Advertisement
Special communication| Volume 93, ISSUE 9, P1487-1497, September 2012

Download started.

Ok

Basic Concepts of Activity-Based Interventions for Improved Recovery of Motor Function After Spinal Cord Injury

  • Roland R. Roy
    Affiliations
    Department of Integrative Biology and Physiology and the Brain Research Institute, University of California, Los Angeles, CA
    Search for articles by this author
  • Susan J. Harkema
    Affiliations
    Department of Neurological Surgery, Kentucky Spinal Cord Research Center, University of Louisville, Louisville, KY

    Frazier Rehab Institute, Louisville, KY
    Search for articles by this author
  • V. Reggie Edgerton
    Correspondence
    Reprint requests to V. Reggie Edgerton, PhD, Dept of Physiological Science, UCLA, 621 Charles E. Young Dr, Los Angeles, CA 90095-1527
    Affiliations
    Department of Integrative Biology and Physiology and the Brain Research Institute, University of California, Los Angeles, CA

    Department of Neurobiology and Neurosurgery, University of California, Los Angeles, CA
    Search for articles by this author

      Abstract

      Roy RR, Harkema SJ, Edgerton VR. Basic concepts of activity-based interventions for improved recovery of motor function after spinal cord injury.
      Spinal cord injury (SCI) is a devastating condition that affects a large number of individuals. Historically, the recovery process after an SCI has been slow and with limited success. Recently, a number of advances have been made in the strategies used for rehabilitation, resulting in marked improved recovery, even after a complete SCI. Several rehabilitative interventions, that is, assisted motor training, spinal cord epidural stimulation, and/or administration of pharmacologic agents, alone or in combination, have produced remarkable recovery in motor function in both humans and animals. The success with each of these interventions appears to be related to the fact that the spinal cord is smart, in that it can use ensembles of sensory information to generate appropriate motor responses without input from supraspinal centers, a property commonly referred to as central pattern generation. This ability of the spinal cord reflects a level of automaticity, that is, the ability of the neural circuitry of the spinal cord to interpret complex sensory information and to make appropriate decisions to generate successful postural and locomotor tasks. Herein, we provide a brief review of some of the neurophysiologic rationale for the success of these interventions.

      Key Words

      List of Abbreviations:

      CPG (central pattern generation), EMG (electromyogram), SCI (spinal cord injury)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Archives of Physical Medicine and Rehabilitation
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Barbeau H.
        • McCrea D.A.
        • O'Donovan M.J.
        • Rossignol S.
        • Grill W.M.
        • Lemay M.A.
        Tapping into spinal circuits to restore motor function.
        Brain Res Rev. 1999; 30: 27-51
        • Barriere G.
        • Leblond H.
        • Provencher J.
        • Rossignol S.
        Prominent role of the spinal central pattern generator in the recovery of locomotion after partial spinal cord injuries.
        J Neurosci. 2008; 28: 3976-3987
        • Dimitrijevic M.R.
        • Gerasimenko Y.
        • Pinter M.M.
        Evidence for a spinal central pattern generator in humans.
        Ann N Y Acad Sci. 1998; 860: 360-376
        • Edgerton V.R.
        • Courtine G.
        • Gerasimenko Y.P.
        • et al.
        Training locomotor networks.
        Brain Res Rev. 2008; 57: 241-254
        • Field-Fote E.C.
        Spinal cord control of movement: implications for locomotor rehabilitation following spinal cord injury.
        Phys Ther. 2000; 80: 477-484
        • Grillner S.
        • Zangger P.
        How detailed is the central pattern generation for locomotion?.
        Brain Res. 1975; 88: 367-371
        • Grillner S.
        • Zangger P.
        On the central generation of locomotion in the low spinal cat.
        Exp Brain Res. 1979; 34: 241-261
        • Grillner S.
        • Wallén P.
        Central pattern generators for locomotion, with special reference to vertebrates.
        Ann Rev Neurosci. 1985; 8: 233-261
        • Harkema S.J.
