The computation of position sense from spindles in mono- and multiarticular muscles

摘要: It is known that muscle spindles provide the majority of information about limb position, but little how position sense computed from their signals. We have developed a family musculoskeletal models in order to determine some fundamental properties associated with transforming noisy spindle into putative internal coordinate frames for sense. A two-joint model was containing one biarticular and two monoarticular muscles total 1000 sensors distributed among them. The were assumed function like secondary afferents under fusimotor control designed optimize ability encode static presence constant output noise. optimal distribution found depend strongly on frame which measured (intersegmental angle, segment orientation, or end-point limb) topology respect plane motion. similar analysis performed an anthropometric human arm, using previously published counts spindles. In general, actual elbow shoulder does not seem favor any single also looked at potential accuracy detecting changes joint angles based throughout body. individual joints accounts well psychophysical data showing proximodistal descending gradient angular resolution partially reflects relative importance more proximal determining location end-point.