You contain around 206 bones (originally you had more, but many of them joined together during growth). Your skeleton works hard for you: it provides support and shape, protects your internal organs and lets you move. It also grows blood cells, stores calcium and iron, and helps regulate levels of blood sugar and stored fat.
Bone comes in different structural types[1]. Compact bone is dense and strong. It looks smooth and solid, although close examination reveals a structure of cylindrical shapes, interconnected to allow passageways for blood, nutrients and nerves.
Cancellous, or spongy bone, also known as “trabecular” bone[2], is less dense, a honeycomb-like network of bridges (trabeculae) interspersed with spaces, blood vessels and marrow. This type of bone is relatively malleable and can be gradually realigned under stress.
There are four basic bone shapes – long bones, as in your arm or leg, short ones, (sometimes cube-shaped) like those in ankle and wrist, irregular ones such as vertebrae, and flat ones like your shoulder-blade. These descriptions are approximate — some long bones are very short (your toes, for example), and many “flat” bones form convex or concave curves[1]. Their surfaces display lumps, spines, ridges and knobs; these are attachment points for ligaments and muscles, or the interacting surfaces of joints. There are also hollows, channels and openings for nerves and blood vessels. Flat and irregular bones consist of cancellous tissue sandwiched between outer layers of compact bone – short bones are mostly trabecular material.
Long bones are hollow shafts full of bone marrow, with a head at either end. The shaft is compact, the heads mainly cancellous. Between the shaft and the heads is a softer area of cartilage, the epiphyseal plate, where new bone cells are produced and grow. After puberty, with bone growth complete, epiphyseal plates harden off, as their cartilage cells are replaced by bone.
“Know that there is so much more to you than your body. It’s not just about perfecting the steps; you must trust your instincts to tell deep, emotional stories through the steps that you are performing.”
— Karen Kain
Dancers often start their training while quite young, at a crucial phase for bone health. As you age, your skeleton changes. Before puberty, the build-up of mineral content in your bones is slower than your rate of growth[4]. This imbalance lasts between three and four years, heightening the risk of stress fracture — only about two years after puberty does bone mineral content increase significantly.
The skeletons of young children are soft, and the fusion process by which separate bones join together (e.g. the bones of the pelvis) is still ongoing. It’s dangerous to place heavy demands on young students, as their undeveloped skeletons may be seriously damaged. Because of the malleability and relative flexibility of young bones, they may suffer “greenstick” or partial fractures[3], or damage to joints, which might result in permanent instability. During growth spurts, student dancers are especially vulnerable to injury at growth sites on the epiphyseal plates – there is also the problem that bones grow faster than muscles, with the risk of soft tissue damage. (All these factors must be kept in mind by teachers who work with young children or adolescents).
“Ballet is quite unnatural on the joints. My body is just worn. My joints are 10 years older than me“.
— Darcey Bussell
As a dancer, you work hard. Dance is physical labour, and you need the right food in the right quantities to sustain your energy levels. Only a properly balanced diet will give you the energy you need for dance, growth, health, tissue repair, immunity, fertility and the physiological processes of normal life.
“Dancers have more bones than most people, and on the days when you work hard you are sure that you have somehow accumulated more bones than you started with.”
— Martha Graham
In the hope of staying slim, many young dancers under-nourish themselves, and don’t get enough calcium and Vitamin D. This problem, widespread among both dancers and students, restricts bone mineral density, and increases the risk of fractures[5]. Some studies have reported as many as 33- 50% of professional ballet dancers who admit to eating disorders[6]. Given the fundamental importance of bone health to dancers, that figure is pretty shocking. Many dancers also get their nutrition advice from unqualified sources: instead of going to a dietician or a doctor, they prefer a pick-and-mix buffet of diet advice from the internet or popular magazines with no proper scientific grounding [7,8]. If people regularly eat too little, they risk lifelong skeletal problems directly associated with improper, inadequate and poor-quality diet [9,10,11,12].
“Ballet is completely unnatural to the body, just being turned-out… it’s not the way your body is supposed to function, so you actually train your body to be a different structure than you were born with“.
— Neve Campbell
Female dancers are also vulnerable to the Female Athlete Triad [13]. This is a vicious spiral in which inadequate nourishment throws menstrual patterns out of balance, with reduced bone mineral density, bone loss and osteoporosis (increasingly porous, fragile bones)[14]. Amenorrhea (absence of periods) can affect levels of oestrogen and other hormones, causing a drop in levels of blood calcium, and hindering the activity of the parathyroid hormone [15]. Hormone replacement therapy, which is frequently prescribed for this condition, is not always effective [16,17].
“Respect your body. Eat well. Dance for ever“.
— Eliza Gaynor Minden
Poor nutrition in dancers is associated with decreased bone mass and levels of leptin (the hormone that stops you feeling hungry). Supplemental oestrogen therapy cannot always restore normal bone density [10]. The low bone mass associated with amenorrhea increases dancers’ risk both of current fractures and of osteoporosis later on, at the onset of the menopause [11]. This risk begins early in a dancer’s life; there are clear links between late menarche (the age at which periods begin) and increased incidence of scoliosis (spinal curvature) and fracture among young dancers[18].