        • Dobkin B.H.
        • Edgerton V.R.
        Pattern generators in locomotion: implications for recovery of walking after spinal cord injury.
        Top Spinal Cord Inj Rehabil. 2000; 6: 82-96
        • Harkema S.J.
        Plasticity of interneuronal networks of the functionally isolated human spinal cord.
        Brain Res Rev. 2008; 57: 255-264
        • Rossignol S.
        • Barriere G.
        • Alluin O.
        • Frigon A.
        Re-expression of locomotor function after partial spinal cord injury.
        Physiology. 2009; 24: 127-139
        • Shik M.L.
        • Orlovsky G.N.
        Neurophysiology of locomotor automatism.
        Physiol Rev. 1976; 56: 465-501
        • Andersson O.
        • Grillner S.
        • Lindquist M.
        • Zomlefer M.
        Peripheral control of the spinal pattern generators for locomotion in cat.
        Brain Res. 1978; 150: 625-630
        • Barbeau H.
        • Fung J.
        • Leroux A.
        • Ladouceur M.
        A review of the adaptability and recovery of locomotion after spinal cord injury.
        Progr Brain Res. 2002; 137: 9-25
        • Beres-Jones J.A.
        • Harkema S.J.
        The human spinal cord interprets velocity-dependent afferent input during stepping.
        Brain. 2004; 127: 2232-2246
        • Bouyer L.
        • Rossignol S.
        The contribution of cutaneous inputs to locomotion in the intact and the spinal cat.
        Ann N Y Acad Sci. 1998; 860: 508-512
        • Dietz V.
        Human neuronal control of automatic functional movements: interaction between central programs and afferent input.
        Physiol Rev. 1992; 72: 33-69
        • Dietz V.
        Role of peripheral afferents and spinal reflexes in normal and impaired human locomotion.
        Rev Neurol (Paris). 1987; 143: 241-254
        • Dietz V.
        Interaction between central programs and afferent input in the control of posture and locomotion.
        J Biomech. 1996; 29: 841-844
        • Dietz V.
        Supraspinal pathways and the development of muscle-tone dysregulation.
        Dev Med Child Neurol. 1999; 41: 708-715
        • Grillner S.
        Interaction between central and peripheral mechanisms in the control of locomotion.
        Prog Brain Res. 1979; 50: 227-235
        • Grillner S.
        Interaction between sensory signals and the central networks controlling locomotion in lamprey, dogfish, and cat.
        in: Grillner S. Stein P.S.G. Stuart D.G. Forssberg F. Herman R.M. Neurobiology of vertebrate locomotion. Vol. 45. Macmillan, London1986: 505-512
        • Harkema S.J.
        • Hurley S.L.
        • Patel U.K.
        • Requejo P.S.
        • Dobkin B.H.
        • Edgerton V.R.
        Human lumbosacral spinal cord interprets loading during stepping.
        J Neurophysiol. 1997; 77: 797-811
        • Pearson K.G.
        • Misiaszek J.
        • Fouad K.
        Enhancement and resetting of locomotor activity by muscle afferents.
        Ann N Y Acad Sci. 1998; 860: 203-215
        • Rossignol S.
        • Dubuc R.
        • Gossard J.P.
        Dynamic sensorimotor interactions in locomotion.
        Physiol Rev. 2006; 86: 89-154
        • Brown G.T.
        The intrinsic factors in the act of progression in the mammal.
        Roy Soc Proc. 1911; 84: 308-319
        • Orlovsky G.N.
        • Deliagina T.G.
        • Grillner S.
        Neuronal control of locomotion: from mollusk to man.
        Oxford Univ Pr, Oxford1999
        • Grillner S.
        On the generation of locomotion in the spinal dogfish.
        Exp Brain Res. 1974; 20: 459-470
        • Grillner S.
        Locomotion in vertebrates-central mechanisms and reflex interaction.
        Physiol Rev. 1975; 55: 247-304
        • Andersson O.
