L11 - deterministic models Flashcards
(33 cards)
What is a deterministic model in biomechanics?
A model that breaks down performance into measurable, hierarchical components influencing the final outcome.
What is Level 1 of a deterministic model?
Performance outcome (e.g., result, criterion score).
What is Level 2 of a deterministic model?
Subdivisions of the performance outcome (e.g., specific result contributors).
What is Level 3 of a deterministic model?
Biomechanical principles (may swap with Level 2 depending on model).
What are Levels 4 and beyond in a deterministic model?
Critical features – specific body actions or movements that produce the result.
What is meant by sequential action of muscles, and where is it important?
Important in high-speed activities like discus.
Refers to proximal-to-distal sequencing to generate angular momentum.
Equation: L = Iω, where
L = angular momentum
I = moment of inertia (I = mr²)
ω = angular velocity
What is the relationship between angular momentum, moment of inertia, and angular velocity?
L = Iω, where angular momentum is the product of moment of inertia and angular velocity.
Why is minimising moment of inertia important in sport?
Crucial in endurance and speed activities.
Reducing distal segment mass or radius decreases inertia, making movement more efficient.
Formula: I = mr²
What is impulse in biomechanics?
The product of force and the time over which it is applied.
What principle relates to force and speed activities through impulse?
The impulse-momentum relationship
FΔt = Δ(mv)
Impulse increases momentum by increasing either force or time.
What is meant by maximising the acceleration path, and where is it important?
Important in movements requiring force and speed.
The longer the distance over which force is applied, the more work is done.
Work-energy formula: W = F·d or W = (ma)d
What factors increase stability in movement?
A wider base of support
A lower centre of mass
Important in both static and dynamic activities
How are biomechanical principles typically interconnected?
For example, increasing time (as in impulse) can also increase the acceleration path, influencing multiple principles at once.
What is a Phase Analysis Model?
A model that summarises mechanical principles within each phase of a movement or event (e.g., preparation, action, follow-through).
What is the Elite Performance Template?
A model based on the technique of elite athletes.
What is the purpose of a Deterministic Model?
To extract and prioritise movement features that are critical to performance outcomes.
What are the four stages in the technique analysis model (e.g., front salto)?
Preparation
Retraction
Action
Follow-through
What are movement principles used in each phase of a front salto?
Preparation: Linear motion, high endpoint speed
Retraction: CoM positioning, action-reaction principle
Action: Stretch-shortening cycle
Follow-through: Moment of inertia and rotational motion principles
What factors influence flight distance in long jump?
Take-off vertical velocity
Take-off horizontal velocity
Take-off height
(Aerodynamics typically ignored)
What factors influence horizontal velocity at take-off?
Work done on board
Athlete’s mass
Touchdown horizontal velocity
Horizontal acceleration/deceleration path of CoM
Mean horizontal braking and accelerating force
What are the critical features (CFs) for take-off velocity in long jump?
CF1: Fast run-up speed
CF2: Fast, full extension of take-off leg
CF3: Fast, high swing of free leg
CF4: Fast, high swing of arms
CF5: Lateral shift of CoM
CF6: ‘Active’ landing to reduce deceleration
CF7: Take-off with CoM ahead of foot
What are the CFs for take-off distance?
CF7: Centre of mass ahead of foot at take-off
CF8: Plant foot at front of take-off board
(dependent on control of run-up)
What are the CFs for landing distance in long jump?
CF9: Hips flexed, knees extended
CF10: Don’t touch sand behind landing point
CF11: Use hitch-kick to control rotation
What are some general criticisms of applied sports biomechanics?
Often atheoretical (descriptive, not explanatory)
Questionable research practices
Improved technology hasn’t led to improved understanding
