Transcutaneous spinal stimulation paired with visual feedback facilitates retention of improved weight transfer toward the affected side in people post-stroke

Background: Many individuals with hemiparesis after stroke are reluctant to transfer their body weight toward the affected side and rely more heavily on the unaffected leg while walking. Although visual feedback (VF) has been utilized to improve their weight transfer during walking, the effects of transcutaneous spinal stimulation (TSS) paired with VF during locomotor training in people post-stroke remain largely unexplored. The purpose of this study, therefore, was to determine whether phasic TSS paired with VF regarding weight shifting to the affected leg during treadmill walking would enhance weight transfer toward the affected side. Methods: Eleven individuals post-stroke participated in two testing conditions (i.e., TSS + VF & Sham + VF) in a random order with a 10-minute break. Each condition consisted of (1) walking 30 strides (baseline), (2) walking 100 strides with either TSS + VF or Sham + VF (adaptation), and (3) walking 30 strides (post-adaptation). Results: Participants exhibited similar changes in weight transfer toward the affected side during the early post-adaptation period for both testing conditions (P = 0.20). However, enhanced weight transfer was shown during the late post-adaptation period in the TSS + VF condition, compared with the Sham + VF condition (P = 0.019). Further, the TSS + VF condition induced greater enhancement in muscle activation of affected hip abductors (P = 0.002) during the early post-adaptation period, along with greater improvements in stance time of the affected leg (P = 0.04) and symmetry of stance time (P = 0.01), compared with the effect of the Sham + VF condition. Conclusion: Targeted spinal stimulation paired with visually guided weight transfer during locomotor training can facilitate improvements in weight transfer and enhanced use of the affected leg, which may lead to symmetrical gait patterns in individuals with hemiparesis after a stroke.