Postural stability by foot-to-ground force measurement

Abstract

The present study was made in an attempt to provide methods which by use of foot-to-ground forces were able to measure gait and postural stability parameters in a form apt for clinical use. The present study is based on 7 publications on the methods and results of gait analysis and 6 previously published studies on postural stability and one study using both methods. The present study is a more extensive description of the methods applied. The gait analysis is performed on an instrumented treadmill measuring continuous ground reaction forces for each foot separately. The advantage of the system is an extensive description of gait. The temporal factors, gait unsafety or ataxia is determined, and by the use of the Laws of Newton, the external positive and negative work is calculated for each foot. A material on normal gait has been published. Studies of gait describe improvement after a neurosurgical intervention as well as the influence of intake of alcohol on gait. The postural stability is measured by calculation of the average variations in the centre of the feet's pressure on a force plate. The advantage compared to previous studies is that one figure is considered a sufficient expression of the postural stability. A material of normal persons have been established and sequent studies have shown informative concerning the influence of various drugs and surgical interventions on the postural stability. The developed methods provide objective data permitting further basic studies. Applied studies should be done within the specialties of orthopedics, anaesthesia, neurosurgery, neurology and as part of search for effects and side-effects in pharmacology.