Behrman, A. L., Ardolino, E. M. & Harkema, S. J. Activity-based therapy: from basic science to clinical application for recovery after spinal cord injury. J. Neurol. Phys. Ther. 41, S39–S45 (2017).
Jones, M. L. et al. Activity-based therapy for recovery of walking in individuals with chronic spinal cord injury: results from a randomized clinical trial. Arch. Phys. Med. Rehabil. 95, 2239–2246 (2014).
Field-Fote, E. C., Lindley, S. D. & Sherman, A. L. Locomotor training approaches for individuals with spinal cord injury: a preliminary report of walking-related outcomes. J. Neurol. Phys. Ther. 29, 127–137 (2005).
Edgerton, V. R. et al. Training locomotor networks. Brain Res. Rev. 57, 241–254 (2008).
Côté, M. P., Murray, M. & Lemay, M. A. Rehabilitation strategies after spinal cord injury: inquiry into the mechanisms of success and failure. J. Neurotrauma 34, 1841–1857 (2017).
Borton, D., Micera, S., Millán, J. d. R. & Courtine, G. Personalized neuroprosthetics. Sci. Transl. Med. 5, 210rv2 (2013).
Field-Fote, E. C. & Roach, K. E. Influence of a locomotor training approach on walking speed and distance in people with chronic spinal cord injury: a randomized clinical trial. Phys. Ther. 91, 48–60 (2011).
Minassian, K., McKay, W. B., Binder, H. & Hofstoetter, U. S. Targeting lumbar spinal neural circuitry by epidural stimulation to restore motor function after spinal cord injury. Neurotherapeutics 13, 284–294 (2016).
Angeli, C. A. et al. Recovery of over-ground walking after chronic motor complete spinal cord injury. N. Engl. J. Med. 379, 1244–1250 (2018).
Gill, M. L. et al. Neuromodulation of lumbosacral spinal networks enables independent stepping after complete paraplegia. Nat. Med. https://doi.org/10.1038/s41591-018-0175-7 (2018).
Barolat, G., Myklebust, J. B. & Wenninger, W. Enhancement of voluntary motor function following spinal cord stimulation-case study. Appl. Neurophysiol. 49, 307–314 (1986).
Angeli, C. A., Edgerton, V. R., Gerasimenko, Y. P. & Harkema, S. J. Altering spinal cord excitability enables voluntary movements after chronic complete paralysis in humans. Brain 137, 1394–1409 (2014).
Danner, S. M. et al. Human spinal locomotor control is based on flexibly organized burst generators. Brain 138, 577–588 (2015).
Grahn, P. J. et al. Enabling task-specific volitional motor functions via spinal cord neuromodulation in a human with paraplegia. Mayo Clin. Proc. 92, 544–554 (2017).
Carhart, M. R., He, J., Herman, R., D’Luzansky, S. & Willis, W. T. Epidural spinal-cord stimulation facilitates recovery of functional walking following incomplete spinal-cord injury. IEEE Trans. Neural Syst. Rehabil. Eng. 12, 32–42 (2004).
Minassian, K. et al. Stepping-like movements in humans with complete spinal cord injury induced by epidural stimulation of the lumbar cord: electromyographic study of compound muscle action potentials. Spinal Cord 42, 401–416 (2004).
Rattay, F., Minassian, K. & Dimitrijevic, M. R. Epidural electrical stimulation of posterior structures of the human lumbosacral cord: 2. Quantitative analysis by computer modeling. Spinal Cord 38, 473–489 (2000).
Capogrosso, M. et al. A computational model for epidural electrical stimulation of spinal sensorimotor circuits. J. Neurosci. 33, 19326–19340 (2013).
Moraud, E. M. et al. Closed-loop control of trunk posture improves locomotion through the regulation of leg proprioceptive feedback after spinal cord injury. Sci. Rep. 8, 76 (2018).
Gerasimenko, Y., Roy, R. R. & Edgerton, V. R. Epidural stimulation: comparison of the spinal circuits that generate and control locomotion in rats, cats and humans. Exp. Neurol. 209, 417–425 (2008).
Wenger, N. et al. Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury. Nat. Med. 22, 138–145 (2016).
Wenger, N. et al. Closed-loop neuromodulation of spinal sensorimotor circuits controls refined locomotion after complete spinal cord injury. Sci. Transl. Med. 6, 255ra133 (2014).
Capogrosso, M. et al. A brain-spine interface alleviating gait deficits after spinal cord injury in primates. Nature 539, 284–288 (2016).
