Influence of passive leg movements on blood circulation on the tilt table in healthy adults

Journal of NeuroEngineering and Rehabilitation, Oct 2004

Background One problem in the mobilization of patients with neurological diseases, such as spinal cord injury, is the circulatory collapse that occurs while changing from supine to vertical position because of the missing venous pump due to paralyzed leg muscles. Therefore, a tilt table with integrated stepping device (tilt stepper) was developed, which allows passive stepping movements for performing locomotion training in an early state of rehabilitation. The aim of this pilot study was to investigate if passive stepping and cycling movements of the legs during tilt table training could stabilize blood circulation and prevent neurally-mediated syncope in healthy young adults. Methods In the first experiment, healthy subjects were tested on a traditional tilt table. Subjects who had a syncope or near-syncope in this condition underwent a second trial on the tilt stepper. In the second experiment, a group of healthy subjects was investigated on a traditional tilt table, the second group on the tilt ergometer, a device that allows cycling movements during tilt table training. We used the chi-square test to compare the occurrence of near-syncope/syncope in both groups (tilt table/tilt stepper and tilt table/tilt ergometer) and ANOVA to compare the blood pressure and heart rate between the groups at the four time intervals (supine, at 2 minutes, at 6 minutes and end of head-up tilt). Results Separate chi-square tests performed for each experiment showed significant differences in the occurrence of near syncope or syncope based on the device used. Comparison of the two groups (tilt stepper/ tilt table) in experiment one (ANOVA) showed that blood pressure was significantly higher at the end of head-up tilt on the tilt stepper and on the tilt table there was a greater increase in heart rate (2 minutes after head-up tilt). Comparison of the two groups (tilt ergometer/tilt table) in experiment 2 (ANOVA) showed that blood pressure was significantly higher on the tilt ergometer at the end of head-up tilt and on the tilt table the increase in heart rate was significantly larger (at 6 min and end of head-up tilt). Conclusions Stabilization of blood circulation and prevention of benign syncope can be achieved by passive leg movement during a tilt table test in healthy adults.

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Influence of passive leg movements on blood circulation on the tilt table in healthy adults

Journal of NeuroEngineering and Rehabilitation Influence of passive leg movements on blood circulation on the tilt table in healthy adults David Czell 2 Reinhard Schreier 2 Rüdiger Rupp 1 Stephen Eberhard 2 Gery Colombo 0 2 Volker Dietz 2 0 Hocoma AG, Medical engineering , Volketswil , Switzerland 1 Orthopaedic Hospital of Heidelberg University, Department II , Heidelberg , Germany 2 Spinal Cord Injury Center, Balgrist University Hospital , Zurich , Switzerland Background: One problem in the mobilization of patients with neurological diseases, such as spinal cord injury, is the circulatory collapse that occurs while changing from supine to vertical position because of the missing venous pump due to paralyzed leg muscles. Therefore, a tilt table with integrated stepping device (tilt stepper) was developed, which allows passive stepping movements for performing locomotion training in an early state of rehabilitation. The aim of this pilot study was to investigate if passive stepping and cycling movements of the legs during tilt table training could stabilize blood circulation and prevent neurallymediated syncope in healthy young adults. Methods: In the first experiment, healthy subjects were tested on a traditional tilt table. Subjects who had a syncope or near-syncope in this condition underwent a second trial on the tilt stepper. In the second experiment, a group of healthy subjects was investigated on a traditional tilt table, the second group on the tilt ergometer, a device that allows cycling movements during tilt table training. We used the chi-square test to compare the occurrence of near-syncope/syncope in both groups (tilt table/tilt stepper and tilt table/tilt ergometer) and ANOVA to compare the blood pressure and heart rate between the groups at the four time intervals (supine, at 2 minutes, at 6 minutes and end of head-up tilt). Results: Separate chi-square tests performed for each experiment showed significant differences in the occurrence of near syncope or syncope based on the device used. Comparison of the two groups (tilt stepper/ tilt table) in experiment one (ANOVA) showed that blood pressure was significantly higher at the end of head-up tilt on the tilt stepper and on the tilt table there was a greater increase in heart rate (2 minutes after head-up tilt). Comparison of the two groups (tilt ergometer/tilt table) in experiment 2 (ANOVA) showed that blood pressure was significantly higher on the tilt ergometer at the end of headup tilt and on the tilt table the increase in heart rate was significantly larger (at 6 min and end of head-up tilt). Conclusions: Stabilization of blood circulation and prevention of benign syncope can be achieved by passive leg movement during a tilt table test in healthy adults. Background Several studies have confirmed that lack of movement leads quickly to profound negative physiological and biochemical changes in all organs and systems of the body [ 15 ]. It is important for patients suffering from diseases such as stroke, spinal cord and traumatic brain injury to be mobilized at an early state of rehabilitation [ 6 ]. As these patients are bedridden, their lower limbs are mainly mobilized through manual therapy or with cycling ergometers. Patients with spinal cord injuries are disposed to the occurrence of circulatory collapse when changing from a horizontal to a vertical position because of the lack of sympathetic activity and the missing contractions of leg muscles in the lower extremities that normally act as muscle pumps [ 7,8 ]. This instability of the circulatory system occurs at an early stage of rehabilitation and leads to delayed functional training of these patients. In a chronic phase, an overactivity of the spinal sympathetic system could take place, which can lead to vasoconstriction and hypertension [9]. Head-up tilt table testing has been used for over 50 years by physiologists and physicians for many purposes. This includes the study of the human body's heart rate and blood pressure adaptations to changes in position, for modeling responses to hemorrhage, as a technique for evaluating of orthostatic hypotension, as a method to study hemodynamic and neuroendocrine responses in congestive heart failure, autonomic dysfunction and hypertension, as well as a tool for drug research [ 7,10-14 ]. It also has become a useful device in the mobilization of spinal cord and traumatic brain injured patients, as well as in patients suffering from stroke [15]. The key feature of a tilt table is the continuously adjustable position of a patient from horizontal to vertical. This represents an orthostatic challenge, because blood pools in the lower extremities, with the danger that in susceptible individuals vasovagal syncope could occur within approximately 20 minutes. The afferent end of this reflex pathway may be mediated by left ventricular or right atrium mechanoreceptors that are activated during vigorous contraction around under-filled c (...truncated)


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David Czell, Reinhard Schreier, Rüdiger Rupp, Stephen Eberhard, Gery Colombo, Volker Dietz. Influence of passive leg movements on blood circulation on the tilt table in healthy adults, Journal of NeuroEngineering and Rehabilitation, 2004, pp. 4, 1, DOI: 10.1186/1743-0003-1-4