dr. david q. thomas
TRANSCRIPT
Dr. David Q. Thomashttp://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
S ta tics-a t re st
-co n sta n t ve lo c ity
K in e m a tics-d e sc rip tio n o f m o tion
K in e tics-s tud y o f the fo rce s th a t cau se
o r te n d to cau se thech an g es in m otion
D yn a m ics-ch a ng in g m otio n (a cce le ra tio n )
R ig id B o dyM e ch a n ics
science concerned with effects of forces acting on a system (body)
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.
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To understand how people can move.
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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=csrb-GCUxzg&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 0.288Female 6' 72 0.108 7.78 28.625 0.272
Average NBAers hand is 28.8% of ball lengthAverage 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
MalesVersus
Females
Destroy myths
Can a cow really jump over the moon?
http://zebu.uoregon.edu/~dmason/probs/mech/work/cowmoon/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
Bio
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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 Theatre1920’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
S ta tics-a t re st
-co n sta n t ve lo c ity
K in e m a tics-d e sc rip tio n o f m o tion
K in e tics-s tud y o f the fo rce s th a t cau se
o r te n d to cau se thech an g es in m otion
D yn a m ics-ch a ng in g m otio n (a cce le ra tio n )
R ig id B o dyM e ch a n ics
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 far did she run? How long to run that far? How fast was she? How 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 inertiaresistance 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)
LengthTimeMass
Force: defined from the above◦ a push or pull acting on a body
All that is needed to describeand explain the motion of objects
BiomechanicsLab at ISU
Research
Not to know is bad. Not to wish to know
is worse.