date: 09/28/1997
author: Bondar RL, Dunphy PT, Moradshahi P, Kassam MS, Blaber AP, Stein F, Freeman R.
publication: Stroke. 1997 Sep;28(9):1677-85.
pubmed_ID: 9303009
BACKGROUND AND PURPOSE: Patients with autonomic nervous system failure often experience symptoms of orthostatic intolerance while standing. It is not known whether these episodes are caused primarily by a reduced ability to regulate arterial blood pressure or whether changes in cerebral autoregulation may also be implicated. METHODS: Eleven patients and eight healthy age- and sex-matched control subjects were studied during a graded-tilt protocol. Changes in their steady state middle cerebral artery mean flow velocities (MFV), measured by transcranial Doppler, brain-level mean arterial blood pressures (MABPbrain), and the relationship between the two were assessed. RESULTS: Significant differences between patients and control subjects (P < .05) were found in both their MFV and MABPbrain responses to tilt. Patients’ MFV dropped from 60 +/- 10.2 cm/s in the supine position to 44 +/- 14.0 cm/s at 60 degrees head-up tilt, whereas MABPbrain fell from 109 +/- 11.7 to 42 +/- 16.9 mm Hg. By comparison, controls’ MFV dropped from 54 +/- 7.8 cm/s supine to 51 +/- 8.8 cm/s at 60 degrees, whereas MABPbrain went from 90 +/- 11.2 to 67 +/- 8.2 mm Hg. Linear regression showed no significant difference in the MFV-MABPbrain relationship between patients and control subjects, with slopes of 0.228 +/- 0.09 cm.s-1.mm Hg-1 for patients and 0.136 +/- 0.16 cm.s-1.mm Hg-1 for control subjects. CONCLUSIONS: The present study found significant differences between patients and control subjects in their MFV and MABPbrain responses to tilt but no difference in the autoregulatory MFV-MABPbrain relationship. These results suggest that patients’ decreased orthostatic tolerance may primarily be the result of impaired blood pressure regulation rather than a deficiency in cerebral autoregulation.
Category: Research and Articles
Standing with the assistance of a tilt table improves minute ventilation in chronic critically ill patients.
date: 12/01/2004
author: Chang AT, Boots RJ, Hodges PW, Thomas PJ, Paratz JD.
publication: Arch Phys Med Rehabil. 2004 Dec;85(12):1972-6.
pubmed_ID: 15605335
OBJECTIVE: To investigate the effect of standing with assistance of the tilt table on ventilatory parameters and arterial blood gases in intensive care patients. DESIGN: Consecutive sample. SETTING: Tertiary referral hospital. PARTICIPANTS: Fifteen adult patients who had been intubated and mechanically ventilated for more than 5 days (3 subjects successfully weaned, 12 subjects being weaned). INTERVENTION: Passive tilting to 70 degrees from the horizontal for 5 minutes using a tilt table. MAIN OUTCOME MEASURES: Minute ventilation (VE), tidal volume (VT), respiratory rate, and arterial partial pressure of oxygen (PaO2) and carbon dioxide (PaCO2). RESULTS: Standing in the tilted position for 5 minutes produced significant increases in VE (P <.001) and produced both increases in respiratory rate (P <.001) and VT (P =.016) compared with baseline levels. These changes were maintained during the tilt intervention and immediately posttilt. Twenty minutes after the tilt, there were no significant changes in ventilatory measures of VE, VT, or arterial blood gases PaO2 and PaCO2 compared with initial values. CONCLUSIONS: Standing for 5 minutes with assistance of a tilt table significantly increased ventilation in critical care patients during and immediately after the intervention. There were no improvements in gas exchange posttilt. Using a tilt table provided an effective method to increase ventilation in the short term.
New assistive technology for passive standing.
date: 03/01/1999
author: Gear AJ, Suber F, Neal JG, Nguyen WD, Edlich RF.
publication: J Burn Care Rehabil. 1999 Mar-Apr;20(2):164-9.
pubmed_ID: 10188115
The anesthetic skin of patients with spinal cord injuries makes these patients a high-risk population for burn injuries. Innovations in rehabilitation engineering can now provide the disabled with mechanical devices that allow for passive standing. Passive standing has been shown to counteract many of the effects of chronic immobilization and spinal cord injury, including bone demineralization, urinary calculi, cardiovascular instability, and reduced joint range of motion and muscular tone. This article will describe several unique assistive devices that allow for passive standing and an improvement in daily living for people with disabilities.
