Experiments and models of sensorimotor interactions during locomotion

During locomotion sensory information from cutaneous and muscle receptors is continuously integrated with the locomotor central pattern generator (CPG) to generate an appropriate motor output to meet the demands of the environment. Sensory signals from peripheral receptors can strongly impact the timing and amplitude of locomotor activity. This sensory information is gated centrally depending on the state of the system (i.e., rest vs. locomotion) but is also modulated according to the phase of a given task. Consequently, if one is to devise biologically relevant walking models it is imperative that these sensorimotor interactions at the spinal level be incorporated into the control system.

[1]  C. Sherrington Flexion‐reflex of the limb, crossed extension‐reflex, and reflex stepping and standing , 1910, The Journal of physiology.

[2]  Örjan Ekeberg,et al.  A neuro-mechanical model of legged locomotion: single leg control , 1998, Biological Cybernetics.

[3]  S. Rossignol,et al.  Recovery of locomotion after chronic spinalization in the adult cat , 1987, Brain Research.

[4]  D. McCrea,et al.  Modelling spinal circuitry involved in locomotor pattern generation: insights from the effects of afferent stimulation , 2006, The Journal of physiology.

[5]  K. Pearson,et al.  Contribution of force feedback to ankle extensor activity in decerebrate walking cats. , 2004, Journal of neurophysiology.

[6]  O. Kiehn Locomotor circuits in the mammalian spinal cord. , 2006, Annual review of neuroscience.

[7]  S. Rossignol,et al.  Contribution of cutaneous inputs from the hindpaw to the control of locomotion. I. Intact cats. , 2003, Journal of neurophysiology.

[8]  J. Smith,et al.  Adaptive control for backward quadrupedal walking. II. Hindlimb muscle synergies. , 1990, Journal of neurophysiology.

[9]  J. Cabelguen,et al.  Main characteristics of the hindlimb locomotor cycle in the decorticate cat with special reference to bifunctional muscles , 1980, Brain Research.

[10]  F. Zajac Understanding muscle coordination of the human leg with dynamical simulations. , 2002, Journal of biomechanics.

[11]  M. Gorassini,et al.  Corrective responses to loss of ground support during walking. I. Intact cats. , 1994, Journal of neurophysiology.

[12]  W J SHARRARD,et al.  THE SEGMENTAL INNERVATION OF THE LOWER LIMB MUSCLES IN MAN. , 1964, Annals of the Royal College of Surgeons of England.

[13]  S. Rossignol,et al.  Phase dependent reflex reversal during walking in chronic spinal cats , 1975, Brain Research.

[14]  P Bessou,et al.  Discharge patterns of gamma motoneurone populations of extensor and flexor hindlimb muscles during walking in the thalamic cat. , 1989, Progress in brain research.

[15]  J. Coast Handbook of Physiology. Section 12. Exercise: Regulation and Integration of Multiple Systems , 1997 .

[16]  G. Viala,et al.  Inhibition des activités spinales à caractère locomoteur par une modalité particulière de stimulation somatique chez le lapin , 2004, Experimental Brain Research.

[17]  A. Lundberg HALF-CENTRES REVISITED , 1981 .

[18]  P. Matthews,et al.  The sensitivity of muscle spindle afferents to small sinusoidal changes of length , 1969, The Journal of physiology.

[19]  A. Prochazka,et al.  Sensory control of locomotion: reflexes versus higher-level control. , 2002, Advances in experimental medicine and biology.

[20]  K G Pearson,et al.  Neural adaptation in the generation of rhythmic behavior. , 2000, Annual review of physiology.

[21]  Jens Schouenborg,et al.  Modular organisation and spinal somatosensory imprinting , 2002, Brain Research Reviews.

[22]  K. Pearson,et al.  Inhibition of flexor burst generation by loading ankle extensor muscles in walking cats , 1980, Brain Research.

[23]  R Durbaba,et al.  Direct and indirect assessment of gamma-motor firing patterns. , 2004, Canadian journal of physiology and pharmacology.

[24]  P. Wallén,et al.  Fictive locomotion in the lamprey spinal cord in vitro compared with swimming in the intact and spinal animal. , 1984, The Journal of physiology.

[25]  J. Duysens,et al.  Load-regulating mechanisms in gait and posture: comparative aspects. , 2000, Physiological reviews.