        • Grillner S.
        Peripheral control of the cat's step cycle.
        Acta Physiol Scand. 1981; 113: 89-101
        • Andersson O.
        • Grillner S.
        Peripheral control of the cat's step cycle.
        Acta Physiol Scand. 1983; 118: 229-239
        • Duysens J.
        • van de Crommert H.W.
        Neural control of locomotion; the central pattern generator from cats to humans.
        Gait Posture. 1998; 7: 131-141
        • Duysens J.
        • van de Crommert H.W.
        • Hopman M.
        • Mulder T.
        Electrical stimulation for activation of the central pattern generator for locomotion.
        in: Van der Woude Biomedical aspects of manual wheelchair propulsion. IOS-Press, Amsterdam1999: 277-286
        • Kiehn O.
        • Kjaerulff O.
        Distribution of central pattern generators for rhythmic motor outputs in the spinal cord of limbed vertebrates.
        Ann N Y Acad Sci. 1998; 860: 110-129
        • Sigvardt K.
        • Miller W.
        Analysis and modeling of the locomotor central pattern generator as a network of coupled oscillators.
        Ann N Y Acad Sci. 1998; 860: 250-265
        • Smith J.L.
        • Carlson-Kuhta P.
        • Trank T.V.
        Motor patterns for different forms of walking: cues for the locomotor central pattern generator.
        Ann N Y Acad Sci. 1998; 860: 452-455
        • van de Crommert H.W.
        • Mulder T.
        • Duysens J.
        Neural control of locomotion: sensory control of the central pattern generator and its relation to treadmill training.
        Gait Posture. 1998; 7: 251-263
        • Edgerton V.
        • Roy R.
        • de Leon R.
        Neural Darwinism in the mammalian spinal cord.
        in: Patterson M.M. Grau J. Spinal cord plasticity: alterations in reflex function. Kluwer Academic, Boston2001: 185-206
        • Grillner S.
        The motor infrastructure: from ion channels to neuronal networks.
        Nat Rev Neurosci. 2003; 4: 573-586
        • Edgerton V.R.
        • Tillakaratne N.J.
        • Bigbee A.J.
        • de Leon R.D.
        • Roy R.R.
        Plasticity of the spinal neural circuitry after injury.
        Annu Rev Neurosci. 2004; 27: 145-167
        • Forssberg H.
        • Grillner S.
        • Halbertsma J.
        The locomotion of the low spinal cat.
        Acta Physiol Scand. 1980; 108: 269-281
        • Forssberg H.
        • Grillner S.
        • Halbertsma J.
        • Rossignol S.
        The locomotion of the low spinal cat.
        Acta Physiol Scand. 1980; 108: 283-295
        • Edgerton V.R.
        • Roy R.R.
        • Hodgson J.A.
        • Gregor R.
        • de Guzman C.P.
        Recovery of full weight-supporting locomotion of the hindlimbs after complete thoracic spinalization of adult and neonatal cats.
        in: Wernig A. Restorative neurology, plasticity of motoneuronal connections. Vol 5. Elsevier, New York1991: 405-418
        • Edgerton V.R.
        • de Guzman C.P.
        • Gregor R.
        • Roy R.R.
        • Hodgson J.A.
        • Lovely R.G.
        Trainability of the spinal cord to generate hindlimb stepping patterns in adult spinalized cats.
        in: Shimamura M. Grillner S. Edgerton V.R. Neurobiological basis of human locomotion. Japan Scientific Societies Pr, Tokyo1991: 411-423
        • Edgerton V.R.
        • Roy R.R.
        • Hodgson J.A.
        • Prober R.J.
        • de Guzman C.P.
        • de Leon R.D.
        Potential of adult mammalian lumbosacral spinal cord to execute and acquire improved locomotion in the absence of supraspinal input.
        J Neurotrauma. 1992; 9: S119-S128
        • Barbeau H.
        • Rossignol S.
        Recovery of locomotion after chronic spinalization in the adult cat.
