A unique and versatile dynamic posturography platform
06 / 2005 - unknown
Falls commonly occur with ageing or disease, and their incidence will continue to rise due to graying of the population. Their impact is devastating, due to injuries, physical and psychosocial decline, reduced quality of life, and diminished survival. Falls also impose high costs to the public health service. Better strategies to prevent falls are urgently needed. Developing such strategies requires an improved understanding of the complex and typically multifactorial pathophysiology underlying falls. Current experimental systems have not been successful at recreating the wide range of situations that contribute to falls in everyday life. We ask support for an innovative balance perturbation system that accommodates the drawbacks of existing systems and allows for ecologically valid investigations of fall mechanisms. Specifically, the equipment is designed to study human postural reactions to sudden balance perturbations, delivered by a multifunctional moving platform (?dynamic posturography?). The system combines technical innovation (new perturbation profiles) with a series of previously validated features that are, for the first time, jointly integrated. Of particular importance are the ability: (a) to deliver ?real-life? balance perturbations, permitting study of everyday fall circumstances, such as mimicked slips or unpredictable falls in different directions; (b) to deliver highly destabilizing perturbations, permitting analysis of critical fall mechanisms around and past the limits of stability; and (c) to employ different perturbation types, providing complementary insights into the spectrum of balance responses. The new system will be implemented into a comprehensive ?falls simulation unit? that will have a unique position within the Netherlands and beyond, for various reasons. Through our extensive local, national and international collaboration, we plan to combine the new equipment with other neuroscience tools, such as our fully equipped gait laboratory, transcranial magnetic stimulation, microneurography and virtual reality. The proximity to large and well-defined patient populations from multiple disciplines permits studies of a wide range of balance disorders (e.g. neurodegenerative disorders such as Parkinson?s or Huntington?s disease; neuromuscular disorders; dementias; orthopedic patients with joint replacements). Our collaboration with various Dutch universities facilitates access to additional rare patients (e.g. hyperekplexia), and provides challenging opportunities to analyze our data with advanced procedures present elsewhere in the Netherlands. Taken together, this creates a versatile and multidisciplinary approach to the study of fall mechanisms and balance control in health and disease. Specific examples of proposed research include projects to: (a) comprehend the mechanisms that play a role during ?real-life? falls, with emphasis on the role of startle reactions; (b) understand the normal physiology of balance, in particular the role of cognitive influences and stiffness regulation; (c) systematically examine patients with focal lesions, in order to unravel their falling mechanisms, to identify predictors of falls, and to clarify how damaged areas normally regulate postural control; (d) determine how such patients compensate for chronic deficits using residual intact systems, as a basis for rehabilitation strategies; and (e) evaluate the effect of new treatments under ecologically valid circumstances. Our long-term perspective is to translate this basic knowledge into tailored intervention strategies aimed to reduce falls in affected patients and the growing ageing population.