[26]  S. Rossignol,et al.  On the initiation of the swing phase of locomotion in chronic spinal cats , 1978, Brain Research.

[27]  N. Petersen,et al.  Flexor reflex afferents reset the step cycle during fictive locomotion in the cat , 1998, Experimental Brain Research.

[28]  Örjan Ekeberg,et al.  The Neural Control of Fish Swimming Studied Through Numerical Simulations , 1995, Adapt. Behav..

[29]  Trevor Drew,et al.  The Spinal Cat , 2000 .

[30]  D A McCrea,et al.  Group I disynaptic excitation of cat hindlimb flexor and bifunctional motoneurones during fictive locomotion , 2000, The Journal of physiology.

[31]  Auke Jan Ijspeert,et al.  Simulation and Robotics Studies of Salamander Locomotion Applying Neurobiological Principles to the Control of Locomotion in Robots , 2005 .

[32]  G. E. Loeb,et al.  The distal hindlimb musculature of the cat , 1985, Experimental Brain Research.

[33]  K. Pearson,et al.  Proprioceptive modulation of hip flexor activity during the swing phase of locomotion in decerebrate cats. , 2001, Journal of neurophysiology.

[34]  Nobutoshi Yamazaki,et al.  Generation of human bipedal locomotion by a bio-mimetic neuro-musculo-skeletal model , 2001, Biological Cybernetics.

[35]  A. Lundberg,et al.  The effect of DOPA on the spinal cord. 6. Half-centre organization of interneurones transmitting effects from the flexor reflex afferents. , 1967, Acta physiologica Scandinavica.

[36]  Hiroshi Shimizu,et al.  Self-organized control of bipedal locomotion by neural oscillators in unpredictable environment , 1991, Biological Cybernetics.

[37]  Shik Ml,et al.  Control of walking and running by means of electrical stimulation of the mesencephalon. , 1969 .

[38]  Sergiy Yakovenko,et al.  Spatiotemporal activation of lumbosacral motoneurons in the locomotor step cycle. , 2002, Journal of neurophysiology.

[39]  S. Schäfer,et al.  The discharge frequencies of primary muscle spindle endings during simultaneous stimulation of two fusimotor filaments , 2004, Pflügers Archiv.

[40]  Sergiy Yakovenko,et al.  Contribution of stretch reflexes to locomotor control: a modeling study , 2004, Biological Cybernetics.

[41]  H. Hultborn Spinal reflexes, mechanisms and concepts: From Eccles to Lundberg and beyond , 2006, Progress in Neurobiology.

[42]  Ian E. Brown,et al.  Mechanics of feline soleus: II design and validation of a mathematical model , 1996, Journal of Muscle Research & Cell Motility.

[43]  D. McCrea,et al.  Intracellular analysis of reflex pathways underlying the stumbling corrective reaction during fictive locomotion in the cat. , 2005, Journal of neurophysiology.

[44]  Douglas G. Stuart,et al.  Neural Control of Locomotion , 1976, Advances in Behavioral Biology.

[45]  D. McCrea,et al.  Stumbling corrective reaction during fictive locomotion in the cat. , 2005, Journal of neurophysiology.

[46]  Gentaro Taga,et al.  A model of the neuro-musculo-skeletal system for human locomotion , 1995, Biological Cybernetics.

[47]  R B Stein,et al.  Gain of the triceps surae stretch reflex in decerebrate and spinal cats during postural and locomotor activities. , 1996, The Journal of physiology.

[48]  Gentaro Taga,et al.  A model of the neuro-musculo-skeletal system for anticipatory adjustment of human locomotion during obstacle avoidance , 1998, Biological Cybernetics.

[49]  Holk Cruse,et al.  A modular artificial neural net for controlling a six-legged walking system , 1995, Biological Cybernetics.

[50]  H. Cruse What mechanisms coordinate leg movement in walking arthropods? , 1990, Trends in Neurosciences.

[51]  G Colombo,et al.  Influence of body load on the gait pattern in Parkinson's disease , 1998, Movement disorders : official journal of the Movement Disorder Society.

[52]  P. Zangger,et al.  ‘Fusimotor set’: new evidence for α-independent control of γ-motoneurones during movement in the awake cat , 1985, Brain Research.

[53]  M. Gorassini,et al.  Models of ensemble firing of muscle spindle afferents recorded during normal locomotion in cats , 1998, The Journal of physiology.

