Chapter 3

1. Chapter 3 Basic Concepts of Anthropometry

2. Objective (from syllabus) • To understand the relationship between human body size, shape and composition, and movement capability

3. Anthropometry • Definition: • Dimensions and composition of the body • E.g. bone thickness & proportions, body fat %, lean body mass • See also kinanthropometry, which is the same thing but as applied to movement • Tools for measurement • All kinds of rulers, calipers and so on (and for lean body mass, some regression models to estimate body fat % based on a variety of assumptions) • Stadiometers, anthropometers, bicondylar calipers, skinfold calipers etc... • Height, body segment length, bone diameter, skinfold + fat width

4. Anthropometry • Body size • It’s a field for the obsessive in terms of measuring protocols • Determination of body shape • A variety of proportions are measured • BMI (mass/ht2) • [(Sitting ht)/)(standing ht)] x 100 • Certain proportions and shapes have been found to be associated with health or performance in certain activities, hence the interest • dimensionality • Limb length relative to torso • Bulk (fatness?) • Consider also cause and effect • Exceptions are always interesting though (e.g. Usain Bolt)

5. Anthropometry • Tissues composing the body • Anthropometry is interested in estimating tissue proportion in the living • Most popular example is lean body mass & fat – gives the 2-component anthropometric model • The book cites errors even with underwater weighing, which is normally the gold standard for estimation of body fat % • Should bear in mind that with all estimation techniques, they work best for typical people • DEXA (dual x-ray absorpiometry): 3-component model – lean tissue divided into calcified tissue and other non-fat tissue • More accurate, but a lot more expensive than a set of calipers • General idea here...as opposed to losing weight, you should increase lean body mass (yes, increase...or at least not lose it). • So, abnormally fat, thin, or muscular people don’t get such accurate estimates • MRI, CAT scans even better but even more expensive • Implies increased training to build muscle mass...which in turn leads to fat loss

6. Anthropometry • Somatotyping • The practice of classifying body types according to 3 dimensions (following the most popular Heath-Carter method) • Endomorphy (fatness) • Mesomorphy (muscularity & bone size) • Ectomorphy (thinness) • Replete with measurement errors, but still tends to be quite reliably associated with performance stereotypes • Bone girth relative to arm, leg girth, with fatness taken out • Skinfolds relative to height • Weight relative to height

7. Anthropometry • Human variation • Emerges from a variety of causes • Age and activity are covered in the next chapters • In the musculoskeletal system • Nothing very interesting here (and open to misinterpretation) • In physical dimensions • As before, these are open to misinterpretation and stereotyping (androgyny, ethnic differences [not racial]) • Features that are more determined by genetics might (??) be more reasonably analyzed (e.g. jaw line in males generally larger) • “typical” make up of males and females is an example of this – see Caster Semenya controversy

8. Chapter 4 Musculoskeletal changes across the life span

9. Objective from syllabus • To summarize how concepts related to the musculoskeletal system and anthropometry are affected by growth and maturation

10. Auxology and gerontology defined • Auxology – the science of growth • Is physical age proceeding apace with chronological age? • Gerontology – the science of aging • What does aging do to your body & mind? • Tools for measurement • Similar to anthropometry (after all, it’s still measurement)

11. Changes across the lifespan • Physical growth, maturation, and aging • Embryological development • Ovum + spermatozoan  zygote (fertilized cell) • Zygote repeatedly divides and multiplies • Mesodermic development follows • Growth of organs, tissues, musculoskeletal system • Marked by hyperplastic growth (increase in # cells) • The postnatal years • Keep on growing, keep on maturing (a term implying genetically determined growth) • Exercise and aging – see ch. 12 • As opposed to hypertrophic – growth in size of cells • Ability of exercise to offset effects of aging is quite strong

12. Changes across the lifespan • Age-related changes in the skeletal and articular systems • Two main phases • Foetal (hyperplasia) • Pubertal (hypertrophy) • Stages in development of bone • Bone grows initially from cartilage • Cells calcify and then remodeling proceeds via formation and erosion of cells to give the final shape • Growth of length and width of bone • Epiphyseal (growth) plate in which cartilage calcifies causes bone to lengthen • Continues until cartilage ceases to calcify • Change in thickness/diameter not limited by age (see ch. 5) • “Endochondral ossification” • Process:  in # of cartilage cells, then  in size, then surrounds are calcified...then ossified/remodeled (osteoblasts /osteoclasts) • “Appositional growth”

13. Changes across the lifespan • Age-related changes in the skeletal and articular systems • Skeletal composition changes across the life span • Childhood: more collagen, thus more flexible bone • (Young) Adulthood: more salt, thus more strength • Old Adulthood: yet more salt, so more brittle, but also total mass of bone decreases • Increased porosity, decreased density, increased hardness, more brittle...not good news... • 2/3 of bone is cartilaginous • 2/3 is mineral (calcified) • Only 10% of bone is cartilaginous • Old bone only 40% - 55% of the density of young bone at its peak

14. Changes across the lifespan • Age-related changes in the skeletal and articular systems • Osteoporosis • In post-menopausal women, linked to estrogen depletion, so that bone absorption increases relative to it’s growth • To offset this, as bone mass peaks at 16 to 20, health experts recommend maximizing bone mass by that time • Osteoporosis in males is accelerating (lifestyle changes) • Bone failure in relation to bone development, age or activity • Type of fractures change with age and type of bone • Forearm fractures in childhood • Hip and wrist fractures in elderly women • Effect of various factors on range of motion • Decrease with age (how many can still suck their [own] toes)? • Decrease with arthritis • Lack of force absorption • Growth plates • Rheumatoid arthritis: inflammation of synovial membrane. Osteoarthritis: wasting of articular cartilage

