The journey of growth and development from infancy to adolescence is a remarkable one, with vast and rapid changes taking place. This article will focus specifically on the skeletal system (bones and skeletal muscles), and the associated motor skills that are brought about during this transitionary and transformative phase of life. The LTPD provides the framework for attaining the performance goals of the South African Sport Confederation and Olympic Committee (SASCOC) while serving the larger goal to make South Africa “an Active and Winning Nation.” LTPD is a structured pathway model that provides guidance and principles to optimise the development of participants at all ages and stages. 

The SA Sport for Life Long-Term Player Development (LTPD) framework places utmost importance on nurturing the all-encompassing growth of participants. While there has been considerable emphasis on honing skills, enhancing physical literacy, and mastering the technical and tactical aspects of individual sports, the unified LTPD model offers a more holistic view of the multifaceted abilities that demand cultivation at each developmental stage. For both boys and girls the first eighteen years of life are crucial for the development of motor skills, however in girls their development stabilises around puberty (DErcole et al, 2013; Roemmich & Sinning, 1997). Therefore, we will also touch on how physical activity contributes to and positively impacts this growth and development.

Skeletal Growth
Skeletal growth is not a linear process. It is rapid in infancy and early childhood, then steadies during middle childhood, is rapid again during the adolescent spurt, and then is slow as adult stature is attained (fNeoklis et al, 2004; Tanner, 1962). The adolescent growth spurt takes place at about ten years of age in girls and twelve years of age in boys (Idranil, 2014). With this spurt, growth rate increases, reaching a peak at about twelve years in girls and fourteen years in boys, and then gradually declines and eventually ceases with the attainment of adult stature (Tanner, 1962; Malina et al, 2004). The principal sites of growth before the start of this rapid adolescent growth are in the legs and arms (appendicular skeleton) (Tanner, 1962; Malina et al, 2004).

During the adolescent growth spurt, the trunk (axial skeleton) grows most rapidly. During these growth phases, the long bones increase their length by the activity of specialized cells located in the growth plates at either end of the shaft of the long bones, a process termed ossification (Idranil, 2014). As growth nears completion in later adolescence, the growth plate ceases its function and fuses firmly with the shaft of the long bone (Tanner, 1962; Malina et al, 2004). This completion of normal skeletal growth requires adequate production of various hormones and growth factors. Pre-puberty, bone growth depends largely on growth hormone, but sex hormones are essential for the maturation of the bone during and post puberty (Kawai & Rosen, 2012; Holroyd et al, 2012; Bachrach, 2005). Puberty has a fundamental role in the acquisition of bone mass (Turner et al, 1992). This acquisition mirrors that of growth where the gain of mass in the appendicular skeleton is predominant before puberty, after which, there is an increase of mass in the axial skeleton (Stagi et al, 2013). Peak bone mass is achieved in various skeletal sites at different times, however the majority of the skeleton has achieved peak bone mass around 16-18 years of age (Stagi et al, 2013; Ott, 1990).

Motor Skills
Under the influence of hormonal activity, strength and power rapidity increase in proportion to muscle mass. The daily use of age appropriate motor activities, such as incorporation of games and physical activities will allow children to develop gross motor skills such as crawling, walking and eventually running (DErcole et al, 2013; Roemmich & Sinning, 1997; Pahkala et al, 2017). Fine motor skills such as movement of the smaller muscle groups in the hands, fingers, and wrists will continue to develop throughout the developmental stages (Higuera, 2023). During middle childhood, children continue to build on and improve the gross motor skills that they learned during earlier developmental stages. In general, boys develop these skills slightly faster than girls, except for skills involving balance and precise movements such as skipping, jumping and hopping (Idranil, 2014). During middle childhood, children also refine their control over gross motor skills, learning to master where they hop, skip, throw, and jump, due to increases in their flexibility, balance, and agility (DErcole et al, 2013; Roemmich & Sinning, 1997; Pahkala et al, 2017). Children at this age also subsequently learn how to synchronize the movement of their various body parts, which allows for the development of more coordinated whole-body movements that are needed for participation in organized sports.