Biomechanics Flashcards
Segmental/sequential interaction
The transfer of momentum across the joints to provide maximum force
What principles are applied to produce maximum force efficiently? (5 points)
- Use large muscle groups with the largest mass first (legs)
- Sequentially accelerate each body part so that optimum momentum passes from one body part onto the next
- Each body part should have a stable base so that optimum momentum passes from one body part onto the next
- follow through become vital so as the final segment doesn’t not decelerate in the final stages
- ensure all forces are directed towards the target
Simultaneous movement
movement where all body parts move at the same time to produce a force
optimal projection
the relationship between the angle, velocity and height of release/ landing height to attain the goal of the athlete
3 factors which determine the trajectory of the flight path:
- height of release
- velocity of release
- angle of release
angle of release
considers the vertical and horizontal trajectory
athletes should throw/release the projectile approximately at a 45 degree angle to ensure the greatest distance covered
velocity of release
dependant on the force applied-more force=more distance covered
Height of release
if the projectile is released from a higher= flight time is longer=longer distance covered
if the projectile is released lower=decrease in-flight time=shorter distance covered
optimise the distance covered by releasing from the highest point
Force-motion
an object’s motion is affected by the magnitude and direction of an external acting force
What are the three principles of force-motion?
- size or magnitude of a force
- the more acceleration of an object, the more impulse/momentum gained
- direction of the force applied
Force motion principles in detail
- Size or magnitude of force- more force applied the greater the acceleration of the object
- The more acceleration of an object, the more impulse/momentum gained- faster means harder to stop
- Direction of force applied-force is applied in the direction of the target will increase the transfer of momentum through the object or target (up for high jump, out for long jump)
Linear motion
the object’s height/mass determines its inertia
angular motion
an object’s inertia or moment of inertia has two components:
it’s weight and mass and the distance that the weight of the object is distributed away from the axis of rotation
greater angle and mass= more inertia
increase speed to create force
motion
mass and acceleration
Moment of inertia
the resistance of the rotating object has to change its state of motion
- the closer the mass is distributed to the axis of rotation, the easier it is to rotate because its able to generate more angular velocity
- shorten the axis of rotation= lower MOI=faster
angular velocity
- Moment of inertia increases angular velocity decreases
* Moment of inertia decreases angular velocity increases
Angular momentum
conservation of angular momentum means that a spinning body will continue spinning indefinitely unless external forces act on it
- it its constant and only changes once it hits the ground
??? momentum
the amount of angular motion possessed by a rotating body measured as a product of MOI and angular velocity
(spinning- furthest away=spins faster)
(greater mass of an object and faster it moving=harder to slow down and stop)
how do we change rotational inertia?
- Change the radius of rotational inertia (hands closer to the axis as it reduces MOI)
- Change the mass of the object (a heavier or lighter piece of equipment and move the mass of the object away from axis and increase MOI)
levers
A rigid bar-like object that turns around a fixed point to move an object at one end by applying pressure to the other
Three elements of levers
axis (joints)
resistance (weight of an object or limb)
force (contracting muscle)
force arm (levers)
distance from the axis (joint) to muscle attachment of the bone
dictates our ability to apply force
larger force arm= more force produced (bar closer to the body to generate more force)
resistance arm
the distance from the axis (joint) to the resistance
dictates our ability to apply velocity/speed
larger resistance arm=more speed/velocity generated
shorten force arm and increase resistance arm to increased speed
types of lever
first-class (A in the middle) second class (R in the middle) third class (F in the middle)