Cervical spinal cord injury (SCI) causes profound and persistent loss of hand function, and effective neuromodulation strategies remain limited. We report the first-in-human implantation of a 32-contact cervical epidural paddle array in two individuals with severe chronic SCI. Individualized motor pool recruitment maps, derived from systematic bipolar and multipolar configurations, enabled person-specific stimulation parameters. Optimized stimulation restored volitional hand opening, closing and coordinated upper-limb movements that were previously unattainable. This approach achieved a >91% success rate in complex reach-grasp-lift-release sequences, supported by substantial gains in range of motion, grip, and pinch strength. Electrophysiological and kinematic analyses demonstrated parameter-dependent, selective recruitment of flexor and extensor motor pools. Personalized stimulation programs integrated with goal-directed activities enabled functional hand use in home and community settings, sustained over several months of continued autonomous use. These findings establish a mechanistically grounded and translational framework for restoring upper-limb function after chronic severe SCI.

M.M is an employee of Boston Scientific. All other authors declare no conflicts of interests in relation to this work. 

NCT06225245

This work was supported by philanthropic funding from Paula and Joseph C. 'Rusty' Walter III, the Walter Oil & Gas Corporation, and the NeuroSpark seed fund. Additional funding was provided by the National Institutes of Health (NIH) grant 5R01NS119587 and the Craig H. Neilsen Foundation (Research Grant 733278).

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Institutional Review Board of Houston Methodist Research Institute gave ethical approval for this work (IDE protocol G230309).

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