[54]  J V Wait,et al.  Kinematics of locomotion by cats with a single hindlimb deafferented. , 1976, Journal of neurophysiology.

[55]  Andy Ruina,et al.  Energetic Consequences of Walking Like an Inverted Pendulum: Step-to-Step Transitions , 2005, Exercise and sport sciences reviews.

[56]  K. Pearson,et al.  Contribution of hind limb flexor muscle afferents to the timing of phase transitions in the cat step cycle. , 1996, Journal of neurophysiology.

[57]  H. Hultborn,et al.  Transmission in a locomotor-related group Ib pathway from hindlimb extensor muscles in the cat , 2004, Experimental Brain Research.

[58]  S. Rossignol,et al.  A kinematic and electromyographic study of cutaneous reflexes evoked from the forelimb of unrestrained walking cats. , 1987, Journal of neurophysiology.

[59]  H. Cruse,et al.  Simulation of Complex Movements Using Artificial Neural Networks , 1998, Zeitschrift fur Naturforschung. C, Journal of biosciences.

[60]  C. Sherrington,et al.  VIII. Experiments upon the influence of sensory nerves upon movement and nutrition of the limbs. Preliminary communication , 1985, Proceedings of the Royal Society of London.

[61]  Serge Rossignol,et al.  Critical points in the forelimb fictive locomotor cycle and motor coordination: evidence from the effects of tonic proprioceptive perturbations in the cat. , 2004, Journal of neurophysiology.

[62]  K. Pearson,et al.  Computer simulation of stepping in the hind legs of the cat: an examination of mechanisms regulating the stance-to-swing transition. , 2005, Journal of neurophysiology.

[63]  J. Smith,et al.  Adaptive control for backward quadrupedal walking. III. Stumbling corrective reactions and cutaneous reflex sensitivity. , 1993, Journal of neurophysiology.

[64]  Shik Ml,et al.  Control of walking and running by means of electric stimulation of the midbrain , 1966 .

[65]  J. Mcdonald,et al.  Spinal-cord injury , 2002, The Lancet.

[66]  P. Buser,et al.  [Inhibition of spinal locomotor activity by a special method of somatic stimulation in rabbits]. , 1974, Experimental brain research.

[67]  J. Smith,et al.  Mutable and immutable features of paw-shake responses after hindlimb deafferentation in the cat. , 1989, Journal of neurophysiology.

[68]  R. Durbaba A. Taylor,et al.  Static Fusimotor Action During Locomotion in the Decerebrated Cat Revealed by Cross‐Correlation of Spindle Afferent Activity , 2003, Experimental physiology.

[69]  D. McCrea,et al.  Deletions of rhythmic motoneuron activity during fictive locomotion and scratch provide clues to the organization of the mammalian central pattern generator. , 2005, Journal of neurophysiology.

[70]  S Grillner,et al.  Simulations of neuromuscular control in lamprey swimming. , 1999, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[71]  G. Loeb,et al.  Measured and modeled properties of mammalian skeletal muscle: IV. Dynamics of activation and deactivation , 2004, Journal of Muscle Research & Cell Motility.

[72]  D A McCrea,et al.  Disynaptic group I excitation of synergist ankle extensor motoneurones during fictive locomotion in the cat. , 1995, The Journal of physiology.

[73]  T. Twitchell,et al.  Sensory factors in purposive movement. , 1954, Journal of neurophysiology.

[74]  D J Kriellaars,et al.  Mechanical entrainment of fictive locomotion in the decerebrate cat. , 1994, Journal of neurophysiology.

[75]  M. E. Goldberger Locomotor recovery after unilateral hindlimb deafferentation in cats , 1977, Brain Research.

[76]  J. Nielsen,et al.  Major role for sensory feedback in soleus EMG activity in the stance phase of walking in man , 2000, The Journal of physiology.

[77]  S. Rossignol,et al.  A comparison of treadmill locomotion in adult cats before and after spinal transection. , 1996, Journal of neurophysiology.

[78]  C. Sherrington REMARKS ON THE REFLEX MECHANISM OF THE STEP , 1910 .

[79]  S. Rossignol,et al.  Phasic Control of Reflexes During Locomotion in Vertebrates , 1976 .

