Figure 1
EMG, lower limb joint angles and ground reaction forces during sit-to-stand transition and during standing. Electromyography (EMG), hip and knee joint angle, and ground reaction forces recorded from research participant A59 during: (a) sit-to-stand transition and standing with external assistance for hips and knees extension (assisted standing) without spinal cord epidural stimulation (scES); (b) sit-to-stand transition and independent standing using scES; the participant held the hands of a trainer for balance control; (c) assisted standing with scES resulting from an overall continuous activation pattern (top) and from an EMG pattern characterized by the alternation of EMG bursts and little activation (bottom). Stimulation amplitude, frequency and electrode configuration (cathodes in black, anodes in red, and inactive in white) are reported for each standing condition. In (b), the participant was stimulated with 3 programs delivered sequentially at 15 Hz, resulting in an ongoing 45 Hz stimulation frequency. EMG was recorded from the following muscles of the right lower limb: IL, iliopsoas; GL, gluteus maximus; MH, medial hamstring; VL, vastus lateralis; TA, tibialis anterior; SOL, soleus.