Without enough body fat, a young girl will not reach her menarche, and she will miss a vital and limited opportunity for skeletal development [19]. The time of puberty is precisely the age at which her body sets up the bone-growth and renewal patterns she needs for the rest of her life. This bone-growth phase lasts only a few years; from young adulthood onwards, she will lose bone faster than her body can replace it.
“Dance in the body you have“.
— Agnes de Mille
To mess around with your diet out of a mistaken desire to be thin can sabotage this process, with long-lasting and destructive consequences. It is dangerous (and counterproductive) for dancers to try and get or keep what they perceive as the ideal figure by restricting their calorie intake. They risk damaging their health for the rest of their lives. They also increase the likelihood of chronic injury and inability to dance, the precise opposite of what every dancer wants.
“The dance goes on for ever. So shall I. So shall we“.
— Gelsey Kirkland
You’re extremely lucky to be able to dance. Think about how many people would love to do this, and can’t… You owe it to the wonderful, versatile instrument that is your body, to make informed choices about its nourishment, care and maintenance, so that it can give you everything you want, need and deserve in your dancing life.
©Jeremy Leslie-Spinks
References
1. Jarmey C. (2006). The Concise Book of the Moving Body. Chichester: Lotus Publishing, & Berkeley, CA: North Atlantic Books.
2. Calais-Germain B. (1993, 2007). Anatomy of Movement (revised ed.). Seattle, WA: Eastland Press, Inc.
3. Howse J. (1988, 1992, 2000). Dance Technique & Injury Prevention (3rd ed.) London: A & C Black.
4. Burkhardt P. et al (2011). The Effects of Nutrition, puberty and Dancing on Bone Density in Adolescent Ballet Dancers. Journal of Dance Medicine & Science 15(2): pp.51-60.
5. Myburgh K.H. et al (1990). Low Bone Density Is an Etiologic Factor for Stress Fracture in Athletes. Annals of Internal Medicine 113(10): pp.754-759. ©American College of Physicians.
6. Sandri S.C. (1993). On Dancers and Diet. International Journal of Sports Nutrition 3: pp.334-342.
7. Koutedakis Y., Pacy P.J., Carson R.J., & Dick F. (1997). Health and Fitness in Professional Dancers. Medical Problems of Performing Artists (March 1997): pp.23-27.
8. Yannakoulia M. & Matalas A.-L. (2000). Nutrition Intervention for Dancers. Journal of Dance Medicine & Science 4(3): pp.103-108.
9. Frusztajer N.T., Dhuper S., Warren M.P., Brooks-Gunn J. & Fox R.P. (1990). Nutrition and the incidence of stress fractures in ballet-dancers 1-3. The American Journal of Clinical Nurtition 51: pp.779-783.
10. Kaufmann B.A., Warren M.P., Dominguez J.E., Wang J., Heymsfield S.B. & Pierson R.N. (2002). Bone Density and Amenorrhea in Ballet Dancers Are Related to a Decreased Resting Metabolic Rate and Lower Leptin Levels. The Journal of Cliical Endocrinology & Metabolism 87(6): pp.2777-2783.
11. Warren M.P., Brooks-Gunn J., Fox R.P., Holderness C.C., Hyle E.P., Hamilton W.G. & Hamilton L. (2002). Osteoporosis in Exercise-Associated Amenorrhea Using Ballet Dancers as a Model: A Longitudinal Study. The Journal of Clinical Endocrinology & Metabolism 87(7): pp.3162-3168.
12. Russell J.A. (2013). Preventing dance injuries: current perspectives. Journal of Sports Medicine 4: pp.199-210.
13. Yeager K.K., Agostine R., Nattiv A. & Drinkwater B. (1993). The female athlete triad: disordered eating, amenorrhea, osteoporosis. Medicine & Science in Sports & Exercise 25: pp.775-777.
14. Torstveit M.K. & Sundgot-Borgen J. (2005). The Female Athlete Triad Exists in Both Elite Athletes and Controls. Medicine & Science in Sports & Exercise. DOI: 10.1249/01.mss.0000177678.73041.38, pp.1449-1459.
15. Chmelar R.D. & Fitt S.S. (2013). Diet for Dancers; A Complete Guide to Nutrition and Weight Control. Hightstown, NJ: Princeton Book Company Publishers.
16. Robinson E., Bachrach L.K. & Katzmann D.K. (2000). Use of Hormone Replacement Therapy to Reduce the Risk of Osteopenia in Adolescent Girls with Anorexia Nervosa. Journal of Adolescent Health 26(5): pp.343-348.
17. Zanker C.L. & Cooke C.B. (2004). Energy Balance, Bone Turnover and Skeletal Health in Physically Active Individuals. Medicine & Science in Sport & Exercise (2004): pp.1372-1381.
18. Khan K.M., Warren M.P., Stiehl A., McKay H.A. & Wark J.D. (1999). Bone Mineral Density in Active and Retired Ballet Dancers. Journal of Dance Medicine & Science 3(1): pp.15-23.
19. Kaplowitz P.B. (2008). Link Between Body Fat and the Timing of Puberty. Pediatrics 121(Suppl.3): pp.S206-S217.
Copyright secured by Digiprove © 2019 Jeremy Leslie-Spinks