[80]  J. Halbertsma The stride cycle of the cat: the modelling of locomotion by computerized analysis of automatic recordings. , 1983, Acta physiologica Scandinavica. Supplementum.

[81]  K. Pearson,et al.  Fictive motor patterns in chronic spinal cats. , 1991, Journal of neurophysiology.

[82]  S. Grillner,et al.  The effect of dorsal root transection on the efferent motor pattern in the cat's hindlimb during locomotion. , 1984, Acta physiologica Scandinavica.

[83]  T. Drew,et al.  Role of the motor cortex in the control of visually triggered gait modifications. , 1996, Canadian journal of physiology and pharmacology.

[84]  J. Cabelguen,et al.  Central and reflex participation in the timing of locomotor activations of a bifunctional muscle, the semi-tendinosus, in the cat , 1976, Brain Research.

[85]  D. A. Winter,et al.  Simulated control of unilateral, anticipatory locomotor adjustments during obstructed gait , 1994, Biological Cybernetics.

[86]  S. Rossignol,et al.  Locomotion of the hindlimbs after neurectomy of ankle flexors in intact and spinal cats: model for the study of locomotor plasticity. , 1997, Journal of neurophysiology.

[87]  R. Burke,et al.  The use of state-dependent modulation of spinal reflexes as a tool to investigate the organization of spinal interneurons , 1999, Experimental Brain Research.

[88]  P. Buser,et al.  Cutaneous fiber groups involved in the inhibition of fictive locomotion in the rabbit , 2004, Experimental Brain Research.

[89]  Ansgar Büschges,et al.  Assessing sensory function in locomotor systems using neuro-mechanical simulations , 2006, Trends in Neurosciences.

[90]  A. W. Schopper,et al.  A structural fingertip model for simulating of the biomechanics of tactile sensation. , 2004, Medical engineering & physics.

[91]  A. M. Degtyarenko,et al.  Differential modulation of disynaptic cutaneous inhibition and excitation in ankle flexor motoneurons during fictive locomotion. , 1996, Journal of neurophysiology.

[92]  S. Rossignol,et al.  Phasic gain control of reflexes from the dorsum of the paw during spinal locomotion , 1977, Brain Research.

[93]  V. Vanderhorst,et al.  Organization of lumbosacral motoneuronal cell groups innervating hindlimb, pelvic floor, and axial muscles in the cat , 1997, The Journal of comparative neurology.

[94]  U Proske,et al.  Site of impulse initiation in tendon organs of cat soleus muscle. , 1985, Journal of neurophysiology.

[95]  C. Hunt Mammalian muscle spindle: peripheral mechanisms. , 1990, Physiological reviews.

[96]  T. Sinkjaer,et al.  The stretch reflex and H-reflex of the human soleus muscle during walking. , 1999, Motor control.

[97]  G. Loeb,et al.  Mathematical models of proprioceptors. II. Structure and function of the Golgi tendon organ. , 2006, Journal of neurophysiology.

[98]  Jaynie F. Yang,et al.  Loading during the stance phase of walking in humans increases the extensor EMG amplitude but does not change the duration of the step cycle , 1999, Experimental Brain Research.

[99]  Örjan Ekeberg,et al.  From swimming to walking: a single basic network for two different behaviors , 2003, Biological Cybernetics.

[100]  P. Stein,et al.  Modular Organization of Turtle Spinal Interneurons during Normal and Deletion Fictive Rostral Scratching , 2002, The Journal of Neuroscience.

[101]  D. McCrea,et al.  Ankle extensor group I afferents excite extensors throughout the hindlimb during fictive locomotion in the cat. , 1995, The Journal of physiology.

[102]  A. Prochazka,et al.  Neuromuscular responses to gait perturbations in freely moving cats , 2004, Experimental Brain Research.

[103]  B. Jayne,et al.  Muscular mechanisms of snake locomotion: An electromyographic study of lateral undulation of the florida banded water snake (Nerodia fasciata) and the yellow rat snake (Elaphe obsoleta) , 1988, Journal of morphology.

[104]  A. K. Moschovakis,et al.  Anatomical and physiological study of interneurons in an oligosynaptic cutaneous reflex pathway in the cat hindlimb , 1992, Brain Research.

[105]  A. Prochazka Sensorimotor gain control: A basic strategy of motor systems? , 1989, Progress in Neurobiology.

