Restoring somatosensory feedback in individuals with lower-limb amputations would reduce the risk of falls and alleviate phantom limb pain. Here we show, in three individuals with transtibial amputation (one traumatic and two owing to diabetic peripheral neuropathy), that sensations from the missing foot, with control over their location and intensity, can be evoked via lateral lumbosacral spinal cord stimulation with commercially available electrodes and by modulating the intensity of stimulation in real time on the basis of signals from a wireless pressure-sensitive shoe insole. The restored somatosensation via closed-loop stimulation improved balance control (with a 19-point improvement in the composite score of the Sensory Organization Test in one individual) and gait stability (with a 5-point improvement in the Functional Gait Assessment in one individual). And over the implantation period of the stimulation leads, the three individuals experienced a clinically meaningful decrease in phantom limb pain (with an average reduction of nearly 70% on a visual analogue scale). Our findings support the further clinical assessment of lower-limb neuroprostheses providing somatosensory feedback.

恢复下肢截肢患者的体感反馈将降低跌倒的风险并减轻幻肢痛。在这里，我们展示了三名经胫骨截肢者（一名是外伤，两名是糖尿病周围神经病变），通过使用市售电极对侧腰骶脊髓进行刺激，可以通过控制其位置和强度来唤起缺失脚的感觉并根据来自无线压敏鞋垫的信号实时调节刺激强度。通过闭环刺激恢复的体感改善了平衡控制（一名个体的感觉组织测试综合得分提高了 19 分）和步态稳定性（一名个体的功能步态评估提高了 5 分） 。在刺激导线的植入期间，三人的幻肢痛出现了具有临床意义的减少（视觉模拟量表平均减少近 70%）。我们的研究结果支持对提供体感反馈的下肢神经假体进行进一步的临床评估。