Background: Abnormal upper limb movements frequently affect people with acquired brain injury (ABI) during walking. Three-dimensional motion analysis (3DMA) can quantify upper limb abnormality kinematically, with composite scores condensing multiple joint axes data into a single score.

Research Question: Are 3DMA-derived composite scores valid (known-groups and convergent validity), reliable and able to quantify speed-related changes in abnormal upper limb movement during walking?

Methods: This observational study compared 42 adults with ABI and abnormal upper limb movements during walking with 36 healthy controls (HC) at a matched walking speed intention. Participants underwent 3DMA assessment of self-selected and fast walking speeds. Composite scores quantified the affected upper limb’s kinematic abnormality. The Arm Posture Score arithmetic mean version (APSam) and 1.96 standard deviation reference-range scaled versions; the Kinematic Deviation Score mean (KDSm) and worst score (KDSw) were evaluated for association with each other and subjective abnormality rating (Pearson’s r correlation), test-retest reliability (intra-class correlation coefficient (ICC)), and ability to quantify speed-related changes in abnormal upper limb movement (Cohen’s d effect size (ES), % change scores).

Results: Very strong correlations existed between composite scores. The KDSm under-classified upper limb abnormality, whereas the KDSw captured the majority of ABI participants. All scores had moderate-strong correlations with subjective rating of abnormal upper limb movements (r = 0.54-0.79) and very strong test-retest reliability (ICCs>0.81). The APSam demonstrated a 16% (ES 0.76) walking speed-related increase in upper limb abnormality, whilst decreases were demonstrated in the KDSm 26% (ES 0.90) and KDSw 35% (ES 0.96).

Significance: The APSam, KDSw, and number of abnormal joint axes comprehensively assess the whole upper limb abnormal movements, accurately classifies abnormality, and quantifies severity. This study illustrated notable presence of abnormal upper limb movements at self-selected walking speed and small increase at fast speeds. However, when scaled to HC variability, the fast walk kinematics became less abnormal due to increased HC movement variability.

背景：异常的上肢运动经常影响步行过程中获得性脑损伤（ABI）的人。三维运动分析（3DMA）可以通过运动学分数来量化上肢异常，其综合评分将多个关节轴数据浓缩为一个评分。

研究问题：3DMA派生的综合评分是否有效（已知组和收敛效度），可靠且能够量化步行过程中上肢异常运动中与速度相关的变化？

方法：这项观察性研究将42位ABI成年人和行走过程中上肢异常运动与36位健康对照（HC）进行了比较，他们的行走速度与意图相符。参与者进行了3DMA自我选择和快速步行速度的评估。综合评分量化了受影响的上肢的运动异常。Arm姿势评分算术平均值版本（APSam）和1.96标准偏差参考范围比例版本；评估运动偏差评分平均值（KDSm）和最差评分（KDSw）之间的关联以及主观异常评分（Pearson r相关性），重测信度（类内相关系数（ICC））和量化能力与速度有关的异常上肢运动变化（Cohen d效应大小（ES），变化分数％）。

结果：综合得分之间存在非常强的相关性。KDSm对上肢异常进行了分类，而KDSw捕获了大多数ABI参与者。所有分数与异常上肢运动的主观评分（r = 0.54-0.79）和非常强的重测信度（ICC> 0.81）具有中等强相关性。APSam证明与上肢异常相关的步行速度增加了16％（ES 0.76），而KDSm减少了26％（ES 0.90）和KDSw 35％（ES 0.96）。

意义：APSam，KDSw和异常关节轴的数量可以全面评估整个上肢异常运动，准确地对异常进行分类并量化严重程度。这项研究表明，在自行选择的步行速度下，明显出现了异常的上肢运动，而在快速速度下，则出现小幅上升。但是，当按HC可变性进行缩放时，由于HC运动可变性增加，快走运动学的异常现象变得较少。