[106]  Richard R Neptune,et al.  Biomechanics and muscle coordination of human walking: part II: lessons from dynamical simulations and clinical implications. , 2003, Gait & posture.

[107]  A. Büschges,et al.  Dynamic simulation of insect walking. , 2004, Arthropod structure & development.

[108]  S. Grillner,et al.  On the central generation of locomotion in the low spinal cat , 1979, Experimental Brain Research.

[109]  R. E. Burke,et al.  Peripheral and central control of flexor digitorum longus and flexor hallucis longus motoneurons: The synaptic basis of functional diversity , 2004, Experimental Brain Research.

[110]  Thomas A. McMahon,et al.  Muscles, Reflexes, and Locomotion , 1984 .

[111]  F Lacquaniti,et al.  Spinal cord maps of spatiotemporal alpha-motoneuron activation in humans walking at different speeds. , 2006, Journal of neurophysiology.

[112]  B. Dobkin,et al.  Human lumbosacral spinal cord interprets loading during stepping. , 1997, Journal of neurophysiology.

[113]  K. Pearson,et al.  Functional role of muscle reflexes for force generation in the decerebrate walking cat , 2000, The Journal of physiology.

[114]  L. M. Jordan,et al.  On the regulation of repetitive firing in lumbar motoneurones during fictive locomotion in the cat , 1992, Experimental Brain Research.

[115]  S. Rossignol,et al.  Dynamic sensorimotor interactions in locomotion. , 2006, Physiological reviews.

[116]  R. Poppele,et al.  Small-signal analysis of response of mammalian muscle spindles with fusimotor stimulation and a comparison with large-signal responses. , 1978, Journal of neurophysiology.

[117]  U Proske,et al.  Motor unit contractions initiating impulses in a tendon organ in the cat. , 1981, The Journal of physiology.

[118]  A Prochazka,et al.  'Fusimotor set': new evidence for alpha-independent control of gamma-motoneurones during movement in the awake cat. , 1985, Brain research.

[119]  S. Rossignol,et al.  Contribution of cutaneous inputs from the hindpaw to the control of locomotion. II. Spinal cats. , 2003, Journal of neurophysiology.

[120]  E. Zehr,et al.  What functions do reflexes serve during human locomotion? , 1999, Progress in Neurobiology.

[121]  S. Grillner Control of Locomotion in Bipeds, Tetrapods, and Fish , 1981 .

[122]  U Proske,et al.  The responses of Golgi tendon organs to stimulation of different combinations of motor units. , 1979, The Journal of physiology.

[123]  B. Conway,et al.  Proprioceptive input resets central locomotor rhythm in the spinal cat , 2004, Experimental Brain Research.

[124]  A. M. Degtyarenko,et al.  Patterns of locomotor drive to motoneurons and last-order interneurons: clues to the structure of the CPG. , 2001, Journal of neurophysiology.

[125]  S. Rossignol,et al.  The locomotion of the low spinal cat. II. Interlimb coordination. , 1980, Acta physiologica Scandinavica.

[126]  Edward Taub,et al.  Motor Behavior Following Deafferentation in the Developing and Motorically Mature Monkey , 1976 .

[127]  K. Pearson,et al.  Chemical ablation of sensory afferents in the walking system of the cat abolishes the capacity for functional recovery after peripheral nerve lesions , 2003, Experimental Brain Research.

[128]  Ilya A Rybak,et al.  Endogenous rhythm generation in the pre‐Bötzinger complex and ionic currents: modelling and in vitro studies , 2003, The European journal of neuroscience.

[129]  Serge Rossignol,et al.  Critical points in the forelimb fictive locomotor cycle and motor coordination: effects of phasic retractions and protractions of the shoulder in the cat. , 2004, Journal of neurophysiology.

[130]  F. Zajac Muscle and tendon: properties, models, scaling, and application to biomechanics and motor control. , 1989, Critical reviews in biomedical engineering.

[131]  P H Ellaway,et al.  Direct and indirect assessment of γ-motor firing patterns , 2004 .

[132]  S. Grillner,et al.  Peripheral control of the cat's step cycle. II. Entrainment of the central pattern generators for locomotion by sinusoidal hip movements during "fictive locomotion.". , 1983, Acta physiologica Scandinavica.

[133]  J. Duysens,et al.  Modulation of ipsi- and contralateral reflex responses in unrestrained walking cats. , 1980, Journal of neurophysiology.

