Transcript BIOMECHANICS

What is Biomechanics?
 The study of human movement and the
forces acting upon it both internal and
external, during motion and when stationary.
 It is important to study because
it helps to identify the best
techniques to perform an action
 It allows a skill to be broken down into its sub
skills.
Force & Torque
 FORCE
 A force is a push or pull acting upon an object as
a result of its interaction with another object
 All sporting activities have forces acting upon the
athlete
 The main force acting upon your body is Gravity
 TORQUE
 Torque is the tendency of a force to cause or
change rotational motion of a body.
 Since force is a push or pull, Torque would be a twist
Velocity & Acceleration
 Velocity is the rate that an object moves
from one place to another.
Ex. A person running a race
 Acceleration is the rate at which an object
changes its velocity
Ex. Some one who is running a long race pacing
them selves and then sprints at the end.
Stability
 Stability is vital to all movements.
 It is the ‘ability of an object to remain balanced’
 This is extremely important in sport and physical
activity, as the more stable you are the easier it is
to perform skills to a high level.
 Stability is improved through
 Widening the base of support
 Lowering the centre of gravity
 Keeping the line of gravity within the base of support.
Types of Motion
► It is important to distinguish between two types of
motion:
 ► Linear
(or Translational) Motion
 Movement in particular direction (and
would include the resultant of more than
one linear force acting on an object).
Example: a sprinter accelerating down the
track.
 ► Rotational Motion
 Movement about an axis. The force does
not act through the centre of mass, but
rather is “off off-centre,” and this results in
rotation. Example: ice ice-skater’s spin.
Seven Principles of Biomechanical
Analysis
 ► STABILITY
 Principle 1: The lower the center of
mass, the larger the base of support,
the closer the center of mass to the
base of support, and the greater the
mass, the more stability increases.
Four subcomponents
Example: Sumo wrestling
Seven Principles of Biomechanical
Analysis
MAXIMUM EFFORT
 Principle 2: The production of maximum
force requires the use of all possible joint
movements that contribute to the task’s
objective.
 Examples: golf, bench press
Seven Principles of
Biomechanical Analysis
 MAXIMUM VELOCITY
 Principle 3 : The production of maximum
velocity requires the use of joints in orderfrom largest to smallest.
 Examples: hockey slap shot , hitting a golf
ball
Seven Principles of
Biomechanical Analysis
 LINEAR MOTION
 Principle 4: The greater the applied impulse,
the greater the increase in velocity.
 Example: slam-dunking a basketball
Seven Principles of
Biomechanical Analysis
► LINEAR MOTION
 Principle 5 : Movement usually occurs in the
direction opposite that of the applied force.
 Examples: high jumper, cyclists, runners
Seven Principles of
Biomechanical Analysis
ANGULAR MOTION
 Principle 6: Angular motion is
produced by the application of a force
acting at some distance from an axis,
that is, by torque.
 Example: baseball pitchers
Seven Principles of
Biomechanical Analysis
 ► ANGULAR MOMENTUM
 Principle 7: Angular momentum is constant
when an athlete or object is free in the air.
 once an athlete is airborne, he or she will
travel with constant angular momentum.
 Example: Diver