Design and Development of Limits of Stability and Postural Stability Protocols for a Computerized Dynamic Posturography


1 Science and Research Branch,Islamic Azad University, Tehran

2 Amirkabir university of technology Tehran, Iran


Upright balance control is an important human skill which can be impaired by aging and different disorders. Therefore, clinical and laboratory measures of balance assessment were established. The latest technology in the laboratory methods is a stabilometer with a computer or computerized dynamic posturography which assesses static and dynamic balance using body sways. A computerized dynamic posturography system consists of a computer and a stabilometer which is an unstable platform under patient's feet and calculates center of pressure on the platform to display it immediately on the screen. To evaluate weight shift ability, the patient should move his center of pressure in a determined path. Also, he should stay upright on the unstable platform or decreases its sways to show his ability to recover balance. For these purposes in the present study, two protocols "Limits of stability" (LOS) and "Postural stability" (PS) were designed and developed for a pre-made stabilometer with a maximum of 20 degrees deviation from horizontal in all direction to achieve the mentioned purposes. In the limits of stability protocol eight blinking targets are shown on the ideal limits of stability for the person randomly which he must reach by moving his body. In this case, the person's center of pressure is shown as a point on the screen that the person should transfer it to the targets. The other protocol is postural stability in which the person must minimize the platform swings. Hereby, another point is defined as the center of balance by which the deflections of the platform about two axes are converted into a point and represented on the display, so the person can see his function feedback. Finally, the protocols calculate and display the person's functional characteristics that can be saved to the computer of computerized dynamic posturography to demonstrate a diagram of the patient's functional progression. In addition to the balance assessment, the device improves balance and neuromuscular strength and is useful in medicine, laboratory researches, physiotherapy, sport and bodybuilding.