        Brain Res. 1987; 412: 84-95
        • Barbeau H.
        • Chau C.
        • Rossignol S.
        Noradrenergic agonists and locomotor training affect locomotor recovery after cord transection in adult cats.
        Brain Res Bull. 1993; 30: 387-393
        • Lovely R.G.
        • Gregor R.
        • Roy R.R.
        • Edgerton V.R.
        Effects of training on the recovery of full-weight-bearing stepping in the adult spinal cat.
        Exp Neurol. 1986; 92: 421-435
        • de Leon R.
        • Reinkensleyer D.
        • Timoszyk W.
        • London N.
        • Roy R.R.
        • Edgerton V.R.
        Use of robotics in assessing the adaptive capacity of the rat lumbar spinal cord.
        Progr Brain Res. 2002; 137: 141-149
        • de Leon R.D.
        • Hodgson J.A.
        • Roy R.R.
        • Edgerton V.R.
        Full weight-bearing hindlimb standing following stand training in the adult spinal cat.
        J Neurophysiol. 1998; 80: 83-91
        • de Leon R.D.
        • Hodgson J.A.
        • Roy R.R.
        • Edgerton V.R.
        Locomotor capacity attributable to step training versus spontaneous recovery after spinalization in adult cats.
        J Neurophysiol. 1998; 79: 1329-1340
        • de Leon R.D.
        • Hodgson J.A.
        • Roy R.R.
        • Edgerton V.R.
        Retention of hindlimb stepping ability in adult spinal cats after the cessation of step training.
        J Neurophysiol. 1999; 81: 85-94
        • Cha J.
        • Heng C.
        • Reinkensmeyer D.J.
        • Roy R.R.
        • Edgerton V.R.
        • de Leon R.D.
        Locomotor ability in spinal rats is dependent on the amount of activity imposed on the hindlimbs during treadmill training.
        J Neurotrauma. 2007; 24: 1000-1012
        • Edgerton V.R.
        • Roy R.R.
        • de Leon R.
        • Tillakaratne N.
        • Hodgson J.A.
        Does motor learning occur in the spinal cord?.
        Neuroscientist. 1997; 3: 287-294
        • Allum J.H.
        • Dietz V.
        • Freund H.J.
        Neuronal mechanisms underlying physiological tremor.
        J Neurophysiol. 1978; 41: 557-571
        • Bawa P.
        • Stein R.B.
        Frequency response of human soleus muscle.
        J Neurophysiol. 1976; 39: 788-793
        • Dimitrijevic M.R.
        • Nathan P.W.
        Studies of spasticity in man. 2.
        Brain. 1967; 90: 333-358
        • Dimitrijevic M.R.
        • Nathan P.W.
        Studies of spasticity in man. 1.
        Brain. 1967; 90: 1-30
        • Dimitrijevic M.R.
        • Nathan P.W.
        • Sherwood A.M.
        Clonus: the role of central mechanisms.
        J Neurol. 1980; 43: 321-332
        • Gottlieb G.L.
        • Agarwal G.C.
        Physiological clonus in man.
        Exp Neurol. 1977; 54: 616-621
        • Hagbarth K.E.
        • Wallin G.
        • Leofstedt L.
        • Aquilonius S.M.
        Muscle spindle activity in alternating tremor of Parkinsonism and in clonus.
        J Neurol Neurosurg Psychiat. 1975; 38: 636-641
        • Walsh E.G.
        Clonus: beats provoked by the application of a rhythmic force.
        J Neurol Neurosurg Psychiat. 1976; 39: 266-274
        • Barbeau H.
        • Basso M.
        • Behrman A.
        • Harkema S.
        Treadmill training after spinal cord injury: good but not better.
        Neurology. 2006; 67: 1900-1901
        • Behrman A.L.
        • Harkema S.J.
        Locomotor training after human spinal cord injury: a series of case studies.
        Phys Ther. 2000; 80: 688-700
        • Behrman A.K.