[134]  J. Szentágothai,et al.  Regulatory functions of the CNS : principles of motion and organization , 1981 .

[135]  M G Pandy,et al.  Computer modeling and simulation of human movement. , 2001, Annual review of biomedical engineering.

[136]  Ilya A. Rybak,et al.  Modeling the spinal cord neural circuitry controlling cat hindlimb movement during locomotion , 2003, Neurocomputing.

[137]  A. K. Moschovakis,et al.  Differential control of short latency cutaneous excitation in cat FDL motoneurons during fictive locomotion , 2004, Experimental Brain Research.

[138]  T. Drew,et al.  Motor cortical cell discharge during voluntary gait modification , 1988, Brain Research.

[139]  J. Duysens,et al.  Significance of load receptor input during locomotion: a review. , 2000, Gait & posture.

[140]  K. Pearson,et al.  Intralimb and interlimb coordination in the cat during real and fictive rhythmic motor programs , 1993 .

[141]  C. M. Chanaud,et al.  Functionally complex muscles of the cat hindlimb , 1991, Experimental Brain Research.

[142]  Chandana Paul,et al.  Development of a human neuro-musculo-skeletal model for investigation of spinal cord injury , 2005, Biological Cybernetics.

[143]  Emilio Bizzi,et al.  Modular organization of motor behavior in the frog's spinal cord , 1995, Trends in Neurosciences.

[144]  K. Pearson,et al.  Contribution of sensory feedback to ongoing ankle extensor activity during the stance phase of walking. , 2004, Canadian journal of physiology and pharmacology.

[145]  H. Forssberg Stumbling corrective reaction: a phase-dependent compensatory reaction during locomotion. , 1979, Journal of neurophysiology.

[146]  D. McCrea,et al.  Modelling spinal circuitry involved in locomotor pattern generation: insights from deletions during fictive locomotion , 2006, The Journal of physiology.

[147]  Z. Hasan A model of spindle afferent response to muscle stretch. , 1983, Journal of neurophysiology.

[148]  J. Cabelguen,et al.  CENTRAL PATTERN GENERATION OF FORELIMB AND HINDLIMB LOCOMOTOR ACTIVITIES IN THE CAT , 1981 .

[149]  R. E. Burke,et al.  Phasic modulation of short latency cutaneous excitation in flexor digitorum longus motoneurons during fictive locomotion , 2004, Experimental Brain Research.

[150]  A. Prochazka,et al.  Comparison of natural and artificial control of movement , 1993 .

[151]  J. Houk,et al.  Dependence of dynamic response of spindle receptors on muscle length and velocity. , 1981, Journal of neurophysiology.

[152]  L. Jami Golgi tendon organs in mammalian skeletal muscle: functional properties and central actions. , 1992, Physiological reviews.

[153]  Serge Rossignol,et al.  Low-threshold, short-latency cutaneous reflexes during fictive locomotion in the “semi-chronic” spinal cat , 2004, Experimental Brain Research.

[154]  E. J. Cheng,et al.  Measured and modeled properties of mammalian skeletal muscle. II. The effectsof stimulus frequency on force-length and force-velocity relationships , 1999, Journal of Muscle Research & Cell Motility.

[155]  J. Noebels,et al.  Analysis of voltage-gated and synaptic conductances contributing to network excitability defects in the mutant mouse tottering. , 1994, Journal of neurophysiology.

[156]  Richard R Neptune,et al.  Biomechanics and muscle coordination of human walking. Part I: introduction to concepts, power transfer, dynamics and simulations. , 2002, Gait & posture.

[157]  J. Rinzel,et al.  Compartmental model of vertebrate motoneurons for Ca2+-dependent spiking and plateau potentials under pharmacological treatment. , 1997, Journal of neurophysiology.

[158]  Auke Jan Ijspeert,et al.  A connectionist central pattern generator for the aquatic and terrestrial gaits of a simulated salamander , 2001, Biological Cybernetics.

[159]  G. Loeb,et al.  Mathematical models of proprioceptors. I. Control and transduction in the muscle spindle. , 2006, Journal of neurophysiology.

[160]  F. Plum Handbook of Physiology. , 1960 .

[161]  Chris Eliasmith,et al.  Integrating behavioral and neural data in a model of zebrafish network interaction , 2005, Biological Cybernetics.

