The stroke participants will receive trans-spinal electrical stimulation (tsES), peripheral activation via neuromuscular electrical stimulation (NMES), and task-specific upper limb robotic training. A mobile hybrid neuromuscular electrical stimulation (NMES)-robot, i.e., exoneuromusculoskeleton (ENMS) was adopted in the experiment.

The stroke participants will receive a task-oriented occupational therapy(OT), along with trans-spinal electrical stimulation (tsES) rehabilitation.

The stroke participants will receive a task-oriented occupational therapy, along with sham trans-spinal electrical stimulation (tsES) rehabilitation.

The recruited subjects will receive 20 sessions of robot-assisted upper limb training combined with central-to-peripheral electrical stimulation, delivered at a frequency of 3 to 5 sessions per week, which will be completed within 4 to 7 consecutive weeks. Each rehabilitation session will begin with a 10-minute preparation phase, followed by 20 minutes of NMES and tsES-assisted robotic training. After a 10-minute break, the session will continue with an additional 20 minutes of robotic-assisted training combined with NMES alone, with tsES turned off during this phase. During the training, patients will perform repeated wrist and finger flexion-extension tasks. The training protocol is designed to activate wrist extension voluntarily (exceeding 10% of their initial MVC), which then triggers NMES and inflation of the robotic hand to assist finger opening.

The Fugl-Meyer Assessment (FMA) Scale for the upper limb measures voluntary motor function in the shoulder, wrist, and hand. The total score ranges from 0 to 66, with higher scores indicating better motor function. The scale can be further divided into two subscores: shoulder/elbow (0-42) and wrist/hand (0-24).

The Modified Ashworth Scale (MAS) assesses muscle spasticity by measuring resistance during passive joint movement, particularly in the flexor muscles. The MAS consists of six levels, ranging from 0 to 4 (with an additional grade of 1+), where higher scores indicate increased resistance and greater muscle spasticity.

The Action Research Arm Test (ARAT) evaluates upper limb motor function by measuring the ability to perform specific tasks related to grasp, grip, pinch, and gross movement. It consists of 19 items, each scored from 0 to 3, with a total score ranging from 0 to 57. Higher scores represent better upper limb functional performance.

The Wolf Motor Function Test (WMFT) assesses upper extremity motor ability through a series of timed and functional tasks. It includes 15 function-based items and 2 strength-based items. Each task is timed and rated on a 6-point functional ability scale, where higher scores and faster completion times reflect better motor performance.