Motor Control Theories

What is a Theory?

• Theories are used in all fields of science to:
  • Understand phenomena
  • Explain why phenomena exist or behave certain ways
• Stephen Hawking: A good theory should describe a large class of observations and predict future observations.
• In behavioral sciences, theories explain human behavior.
• Motor control is a behavioral science.

Role of Motor Control Theories

• Explain why skills are performed the way they are.
• Identify variables accounting for performance differences between individuals or trials.
• Explain specific capabilities and effective interventions (e.g., injury rehabilitation, physical therapy).
• Provide foundation for:
  • Developing skill instruction programs
  • Enhancing performance through practice environment adjustments
  • Creating effective rehabilitation programs

Behavioral Motor Control Theories

• Focus on how the nervous system coordinates movement in different contexts.
• Emphasize behavioral theories over neural-level theories.
• Govern coordinated human motor behavior through laws and principles.

Key Issues in Behavioral Motor Control Theories

Coordination

• Involves patterning of head, body, and limb movements relative to environmental objects and events.
• Requires consideration of:
  • Time point during skill performance
  • Relationship between limb and segment movements
  • Environmental context and constraints (e.g., stepping over obstacles)
  • Action goals affected by the environment

Degrees of Freedom Problem

• Refers to number of independent components in a system and ways components can vary.
• Example:
  • Shoulder joint: 6 degrees of freedom
  • Elbow joint: 4 degrees of freedom
  • Total for shoulder and elbow: 10 degrees of freedom
• Degrees of freedom also defined by motor units recruited, muscles activated, etc.
• Challenge: Many different ways to achieve the same movement goal (e.g., reaching for an object).
• Problem: Determining the correct strategy to constrain the system for a specific result.
• Various theories address how to resolve the degrees of freedom problem.

The lecture introduces key concepts in motor control theories, focusing on coordination and degrees of freedom problem, foundational for understanding motor skills, performance, and interventions.