date: 11/01/2001
author: Faghri PD, Yount JP, Pesce WJ, Seetharama S, Votto JJ.
publication: Arch Phys Med Rehabil. 2001 Nov;82(11):1587-95
pubmed_ID: 11689980
Outside_URL: http://www.ncbi.nlm.nih.gov/pubmed/11689980
OBJECTIVE: To evaluate the effects of functional electric stimulation (FES) of lower limb muscles during 30 minutes of upright standing on the central and peripheral hemodynamic response in persons with spinal cord injury (SCI). DESIGN: A repeated-measure design. Subjects were used as their own control and underwent 2 testing protocols of FES-augmented standing (active standing) and non-FES standing (passive standing). SETTING: Rehabilitation hospital. PARTICIPANTS: Fourteen individuals with SCI (7 with tetraplegia, 7 with paraplegia). INTERVENTIONS: During active standing, FES was administered to 4 muscle groups of each leg in an overlapping fashion to produce a pumping mechanism during standing. During passive standing, subjects stood for 30 minutes using a standing frame with no FES intervention. MAIN OUTCOME MEASURES: Central hemodynamic responses of stroke volume, cardiac output, heart rate, arterial blood pressure, total peripheral resistance (TPR), and rate pressure product (RPP) were evaluated by impedance cardiography. All measurements were performed during supine and sitting positions before and after standing, and during 30 minutes of upright standing. RESULTS: Comparisons between the groups with paraplegia and tetraplegia showed a significant increase in heart rate in the paraplegics after 30 minutes of active standing. During active standing, paraplegics’ heart rate increased by 18.2% (p = .015); during passive standing, it increased by 6% (p = .041). TPR in the tetraplegics significantly (p = .003) increased by 54% when compared with the paraplegics during passive standing. Overall, the tetraplegic group had a significantly lower systolic blood pressure (p = .013) and mean arterial pressure (p = .048) than the paraplegics during passive standing. These differences were not detected during active standing. When data were pooled from both groups and the overall groups response to active and passive standing were compared, the results showed that cardiac output, stroke volume, and blood pressure significantly decreased (p < .05) during 30 minutes of passive standing, whereas TPR significantly increased (p < .05). All of the hemodynamic variables were maintained during 30 minutes of active standing, and there were increases in RPP and heart rate after 30 minutes of active standing. CONCLUSION: FES of the lower extremity could be used by persons with SCI as an adjunct during standing to prevent orthostatic hypotension and circulatory hypokinesis. This effect may be more beneficial to those with tetraplegia who have a compromised autonomic nervous system and may not be able to adjust their hemodynamics to the change in position. Copyright 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation
Category: Research and Articles
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.
Functional neuromuscular stimulation for standing after spinal cord injury.
date: 03/01/1900
author: Yarkony GM, Jaeger RJ, Roth E, Kralj AR, Quintern J.
publication: Arch Phys Med Rehabil. 1990 Mar;71(3):201-6.
pubmed_ID: 2317138
Outside_URL: http://www.ncbi.nlm.nih.gov/pubmed/2317138
A study was undertaken to determine if functional neuromuscular stimulation could be used to obtain standing in patients with traumatic spinal cord injury. Twenty-five subjects were selected during the study, and standing was accomplished in 21 using bilateral quadriceps stimulation with the hips in hyperextension. Four subjects elected not to continue participation to the point of standing. Stimulation parameters were 0 to 120V pulse amplitude, frequency 13Hz or 20Hz, and pulse width of 0.4msec. Confirmation of standing with support of 95% of the body weight by the legs was verified by quantitative measurements with a dual-scale force platform or a biomechanics force platform. Subjects initially selected had injury levels between C7 and T11 and ranged in age from 22 to 47 years, with duration of injury from one to 13 years. The subjects had complete lesions, with no active motor function below the last normal level, and absent sensation or partial sparing of sensation with vague perception of pinprick, but no position sense. Six subjects stood at home and 15 stood only in the laboratory. This five-year experience indicates that paraplegic individuals may obtain standing with functional neuromuscular stimulation.
