Transcript KNR 205: Scientific Principles of Coaching

KNR 205: Scientific
Principles of Coaching
Introduction
Slide 2
General course stuff
 The course is designed for athletic coaching
minors, but available to KNR majors
 Have you had any of these...
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181 (A&P), 240 (Fitness), 280 (Ex. Phys.), 282
(biomechanics)?
If so, you’ll be duplicating information you’ve
already covered.
This course was designed to cover aspects of all
those courses, as well as 254 and 257, so that it
would function as a general intro to kinesiology for
minors
Slide 3
General course stuff
 Consequences for course organization
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A lot of material
Broad and shallow approach
Focusing on “getting the idea” of a number of
areas
Assessments that survey basic familiarity rather
than mastery
Slide 4
General course stuff
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To do this week...
1.
2.
Download these slides (chapters 1 and 2) and
print them up. You should be able to print
multiple slides per page – I recommend 3 slides a
page
Read chapters 1 & 2 and answer the online quiz
on chapter 2 (deadline to be announced – it’ll be
some time next week)
Slide 5
Chapter 1: Introduction
 We’re going to skim this and get into the nitty
gritty of chapter 2 ASAP
 As this course is designed as the survey course for
the coaching minor, it makes sense to read about
the discipline a little first.
 The best summary I can see in the text is on page
4, figure 1.1
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As you can see, it’s busy. There’s a lot of stuff, and
a lot of influences
Or, as we call it, kinesiology
Part One: Anatomical
Bases of Human
Movement
Functional Anatomy
Slide 8
General intro...
 Again, we’ll skim this introduction so we can get to the
meat of chapter 2.
 Human anatomy is essentially about the structure and
function of the human body
 Functional anatomy is about human anatomy doing its
daily business – moving and being physically active (3
areas – bones, joints, muscles)
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“dynamic anatomy”
 Can be from a number of levels of analysis
 Subcellular
 Tissues
 Organs
Chapter 2
Basic Concepts of the Musculoskeletal
System
Slide 10
Objective (from syllabus)
 To understand key concepts related to the
structure and function of the skeletal, articular
(joint) and muscular systems
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You’ll find I stick very closely to the book
throughout (like a drowning man clutching
driftwood)
I see my role as a facilitator, whose job it is to
simply relate and explain the content of the text
to you
As such, I need you to simply point out where I’m
not being clear
Slide 11
Tools for Measurement
 Bone density:
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radiology
 Bone structure
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chemical preparation
 Bone composition
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chemical analysis
 Movement:
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goniometry (joint motion)
dynamometers (muscle force)
Slide 12
The skeletal system
 Functions
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Mechanical
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Weight bearing
Protection (e.g. brain, lungs)
Contribution to movement (linkages, muscle
attachment sites)
Physiological
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Bone can heal itself & perform maintenance
 “Living” vs. “dead” bone
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Mineral storage (calcium, phosphorus)
Marrow – produces blood cells
Slide 13
The skeletal system
 Bone composition
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Mechanical properties & bone composition
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Stiffness, flexibility, tensile strength, etc...
 Multiple components – the whole is greater than the sum
of the parts
 ¼ water...also contains minerals like calcium,
phosphorous
 Healthy bone: 1/3 organic (collagen), 2/3 mineral (salts)
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We don’t have to learn the exact properties!
