Control of Locomotion in Bipeds, Tetrapods, and Fish

Abstract

The sections in this article are: 1 Biomechanical and Electromyographical Information 1.1 Single Limb During Locomotion 1.1.1 Step Cycle at Different Velocities—Amplitudes and Period Lengths 1.1.2 Forces 1.1.3 Electromyographical Activity in Limb Muscles During Locomotion 1.1.4 Active and Passive Factors Controlling a Limb 1.2 Interlimb Coordination 1.2.1 Alternating Gaits 1.2.2 Nonalternating Gaits 1.3 Treadmill Versus Overground Locomotion 1.4 Trunk Movements During Locomotion 1.4.1 Fishes 1.4.2 Lateral Trunk Movements in Alternating Gaits 1.4.3 Dorsoventral Movements of the Spine in Gallop and Leaping 1.4.4 Torsion Around Longitudinal Axis 1.5 Pathological Gaits 1.5.1 Disturbances Due to Peripheral Damage 1.5.2 Disturbances Due to CNS Damage 1.6 Summary 2 Neural Generation of “Basic Locomotor Synergy” 2.1 Central Versus Peripheral 2.2 Parts of CNS of Primary Importance for Neural Control of Basic Locomotor Synergy 2.3 Spinal Centers for Locomotion—Behavioral Results 2.4 Reflex Control of Basic Locomotor Synergy 2.4.1 Load Sensitivity 2.4.2 Influence of Hip Position and Movement 2.4.3 Feedback on Fish Central Pattern Generator (CPG) 2.5 Activity in Certain Spinal, Cerebellar, and Brain Stem Neurons and in Certain Reflex Pathways During Locomotion 2.5.1 α-Motoneurons 2.5.2 Fusimotor Neurons 2.5.3 Ia-Interneurons 2.5.4 Renshaw Cells 2.5.5 Other Spinal Interneurons 2.5.6 Tonic Gating of Segmental Reflex Effects Evoked from Skin and Groups II and III Muscular Afferents and Joint Afferents 2.5.7 Tonic Gating of Vestibular Effects (Lateral Tilt) to Vestibulospinal Neurons 2.5.8 Mossy Fiber Input to Cerebellum 2.5.9 Climbing Fiber Input to Cerebellum 2.5.10 Cerebellar Output 2.6 Cerebellum and Locomotion 2.7 Initiation of Locomotion—Brain Stem Circuitry 2.7.1 Corticobulbar Control 2.7.2 Subthalamic Locomotor Region 2.7.3 Mesencephalic and Pontine Locomotor Regions 2.7.4 Conclusions 2.7.5 Background Excitability 2.7.6 Specific Control Systems 2.8 Central Organization of Spinal Pattern Generation 2.8.1 Single-Limb Control—A Mosaic of Unit Burst Generators? 2.8.2 Interlimb Coordination 2.9 Possible Rhythm-Generating Mechanisms and Models—Facts and Fiction 2.9.1 Models 2.9.2 Neuronal Mechanisms 2.10 Developmental Aspects 2.11 Summary 3 Adapting Basic Locomotor Synergy to Animal's Needs 3.1 Changing Speed 3.2 Goal-Directed Locomotion—Turning and Walking Along Curvatures 3.3 Modifications of “Locomotor Posture” 3.4 Positioning of Limb in Each Step 3.5 Reflex Adaptation of Step 3.6 Summary 4 Concluding Remarks