To validate a clinically accessible approach for quantifying the Upper Extremity Reachable Workspace (UERW) using a single (monocular) camera and Artificial Intelligence (AI)-driven Markerless Motion Capture (MMC) for biomechanical analysis. Objective assessment and validation of these techniques for specific clinically oriented tasks are crucial for their adoption in clinical motion analysis. AI-driven monocular MMC reduces the barriers to adoption in the clinic and has the potential to reduce the overhead for analysis of this common clinical assessment. Nine adult participants with no impairments performed the standardized UERW task, which entails reaching targets distributed across a virtual sphere centered on the torso, with targets displayed in a VR headset. Movements were simultaneously captured using a marker-based motion capture system and a set of eight FLIR cameras. We performed monocular video analysis on two of these video camera views to compare a frontal and offset camera configurations. The frontal camera orientation demonstrated strong agreement with the marker-based reference, exhibiting a minimal mean bias of $0.61 \pm 0.12$ \% reachspace reached per octanct (mean $\pm$ standard deviation). In contrast, the offset camera view underestimated the percent workspace reached ($-5.66 \pm 0.45$ \% reachspace reached). Conclusion: The findings support the feasibility of a frontal monocular camera configuration for UERW assessment, particularly for anterior workspace evaluation where agreement with marker-based motion capture was highest. The overall performance demonstrates clinical potential for practical, single-camera assessments. This study provides the first validation of monocular MMC system for the assessment of the UERW task. By reducing technical complexity, this approach enables broader implementation of quantitative upper extremity mobility assessment.

翻译：本研究旨在验证一种临床可及的方法，用于通过单目摄像头和人工智能驱动的无标记运动捕捉技术对上肢可达工作空间进行量化分析。针对特定临床导向任务，对这些技术进行客观评估和验证对其在临床运动分析中的应用至关重要。人工智能驱动的单目无标记运动捕捉降低了临床采用门槛，并有望减少这一常见临床评估的分析开销。九名无障碍成年参与者执行了标准化的上肢可达工作空间任务，该任务要求触及以躯干为中心的虚拟球体上分布的目标，目标通过VR头显呈现。运动数据同时通过基于标记的运动捕捉系统和八台FLIR摄像头组进行采集。我们选取其中两个摄像机视角进行单目视频分析，以比较正面与偏移摄像机配置。正面摄像机方向与基于标记的参考系统表现出高度一致性，每八分象限达到的平均偏差极小，为$0.61 \pm 0.12$\% 可达空间（均值$\pm$标准差）。相比之下，偏移摄像机视角低估了达到的工作空间百分比（$-5.66 \pm 0.45$\% 可达空间）。结论：研究结果支持正面单目摄像机配置用于上肢可达工作空间评估的可行性，特别是在与基于标记运动捕捉一致性最高的前侧工作空间评估中。整体性能展示了实用型单摄像头评估的临床潜力。本研究首次验证了单目无标记运动捕捉系统在上肢可达工作空间任务评估中的应用。通过降低技术复杂性，该方法为定量上肢活动能力评估的更广泛实施提供了可能。