Movement Science 2 Unit 10 Eccentrics and Explosives and Unit 11 Plyometric Exercise Flashcards
What are unique characteristics of Eccentric Exercises?
- Greater force production
- Consumes less energy
- Increases muscular strength more efficiently than concentric exercise
- The Forces increase as speed increases
Why should there be caution with Eccentric Exercise?
Higher risk of DOMS
- Onset 24-48 hrs
- Last 3-4 days
- Tissue damage
- Repeated-bout effect
Greater force production leads to greater stress on tendons
Can Eccentrics be used for Tendon Injuries?
Yes, tendons need to increase in tensile strength
For ex. Achilles Tendinopathy:
- pt would work through mild pain (5/10)
- load can be increased when their is no discomfort
NOT IN ACUTE CASES!!!!
What are the Management Guidelines with Eccentric exercises?
- In acute phase: eccentric exercise is not recommended
- In Sub-acute phase: exercise should be sub maximal and at slow speeds
- In settled/Chronic phase: Exercise progess to max load, fast speeds
- Isokinetic eccentrics should be saved for the Final Stage of Rehab
What are Explosive Moment Exercises?
Exercises of quick shortening of the muscles and tensioning of the musculotendinous unit
What are Plyometric Exercises?
A quick powerful moment involving a muscle prestretch to activate the stretch shortening cycle (SSC) to produce a stronger concentric contraction
What is the goal of Plyometric Training?
To decrease the amount of time requied between the yielding eccentric muscle contraction and the initiation of the overcoming concentric contraction: Amortization Phase
A shorter amortization phase is more effective because it allows for more efficient use of stored energy. A longer amortization phase wastes energy as heat and makes the stretch reflex less effective
What are the Mechanical Characteristics of Plyometric Exercises?
- Contractile Components (CC)
- Series Elastic Components (SEC)
- Parallel Elastic Components (PEC)
- Prestretch = Stored elastic energy in SEC
- Concentric contract = energy in SEC augments CC (contraction)
What is the purpose of Plyometrics?
- To heighten the exitability of nervous system for impoved reactive ability of the neuromuscular system.
- Any exercise that taps into the myostatic stretch reflex = plyometrics
Plyometrics can be used to train functional movements
What are the General Principles of Plyometric Exercises?
- Muscles around joints must first stretch, then contract to produce expolsive moment
- Plymetrics enhance specificity of training
- UE and LE training principles are the same, BUT UE intentisty is less due to smaller muscular contracture and type of muscle function
How should plyometrics be integrated into the rehabilitation program?
- Medial/Lateral loading
- Rotational loading
- Shock absorption/Deceleration loading
What are the Neurophysiologic Characteristic of Plyometric Exercises?
- Proprioceptive Stretch Reflex
-Muscle Spindles (Muscle belly; responds to magnitude, velocity of stretch)
-GTO (Tendon; responds to tension)
With Plyometrics, Muscle fiber elongation is dependent of what?
- Amount of stretch force applied
- Absolute fiber strength
-Greater tensile strength = less elongation - Ability of muscle spindle to elicit response
-Low sensitivity = Less powerful response
With Plyometrics, how do you improve physiologic performance?
- Increase the speed of the stretch reflex
- Desensitization of GTOs
- Neuromuscular coordination
-Improved coordination
-Enhancing nervous system to become more automatic
What are the Safety Requirements for Plyometric Training?
- Always being with an orthopedic screening evaluation
- Develop an adequate strength base
- Always use good supportive shoes
- Always use good resilient surface
- Train with knowledgeable supervision to ensure proper technique
How can the weight of the person and speed influence the demand on the plyometric exercise?
- If the person in heavier, they would have increased demand
- If there is increased speed, the demand will increase
What it the general guideline for the frequency of Plyometric Exercises?
Must allow 48-72 hours of rest between plyometric exercise training exercies
With Plyometric Exercise, what are the Signs of Fatigue and Overtraining?
- Prolonged foot contact
- Lack of arm/leg movement
- Reduced vertical height or horizontal distance
- Longer rest periods
- Lack of synchronous head and trunk control
- Loss of intrest
What is an Important Key Element with Plyometic Exercise?
Proper Landing
- Emphasize the eccentric or landing phase
- Absorb shock of landing through the ankle, knee and hip joints
