dr. david q. thomas

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

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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.