The maintenance of quiet standing in humans has been the subject of numerous publications over many years. Posturographic measurement quantifying postural sway during upright stance by measurements of center of pressure (CoP) excursions (representing an indirect measure of postural control) have become widely used for clinical purposes. To evaluate an atypical postural development requires knowing the test¿retest reliability of posturographic measurements. Only if test-retest reliability is established, can normative data be determined and used. Furthermore, reliability of static and dynamic posturography is essential for the identification of intervention effects in any setting (sport, motor development, gait and balance disorders rehabilitation, and specifically postural stability decline in ageing). Despite the common practice of assessing postural control and postural stability in people with impairment and in older adults, this book has examined the reliability of complex screening tests in young healthy subjects.