Effect of dynamic weight bearing on neuromuscular activation after spinal cord injury.
date: 06/01/2007
author: Edwards LC, Layne CS.
publication: Am J Phys Med Rehabil. 2007 Jun;86(6):499-506.
pubmed_ID: 17515690
OBJECTIVE: To determine whether individuals who have a spinal cord injury have neuromuscular and physiologic responses to a personalized exercise program during dynamic weight bearing (DWB). DESIGN: Four subjects with spinal cord injuries (T6, T5-6, C2-5, and C5) completed a 12-wk exercise program that included DWB. Surface electromyography (EMG) was recorded from the right gastrocnemius, biceps femoris, rectus femoris, rectus abdominus, and external oblique. Heart rate (HR) and blood pressure (BP) were recorded throughout training. Descriptive statistics were used to analyze the data. RESULTS: The results of this study indicate that the subjects actively responded to exercise during DWB, as measured by EMG, HR, and BP. CONCLUSIONS: The results suggest that exercise during DWB can induce physiologic and neuromuscular responses in individuals who have a spinal cord injury, and that exercise during DWB may serve as a preparatory program for more advanced rehabilitation.
Orthostasis and transcapillary fluid shifts.
date: 01/01/1995
author: Hinghofer-Szalkay HG.
publication: J Gravit Physiol. 1995;2(1):P131-3.
pubmed_ID:Â 11538896
Postural blood volume changes aggravate the regulation of arterial blood pressure and perfusion vis-a-vis the hydrostatic effects of orthostasis, ie, blood pooling below the hydrostatic indifferent points and reduced cardiac preload. Corresponding problems surface with extended passive standing, particularly in highly trained, dehydrated, or otherwise compromised subjects, or after long-lasting immobilization, as with space flight.
Passive ankle dorsiflexion increases in patients after a regimen of tilt table-wedge board standing. A clinical report.
date: 11/01/1985
author: Bohannon RW, Larkin PA.
publication: Phys Ther. 1985 Nov;65(11):1676-8.
pubmed_ID: 4059330
We monitored the result of a tilt table-wedge board routine on the passive ankle dorsiflexion of 20 patients consecutively to determine the effectiveness of the treatment. The calculated frequency of the treatment, which was applied for 30 minutes on each of 5 to 22 treatment days, ranged from 2.3 to 6.4 treatments a week. All patients demonstrated increased passive ankle dorsiflexion. The increases ranged from 3 to 17 degrees and occurred at a calculated rate of 0.11 to 1.0 degrees a day. We believe the treatment is an effective clinical method for increasing passive ankle dorsiflexion in neurologically involved patients.
Randomised trial of the effects of four weeks of daily stretch on extensibility of hamstring muscles in people with spinal cord injuries.
date: 01/01/2003
author: Harvey LA, Byak AJ, Ostrovskaya M, Glinsky J, Katte L, Herbert RD.
publication: Aust J Physiother. 2003;49(3):176-81.
pubmed_ID: 12952517
The aim of this assessor-blind randomised controlled trial was to determine the effect of four weeks of 30 minute stretches each weekday on extensibility of the hamstring muscles in people with recent spinal cord injuries. A consecutive sample of 16 spinal cord-injured patients with no or minimal voluntary motor power in the lower limbs and insufficient hamstring muscle extensibility to enable optimal long sitting were recruited. Subjects’ legs were randomly allocated to experimental and control conditions. The hamstring muscles of the experimental leg of each subject were stretched with a 30 Nm torque at the hip for 30 minutes each weekday for four weeks. The hamstring muscles of the contralateral leg were not stretched during this period. Extensibility of the hamstring muscles (hip flexion range of motion with knee extended, measured with a 48 Nm torque at the hip) of both legs was measured by a blinded assessor at the commencement of the study and one day after the completion of the four-week stretch period. Changes in hamstring muscle extensibility from initial to final measurements were calculated. The effect of stretching was expressed as the mean difference in these changes between stretched and non-stretched legs. The mean effect of stretching was 1 degree (95% CI -2 to 5 degrees). Four weeks of 30 minute stretches each weekday does not affect the extensibility of the hamstring muscle in people with spinal cord injuries.
