Growth, Development, and Maturation: Part 1 - An Introduction
These terms are thrown around quite a lot by coaches and teachers, including the classic "Children are not mini adults" statement. But what does this actually mean and how does this then impact on session planning and delivery? This article will look to break down the literature and provide useful suggestions on how to measure, programme, and apply the science into practice.
What is Growth, Development and Maturation?
Growth is simply the growth in body mass and stature from birth to adulthood. Growth is the result of increased cell size, number, and cell material, which is caused by certain biological processes (for example hypertrophy - building muscle)
Maturation can be broken down into two main categories, skeletal maturity and sexual maturity. Maturity is referred to as the rate of progress, rather than the quantitative increase in cells (growth). Skeletal maturity is defined as a fully ossified (developed) skeleton, this means the skeleton's development is complete and therefore has reached maximum size. Sexual maturity is defined as a fully functional reproductive system, therefore simply put the body is capable of producing children.
Development is a more generalised approach, which considers more qualitative measures, including biological and behavioural characteristics. The biological side considers the formation of specific functional tissues, whereas the behavioural aspect looks at affective (social), cognitive (brain), and psychomotor (movement) development.
There are three age based categories we can use to consider where a child is in certain areas of their development. Generally speaking these are chronological age, biological age, and training age.
Chronological age refers to how old someone is based on when they were born. This is regularly used to determine things like school year and squad age group. However this causes problems in many sport activities and competitions, the image below is a great example.
The image above shows three gymnasts of the same chronological age, but if we look back to the definitions of growth, maturation, and development earlier in this article, we should be able to see how these young gymnasts are all at different stages in their development.
Biological age is a more informative descriptor of a young persons "true age" in terms of growth, maturation, and development. Biological age can be broken down into three areas, skeletal age, sexual age, and somatic age.
Skeletal age is determined by the level of offisification (bone development). This is generally assessed by radiographs, however a huge limitation to this is the radiation dose associated with the scan. Sexual age refers to rapid increases in growth, development of secondary sexual characteristics, and maturation of the reproductive system (3). Finally, Somatic age simply looks at physical maturity, such as height and body mass. Maturity can be measured in this way through ratios, such as sitting height to leg length (2) and talent can be predicted using second to fourth digit ratio (1).
Training age is also important to consider, this is related to the time spent doing an activity, for example a young football player has a training age of 7 years. Although not necessarily a part of growth or maturation, it is important to consider when monitoring young peoples overall development.
Part 2 of this series will look at the practical implications of growth, development, and maturation. Specifically looking at how do we alter our delivery, methods, or programme. Click here for Part 2.
MANNING, J T (2002). The ratio of 2nd to 4th digit length and performance in skiing. Journal of sports medicine and physical fitness. 42 (4), 446-450.
SHERAR, Lauren B, MIRWALD, Robert L, BAXTER-JONES, Adam DG, and THOMIS, Martine (2005). Prediction of adult height using maturity-based cumulative height velocity curves. The Journal of pediatrics. 147 (4), 508-514.
TANNER, J M, GOLDSTEIN, H, and WHITEHOUSE R H (1970). Standards for children's height at ages 2-9 years allowing for heights of parents. Archives of disease in childhood, 45 (244), 755-762.
