Fig. 1

The surface electromyography (sEMG) is sensitive to detect residual motor commands from muscles with motor scores of zero. Spinal cord injury (SCI, red) disrupts motor commands from the brain (blue), hampering the motor output. The figure shows a hypothetical example using the main muscles assessed in the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). The motor output is commonly measured using motor scores (blue, orange or red dots in the left figure for intact, impaired or absent output, respectively). The sEMG assessment is able to capture the residual motor output in greater detail compared to motor scores because muscles with no motor scores can still display sEMG activity (blue, yellow or red dots in the right-side figure for normal, altered or absent sEMG, respectively). Symmetrical impairment has been assumed for ease of visualization