15. Changes across the lifespan • Age-related changes in the muscular system • Umm...the more interesting stuff is in chapter 5 (hopefully) • Change in body dimensions across the life span • The “growth spurt” (peak height velocity) see. P. 49 • In females early maturers ended up being no different to late maturers in height • In males, late maturers started off being shorter and ended up being significantly taller • Bigger people – more muscle fibers • Loss of muscle thru disuse far greater than thru aging

16. Changes across the lifespan • Age-related changes in the muscular system • Combining size measurements to provide information about shape

17. Changes across the lifespan • Age-related changes in the muscular system • Secular trend in body dimensions

18. Changes across the lifespan • Age-related changes in the muscular system • Growth rates of body segments • As expected following fig. 4.5, body parts grow at different rates • Limbs grow faster than trunk; legs grow faster than arms • Growth rates of body tissues • Brain size close to adult early on • Reproductive tissue grows rapidly through puberty

19. Changes across the lifespan • Age-related changes in the muscular system • Sexual dimorphism in growth • Female growth spurt two years earlier than males’ • Females often taller than males between 10-13 years • Fatness progresses differently for males and females

20. Changes across the lifespan • Age-related changes in the muscular system • Somatotype changes during growth, maturation, and aging • 2 pubertal stages in males • First an increase in ectomorphy at around 11-15 yrs • Then an increase in mesomorphy between 15-24 yrs • Methods of determining age • Dentistry, bone growth, menarche and sexual maturity are the methods, but there’s nothing of particular interest here. Correct me if I’m wrong

21. Chapter 5 Musculoskeletal adaptations to training

22. Objective from syllabus • To summarize how concepts related to the musculoskeletal system and anthropometry adapt to physical activity

23. Musculoskeletal adaptations to training • Effects of physical activity on bone • Generally, the more activity a bone sustains, the more it will adapt to be suited to that activity (gets thicker with prolonged use) • Effects of activity level on bone • Elite youth athletes and stress fractures – too much too soon • Loss of bone mass in space • Loss of bone mass at rest (bone needs activity to stay healthily dense) • Exercise generally increases bone mass (weight bearing – swimmers vs. others) • Structural reorganization as well as gain in mass (to resist force most economically) • osteopenia • Lack of P.A.  loss of bone (+muscle) mass • Tennis players’ humerus

24. Musculoskeletal adaptations to training • Effects of physical activity on bone • Effects of activity type on bone • Weight bearing activities best to add bone • Swimmers vs. wtlifters • Takes about 3-4 remodelling cycles to reach new steady state for bone tissue quality • Bone decreases in quality quicker than it increases, so activity should be sustained for maximum effect • Bone repair and physical activity • See fig. 5.1 – the implication is that bone (& other tissue) needs time to repair from any inactivity • Weightlifters have higher bone density than swimmers • 1 remodeling cycle – 3 months

25. Musculoskeletal adaptations to training • Effects of physical activity on joint structure and ranges of motion • Synovial fluid, articular cartilage, and ligaments • Cartilage • Short bout of cyclical exercise results in thickening of cartilage • Thickens as a result of absorbing synovial fluid • Chronic exercise leads to long-term thickening • (except where compressive forces are excessive – e.g. downhill running) •  Better force dissipation

26. Musculoskeletal adaptations to training • Effects of physical activity on joint structure and ranges of motion • Synovial fluid, articular cartilage, and ligaments • Synovial fluid • Short run can increase synovial fluid from about .2-.5ml in the knee to three times as much • Becomes less viscous (hence more easily soaked up by cartilage) • Cartilage soaks it up, so it is probably still the cartilage doing the protection • Ligament • Exercise strengthens and stiffens ligaments (increase in both collagen synthesis & cross linking) • Note v. small volumes • Endurance activity better than sprint?

27. Musculoskeletal adaptations to training • Effects of physical activity on joint structure and ranges of motion • Degenerative joint disease and exercise • Linked with obesity (physical activity?), ageing • Does jogging lead to osteoarthritis (degenerative joint disease)? • Clinicians apparently say so, but the evidence is weak • Epidemiological studies imply the relationship exists only for those with previous ligament damage – so that the joint moves abnormally over a protracted period of time

28. Musculoskeletal adaptations to training • Effects of physical activity on muscle-tendon units • Muscle size decreases with disuse • Flexibility • A function of the muscle-tendon unit, not the joint capsule or ligament • Joint laxity is a bad thing (stretched ligaments) • Highly joint and activity specific • Seems to be primarily increased through stretchiness of connective tissue (some sarcomere adaptation) • Not limited by increased muscularity (being muscle-bound is not inevitable) • People naturally differ in flexibility • Think of male gymnasts

29. Musculoskeletal adaptations to training • Effects of physical activity on muscle-tendon units • Strength training • First 6-8 weeks: neurotrophic stage – improved coordination leads to rapid increases in strength • Then...hypertrophic stage – muscle fibers increase in cross-sectional area • Tendon adaptation • Slower to adapt than muscle • Adapts via collagen synthesis • Injuries most common at muscle-tendon junction

30. Musculoskeletal adaptations to training • Effects of physical activity on body size, shape, and composition • Body composition will alter as a result of exercise, but ectomorphy might not (and weight might increase) • Role of lifestyle factors in determining physique • Many differences between athletes’ physique and those of the “normal” population are simply adaptations to training • Relationship of body sizes and types to sports • Well, we can see it can’t we? • Long distance runners are lighter, sprinters more muscular, gymnasts shorter, and so on... • Why? • Think changes in lean body mass

31. Results of Lab Definitely need to take these with a pinch of salt. We could all do with training/retraining on skinfold techniques, and even then there were some definite issues with the equations Mesomorphy Compare to p.61 Ectomorphy Endomorphy