Cardiorespiratory fitness and muscular strength of wheelchair users.
date: 12/15/1981
author: Davis GM, Kofsky PR, Kelsey JC, Shephard RJ.
publication: Can Med Assoc J. 1981 Dec 15;125(12):1317-23.
pubmed_ID: 6459841
The classification of lower-limb disabilities is commonly based on the site of the spinal cord lesion or the amount of functional muscle. Another important variable in assessing wheelchair users is their ability to carry out the activities of daily living. The cardiorespiratory fitness of those with lower-limb disabilities is usually assessed with arm-ergometry and wheelchair tests, each of which has some advantages. Muscle strength and endurance are also important aspects of the disabled person’s ability to function. Fitness is often poor in the disabled, and normal wheelchair use does not seem to prove an adequate training stimulus. Exercise with an arm ergometer and with pulleys and participation in vigorous wheelchair sports can improve physical condition. Participation in exercise programs should be based on the results of a fitness assessment and on the level of the spinal cord lesion in those with paraplegia. Progression in such programs should be gradual to ensure that the exerciser does not become discouraged and drop out of classes before fitness is increased. Data on wheelchair athletes suggest that, with persistence, many individuals in wheelchairs can adjust relatively well to their disabilities.
Long-term followup of renal function after spinal cord injury.
date: 09/01/1985
author: Kuhlemeier KV, Lloyd LK, Stover SL.
publication: J Urol. 1985 Sep;134(3):510-3.
pubmed_ID: 4032551
Effective renal plasma flow was measured in acute spinal cord injury patients for up to 10 years after injury to determine the extent of renal deterioration in these patients and to identify the factors associated with a loss of renal function. The over-all mean decrease in effective renal plasma flow for all patients as a whole was 4.5 ml. per year. Factors associated with a statistically significant reduction in effective renal plasma flow included age, gender, renal calculi, quadriplegia, and a history of chills and fever. Other factors examined but not found to be statistically significant included years since injury, presence of severe decubiti, bladder calculi, bacteriuria and extent of injury. This study suggests that renal function usually can be preserved in spinal cord injury patients if the treatable risk factors are managed properly.
Standing and walking for the T6 paraplegic.
date: 02/01/1983
author: Duffus A, Wood J.
publication: Physiotherapy. 1983 Feb;69(2):45-6.
pubmed_ID: 6867159
No abstract
Pressure sore prevention for the wheelchair-bound spinal injury patient.
date: 12/18/1980
author: Ferguson-Pell MW, Wilkie IC, Reswick JB, Barbenel JC.
publication: Paraplegia. 1980 Feb;18(1):42-51.
pubmed_ID: 7375126
The concept of a wheelchair cushion fitting clinic for the prevention of pressure sores is reviewed in the light of recent estimates of the cost of pressure sores in the U.K. A method for measuring the pressure beneath the ischial tuberosities is discussed and techniques for measuring a patient’s habitual exercise frequency and seated posture are described. Results from the records of 600 spinal injury patients including Rancho Los Amigos Hospital are reported and used to demonstrate the importance of low pressure beneath the ischial tuberosities as an indicator of wheelchair cushion suitability.
Bone density and metabolism in children and adolescents with moderate to severe cerebral palsy.
date: 07/01/2002
author: Henderson RC, Lark RK, Gurka MJ, Worley G, Fung EB, Conaway M, Stallings VA, Stevenson RD.
publication: Pediatrics. 2002 Jul;110(1 Pt 1):e5.
