FIG. 6.

Effects of stand training intervention on functional features. (A) The COP trajectory during the “Circle” game-based exercise without (blue traces) and in presence of spinal stimulation (red traces) in a representative participant (P4). (B) The COP trajectory during the “Basketball” exercise during spinal stimulation in a representative participant (P6). Note the increased score after the stand training. Gradient colors at the horizontal bars present time series synchronized with the cumulative COP trajectories displayed above. (C) Pooled data (n = 6) of the performance during the first and last training sessions of the stand training. The average score was calculated from three trials of each exercise. Examples of the game-based exercises are presented in the top left corner of each graph. (D) Progressive decrease of the level of assistance provided by trainer to the left and right knees during standing in the presence of tSCS (pink and red) as percent of the values during standing without stimulation (NS, gray and black) recorded using the FSR sensors within each session. Zero value indicates that the knee is independently extended (no assistance needed). Participants P2 and P3 (not displayed) did not require any knee assistance during standing in the presence of tSCS starting from training session 1. Hip assistance was not needed during standing in the presence of tSCS for participants P1 and P2 starting from training session 1, and for participant P3—starting from training session 4. Participants P4–P6 required hip assistance during standing in the presence of tSCS throughout the training period. (E) The COP area during self-initiated body-weight displacements performed without and in the presence of spinal stimulation during the training period (n = 6). Horizontal bars indicate significant differences of the COP area between training sessions. COP, center of pressure; FSR, force-sensing resistor; tSCS, transcutaneous electrical spinal cord stimulation.