motor control lectures

• Motor control: The study of nature and control of movement – thinking about what we need to do to control movement  
•  

  A behavioural understanding of “the ability to regulate or direct the mechanisms essential to movement” 
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  Theory of motor control: 

  Help us to understand and explain motor skill performance, constraints, limits, potential deficit 
• Enables us: 

  to identify performance problems 

  Predict effectiveness of intervention strategies  

  Develop intervention strategies to help overcome performance problems 

  Create new intervention strategies  

  Develop systemic approach to help person increase skill performance capabilities 

  Evaluate effectiveness of intervention strategies  
• What are theories of motor control? 

  • A group of abstract ideas about the control of movement  
  • Built up from evidence   
  • Change over time/research  
  • A good theory must “accurately describe a large class of observations…and make definite predictions about the results of future observations” 
• 1. Dynamic action theory 

    - some elements of movement were self organised – that at certain parameters critical changes in patterns were produced. 
• 1. Reflex theory 

    - movement should be understood as a series of reactions to sensory stimuli  

    - we must understand sensory components and influence of movement 

    - stimulus --> response  
• 1. Hierarchical theory 

    - hierarchy of neural circuits at different levels of CNS 

    - we must understand the complex communication within the neural systems 
• 1. Ecological theory 

    - organisation of movement is specific to task and environment. Consequently perception is key to output 

    - we must consider task and environment in which the movement needs to occur 

   
• 1. Systems theory 

    - Movement system with both internal and external influences 

      - Mastering movement involves controlling multiple degrees of freedom of multiple joints. 

      - Movement synergies - muscles working together as a unit (efficiency) 

   

    - we need to promote synergic patterns i.e. functional movements not individual muscle work 

    - Efficiency of motor control must consider multiple degrees of freedom 
• 1. Motor programme theory  

    - Generalised Motor Programme (GMP) - unique set of features set in our memory  

    - Central motor patterns/ Central Pattern Generators (CPG’s) 

    - Spinally mediated motor programmes may exist (modified by incoming sensory inputs)  

    - may need to tap into programmes of movement – whole task practice  

   
•  

  Summary: 

  • Sensation is important 
  • Neural components are important – different levels of interactive control 
  • Patterns of movement exist  
  • Neural  
  • Muscular  
  • Particular components trigger changes in patterns e.g. speed  
  • Task and environment are important as are how we perceive them 
• Integrated systems theory: 

  Individual  

  Environment 

  Task 
•  

  The individual then has 3 further parts: 

  Perception 

  Action 

  Cognition  
• Action: 

  Motor output – sensory and nervous system to motor system 

  Interaction of these systems to produce coordinated, controlled functional movements. 
•  

  Perception: 

  Interpretation and meaning of sensory input (peripheral and central) - stimulus identification and comparison stages 

   

  Skill has a strong influence over our perception 
• Info comes from: 

  • Somatosensory system 

    - proprioception 

      - muscle spindles 

      - GTO 

      - joint receptors 

   

    - cutaneous receptors 

      - mechanoreceptors (touch) 

      - thermoreceptors (temp change) 

      - nociceptors 

   

  • Visual system 
  • Vestibular system 
• Cognition: 

  • Skill 
  • Memory - (working, declarative/procedural) - experience 
  • State of activation 

    - anxiety/stress 

    - motivation (goals) 

    - arousal 

  • Attention  

    - personal characteristics 

    - nature of activity 
• What relevance is this to physios?  (individual)

  1. If any of these mechanisms are altered then they can impact on movement (type, efficiency and effectiveness).  

  2. We can use these mechanisms to facilitate rehabilitation 
• Task: 

  • The nature of the task being performed determines the type of movement control needed  
  • Therefore we need to understand task attributes and how they may influence movement  

   
• Task has 3 components: 

  • Mobility 

    - Is the task discrete or continuous? How many different body segments need to be moving? 

   

  • Stability 

    - What is the base of support in this task? Is it changing? What is the balance between stability and mobility of body segments? 

   

  • Manipulation  

    - What is being manipulated? What are its properties? How does this influence the required stability and mobility relationship?  
• What relevance is this to physios?  (task)

  1. In rehabilitation the nature & complexity of the task needs to considered  

  2. Consider hierarchies of task  

  3. Task practice should be developmental (but not rigid)  

  4. Tasks must be MEANINGFUL for the individual 
• task In treatment: 

  • Start with a task they can just achieve  
  • Add complexity to progress  
  • Make sure the task is motivating and salient 
• Movement is influenced by features in the environment 

   

  Environment has 2 features: 

  • Regulatory 

    - Things that shape the movement itself – movement must conform to these influences 

   

  • Non – regulatory 

    - things that may influence movement but do not directly alter it 
• What relevance is this to physios?  (environment)

  1. Must consider how the environment interacts with the individual and task  

  2. Remove environmental influences which are negative to the specific focus  

  3. Use the environment to create appropriate challenges  

  4. Make your rehabilitation ‘real’ by creating or using multiple environments 
• Summary: 

  Motor control has a long history of research with multiple theories  

  We are working with the integrated systems model which emphasises the interaction between individual, task and environment  

  Knowing the components and features of these facilitates your ability to understand movement and plan appropriate rehabilitation strategies