Download Biomechanics - K

What is Biomechanics?
• Biomechanics:
– Hall. Basic biomechanics, p. 3
“... application of mechanical principles to the study of living
organisms.” and “… use of the tools of mechanics . . . to study the
anatomical and functional aspects of living organisms.”
• Biomechanics of human movement:
– Kreighbaum & Barthels. Biomechanics: A qualitative study of
human movement , p 1
“that area of study wherein the knowledge and methods of mechanics
are applied to the structure and function of the living human
system.”
• This course focuses on the biomechanics of human
movement
• Good website on biomechanics: Biomechanics world wide
Home
The Discipline of Kinesiology
Various types/contexts of human movement
Occupational
biomechanics
Sport
biomechanics
Rehab biomech
Orthopedic biom
Exercise biom?
Sport medicine?
(Aging)
Branches of Sports Medicine
D = discipline P = profession
D
D
D
P
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D
D
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P
P
Selected practical problems that biomechanics
can help resolve
• Exercise biomechanics:
– What is the most effective exercise for the abdominal muscles?
– Do you really need an abdominal exercise device? Which type is
best?
– What types of exercises are effective in promoting bone density?
• Sport biomechanics:
– What specific factors should a coach or athlete focus on in order to
produce an increase in performance?
– Which mode of exercise is best for producing increased power
performance?
– Which sport implement or exercise device is best suited for you?
– How does the height of the mound affect pitching technique and/or
potential for injury?
Issues & problems, cont’d
• Developmental/aging biomechanics
– Does exercise play a role in promoting bone density or preventing
osteoporosis? How?
– Does activity level/type during formative years affect bone density
later in life?
– How can we prevent falls in aging people?
– What special bone growth/injury problems do we have in youth?
(mound height study)
• Occupational biomechanics (ergonomics):
– What movements and stresses contribute to carpal tunnel
syndrome? Low back pain? Shoulder joint impingement?
– What is the most efficient, or effective way to do a particular work
task?
Problems & issues, cont’d
• In what category does each belong?
– How can we prevent decreasing bone density in prolonged micro
gravity environments?
– What is the effect of aging on skeletal muscle?
– Which type of tennis backhand is best - one-handed or two
handed?
– What is the effect of testosterone supplementation on osteporosis?
– What is the effect of exercise on bone mineral content in pregnant
women?
– What are the ground reaction forces during various types of
aerobic dancing ? Which types are contraindicated for older
women?
– Biomechanical assessment of knee arthroplasty
– Osteoporosis in paraplegics
– The scientific basis for closed-kinetic chain exercise after anterior
cruciate ligament reconstruction
Biomechanics of Human Movement
• Basic approaches to studying human movement
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Kinetic vs Kinematic
Static vs Dynamic
Qualitative vs Quantitative
Maximize, minimize, or optimize
• Factors-Results - a qualitative, heirarchial, deterministic model
(Adrian, p 17)
– Identify result
– List factors that produce the result
• Holistic Principle Model
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Describe the movement
Describe overall performance goal in specific biomechanical terms
Divide movement into phases
Describe purpose/goal of each phase
Identify anatomical, mechanical, and environmental considerations
Determine biomechanical principles for successful performance of each phase
and total movement
– Assess performance based on these principles
Hay’s heirarchial factors-results analysis model. Each
lower factor influences the linked factor above
The Holistic Model: The
baseball swing
Holistic Model –
the baseball
swing
Problems for Discussion Mon, Feb 3
• Straight-forward, formal quantitative problem involving simple
kinematic equation:
• Does the softball or baseball hitter have more time to react to a
pitch? Assume that the baseball pitcher throws to home plate (60.5
ft, or 18.44 m from pitcher’s rubber) at a velocity of 90 mph (40
m/s) and the softball pitcher throws (46 ft, or 14.02 m from pitcher’s
rubber) at a velocity of 60 mph (27 m/s).
• More general, complex quantitative problem:
• A man fell from the railing of a walkway on a second-story
apartment building. He was found lying unconscious on his back
with his center of mass located 5 feet horizontally from a second
story walkway and railing. The top of the railing was 21.6 ft above
the ground. His blood alcohol content was found to be .30
(inebriated) and he has no memory of how he fell. In order to
appraise liability for the accident, we need to determine if the victim
walked into the railing or if he was sitting on the railing and fell off.
Can this be done from the information given? How?
Assignment for Monday, Feb 3
• Go to the Biomechanics world wide Home
website
• Locate a website that deals with problems and
issues in an area of special interest to you
• Give a short verbal summary of the contents of the
site to the class. Include in your comments the
following: (1) site URL and description,
(2)general purpose, (3) intended audience, and (4)
specifically, how the site is beneficial to you and
others.