Estimating the position of the whole-body centre of mass (CoM) based on skin markers and anthropometric tables requires tracking the pelvis and lower body, which is impossible for wheelchair users due to occlusion. In this work, we present a method to track the user's whole-body CoM using visible markers affixed to the user and wheelchair where the user remains seated in their wheelchair, by expressing the pelvis and lower body segments in wheelchair coordinates. The accuracy of this method was evaluated on the anterior-posterior (AP) and medial-lateral (ML) axes by comparing the projected CoM to the centre of pressure measured by four force plates, for 11 able-bodied participants adopting 9 static postures that include extreme reaching postures. The estimation accuracy was within 33 mm (AP) and 9 mm (ML), with a precision within 23 mm (AP) and 12 mm (ML). Tracking the whole-body CoM during wheelchair propulsion will allow researchers to better understand the dynamics of propulsion, which may help devise new approaches to increase the energy transfer from the arms to the ground and reduce the risks of developing musculoskeletal disorders.

翻译：基于皮肤标记和人体测量表估算全身质心位置需要追踪骨盆和下肢，但因遮挡问题，轮椅使用者无法实现这一目标。本研究提出一种方法，通过将骨盆和下肢节段表达于轮椅坐标系中，利用固定于使用者和轮椅上的可见标记，追踪乘坐于轮椅中的全身质心位置。通过比较投影质心与四个力台测量的压力中心，在前后轴和内外轴上对11名健康受试者采用9种静态姿势（包括极限伸展姿势）时的准确性进行评估。结果显示，前后轴估算精度在33毫米以内，内外轴在9毫米以内；前后轴精密度在23毫米以内，内外轴在12毫米以内。在轮椅推进过程中追踪全身质心，将有助于研究人员更深入理解推进动力学，进而为提升从手臂到地面的能量传递效率、降低肌肉骨骼系统疾病风险提供新思路。