Motor skills are indispensable components of human physical activity, providing the possibility of specific efforts and, harnessing the functional potential of the body. Motor skills naturally develop to a certain level, depending on many factors, and are perfectible through practice. We believe that medium pupils' motricity development is of paramount importance because it favourably influences the major functional indices and their volitional qualities. At the same time, it has an important role in proper and harmonious physical development, contributing to healthy growth. After puberty, which is characterized by significant and rapid somato-functional and psychomotor changes, there follows the stage of growth and development called the post-pubertal period, which is characterized by a slower rate of development and growth. The bone structure during this period is similar to that of the adult. Muscle mass also increases by 44.2% for girls. Body weight increases for both girls and boys. As children increase in age, they change as a result of growth and development processes which are subject to the laws of growth and the developmental stages. Growth refers to the quantitative aspect, whereas development is more qualitative. The two processes cannot be separated, because they are interconnected. Biological development consists of growth and physical maturity processes, changes of the internal biochemistry, and quantitative and qualitative alterations of the higher nervous activity.