Affiliations: Musculoskeletal Research Centre, Isfahan University of
Medical Sciences, Isfahan, Iran | Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran
Note: [] Corresponding author: Mohammad Taghi Karimi, PhD,
Orthotics and Prosthetics Department, Rehabilitation Faculty, University of
Medical Sciences, Hezar Jerib Ave., Isfahan, Iran. Tel.: +98 3117922120; Fax:
+98 3116687270; E-mail: [email protected]
Abstract: BACKGROUND: Stability during standing is achieved by a complex
process which involves the performance of various systems. Using a force plate
for analysing the stability for a period of one minute has been reported
exclusively by many investigators. Most of people stand for a long period of
time when chatting with somebody, doing a job and when waiting in a queue.
However nobody has analysed the stability during quiet standing for a prolonged
standing (5 minutes). OBJECTIVE: The main aim of this research study was to analyse the
performance of the subjects regarding stability for a period of 5 minutes. METHOD: A group of 40 normal subjects from the staff and students of
Rehabilitation Faculty of Isfahan University of Medical Sciences were recruited
in this research project. They were asked to stand on the force plate (Kistler)
for a period of 5 minutes. They were instructed to look straight ahead and with
their head erect and their arms at their sides in a comfortable position. The
excursions of the COP sway in both planes were measured for all 20 seconds
periods of data collection. RESULTS: The results of this research study showed that stability
analysing based on the sway of the COP, while the test was collected for one
minute, is not recommended. There is a significant difference between the
excursions of the COP during the first to fifth minutes. The stability of the
subject was optimum in the third and fourth minutes of standing. CONCLUSION: Using the COP sway, based on the first minute of
standing, is neither a good representative of the more stable position nor the
unstable position. It is recommended to discuss the stability of subjects based
on their ability to return from an unstable position to a more stable
position.
