Despite advances in upper-limb (UL) prosthetic design, achieving intuitive control of intermediate joints - such as the wrist and elbow - remains challenging, particularly for continuous and velocity-modulated movements. We introduce a novel movement-based control paradigm entitled Compensation Effect Amplification Control (CEAC) that leverages users' trunk flexion and extension as input for controlling prosthetic elbow velocity. Considering that the trunk can be both a functional and compensatory joint when performing upper-limb actions, CEAC amplifies the natural coupling between trunk and prosthesis while introducing a controlled delay that allows users to modulate both the position and velocity of the prosthetic joint. We evaluated CEAC in a generic drawing task performed by twelve able-bodied participants using a supernumerary prosthesis with an active elbow. Additionally a multiple-target-reaching task was performed by a subset of ten participants. Results demonstrate task performances comparable to those obtained with natural arm movements, even when gesture velocity or drawing size were varied, while maintaining ergonomic trunk postures. Analysis revealed that CEAC effectively restores joint coordinated action, distributes movement effort between trunk and elbow, enabling intuitive trajectory control without requiring extreme compensatory movements. Overall, CEAC offers a promising control strategy for intermediate joints of UL prostheses, particularly in tasks requiring continuous and precise coordination.

翻译：尽管上肢假肢设计取得了进展，但实现中间关节（如腕关节和肘关节）的直观控制仍然具有挑战性，特别是在连续和速度调节的运动中。我们提出了一种新颖的基于运动的控制范式，称为补偿效应放大控制（CEAC），该范式利用用户躯干的屈伸运动作为输入来控制假肢肘部速度。考虑到躯干在执行上肢动作时既可作为功能关节也可作为代偿关节，CEAC在放大躯干与假肢之间自然耦合的同时，引入了可控延迟，使用户能够同时调节假肢关节的位置和速度。我们通过十二名健全参与者使用配备主动肘部的额外假肢完成通用绘图任务来评估CEAC。此外，十名参与者的子集完成了多目标指向任务。结果表明，即使在手势速度或绘图尺寸变化的情况下，任务表现仍可与自然手臂运动相媲美，同时保持了符合人体工学的躯干姿势。分析显示，CEAC有效恢复了关节协调动作，将运动负荷分配于躯干和肘部之间，实现了直观的轨迹控制，且无需极端的代偿运动。总体而言，CEAC为上肢假肢中间关节提供了一种前景广阔的控制策略，尤其适用于需要连续精确协调的任务。