Motor-Space Coding in the Central Nervous System
This extract was created in the absence of an abstract.
Excerpt
The work presented in this paper is addressed to a motor-control hypothesis known as the “equilibrium-point hypothesis” (Feldman 1974; Bizzi et al. 1984; Hogan 1984). According to this hypothesis, the central nervous system (CNS) takes advantage of the mechanical properties of muscles for solving the complex computational problems related to the control and representation of limb posture and movement.
The equilibrium-point hypothesis is rooted in the observation that muscles are characterized by viscoelastic properties: In other words, when a motor nerve is activated by a train of impulses at a fixed frequency, the force produced by the innervated muscle depends on the length and rate of shortening of the muscle. Under static conditions, the tension developed by the muscle depends on its operating length in a way that is reminiscent of a spring: If we stretch the stimulated muscle, we measure a restoring force that depends on the amount of...