        • Lawless-Dixon A.R.
        • Davis S.B.
        • et al.
        Locomotor training progression and outcomes after incomplete spinal cord injury.
        Phys Ther. 2005; 85: 1356-1371
        • Behrman A.L.
        • Bowden M.G.
        • Nair P.M.
        Neuroplasticity after spinal cord injury and training: an emerging paradigm shift in rehabilitation and walking recovery.
        Phys Ther. 2006; 86: 1406-1425
        • Behrman A.L.
        • Nair P.M.
        • Bowden M.G.
        • et al.
        Locomotor training restores walking in a nonambulatory child with chronic, severe, incomplete cervical spinal cord injury.
        Phys Ther. 2008; 88: 580-590
        • Dietz V.
        • Colombo G.
        Recovery from spinal cord injury−underlying mechanisms and efficacy of rehabilitation.
        Acta Neurochir Suppl. 2004; 89: 95-100
        • Dietz V.
        Body weight supported gait training: from laboratory to clinical setting.
        Brain Res Bull. 2009; 78 (15): I-VI
        • Dobkin B.H.
        An overview of treadmill locomotor training with partial body weight support: a neurophysiologically sound approach whose time has come for randomized clinical trials.
        Neurorehabil Neural Repair. 1999; 13: 157-165
        • Dobkin B.
        • Apple D.
        • Barbeau H.
        • et al.
        Weight-supported treadmill vs over-ground training for walking after acute incomplete SCI.
        Neurology. 2006; 66: 484-493
        • Edgerton V.R.
        • Kim S.J.
        • Ichiyama R.M.
        • Gerasimenko Y.P.
        • Roy R.R.
        Rehabilitative therapies after spinal cord injury.
        J Neurotrauma. 2006; 23: 560-570
        • Field-Fote E.C.
        Combined use of body weight support, functional electric stimulation, and treadmill training to improve walking ability in individuals with chronic incomplete spinal cord injury.
        Arch Phys Med Rehabil. 2001; 82: 818-824
        • Harkema S.J.
        Neural plasticity after human spinal cord injury: application of locomotor training to the rehabilitation of walking.
        Neuroscientist. 2001; 7: 455-468
        • Harkema S.J.
        • Behrman A.L.
        Locomotor training: principles and practice.
        Robomedica, Los Angeles2002
        • Musselman K.E.
        • Fouad K.
        • Misiaszek J.E.
        • Yang J.F.
        Training of walking skills overground and on the treadmill: case series on individuals with incomplete spinal cord injury.
        Phys Ther. 2009; 89: 601-611
        • Nooijen C.F.
        • Ter H.N.
        • Field-Fote E.C.
        Gait quality is improved by locomotor training in individuals with SCI regardless of training approach.
        J Neuroeng Rehabil. 2009; 6: 36
        • Nymark J.
        • Deforge D.
        • Barbeau H.
        • Badour M.
        • Bercovitch S.
        Body weight support treadmill gait training in the subacute recovery of incomplete spinal cord injury.
        J Neuro Rehab. 1998; 12: 119-138
        • Wernig A.
        • Müller S.
        Improvement of walking in spinal cord injured persons after treadmill training.
        in: Wernig A. Restorative neurology, plasticity of motoneuronal connections. Vol 5. Elsevier, New York1991: 475-485
        • Wernig A.
        • Müller S.
        Laufband locomotion with body weight support improved walking in persons with severe spinal cord injuries.
        Paraplegia. 1992; 30: 229-238
        • Wernig A.
        • Nanassy A.
        • Muller S.
        Laufband (treadmill) therapy in incomplete paraplegia and tetraplegia.
        J Neurotrauma. 1999; 16: 719-726
        • Wernig A.
        Long-term body-weight supported treadmill training and subsequent follow-up in persons with chronic SCI: effects on functional walking ability and measures of subjective well-being.
        Spinal Cord. 2006; 44: 265-266
        • Wessels M.
        • Lucas C.
        • Eriks I.
        • de Groot S.