pubmed_ID: 12093986
OBJECTIVES: Diminished bone density and a propensity to fracture with minimal trauma are common in children and adolescents with moderate to severe cerebral palsy (CP). The purpose of this study was to provide a detailed evaluation of bone mineral density (BMD) and metabolism in this population and to assess the relationship of these measures to multiple other clinical, growth, and nutrition variables. METHODS: The study group consisted of 117 subjects ages 2 to 19 years (mean: 9.7 years) with moderate to severe CP as defined by the Gross Motor Functional Classification scale. Population-based sampling was used to recruit 62 of the participants, which allows for estimations of prevalence. The remaining 55 subjects were a convenience sampling from both hospital- and school-based sources. The evaluation included measures of BMD, a detailed anthropometric assessment of growth and nutritional status, medical and surgical history, the Child Health Status Questionnaire, and multiple serum analyses. BMD was measured in the distal femur, a site specifically developed for use in this contracted population, and the lumbar spine. BMD measures were converted to age and gender normalized z scores based on our own previously published control series (n > 250). RESULTS: Osteopenia (BMD z score <-2.0) was found in the femur of 77% of the population-based cohort and in 97% of all study participants who were unable to stand and were older than 9 years. BMD was not as low in the lumbar spine (population-based cohort mean +/- standard error z score: -1.8 +/- 0.1) as in the distal femur (mean z score: -3.1 +/- 0.2). Fractures had occurred in 26% of the children who were older than 10 years. Multiple clinical and nutritional variables correlated with BMD z scores, but interpretation of these findings is complicated by covariance among variables. In stepwise regression analyses, it was found that severity of neurologic impairment as graded by Gross Motor Functional Classification level, increasing difficulty feeding the child, use of anticonvulsants, and lower triceps skinfold z scores (in decreasing order of importance) all independently contribute to lower BMD z scores in the femur. CONCLUSIONS: Low BMD is prevalent in children with moderate to severe CP and is associated with significant fracture risk. The underlying pathophysiology is complex, with multiple factors contributing to the problem and significant variation between different regions of the skeleton.
Weight-bearing exercise training and lumbar bone mineral content in postmenopausal women.
date: 06/01/1988
author: Dalsky GP, Stocke KS, Ehsani AA, Slatopolsky E, Lee WC, Birge SJ.
publication: Ann Intern Med. 1988 Jun;108(6):824-8.
pubmed_ID: 3259410
STUDY OBJECTIVE: To assess the effect of weight-bearing exercise training and subsequent detraining on lumbar bone mineral content in postmenopausal women. DESIGN: Non-randomized, controlled, short-term (9 months) trial and long-term (22 months) exercise training and detraining (13 months). SETTING: Section of applied physiology at a university school of medicine. PATIENTS: Thirty-five healthy, sedentary postmenopausal women, 55 to 70 years old. All women completed the study. There was 90% compliance with exercise training. INTERVENTIONS: All women were given calcium, 1500 mg daily. The exercise group did weight-bearing exercise (walking, jogging, stair climbing) at 70% to 90% of maximal oxygen uptake capacity for 50 to 60 min, 3 times weekly. MEASUREMENTS AND MAIN RESULTS: Bone mineral content increased 5.2% (95% confidence interval [CI], 2.0% to 8.4%; P = 0.0037) above baseline after short-term training whereas there was no change (-1.4%) in the control group. After 22 months of exercise, bone mineral content was 6.1% (95% CI, 3.9% to 8.3% above baseline; P = 0.0001) in the long-term training group. After 13 months of decreased activity, bone mass was 1.1% above baseline in the detraining group. CONCLUSIONS: Weight-bearing exercise led to significant increases above baseline in bone mineral content which were maintained with continued training in older, postmenopausal women. With reduced weight-bearing exercise, bone mass reverted to baseline levels. Further studies are needed to determine the threshold exercise prescription that will produce significant increases in bone mass.
The influence of activity on calcium metabolism.
date: 12/01/1985
author: Whedon GD.
publication: J Nutr Sci Vitaminol (Tokyo). 1985 Dec;31 Suppl:S41-4.
pubmed_ID: 3915756
Outside_URL: http://www.ncbi.nlm.nih.gov/pubmed/3915756
Many studies and observations have shown the bone-losing effects of physical inactivity of various forms. Contrariwise, less precise studies and observations have supported the reasonable premise that mechanical loading of the skeleton via physical activity shifts the balance of bone remodeling in favor of bone formation, and appears to do so at all ages. Some interesting starts have been made in research to discover the mechanisms of the action on bone of mechanical loading, but many pathways remain to be explored. Besides the mechanical forces, we need to know more about the interrelations of muscle function, probably mediated through muscle-tendon pull on periosteum, and more about other likely influences, notably changes in circulation to bones. The practical significance relative to calcium metabolism and aging of what has been learned thus far on the effects of activity, is that prolonged inactivity, either in a chair or in bed, is to be avoided, because of its deleterious effects, and that reasonably energetic gravitational exercise, such as walking or possibly jogging, promotes maintenance of bone health.