Bone-mineral density in children and adolescents who have spastic cerebral palsy.
date:
author: Henderson RC, Lin PP, Greene WB.
publication: J Bone Joint Surg Am. 1995 Nov;77(11):1671-81.
pubmed_ID: 7593076
Bone-mineral density was studied in a heterogeneous group of 139 children (mean age, nine years; range, three to fifteen years) who had spastic cerebral palsy. The evaluation included serum analyses and a nutritional assessment based on a dietary history and anthropometric measurements. The bone-mineral density of the proximal parts of the femora and the lumbar spine was measured with dual-energy x-ray absorptiometry and was normalized for age against a series of ninety-five normal children and adolescents who served as controls. Bone-mineral density varied greatly but averaged nearly one standard deviation below the age-matched normal means for both the proximal parts of the femora (-0.92 standard deviation) and the lumbar spine (-0.80 standard deviation). Ambulatory status was the factor that best correlated with bone-mineral density. Nutritional status, assessed on the basis of caloric intake, skinfolds, and body-mass index, was the second most significant variable. The pattern of involvement, durations of immobilization in a cast, and a calcium intake of less than 500 milligrams per day were additional factors of less significance. The age when the child first walked, previous fractures, use of anticonvulsants, and serum vitamin-D levels did not correlate with bone-mineral density after adjustment for covariance with the ambulatory status and the nutritional status. Serum levels of calcium, phosphate, alkaline phosphatase, and osteocalcin were not reliable indicators of low bone-mineral density.
Lower extremity functional neuromuscular stimulation in cases of spinal cord injury.
date: 07/15/1984
author: Cybulski GR, Penn RD, Jaeger RJ.
publication: Neurosurgery. 1984 Jul;15(1):132-46.
pubmed_ID: 6382044
Outside_URL: http://www.ncbi.nlm.nih.gov/pubmed/6382044
Functional neuromuscular stimulation (FNS) provides a mechanism for the activation of muscles paralyzed by injury to the spinal cord. Although this technique was first used to treat patients with spinal cord injury over 20 years ago, only recent advances in electronics and biomechanics have made it a promising aid for the rehabilitation of these patients. Thus far, restoration of palmar prehension and lateral prehension in quadriplegics and of standing and biped gait in paraplegics has been achieved under carefully controlled laboratory conditions. This article reviews the current status of FNS and its potential as a practical tool to aid spinal cord-injured patients. Neurosurgeons who care for these patients might be expected to be involved in the future use of FNS if implantable systems are developed and tested.
Estimating the user population of a simple electrical stimulation system for standing.
date: 10/01/1990
author: Jaeger RJ, Yarkony GM, Roth EJ, Lovell L.
publication: Paraplegia. 1990 Oct;28(8):505-11
pubmed_ID: 2263407
Outside_URL: http://www.ncbi.nlm.nih.gov/pubmed/2263407
Many laboratory demonstrations have been reported on standing or walking with the aid of electrical stimulation. These demonstrations have typically been in small numbers of selected spinal cord injured individuals. The extent to which this technology might ultimately be applicable to the spinal cord injured population at large is not presently known. This study reports estimates of the size of the potential user population of a specific surface electrical stimulation device and protocol. The medical records were reviewed of 192 patients with traumatic thoracic, lumbar, or sacral spinal cord injury resulting in paraplegia. Based on the inclusionary criteria, between 20 and 48 patients (10.4% and 25%) of this sample population could be considered eligible for this surface stimulation protocol. As approximately 45% of the USA population of spinal cord injured individuals have paraplegia, the results suggest that between 4.7% and 11.25% of all spinal cord injured persons in the USA might be potential users of this particular electrical stimulation technology.