        Body weight-supported gait training for restoration of walking in people with an incomplete spinal cord injury: a systematic review.
        J Rehabil Med. 2010; 42: 513-519
        • Winchester P.
        • McColl R.
        • Querry R.
        • et al.
        Changes in supraspinal activation patterns following robotic locomotor therapy in motor-incomplete spinal cord injury.
        Neurorehabil Neural Repair. 2005; 19: 313-324
        • Wirz M.
        • Colombo G.
        • Dietz V.
        Long term effects of locomotor training in spinal humans.
        J Neurol Neurosurg Psychiatry. 2001; 71: 93-96
        • Wirz M.
        • Zemon D.H.
        • Rupp R.
        • et al.
        Effectiveness of automated locomotor training in patients with chronic incomplete spinal cord injury: a multicenter trial.
        Arch Phys Med Rehabil. 2005; 86: 672-680
        • Dobkin B.H.
        • Harkema S.
        • Requejo P.
        • Edgerton V.R.
        Modulation of locomotor-like EMG activity in subjects with complete and incomplete spinal cord injury.
        J Neurol Rehabil. 1995; 9: 183-190
        • Field-Fote E.C.
        • Tepavac D.
        Improved intralimb coordination in people with incomplete spinal cord injury following training with body weight support and electrical stimulation.
        Phys Ther. 2002; 82: 707-715
        • Gorgey A.S.
        • Poarch H.
        • Miller J.
        • Castillo T.
        • Gater D.R.
        Locomotor and resistance training restore walking in an elderly person with a chronic incomplete spinal cord injury.
        NeuroRehabilitation. 2010; 26: 127-133
        • Hardin E.
        • Kobetic R.
        • Murray L.
        • et al.
        Walking after incomplete spinal cord injury using an implanted FES system: a case report.
        J Rehabil Res Dev. 2007; 44: 333-346
        • Jayaraman A.
        • Shah P.
        • Gregory C.
        • et al.
        Locomotor training and muscle function after incomplete spinal cord injury: case series.
        J Spinal Cord Med. 2008; 31: 185-193
        • Pepin A.
        • Norman K.E.
        • Barbeau H.
        Treadmill walking in incomplete spinal-cord-injured subjects: 1.
        Spinal Cord. 2003; 41: 257-270
        • Pepin A.
        • Ladouceur M.
        • Barbeau H.
        Treadmill walking in incomplete spinal-cord-injured subjects: 2.
        Spinal Cord. 2003; 41: 271-279
        • Waters R.L.
        • Adkins R.H.
        • Yakura J.S.
        • Sie I.
        Motor and sensory recovery following incomplete paraplegia.
        Arch Phys Med Rehabil. 1994; 75: 67-72
        • Waters R.L.
        • Adkins R.H.
        • Yakura J.S.
        • Sie I.
        Motor and sensory recovery following incomplete tetraplegia.
        Arch Phys Med Rehabil. 1994; 75: 306-311
        • Adams M.M.
        • Ditor D.S.
        • Tarnopolsky M.A.
        • Phillips S.M.
        • McCartney N.
        • Hicks A.L.
        The effect of body weight-supported treadmill training on muscle morphology in an individual with chronic, motor-complete spinal cord injury: a case study.
        J Spinal Cord Med. 2006; 29: 167-171
        • Crozier K.S.
        • Graziani V.
        • Ditunno J.F.
        • Herbison G.J.
        Spinal cord injury: prognosis for ambulation based on sensory examination in patients who are initially motor complete.
        Arch Phys Med Rehabil. 1991; 72: 119-121
        • Ferris D.P.
        • Gordon K.E.
        • Beres-Jones J.A.
        • Harkema S.J.
        Muscle activation during unilateral stepping occurs in the nonstepping limb of humans with clinically complete spinal cord injury.
        Spinal Cord. 2004; 42: 14-23
        • Forrest G.F.
        • Sisto S.A.
        • Barbeau H.
        • et al.