Dominici, N. et al. Versatile robotic interface to evaluate, enable and train locomotion and balance after neuromotor disorders. Nat. Med. 18, 1142–1147 (2012).
Asboth, L. et al. Cortico-reticulo-spinal circuit reorganization enables functional recovery after severe spinal cord contusion. Nat. Neurosci. 21, 576–588 (2018).
van den Brand, R. et al. Restoring voluntary control of locomotion after paralyzing spinal cord injury. Science 336, 1182–1185 (2012).
Mignardot, J. B. et al. A multidirectional gravity-assist algorithm that enhances locomotor control in patients with stroke or spinal cord injury. Sci. Transl. Med. 9, eaah3621 (2017).
Cappellini, G., Ivanenko, Y. P., Dominici, N., Poppele, R. E. & Lacquaniti, F. Migration of motor pool activity in the spinal cord reflects body mechanics in human locomotion. J. Neurophysiol. 104, 3064–3073 (2010).
Yakovenko, S., Mushahwar, V., VanderHorst, V., Holstege, G. & Prochazka, A. Spatiotemporal activation of lumbosacral motoneurons in the locomotor step cycle. J. Neurophysiol. 87, 1542–1553 (2002).
Asanuma, H. & Mackel, R. Direct and indirect sensory input pathways to the motor cortex; its structure and function in relation to learning of motor skills. Jpn. J. Physiol. 39, 1–19 (1989).
Gourab, K. & Schmit, B. D. Changes in movement-related β-band EEG signals in human spinal cord injury. Clin. Neurophysiol. 121, 2017–2023 (2010).
Capogrosso, M. et al. Configuration of electrical spinal cord stimulation through real-time processing of gait kinematics. Nat. Protoc. 13, 2031–2061 (2018).
Schieppati, M. The Hoffmann reflex: a means of assessing spinal reflex excitability and its descending control in man. Prog. Neurobiol. 28, 345–376 (1987).
Schindler-Ivens, S. & Shields, R. K. Low-frequency depression of H-reflexes in humans with acute and chronic spinal-cord injury. Exp. Brain Res. 133, 233–241 (2000).
Formento, E. et al. Electrical spinal cord stimulation must preserve proprioception to enable locomotion in humans with spinal cord injury. Nat. Neurosci. https://doi.org/10.1038/s41593-018-0262-6 (2018).
Moraud, E. M. et al. Mechanisms underlying the neuromodulation of spinal circuits for correcting gait and balance deficits after spinal cord injury. Neuron 89, 814–828 (2016).
Takeoka, A., Vollenweider, I., Courtine, G. & Arber, S. Muscle spindle feedback directs locomotor recovery and circuit reorganization after spinal cord injury. Cell 159, 1626–1639 (2014).
Holtmaat, A. & Svoboda, K. Experience-dependent structural synaptic plasticity in the mammalian brain. Nat. Rev. Neurosci. 10, 647–658 (2009).
Nishimura, Y., Perlmutter, S. I., Eaton, R. W. & Fetz, E. E. Spike-timing-dependent plasticity in primate corticospinal connections induced during free behavior. Neuron 80, 1301–1309 (2013).
Perez, M. A., Field-Fote, E. C. & Floeter, M. K. Patterned sensory stimulation induces plasticity in reciprocal Ia inhibition in humans. J. Neurosci. 23, 2014–2018 (2003).
Urbin, M. A., Ozdemir, R. A., Tazoe, T. & Perez, M. A. Spike-timing-dependent plasticity in lower-limb motoneurons after human spinal cord injury. J. Neurophysiol. 118, 2171–2180 (2017).
Dietz, V. Behavior of spinal neurons deprived of supraspinal input. Nat. Rev. Neurol. 6, 167–174 (2010).
West, C. R. et al. Association of epidural stimulation with cardiovascular function in an individual with spinal cord injury. JAMA Neurol. 75, 630–632 (2018).
Herrity, A. N., Williams, C. S., Angeli, C. A., Harkema, S. J. & Hubscher, C. H. Lumbosacral spinal cord epidural stimulation improves voiding function after human spinal cord injury. Sci. Rep. 8, 8688 (2018).
van Middendorp, J. J. et al. A clinical prediction rule for ambulation outcomes after traumatic spinal cord injury: a longitudinal cohort study. Lancet 377, 1004–1010 (2011).
Sharrard, W. J. The segmental innervation of the lower limb muscles in man. Ann. R. Coll. Surg. Engl. 35, 106–122 (1964).