[162]  S. Grillner,et al.  Neuronal Control of Locomotion 'From Mollusc to Man ' , 1999 .

[163]  J L Smith,et al.  Stepping behaviors in chronic spinal cats with one hindlimb deafferented , 1987, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[164]  T. A. Abelew,et al.  Local loss of proprioception results in disruption of interjoint coordination during locomotion in the cat. , 2000, Journal of neurophysiology.

[165]  J. Cabelguen,et al.  Chapter 4 Discharge patterns of γ motoneurone populations of extensor and flexor hindlimb muscles during walking in the thalamic cat , 1989 .

[166]  B. Andrews,et al.  Improving limb flexion in FES gait using the flexion withdrawal response for the spinal cord injured person. , 1993, Journal of biomedical engineering.

[167]  M. Taussig The Nervous System , 1991 .

[168]  J. Duysens,et al.  Phase-dependent reversal of reflexly induced movements during human gait , 2004, Experimental Brain Research.

[169]  S. Grillner,et al.  Neuronal Control of LocomotionFrom Mollusc to Man , 1999 .

[170]  J. C. Smith,et al.  Models of respiratory rhythm generation in the pre-Bötzinger complex. II. Populations Of coupled pacemaker neurons. , 1999, Journal of neurophysiology.

[171]  T Drew,et al.  Spinal locomotion: a comparison of the kinematics and the electromyographic activity in the same animal before and after spinalization. , 1988, Acta biologica Hungarica.

[172]  R. Kalb,et al.  Neurobiology of Spinal Cord Injury , 2000, Contemporary Neuroscience.

[173]  C. M. Chanaud,et al.  Functionally complex muscles of the cat hindlimb , 2004, Experimental Brain Research.

[174]  J H Anderson,et al.  Dynamic characteristics of Golgi tendon organs. , 1974, Brain research.

[175]  S. Grillner,et al.  The locomotion of the low spinal cat. I. Coordination within a hindlimb. , 1980, Acta physiologica Scandinavica.

[176]  E. Zehr,et al.  Cutaneous reflexes during human gait: electromyographic and kinematic responses to electrical stimulation. , 1997, Journal of neurophysiology.

[177]  K. Pearson,et al.  The role of proprioceptive feedback in the regulation and adaptation of locomotor activity. , 2002, Advances in experimental medicine and biology.

[178]  Gentaro Taga,et al.  A model of the neuro-musculo-skeletal system for human locomotion , 1995, Biological Cybernetics.

[179]  L. Rowell,et al.  Exercise : regulation and integration of multiple systems , 1996 .

[180]  A Prochazka,et al.  Ensemble firing of muscle afferents recorded during normal locomotion in cats , 1998, The Journal of physiology.

[181]  D. McCrea,et al.  Group I extensor afferents evoke disynaptic EPSPs in cat hindlimb extensor motorneurones during fictive locomotion. , 1996, The Journal of physiology.

[182]  M. Pandy Simple and complex models for studying muscle function in walking. , 2003, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[183]  J. F. Yang,et al.  Contribution of peripheral afferents to the activation of the soleus muscle during walking in humans , 2004, Experimental Brain Research.

[184]  S. Grillner,et al.  Peripheral control of the cat's step cycle. I. Phase dependent effects of ramp-movements of the hip during "fictive locomotion". , 1981, Acta physiologica Scandinavica.

[185]  T. Brown On the nature of the fundamental activity of the nervous centres; together with an analysis of the conditioning of rhythmic activity in progression, and a theory of the evolution of function in the nervous system , 1914, The Journal of physiology.

[186]  Örjan Ekeberg,et al.  A combined neuronal and mechanical model of fish swimming , 2005, Biological Cybernetics.

[187]  S. Rossignol,et al.  Mid-lumbar segments are needed for the expression of locomotion in chronic spinal cats. , 2005, Journal of neurophysiology.

[188]  Paul J. Reier,et al.  Spinal Cord Reconstruction , 1982 .

[189]  J Houk,et al.  Responses of Golgi tendon organs to forces applied to muscle tendon. , 1967, Journal of neurophysiology.

[190]  I. Engberg,et al.  An electromyographic analysis of muscular activity in the hindlimb of the cat during unrestrained locomotion. , 1969, Acta physiologica Scandinavica.