An Introduction to Biomechanics

An Introduction to
PSK 4U Lecture Series
A field within Kinesiology…
The science of human movement
 Applying mechanical principles to the human body
(eg. Force, velocity, acceleration, centre of gravity)
 Internal forces produced by muscles and
tendons working against external forces of
gravity, air resistance, water resistance and friction
 Helps to evaluate performance of athletes and aid
in recovery and prevent/examine sports injuries
 In my degree…this was a 2nd year required course
Careers within Biomechanics?
As an ‘engineer of the body’…you might:
Analyze a movement?
Help a patient recover?
Analysis of Movement
Practically all sports will
have at least a
preparatory phase, a
movement phase and
a follow through
phase, whereas many
will begin with a
stance phase and end
with a recovery
Movement Phases
Allows the athlete to assume a comfortable and
balanced body position from which to initiate
the sport skill.
Often called the wind up phase, is used to
lengthen the appropriate muscles so that they
concentrically contract in the next phase
Movement Phases
Follow Through
Sometimes called the acceleration, motion or contact (is
the action of the skill)
Begins immediately after the climax of the movement
phase in order to bring about negative acceleration of
the involved limb
Used to regain balance and positioning to be ready for
the next sport demand
TASK 1: Choose a familiar sport movement and describe
each phase with the information you have been given.
Physics review: Newton’s 3
Laws of Motion
1. The Law of Inertia
2. The Law of Acceleration
Every object in a state of uniform motion tends to
remain in that state of motion unless an external force is
applied to it.
Force applied to an object causes acceleration of that
object proportional to the force, in the direction of the
applied force, and inversely proportional to the object’s
3. The Law of Reaction
For every action there is an equal and opposite reaction.
A quick quiz…
Let’s apply these laws in the following
Bobsled start
Hockey stop
Golf ball during a putt
Biomechanical Formula
A = (v2-v1) / t
In this formula, the v2 is the object’s final velocity, v1
is its starting velocity, and t is the time it takes an
object to travel a set distance. Expressed in m/s2.
Biomechanical Formula
F = ma
Where force is represented by F, acceleration is a,
and mass of an object is m. Expressed in N
Biomechanical Formula
M = mv
Where M is momentum, m is mass and v is velocity.
Expressed in kg m/s.
7 Biomechanical Principles
Text Chapter 12
With a partner, choose one biomechanical
principle and write an abstract (summary)
using appropriate vocabulary and
Use a sport specific example (not from the
text!) to illustrate your principle.
There will be class time to discuss your
principle and to take notes on others’ work.