        Neuromotor and musculoskeletal responses to locomotor training for an individual with chronic motor complete AIS-B spinal cord injury.
        J Spinal Cord Med. 2008; 31: 509-521
        • Frigon A.
        • Rossignol S.
        Functional plasticity following spinal cord lesions.
        Prog Brain Res. 2006; 157: 231-260
        • Graupe D.
        • Cerrel-Bazo H.
        • Kern H.
        • Carraro U.
        Walking performance, medical outcomes and patient training in FES of innervated muscles for ambulation by thoracic-level complete paraplegics.
        Neurol Res. 2008; 30: 123-130
        • Lunenburger L.
        • Bolliger M.
        • Czell D.
        • Muller R.
        • Dietz V.
        Modulation of locomotor activity in complete spinal cord injury.
        Exp Brain Res. 2006; 174: 638-646
        • Minassian K.
        • Jilge B.
        • Rattay F.
        • 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. 2004; 42: 401-416
        • Minassian K.
        • Persy I.
        • Rattay F.
        • Pinter M.M.
        • Kern H.
        • Dimitrijevic M.R.
        Human lumbar cord circuitries can be activated by extrinsic tonic input to generate locomotor-like activity.
        Hum Mov Sci. 2007; 26: 275-295
        • Rossignol S.
        • Chau C.
        • Brustein E.
        • Belanger M.
        • Barbeau H.
        • Trevor D.
        Locomotor capacities after complete and partial lesions of the spinal cord.
        Acta Neurobiol Exp. 1996; 56: 449-463
        • Wernig A.
        • Nanassy A.
        • Müller S.
        Maintenance of locomotor abilities following Laufband (treadmill) therapy in para- and tetraplegic persons: follow-up studies.
        Spinal Cord. 1998; 36: 744-749
        • Bussel B.
        • Roby-Brami A.
        • Azouvi P.
        • Biraben A.
        • Yakovleff A.
        • Held J.P.
        Myoclonus in a patient with spinal cord transection: possible involvement of the spinal stepping generator.
        Brain. 1988; 111: 1235-1245
        • Bussel B.
        • Roby-Brami A.
        • Yakovleff A.
        • Bennis N.
        Late flexion reflex in paraplegic patients.
        Brain Res Bull. 1989; 22: 53-56
        • Bussel B.
        • Roby-Brami A.
        • Neris O.R.
        • Yakovleff A.
        Evidence for a spinal stepping generator in man.
        Acta Neurobiol Exp. 1996; 56: 465-468
        • Bussel B.
        • Roby-Brami A.
        • Neris O.R.
        • Yakovleff A.
        Evidence for a spinal stepping generator in man.
        Paraplegia. 1996; 34: 91-92
        • Dimitrijevic M.R.
        Motor control in chronic spinal cord injury patients.
        Scand J Rehabil Med Suppl. 1994; 30: 53-62
        • Dimitrijevic M.R.
        • McKay W.B.
        • Sherwood A.M.
        Motor control physiology below spinal cord injury: residual volitional control of motor units in paretic and paralyzed muscles.
        Adv Neurol. 1997; 72: 335-345
        • Lovely R.G.
        • Gregor R.
        • Roy R.R.
        • Edgerton V.R.
        Weight-bearing hindlimb stepping in treadmill-exercised adult spinal cats.
        Brain Res. 1990; 514: 206-218
        • Forssberg H.
        Stumbling corrective reaction: a phase-dependent compensatory reaction during locomotion.
        J Neurophysiol. 1979; 42: 936-953
        • Edgerton V.R.
        • Leon R.D.
        • Harkema S.J.
        • et al.
        Retraining the injured spinal cord.
        J Physiol. 2001; 533: 15-22
        • Hodgson J.A.
        • Roy R.R.
        • de Leon R.D.
        • Dobkin B.H.
        • Edgerton V.R.
        Can the mammalian lumbar spinal cord learn a motor task?.
        Med Sci Sports Exerc. 1994; 26: 1491-1497
        • Musienko P.
