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KNR 205: Scientific Principles of Coaching. Introduction. General course stuff. The course is designed for athletic coaching minors, but available to KNR majors Have you had any of these... 181 (A&P), 240 (Fitness), 280 (Ex. Phys.), 282 (biomechanics)?
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KNR 205: Scientific Principles of Coaching Introduction
General course stuff • The course is designed for athletic coaching minors, but available to KNR majors • Have you had any of these... • 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
General course stuff • Consequences for course organization • 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
General course stuff • To do this week... • 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)
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 • As you can see, it’s busy. There’s a lot of stuff, and a lot of influences
Part One: Anatomical Bases of Human Movement Functional Anatomy
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) • “dynamic anatomy” • Can be from a number of levels of analysis • Subcellular • Tissues • Organs
Chapter 2 Basic Concepts of the Musculoskeletal System
Objective (from syllabus) • To understand key concepts related to the structure and function of the skeletal, articular (joint) and muscular systems • 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
Tools for Measurement • Bone density: • radiology • Bone structure • chemical preparation • Bone composition • chemical analysis • Movement: • goniometry (joint motion) • dynamometers (muscle force)
The skeletal system • Functions • Mechanical • Weight bearing • Protection (e.g. brain, lungs) • Contribution to movement (linkages, muscle attachment sites) • Physiological • Bone can heal itself & perform maintenance • “Living” vs. “dead” bone • Mineral storage (calcium, phosphorus) • Marrow – produces blood cells
The skeletal system • Bone composition • Mechanical properties & bone composition • 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) • We don’t have to learn the exact properties! • Osteocytes – basic cells • Osteoblasts – bone-forming cells • Osteoclasts – bone-eroding cells Bone remodeling – 3 months
The skeletal system • Bone composition • Types of bone • Spongy • More porous, springy – easy to supply with blood (and keep alive) • 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
The skeletal system • Architecture of bone • Light and weight bearing – implies efficiency • Shape and organization • 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
The articular system • Classification of joints • The different classifications are based on the different materials forming each type. Types are: • 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 Neither allows much movement
The articular system • Features of synovial joints • Cartilage – sponge (smooth surface and force absorber) • Joint capsule – more firm (joint stability, forms boundary) • Synovial membrane – inner layer of capsule, forms synovial fluid, removes cell debris • Synovial fluid: • Lubricates • Protects • Provides nutrition (for cartilage) • Ligaments – attach across bones to protect against large movement of the joint Collagen fibers Changes viscosity & volume with activity Blood bits, synovial membrane secretions, debris Activity also “flushes” the joint 90% Collagen fibers
The articular system Spheroid, hinge, uniaxial, biaxial, simple, compound, complex • 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 • See 2.5 again – add cartilage for sponge, and synovial fluid for slipperiness
The articular system • The joint as the functional unit of the musculoskeletal system • 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 • 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”)
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)
The muscular system • Structure • Distinguishing properties • Excitable • Contracts • Conducts • Can extend • Is elastic The muscle and its parts The muscle as a whole
The muscular system Muscles contract via overlap of protein filaments (going from not much overlapping to much overlapping) • Structure • Muscle contractions • Sliding filament hypothesis • Cross-bridge hypothesis • 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... Myosin attaches to actin and pulls on z-line (shortening sarcomere) Rapid – 2ms Release of calcium ions...exposure of active sites on actin – myosin attaches
The muscular system Cross-bridge cycling... Power stroke
The muscular system • Mechanics of muscular action • Types of contraction • Concentric produces movement • Isometric stabilizes joint • Eccentric controls movement
The muscular system • Mechanics of muscular action • Explaining joint actions • 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 • See ch. 6!