Dr. David Q. Thomas
http://www.castonline.ilstu.edu/Thomas/

Credit goes to Dr. McCaw for his contributions
to these slides.

Traditional teaching and coaching methods
tell you what techniques to teach or coach


Biomechanics tells you why those techniques
are best to teach or coach
It can also tell you why some teaching and
coaching techniques don’t work and need to
be discontinued

AT, OT, and PT students will benefit from
learning biomechanics because it will help in:
◦ determining the cause of injury,
◦ aid in preventing future injury,
◦ and guide in determining best methods for
rehabilitation.

Exercise science students will learn the best
techniques for improving fitness and
enhancing exercise performance

PETE students will learn how to make
instructional decisions based on the science
of human movement

I will provide you with
◦ Concept
◦ Examples

You need to come up with
◦ Application
 How does this concept apply to:
 Physical Education Teacher Education?
 Exercise Science?
 Athletic Training?

Kines: Latin ==> “motion”

logos: “study of”

Kinesiology = Study of Motion
Includes:
 Anatomy & Physiology
 Psychology
 Motor Development
 Pedagogy
 Biomechanics
 Exercise Physiology
 Athletic Training

Bio = life

Mechanics - study of machines

Biomechanics - study of living machines
science concerned with
effects of forces acting
on a system (body)
Rigid Body
Mechanics
Statics
-at rest
-constant velocity
Dynamics
-changing motion (acceleration)
Kinematics
-description of motion
Kinetics
-study of the forces that cause
or tend to cause the
changes in motion



We study biomechanics to understand how
people move
This information may be used to enhance
performance by improving technique
It may also be used to lower the risk for injury

Enhance skill performance
◦ Technique improvement
 Improve current technique (shooting a foul shot)
 Develop new technique (Fosbury Flop, swim hand
recovery, skating in X-country skiing, ski jumping)
◦ Equipment improvement
 Shoes and apparel
 Implements
 Protection devices
◦ Training improvement

Injury Prevention and Rehabilitation
◦ Techniques to reduce injury
◦ Equipment designs to reduce injury

To understand how living bodies can
move.

To understand how people can move.

To understand how people can move.
◦ To enhance skill performance
 elite athletes
 USOC, WNBA, MLB, etc
 Biomechanics in the Olympics
http://www.youtube.com/watch?v=csrbGCUxzg&feature=related

An example using anthropometrics
Study of the body’s size and form
This would include measurements of:
 Height
 Weight
 Circumferences
 Skinfolds
 Girths/diameters
 Etc
Ave Average Hand/Ht Hand
Ball
hand/ball
Ht Ht (inches) Ratio Length Size (inches)
ratio
Male 6'7''
79
0.108
8.53
29.625
0.288
Female 6'
72
0.108
7.78
28.625
0.272
Average NBAers hand is 28.8% of ball length
Average WNBAers hand is 27.2% of ball length
How big should the WNBA ball be to equate males & females?
7.78/0.288 = 27.014 inches

To allow for comparisons
Strength
Males
Versus
Females

Destroy myths
Can a
cow
really
jump over
the
moon?
http://zebu.uoregon.edu/~dmason/probs/mech/work/cow
moon/cowmoon.html

To understand how people can move.
◦ To enhance skill performance
 physical challenges




ACL deficit
CP gait
Wheelchair
Age-related disease

To understand how people can move.
◦ To enhance skill performance
 physical challenges




ACL deficit
CP gait
Wheelchair
Age-related disease

To understand how people can move.
◦ To enhance skill performance
 Physical development
To understand how
people can move.

◦ To enhance
skill performance
 Improve equipment
Biomechanics
and Safety

To understand how people can move.
◦ To enhance skill performance
 Not limited to humans

To understand how people can move.
◦ To enhance skill performance
◦ To lower the risk for injury




Exercise equipment & technique
shoes & surfaces
braces & orthotics
Equine biomechanics
http://www.equinemechanics.com/

To understand how people can move.
◦ To enhance skill performance
◦ To lower the risk for injury
 Automobiles
 collisions
http://collisionresearchltd.com/index.php

To understand how people can move.
◦ To enhance skill performance
◦ To lower the risk for injury
 Automobiles
 collisions

To understand how people can move.
Vsevolod
Meyerhold’s
Biomechanical
Theatre
1920’s

