Ground reaction forces (GRFs) provide fundamental insight into human gait mechanics and are widely used to assess joint loading, limb symmetry, balance control, and motor function. Despite their clinical relevance, the use of GRF remains underutilised in clinical workflows due to the practical limitations of force plate systems. In this work, we present a force-plate-free approach for estimating GRFs using only marker-based motion capture data. This kinematics only method to estimate and decompose GRF makes it well suited for widespread clinical depolyment. By using kinematics from sixteen body segments, we estimate the centre of mass (CoM) and compute GRFs, which are subsequently decomposed into individual components through a minimization-based approach. Through this framework, we can identify gait stance phases and provide access to clinically meaningful kinetic measures without a dedicated force plate system. Experimental results demonstrate the viability of CoM and GRF estimation based solely on kinematic data, supporting force-plate-free gait analysis.

翻译：地面反作用力（GRFs）为人类步态力学提供了基础性见解，并广泛用于评估关节负荷、肢体对称性、平衡控制及运动功能。尽管具有临床重要性，但由于测力台系统的实际限制，GRF在临床工作流程中的应用仍未得到充分利用。本研究提出了一种无需测力台的方法，仅使用基于标记点的运动捕捉数据即可估计GRF。这种仅依赖运动学的GRF估计与分解方法使其非常适合广泛的临床部署。通过利用十六个身体节段的运动学数据，我们估计出质心（CoM）并计算GRF，随后通过基于最小化的方法将其分解为独立分量。该框架能够识别步态支撑相，并在无需专用测力台系统的前提下提供具有临床意义的动力学测量指标。实验结果验证了仅基于运动学数据估计CoM与GRF的可行性，为无测力台步态分析提供了支持。