The document discusses the principles of biomechanics through examples. It states that an increase in acceleration requires an increase in force. It also explains that an object will maintain a constant speed and direction unless acted on by an outside force, and that for every force there is an equal and opposite reaction force. It provides examples of how forces must be applied in the direction of travel and how performance can be improved by redistributing body mass and lowering the center of gravity. Finally, it discusses how maximum force and velocity occur at right angles and how energy is conserved through continuous motion rather than pausing between movements.
2. AN INCREASE IN ACCELERATION EQUALS AN INCREASE IN FORCE. IF
YOU WANT TO DOUBLE THE ACCELERATION, YOU NEED TO DOUBLE
THE FORCE.
In order for the sprinter in this picture to achieve maximum acceleration,
he must produce as much force as is bodily possible in his takeoff. In the
above example, this translates to pressing off the starting step with all of
the power he can through his back leg.
3. AN OBJECT WILL CONTINUE MOVING AT A CONSTANT SPEED AND
DIRECTION UNLESS ACTED UPON BY A FORCE THAT CAUSES ITS SPEED
OR DIRECTION TO CHANGE
The tennis ball will continue in its trajectory unless acted upon by an
outside force. In this case, the tennis player will utilize the racket to
produce equal or greater force than that of the travelling ball, in order to
hit it back in the other direction.
4. FOR EVERY FORCE, THERE IS AN EQUAL AND OPPOSITE REACTION
FORCE
The fighter is producing force to kick her foot towards her training partner.
The training partner with the pad is returning the kick with equal reaction
force so that he is not knocked backwards.
5. YOU MUST APPLY FORCE IN THE DIRECTION THAT YOU WANT TO
TRAVEL
The runner is apply force to the ground behind her. She is also
simultaneously pumping her arms in a vigorous forward cycling motion,
which creates momentum that allows her to move in a forward direction
faster than if her arms were just dead weight at her sides.
6. YOU CAN IMPROVE
PERFORMANCE BY
REDISTRIBUTING THE MASS OF
THE BODY ABOUT THE CENTRE
OF GRAVITY
The athlete in the pictures has her mass distributed too far into her
posterior. A more ideal body position would be having her weight right
around the midfoot of her body, thus allowing the greatest opportunity to
apply linear force directly UP. The position she is in right now is unbalanced.
7. BY INCREASING
YOUR BASE OF
SUPPORT AND
LOWERING YOUR
CENTRE OF
GRAVITY, YOU
WILL INCREASE
YOUR STABILITY
A narrow base of support is easily toppled by outside forces. Lowering your
centre of gravity also decreases your height and essentially makes you more
gravitational stable; there is less outside force acting against the body to
make you lose balance.
8. IN ANGULAR
MOVEMENT, THE
MAXIMUM
EFFECTIVE FORCE
AND VELOCITY
OCCUR WHEN THE
LIMB IS AT RIGHT
ANGLES TO THE
BODY
Right angles are powerful because the limbs are not at excessive flexion or
total extension. Muscles are firing to maintain this position versus in a
state of relaxation, thus allowing for maximum force and velocity potential.
9. ENERGY IS CONSERVED BY NOT PAUSING
BETWEEN TWO MOVEMENTS THAT ARE
BOTH LINEAR
The contact with the ball and post-kick follow through by the soccer player
both occur with the leg travelling in a linear motion. Were the player to stop
immediately after making contact with the ball, the energy required by his
body to halt all of that forward momentum would be far superior than
allowing his leg to continue on the follow-through trajectory.
10. BY USING A TOTAL
RANGE OF
MOTION AND
MAKING USE OF
THE NATURAL
LEVERS OF THE
BODY, GREAT
MUSCULAR FORCE
CAN BE ACHIEVED
A total range of motion and proper lever use not only mean the proper
technique can be applied in any movement. Effort and energy consumption
are also lower, because the body is moving most efficiently for that specific
movement.
