L13 - SSC and universal biomechanical principles Flashcards
(10 cards)
What is the Stretch-Shortening Cycle (SSC)?
A sequence where a muscle is first stretched (eccentric) and then forcefully contracted (concentric), enhancing power output.
What happens to the proximal and distal segments during the SSC?
The proximal segment rotates, while the distal segment lags, stretching the muscle crossing the joint.
What is SSC Mechanism A: Increase Range of Motion?
Increases the distance over which the distal segment can be accelerated
Increases work done (W = F · d)
Increases energy transfer to the end of the limb
What is SSC Mechanism B: Enhanced Concentric Force?
Allows the concentric phase to begin with a greater force due to the force-velocity (F·v) relationship.
What is SSC Mechanism C: Stretch Reflex Activation?
Initiates a reflex contraction by increasing neural activity
The reflex is stronger if the muscle is stretched quickly
What is the principle of Energy Minimisation?
Performing effectively while doing less unnecessary work, through:
Passive tension
Gravity
Sequencing
Movement simplification
What is meant by Controlling Redundant Degrees of Freedom (DoF)?
The human body has more DoF than required by the environment
Multiple movement patterns can achieve the same result
Movements with large out-of-plane motion are harder to execute consistently
How can redundant DoF be controlled in practice?
By simplifying movement patterns and improving consistency through sequencing and minimising unnecessary motion.
How are biomechanical principles like SSC and DoF related?
They are often interconnected — e.g., reducing redundant DoF can also help minimise energy use.
How can these principles be used in practice?
They are easy to identify using video analysis
Should be prioritised case-by-case based on the task and the athlete’s strengths/weaknesses.
