LECTURE 4 Flashcards
What is motor control
Essentially, motor control can be defined very broadly but is the anything that involves moving.
Four characteristics of human movement
Flexible, Unique, Consistent, Modifiable
Flexibility
The principle of motor equivalence. We are able to achieve the same goal in a range of different ways. For example, there are a number of different ways of writing the same sentence.
Uniqueness
No two movements performed are exactly the same. Everything is always done slightly differently even if the difference is very subtle.
Context-Conditioned Variability
Internal non-linearities - central drive, elastic properties of locomotor apparatus
External non-linearities - changes in forces and their directions between movements
Consistency
Generally, temporal and spatial pattern of movements remains similar
Advantages of consistency
Train muscles for particular movement so will perform more highly.
Efficiency - start to recruit smaller motor units so use less energy
Disadvantages of consistency
Fatigue, Repetitive Stress Injuries (RSI), Poor performance but individual unaware.
Modifiability
Capability to alter movement patterns during motion and in various environments. For example, slipping and being able to recover.
EXAMPLE: Discrete Skill, Open Environment
Lineout throw
EXAMPLE: Discrete Skill, Closed Environment
Bicep curl
EXAMPLE: Serial Skill, Open Environment
Surfing
EXAMPLE: Serial Skill, Closed Environment
Basketball
EXAMPLE: Continuous Skill, Open Environment
Rowing
EXAMPLE: Continuous Skill, Closed Environment
Treadmill Running
Coordination
Function of constraining the components of the motor system into a behavioural unit
Control
Function of determining the acceptable parameters for the coordinative structures
Skill
Optimisation of coordinative structure behaviour
Feedback Control
Use of information received via sensory receptors to guide movement
Feedforward Control
Movement based on predictions
Anticipatory Postural Adjustments (APA)
Preparatory development of muscle tone and coordination to enable effective future movement
Compensatory/Integrative Postural Adjustments
Muscle actions that enable continued effective behaviour
Movement Enhances Perception
This leads to greater input and increase in visual field - eg. moving around the putting green to find the best angle
Movement Informs perception
For example, wearing a heavy backpack will make the hill appear steeper than it actually is.
Skill - Maximum Certainty
Relatively low performance variability
Skill - Minimum Energy
Efficiency and Economy
Skill - Minimum Time
Related to performance speed eg. pitching a baseball
Three factors solving the degrees of freedom problem
Stability, Efficiency, End State Comfort
Stability
Low movement variability
Efficiency
Low energy expenditure, use gravity, if possible, utilise the physical and mechanical properties of muscles and tendons
End State Comfort
Avoidance of discomfort, maximise potential for future movement.
