EVMM Biomechanics Flashcards
Define the Force-Motion principle
Force is applied over a period of time. Increasing the time allows for greater acceleration or deceleration
Two ways that motion affects force
- Increase time over which the force is applied
2. Increase the range of motion in the joints
What are two forms of muscle, what function does each perform and name a specific muscle as an example of each form
- Parallel – best for increasing the range of motion – Biceps
- Pennate – best for isometric force – Abdominals
Rest is one type of muscle action. What are the other three? . What is the main effect of each of these three actions?
- Concentric – most force at slow speed
- Eccentric most force at faster speed
- Isometric – stabilizing force
Define viscoelastic.
Tissue exhibits a time-dependent behavior under loading, reflecting the complex interactions between collagen fibrils, the non-collagenous matrix and water
When is it best to use stretching. pre or post-exercise and why?
Post-exercise – prolonged stretching decreases muscle performance
Why is it important to walk the horse for 10-20 minutes before training?
Viscoelasticity – cyclic loading makes the tendons better able to withstand higher loads
Define active insufficiency.
Muscles generate the most force when they are near their resting length. Lengthening or shortening the muscle decreases the force it can produce. The muscles have more strength near the resting length because that is where there is the most cross-bridging between acting and myosin filaments.
What is Force-Time delay? How does training affect force-time delay? What mechanism is used for trained movements?
Time delay between the intension to move and the motor action potential. Decreases it. Feed-forward mechanisms
Does a large range of motion increase or decrease force produced?
Increase
Define the stretch-shortening cycle.
Counter-movement is slowed by eccentric action immediately followed by concentric action in the intended direction
How do most high force movements start?
Begins with movement in the opposite direction
How does the stretch-shortening cycle increase force? (4)
- Contractile potentiation
- Reflex potentiation
- Storage of energy
- Increase time of applied force
What is the relationship between stability and mobility?
Dynamic balance