Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- List of abbreviations
- 1 General methodology
- 2 Monosynaptic Ia excitation and post-activation depression
- 3 Muscle spindles and fusimotor drive: microneurography and other techniques
- 4 Recurrent inhibition
- 5 Reciprocal Ia inhibition
- 6 Ib pathways
- 7 Group II pathways
- 8 Presynaptic inhibition of Ia terminals
- 9 Cutaneomuscular, withdrawal and flexor reflex afferent responses
- 10 Propriospinal relay for descending motor commands
- 11 Involvement of spinal pathways in different motor tasks
- 12 The pathophysiology of spasticity and parkinsonian rigidity
- Index
- References
11 - Involvement of spinal pathways in different motor tasks
Published online by Cambridge University Press: 08 August 2009
- Frontmatter
- Contents
- Preface
- Acknowledgements
- List of abbreviations
- 1 General methodology
- 2 Monosynaptic Ia excitation and post-activation depression
- 3 Muscle spindles and fusimotor drive: microneurography and other techniques
- 4 Recurrent inhibition
- 5 Reciprocal Ia inhibition
- 6 Ib pathways
- 7 Group II pathways
- 8 Presynaptic inhibition of Ia terminals
- 9 Cutaneomuscular, withdrawal and flexor reflex afferent responses
- 10 Propriospinal relay for descending motor commands
- 11 Involvement of spinal pathways in different motor tasks
- 12 The pathophysiology of spasticity and parkinsonian rigidity
- Index
- References
Summary
If one excludes discrete movements of the fingers (cf. p. 522), most motor tasks are accompanied by changes in transmission in spinal pathways, due to both the descending activity and changes in the peripheral afferent feedback related to the movement itself (‘reafference’). Both types of input are largely mediated through common spinal interneurones (cf. Jankowska & Lundberg, 1981). In the preceding chapters, changes in transmission in segmental spinal pathways during various motor tasks have been described, and the presumed origin of these changes discussed. In addition, because of the focusing due to the stronger inhibitory control of propriospinal neurones in primates, it has been suggested that the propriospinal system might be used for a more diversified motor repertoire than in the cat (Chapter 10, see Lemon et al., 2004). The present chapter presents an overview of the relative contributions of different spinal pathways to various natural motor tasks: isometric tonic contractions, flexion–extension movements at hinge and ball joints, coordination of multi-joint movements, co-contractions of antagonists at the same joint, postural adjustments, and gait. Despite the risk inherent in speculation, it is important to present an overview of the role of spinal cord circuits in the control of movement. This includes (i) a description of the relative contribution made by spinal pathways to the different features of movement in various motor tasks, and (ii) an attempt to show how these pathways work together harmoniously to achieve the movement.
- Type
- Chapter
- Information
- The Circuitry of the Human Spinal CordIts Role in Motor Control and Movement Disorders, pp. 511 - 555Publisher: Cambridge University PressPrint publication year: 2005
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