Synergic Control of Action Stabilizing Vertical Posture

The performance of voluntary movements requires the coordination of multiple elements, such as motor units, muscles, and joint motions. Humans have more motor elements than necessary to accomplish a given task, and the flexible interaction among those elements promoted the development of the motor abundance principle and the motor synergy hypothesis. The uncontrolled manifold (UCM) framework offers an analytical instrument to investigate this principle and hypothesis and provides insights into how the central nervous system controls and coordinates the motor elements to the task performance. In this chapter, we present the UCM approach, its core principles, and practical applications in the context of the synergic control of the upright posture. We also report how the UCM approach has been employed by researchers to answer hypothesis-driven questions pertaining to motor control in different populations. Lastly, we discuss the UCM approach as a promising tool for early detection of motor impairments and its potential as a valuable biomarker for neurological disorders.