Dynamic primitives in the control of locomotion
Neville Hogan1, Dagmar Sternad
1Newman Laboratory for Biomechanics and Human Rehabilitation, Department of Mechanical Engineering, Brain and Cognitive Sciences, Massachusetts Institute of Technology Cambridge, MA, USA.
Frontiers in Computational Neuroscience
|June 27, 2013
Summary
Human motor control uses dynamic primitives like submovements, oscillations, and mechanical impedances for dexterity. This framework explains complex movements and has implications for robotic control and locomotor rehabilitation.
Area of Science:
- Robotics
- Biomechanics
- Neuroscience
Background:
- Human locomotor dexterity surpasses current robotic capabilities despite biological system limitations.
- Existing models often struggle to capture the full spectrum of human movement.
- Understanding the fundamental units of motor control is crucial for advancing robotics and rehabilitation.
Purpose of the Study:
- To propose a theoretical framework for human motor control based on dynamic primitives.
- To define and integrate three classes of dynamic primitives: submovements, oscillations, and mechanical impedances.
- To explore the implications of this framework for robotic systems and locomotor rehabilitation.
Main Methods:
- Defining submovements and oscillations as fundamental discrete and rhythmic movement primitives.
- Introducing mechanical impedances as primitives for environmental interaction.
- Proposing a generalized equivalent network for combining primitives.
- Discussing experimental identification challenges and potential solutions for these primitives.
Main Results:
- A theoretical framework is presented, unifying submovements, oscillations, and mechanical impedances as core motor control primitives.
- A method using a generalized equivalent network is proposed for combining these primitives to generate complex movements.
- Challenges in experimentally identifying these primitives are highlighted, with potential methods for overcoming them.
Conclusions:
- Human locomotor dexterity can be explained by encoding motor commands using dynamic primitives.
- This framework offers a new perspective on motor control applicable to both biological systems and artificial robots.
- The proposed primitives and their integration method have significant potential for improving locomotor rehabilitation strategies.
Related Concept Videos
Hierarchy of Motor Control
The hierarchy of motor control refers to the different levels of organization and processing involved in controlling movement in the body. These levels range from higher cortical areas involved in planning and decision-making to lower spinal cord reflexes that respond automatically to external stimuli.
Direct Motor Pathways
The direct motor pathways, also known as the pyramidal tracts, are a group of neural pathways that originate in the brain and descend through the spinal cord. They control the voluntary movement of the body. There are two major direct motor pathways: the corticospinal and the corticobulbar tracts.
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and the...
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and the...
Introduction to Joints
The adult human body usually has 206 bones, and except for the hyoid bone in the neck, each bone is connected to at least one other bone. Joints are the location where bones come together. Many joints allow for movement between the bones. At these joints, the articulating surfaces of the adjacent bones can move smoothly against each other. However, the bones of other joints may be joined by connective tissue or cartilage. These joints are designed for stability and provide little or no movement.
Indirect Motor Pathways
The indirect motor or extrapyramidal pathways originate in the brainstem, the lower portion of the brain that connects it to the spinal cord. They consist of several distinct tracts, each with specialized functions. The four main tracts of the indirect motor pathways are the vestibulospinal tract, the reticulospinal tract, the tectospinal tract, and the rubrospinal tract.
The vestibulospinal tract originates in the vestibular nuclei of the brainstem. The vestibular system detects changes in...
The vestibulospinal tract originates in the vestibular nuclei of the brainstem. The vestibular system detects changes in...
Controller Configurations
Controller configurations are crucial in a car's cruise control system because they manage speed over time to maintain a consistent pace regardless of road conditions, thereby meeting design goals. In traditional control systems, fixed-configuration design involves predetermined controller placement. System performance modifications are known as compensation.
Control-system compensation involves various configurations, most commonly series or cascade compensation, in which the controller aligns...
Control-system compensation involves various configurations, most commonly series or cascade compensation, in which the controller aligns...
Actin Treadmilling
Actin filaments undergo polymerization and depolymerization from either end. The polymerization and depolymerization rates depend on the cytosolic concentration of free G-actins. The polymerization rate is generally higher at the plus or barbed end, while the depolymerization rate is higher at the minus or pointed end. At a steady state, critical concentration describes the concentration of free G-actin monomers at which the polymerization rate at the plus end is equal to that of the...

