily functioning. While previous studies have often focused on single types of bimanual tasks, few have systematically examined the performance of school-aged children across different types of bimanual tasks at various developmental stages. Moreover, the coordination performance of children with motor developmental disabilities across diverse daily task contexts remains insufficiently explored. Objective: This study aimed to use a markerless pose tracking technique to (1) examine the bimanual coordination performance of typically developing (TD) children at different developmental stages (lower vs. middle-to-upper grades) across four task conditions (symmetric-simultaneous, symmetric-sequential, asymmetric-simultaneous, and asymmetric-sequential), and (2) describe the coordination performance patterns of children with different types of motor developmental disabilities (unilateral injury, bilateral injury, and developmental coordination disorder; DCD) under the same set of tasks. Method: Participants included 23 lower-grade and 17 middle-to-upper-grade TD children, along with 8 children with motor developmental disabilities (1 with unilateral injury, 4 with bilateral injury, and 3 with DCD). Bimanual coordination was assessed using four daily-life-oriented tasks involving symmetric and asymmetric movements (tray-lifting, cup-collecting, beads-threading, and bottle-opening). Coordination indicators included total time, goal synchronization, and movement overlap. For the first objective, a two-way MANCOVA was used to analyze differences in coordination across tasks and grade groups. For the second objective, descriptive statistics were used to present coordination profiles of each clinical group across tasks. Results: MANCOVA results revealed significant differences in coordination performance across task types in TD children. In general, simultaneous tasks were associated with higher movement overlap and greater interlimb synchrony compared to sequential tasks, reflecting the greater demand for bilateral engagement. Task complexity and hand role differentiation also influenced coordination. In terms of age, the lower grade group showed poorer goal synchronization but similar total time and overlap compared to the middle-to-upper grade group, indicating less mature temporal control. Among children with motor developmental disabilities, the DCD group demonstrated performance generally comparable to that of the TD group in most tasks. In particular, during the most demanding beads-threading task (Task 3), their total time was notably longer. In more challenging tasks, including Tasks 2 to 4, they exhibited greater interlimb timing differences compared to TD children. The child with unilateral injury adopted a more synchronized bimanual strategy in sequential tasks, possibly as a compensatory approach for asymmetric bilateral function. The bilateral injury group showed prolonged total time in the beads-threading task. While their inter-hand timing differences were comparable to that of the TD group in symmetric tasks, they exhibited distinct coordination patterns in asymmetric tasks performed either simultaneously or sequentially. These findings suggest that both task complexity and hand role distribution may influence their motor planning and execution strategies. Overall, the findings of this study demonstrate that varying task demands can reveal distinct patterns of bimanual coordination performance among children with different types of motor developmental disabilities. Conclusion: This study applied a markerless motion tracking technique to investigate bimanual coordination in school-aged children under various task conditions. After controlling for task duration, task type significantly affected coordination performance, particularly in goal synchronization and movement overlap. Grade level also had a significant influence, with younger children showing less mature interlimb timing. Children with motor developmental disabilities displayed coordination strategies different from their TD peers, even in the presence of mild impairments. These findings underscore the importance of using diverse task types and multiple indicators to comprehensively assess bimanual coordination. Among these, goal synchronization was particularly sensitive in distinguishing age and disability-related differences, making it a valuable clinical indicator. Moreover, comparing coordination patterns across disability types and task conditions can help therapists better understand coordination challenges and design targeted intervention strategies.