Figure 1.

Experiment setup. (A) Schematic showing the location of a 1 × 3 activated electrode configuration superimposed over the human spinal cord showing the dorsal column and roots. (B) The custom electronically configurable electrode array placed over the cervical spinal cord of a study participant with a 1 × 3 configuration of activated electrodes (green LEDs). (C) Setup for measuring triceps force. The ulnar protrusion of the wrist is placed over the 25 lb. load cell during the task (red dashed square).