        • Heutschi J.
        • Friedli L.
        • den Brand R.V.
        • Courtine G.
        Multi-system neurorehabilitative strategies to restore motor functions following severe spinal cord injury.
        Exp Neurol. 2012; 235: 100-109
        • Rossignol S.
        • Frigon A.
        Recovery of locomotion after spinal cord injury: some facts and mechanisms.
        Annu Rev Neurosci. 2011; 34: 413-440
        • Edgerton V.R.
        • Roy R.R.
        The nervous system and movement.
        in: Farrell P.A. Joyner M.J. Caiozzo V.J. ACSM's advanced exercise physiology. 2nd ed. Lippincott Williams and Wilkins, Philadelphia2012: 37-96
        • Grillner S.
        Control of locomotion in bipeds, tetrapods, and fish.
        in: Brookhart J.M. Mountcastle V.B. Handbook of physiology. Vol. 2. American Physiological Society, Bethesda1981: 1179-1236
        • Prochazka A.
        • Gorassini M.
        Ensemble firing of muscle afferents recorded during normal locomotion in cats.
        J Physiol. 1998; 507: 293-304
        • Courtine G.
        • Gerasimenko Y.
        • van den Brand R.
        • et al.
        Transformation of nonfunctional spinal circuits into functional states after the loss of brain input.
        Nat Neurosci. 2009; 12: 1333-1342
        • 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. 2008; 209: 417-425
        • Maegele M.
        • Muller S.
        • Wernig A.
        • Edgerton V.R.
        • Harkema S.J.
        Recruitment of spinal motor pools during voluntary movements versus stepping after human spinal cord injury.
        J Neurotrauma. 2002; 19: 1217-1229
        • Vilensky J.A.
        • Moore G.P.
        • Eidelberg E.
        • Walden J.
        Recovery of locomotion in monkeys with spinal cord lesions.
        J Mot Behav. 1992; 24: 288-296
        • Shik M.L.
        • Severin F.V.
        • Orlovsky G.N.
        Control of walking and running by means of electrical stimulation of the mesencephalon.
        Electroencephalogr Clin Neurophysiol. 1969; 26: 549
        • Budakova N.N.
        Stepping movements evoked by repetitive dorsal root stimulation in a mesencephalic cat.
        Neurosci Behav Physiol. 1972; 5: 355-363
        • Depoortere R.
        • Di Scala G.
        • Sandner G.
        Treadmill locomotion and aversive effects induced by electrical stimulation of the mesencephalic locomotor region in the rat.
        Brain Res Bull. 1990; 25: 723-727
        • Grillner S.
        • Shik M.L.
        On the descending control of the lumbosacral spinal cord from the “mesencephalic locomotor region.”.
        Acta Physiol Scand. 1973; 87: 320-333
        • Jordan L.M.
        • Pratt C.A.
        • Menzies J.E.
        Locomotion evoked by brain stem stimulation: occurrence without phasic segmental afferent input.
        Brain Res. 1979; 177: 204-207
        • Noga B.R.
        • Kriellaars D.J.
        • Brownstone R.M.
        • Jordan L.M.
        Mechanism for activation of locomotor centers in the spinal cord by stimulation of the mesencephalic locomotor region.
        J Neurophysiol. 2003; 90: 1464-1478
        • Shefchyk S.J.
        • Jordan L.M.
        Excitatory and inhibitory postsynaptic potentials in α-motoneurons produced during fictive locomotion by stimulation of the mesencephalic locomotor region.
        J Neurophysiol. 1985; 6: 1345-1355
        • Shefchyk S.J.
        • Stein R.B.
        • Jordan L.M.
        Synaptic transmission from muscle afferents during fictive locomotion in the mesencephalic cat.
        J Neurophysiol. 1984; 51: 986-997
        • Skinner R.D.
        • Garcia-Rill E.
        The mesencephalic locomotor region (MLR) in the rat.
        Brain Res. 1984; 323: 385-389