To understand how people can move.
Borelli

Borelli’s major scientific achievements are focused around his investigation
into biomechanics. This work originated with his studies of animals. His
publications, De Motu Animalium I and De Motu Animalium II, relate animals
to machines and utilize mathematics to prove his theories. The anatomists of
the 17th century were the first to suggest the contractile movement of
muscles. Borelli, however, first suggested that ‘muscles do not exercise vital
movement otherwise than by contracting.’ He was also the first to deny
corpuscular influence on the movements of muscles. This was proven
through his scientific experiments demonstrating that living muscle did not
release corpuscles into water when cut. Borelli also recognized that forward
motion entailed movement of a body’s center of gravity forward, which was
then followed by the swinging of its limbs in order to maintain balance. His
studies also extended beyond muscle and locomotion. In particular he
likened the action of the heart to that of a piston. For this to work properly
he derived the idea that the arteries have be elastic. For these discoveries,
Borelli is labeled as the father of modern biomechanics.
 http://en.wikipedia.org/wiki/Giovanni_Alfonso_Borelli

To understand how people can move.
◦ To enhance skill performance
◦ To lower the risk for injury

To understand how people can move.
◦ To enhance skill performance
◦ To lower the risk for
injury

To understand how people can move.
◦ To enhance skill performance
◦ To lower the risk for injury



Some of us are not
doing a good job
◦ Coach: focus on
strategy
◦ Teaching
 skills: “farm system”
 vs
 fitness: CV &
strength
Cater to the converted.
Serve the skilled.

We treat symptoms of
an injury, with less
emphasis on etiology
(cause) of an injury
◦ placebo effect vs true
treatment effects
◦ high rate of reoccurrence
Safety & Performance Trade-Off


Quantitative analysis - mainly a clinical
research perspective.
Qualitative analysis - most teachers/coaches
need this ability.

Science concerned with the effects of forces
acting on objects (body)
◦ body: focus of the analysis





human body
individual body segment
specific tissue / anatomical site
balls, pucks
implement: bat, stick, club

Science concerned with the effects of forces
acting on objects (body)
◦
◦
◦
◦
◦
Rigid-body mechanics
Deformable body mechanics
Fluid mechanics
Relativistic mechanics
Quantum mechanics


Acceptable for analyzing gross movements
Assumptions
◦ body does not deform by bending, stretching or
compressing
◦ segments are rigid links joined by frictionless
hinges at joints
Rigid Body
Mechanics
Statics
-at rest
-constant velocity
Dynamics
-changing motion (acceleration)
Kinematics
-description of motion
Kinetics
-study of the forces that cause
or tend to cause the
changes in motion




Length - of what size?
Time - of what duration?
Mass - how much matter?
Inertia - what resistance to movement?

Describe someone out for a run

Describe someone out for a run
◦ Kinematics




How
How
How
How
far did she run?
long to run that far?
fast was she?
big is she?
◦ Kinetics
 What friction under her feet?
 What forces on her joints?
 What tension in her muscles?

Measure to describe
◦ location at a particular point in her run
◦ how far she ran


Feet, inches, miles
Systeme Internationale d’Unites (SI)
◦ meter
◦ 1 m = 3.28 feet = 39 inches
http://physics.nist.gov/cuu/Units/



Measure to describe how long it takes her
seconds, minutes, hours, days, months, years
Systeme Internationale d’Unites (SI)
◦ second (s)

Space to move in and time during which to
move

speed & velocity==> length per unit of time
◦ miles per hour
◦ m / s or m . sec-1

acceleration
◦ m/s/s or m . sec-1 . sec-1

Inertia
◦ resistance to a change in state of motion

Who is harder to start or stop moving
◦ Olympic weight lifter
◦ Olympic gymnast

Inertia
◦ resistance to a change in state of motion

Who is harder to start or stop moving
◦ Olympic weight lifter: has more inertia
◦ Olympic gymnast

Inertia
◦ resistance to a change in state of motion

Mass
◦ the quantity of matter a body possesses
◦ quantifies inertia (the measure of inertia)
 Greater mass, greater inertia
resistance to change state of motion
◦ units are kilogram (kg) or slug (English)
◦ Not the same as weight

Provide an example of changing motion in
◦ sport
◦ exercise
◦ workplace

Provide an example of changing motion in
◦ Sport: size expectations of different positions (i.e.
interior defensive linemen)
◦ Exercise: alter mass to be moved to increase load
on NMS system (i.e. push-up)
◦ Workplace: alter mass of components to reduce
load (i.e. cement bags, engine blocks)
 Length
 Time
 Mass
All that is needed to describe
and explain the motion of objects

Force: defined from the above
◦ a push or pull acting on a body
Biomechanics
Lab at ISU
Research
Not to know is bad.
Not to wish to know
is worse.