Osteocytes – basic cells
Bone
Osteoblasts – bone-forming cells
remodeling
– 3 months
Osteoclasts – bone-eroding cells
Slide 14
The skeletal system
 Bone composition
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Types of bone
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Spongy
 More porous, springy – easy to supply with blood (and
keep alive)
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Compact
 More solid, different in structure – we won’t go into
details, but it implies that compact bone is organized
specifically to address the difficulty of supplying blood to
the entire bone
Slide 15
The skeletal system
 Architecture of bone
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Light and weight bearing – implies efficiency
Shape and organization
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Generally, the structure mirrors the function. E.g.:
 Long bones – rigid links for movement
 Flat bones of skull – “bicycle helmet” design
 Hindfoot – compact and spongy bits to absorb ground
reaction forces
 Vertebra – mixture of each of these types
The skeletal system
 Architecture of bone
 Architecture of long
bones
 Hollow shafts confer
mechanical
advantages
 Large end points
absorb compression
forces
Slide 17
The articular system
 Classification of joints
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The different classifications are based on the
different materials forming each type. Types are:
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Neither
allows
much
movement
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Fibrous (e.g. teeth to jaw, between bones of skull,
between bones in long bones in arms & legs)
Cartilaginous (e.g. between growth plates in bone, or
between vertebrae)
Synovial – all over the place, and affords most
movement, so the focus here
The articular system
 Features of synovial joints
 Cartilage – sponge (smooth
surface and force absorber)
 Joint capsule – more firm
(joint stability, forms
Collagen
boundary)
fibers
 Synovial membrane – inner
layer of capsule, forms
synovial fluid, removes cell
debris
Changes viscosity
 Synovial fluid:
& volume with
Blood bits,
synovial
membrane
secretions,
debris
90% Collagen
fibers
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Lubricates
Protects
Provides nutrition (for
cartilage)
activity
Ligaments – attach across
bones to protect against large
movement of the joint
Activity
also
“flushes”
the joint
The articular system
 Classification of synovial joints
See figure 2.7 (types)
 Hip, ankle, finger knuckle,
elbow, spinal vertebrae
 Range of movements allowed
by synovial joints
 See 2.8 (movement types)
 Also spin, slide and roll
 Joint protection, lubrication,
and wear
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See 2.5 again – add
cartilage for sponge, and
synovial fluid for
slipperiness
Spheroid,
hinge, uniaxial,
biaxial, simple,
compound,
complex
Slide 20
The articular system
 The joint as the functional unit of the musculoskeletal
system
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The idea here is that there are a lot of factors affecting the
structural integrity (stability) of a joint
 The bones provide the major part of the joint, but also aid
in cushioning forces
 Muscles stabilize the joint by producing force across it
 Tendons transmit muscle forces to the joints
 Motor and sensory nerves allow the joint to function in the
context of the entire body’s movement
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The point here is that injury to one part of a joint can
be seen to affect many other parts of the system
(“chain reaction”)
Slide 21
The muscular system
 Structure
 Bone-tendon-muscle-tendon-bone
 Association of muscles with other structures
 Connection points determine direction of action of
contractile force
 Structural features of muscle
 Types – skeletal, smooth, cardiac
 Shape – normally elliptical, can vary (can’t see how this
matters too much)
 Components – see slide 24 – basic functional component is
the motor unit, which may comprise few or many muscle
fibers (and that is indirectly associated with the degree of
fine control you have over the contraction) (less fibers
p/unit…more fine control)
Slide 22
The muscular system
 Structure
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Distinguishing properties
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Excitable
Contracts
Conducts
Can extend
Is elastic
The muscle and its
parts
The muscle as a
whole
Slide 23
The muscular system
 Structure
 Muscle contractions
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Release of calcium
ions...exposure of
active sites on
actin – myosin
attaches
Sliding filament hypothesis
Myosin attaches to actin and
pulls on z-line (shortening
Cross-bridge hypothesis
sarcomere)
Activation via electrical and mechanical responses:
excitation-contraction coupling
 Chemical release from nerve-muscle junction (causes 
voltage)
 Signal conducts along muscle
 Electricity indirectly causes attachment between actin
and myosin filaments
 Myosin filaments pull actin filaments towards center
 Leads to cross-bridge cycling...
Rapid – 2ms
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Muscles contract via overlap of
protein filaments (going from not
much overlapping to much
overlapping)
The muscular system
Cross-bridge cycling...
Power stroke
The muscular system
 Mechanics of muscular
action
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Types of contraction
 Concentric produces
movement
 Isometric stabilizes
joint
 Eccentric controls
movement
Slide 26
The muscular system
 Mechanics of muscular action
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Explaining joint actions
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Mono-, bi-, and poly-articular muscles
Not easy – muscles interact in very complex ways –
gives rise to a whole sub-discipline
Muscles’ ability to move the joint depends on ability
to shorten and lengthen – has limits (see diagram on
p. 31, and the wrist example)
Determinants of strength
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See ch. 6!