Week 11 (MC) - Energetics as a driver of movement changes

Question 1

What is the formula for Efficiency?

Answer 1

Efficiency (%) = (Mechanical Work done / Energy Used for work) x 100

Where:

Mechanical work = Force X distance

Energy used = food, amount of o2 (metabolic energy expended)

Question 2

What is Economy?

Answer 2

Metabolic energy expended to achieve a skill task or goal.
(e.g., lowered oxygen consumption per fixed task)
= Productivity Indice / O2 consumed

Question 3

Define energetic (efficiency) change according to task adaptation (speed/pace)

Answer 3

Preferred modes (e.g., speeds) of movement coincide with optimal energy efficiency; influenced by anatomical/anthropometric, fitness, biomechanical & prior skills constraints\

e.g. at a moderate, steady pace in running, the body may find an optimal stride and rhythm that minimizes energy use per step. However, when speed increases, efficiency might decrease as more energy is required to maintain the higher pace. Over time, training at various speeds allows the body to adapt, improving efficiency even at previously challenging speeds.

Question 4

Explain common movement & energetic differences between skilled v unskilled performance

Answer 4

Movement:
Skilled: Smooth, precise, coordinated, with efficient use of muscle groups and minimal unnecessary motion.
Unskilled: Jerky, inconsistent, uncoordinated, often with excessive or inefficient movement.

Energetic Efficiency:
Skilled: Lower energy consumption for the same task due to optimized muscle recruitment and technique.
Unskilled: Higher energy expenditure due to inefficient movement patterns and poor technique

Question 5

Explain the range of neural + energetics changes which occur with skill learning

Answer 5

Neural Changes:
Increased motor unit recruitment and synaptic strength for better coordination.
Enhanced neural plasticity, improving movement efficiency and precision.
Better communication between brain areas, reducing cognitive load during performance.

Energetic Changes:
Improved muscle efficiency, requiring less energy for the same movement.
Optimized movement patterns, reducing wasteful motion and conserving energy.
Lowered lactate production and fatigue due to more efficient energy use

TLDR - Skilled motor performance = Lower global & local energy cost & ↑ levels of speed of execution with stability & accuracy.