Simultaneous multi-directional force measurement across all five digits is essential for studying hand coordination, compensatory forces, and myoelectric control, yet existing systems trade off digit coverage, force dimensionality, and anatomical adaptability. Reliable full-hand acquisition remains challenging because multi-axis calibration, hand-size adjustment, and consistent digit-specific force reconstruction are technically demanding. We present MyoKin3X, a customizable full-hand framework for simultaneous 3D force measurement of up to five digits providing robust and validated force reconstruction. It combines an anatomically versatile structure with five integrated 3D force sensors and a standalone software for synchronized electromyography and force acquisition. MyoKin3X provides in-place cross-calibration of all five sensors, single- and multi-digit maximal voluntary contraction recording, and automated coordinate transformation to digit-specific coordinate systems for standardized analysis across subjects and tasks. Calibration validation demonstrates high stability of the axis-specific calibration factors, with a mean coefficient of variation of 0.04% and maximum force error of +- 0.06N at 50N. It also shows effective inter-axis decoupling (mean crosstalk reduction: 92.71%; residual crosstalk below 0.02% for most axis pairs) and high predictive accuracy (R2 > 0.99 across sensors). The software includes four feedback modes: 1D ramps, fatigue protocols, 2D arbitrary target ramps, and 2D exploratory tasks. MyoKin3X therefore enables standardized full-hand force acquisition with validated measurement reliability, flexible protocol control, and real-time visualization for high-fidelity studies of hand motor control, muscle synergies, and human-machine interfacing.

翻译：[translated abstract in Chinese] 同时对所有五根手指进行多方向力测量是研究手部协调、代偿力及肌电控制的关键，然而现有系统在手指覆盖范围、力维度及解剖适应性方面存在权衡。由于多轴标定、手部尺寸调整以及一致的手指特异性力重构在技术上具有挑战性，可靠的全手采集仍面临困难。我们提出MyoKin3X，这是一个可定制的全手框架，能同时测量多达五根手指的三维力，并提供稳健且经过验证的力重构。该框架结合了解剖学通用结构与五个集成三维力传感器，以及用于同步肌电图和力采集的独立软件。MyoKin3X提供所有五个传感器的原地交叉标定、单指及多指最大自主收缩记录，并自动将坐标转换为手指特异性坐标系，以实现跨受试者及任务的标准化分析。标定验证表明，轴特异性标定因子具有高稳定性，平均变异系数为0.04%，在50N力下最大力误差为±0.06N。该框架还表现出有效的轴间解耦（平均串扰降低92.71%；大多数轴对的残余串扰低于0.02%）和高预测精度（传感器间R² > 0.99）。软件包含四种反馈模式：一维斜坡、疲劳协议、二维任意目标斜坡及二维探索任务。因此，MyoKin3X能够实现标准化的全手力采集，具备经过验证的测量可靠性、灵活的协议控制及实时可视化，适用于手部运动控制、肌肉协同及人机接口的高保真研究。