Innovative approaches to flexibility as a physical quality

The article deals with the questions: what is flexibility of a human being: a capability or a quality? Is it appropriate to consider flexibility in terms of passive and active form of manifestation? Which is the most reliable indicator in determining the potential for flexibility development? The authors prove that human flexibility is a philosophical category and a special physical quality which depends on both inner and outer properties. The article also considers the question of predicting reliability of flexibility development. Based on an experiment data the conclusion about the priority of the initial indicator for predicting the flexibility development is presented.