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: Spinal Cord Injury
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.
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.
Changes in physical strain and physical capacity in men with spinal cord injuries.
date: 05/01/1996
author: Janssen TW, van Oers CA, Rozendaal EP, Willemsen EM, Hollander AP, van der Woude LH.
publication: Med Sci Sports Exerc. 1996 May;28(5):551-9.
pubmed_ID: 9148083
To determine longitudinal changes in physical capacity and physical strain during activities of daily living (ADL), 37 men with spinal cord injuries (C4/5-L5) performed an exercise test and various ADL on two occasions (T1 and T2; interval 34.5 +/- 1.5 months). Parameters of physical capacity were aerobic power (VO(2peak)) and maximal power output (PO(max)). Physical strain was estimated by the heart rate response relative to the heart rate reserve. VO(2peak) at T2 (1.75 +/- 0.55 1*min(1)) did not significantly differ from that at T1 (1.67 + 0.47 1*min(-1)). Absolute PO max improved (P < 0.05) from 64.9 +/- 25.9 (T1) to 71.7 +/- 27.2 W (T2), whereas relative PO(max) did not change. Activity level, time since injury, change in body mass, and occurrence of rehospitalization were the most important predictors of changes in physical capacity. Changes in relative VO(2peak) were related (P < 0.05) to changes in strain during transfers to the shower wheelchair (r = -0.39) and shower seat (r = -0.46), and during the curb ascent (r = -0.47). In conclusion, the hypothesized decline in physical capacity did not occur over the 3-yr period. Maintenance of physical capacity, which may in part be achieved through sport participation and improved medical care, together with avoidance of excessive body mass, may be useful to prevent high levels of strain during ADL.
Static vs dynamic loads as an influence on bone remodeling.
date: 01/01/2004
author: Lanyon LE, Rubin CT.
publication: J Biomech. 1984;17(12):897-905.
pubmed_ID: 6520138
Remodeling activity in the avian ulna was assessed under conditions of disuse alone, disuse with a superimposed continuous compressive load, and disuse interrupted by a short daily period of intermittent loading. The ulnar preparation consisted of the 110mm section of the bone shaft between two submetaphyseal osteotomies. Each end of the preparation was transfixed by a stainless steel pin and the shaft either protected from normal functional loading with the pins joined by external fixators, loaded continuously in compression by joining the pins with springs, or loaded intermittently in compression for a single 100s period per day by engaging the pins in an Instron machine. Similar loads (525 N) were used in both static and dynamic cases. The strains engendered were determined by strain gauges, and at their maximum around the bone’s midshaft were -0.002. The intermittent load was applied at a frequency of 1 Hz as a ramped square wave, with a rate of change of strain during the ramp of 0.01 s-1. Peak strain at the midshaft of the ulna during wing flapping in the intact bone was recorded from bone bonded strain gauges in vivo as -0.0033 with a maximum rate of change of strain of 0.056 s-1. Examination of bone sections from the midpoint of the preparation after an 8 week period indicated that in both non-loaded and statically loaded bones there was an increase in both endosteal diameter and intra cortical porosity. These changes produced a decrease in cross sectional area which was similar in the two groups (-13%).(ABSTRACT TRUNCATED AT 250 WORDS)
Calcium balance in paraplegic patients: influence of injury duration and ambulation.
date: 10/01/1978
author: Kaplan PE, Gandhavadi B, Richards L, Goldschmidt J.
publication: Arch Phys Med Rehabil. 1978 Oct;59(10):447-50.
pubmed_ID: 718407
Calcium metabolic balance determinations, which have been done in various clinical and experimental conditions, were applied to the study of 8 spinal cord injured patients receiving a diet with 1600 mg calcium and 85 to 120 gm protein daily. All of the patients had hypercalciuria prior to ambulation. Those with spinal cord injuries of less than 3 months duration (early group) had a calcium balance of -27 mg before ambulation and 235 mg after ambulation. Patients with spinal cord injuries of 6 months or more duration (late group) had calcium balances of 55 mg before ambulation and 175 mg after ambulation. Ambulation significantly decreased the hypercalciuria and modified the calcium balance in a positive direction. Smaller changes were noted in the responses of the late group than in those of the early group. Early ambulation will probably prevent bone loss, calcium stones in the genitourinary tract, and other sequellae of negative calcium balance.
Bone mineral status in paraplegic patients who do or do not perform standing.
date: 05/01/1994
author: Goemaere S, Van Laere M, De Neve P, Kaufman JM.
publication: Osteoporos Int. 1994 May;4(3):138-43.
pubmed_ID: 8069052
:
Bone mineral density (BMD) was assessed by dual-photon X-ray absorptiometry at the lumbar spine (L3, L4), the proximal femur and the femoral shaft, and by single-photon absorptiometry at the forearm in 53 patients with complete traumatic paraplegia of at least 1 year’s duration and in age- and sex-matched healthy controls. The patients did (n = 38) or did not (n = 15) regularly perform passive weightbearing standing with the aid of a standing device. Compared with the controls, the BMD of paraplegic patients was preserved in the lumbar spine and was markedly decreased in the proximal femur (33%) and the femoral shaft (25%). When considering all patients performing standing, they had a better-preserved BMD at the femoral shaft (p = 0.009), but not at the proximal femur, than patients not performing standing. BMD at the lumbar spine (L3, L4) was marginally higher in the standing group (significant only for L3; p = 0.040). A subgroup of patients performing standing with use of long leg braces had a significantly higher BMD at the proximal femur than patients using a standing frame or a standing wheelchair (p = 0.030). The present results suggest that passive mechanical loading can have a beneficial effect on the preservation of bone mass in osteoporosis found in paraplegics.
Cardiopulmonary response in spinal cord injury patients: effect of pneumatic compressive devices.
date: 03/01/1983
author: Huang CT, Kuhlemeier KV, Ratanaubol U, McEachran AB, DeVivo MJ, Fine PR.
publication: Arch Phys Med Rehabil. 1983 Mar;64(3):101-6.
pubmed_ID: 6830418
The purpose of this study was to determine the effects of an inflatable abdominal corset and bilateral pneumatic leg splints on certain physiologic parameters during and after postural change in 27 quadriplegic patients. Data reflecting respiratory rate, tidal volume, heart rate, systolic and diastolic blood pressure were collected and analyzed. Measurements were acquired with patients in supine, 20 degrees head-up, 45 degrees head-up, and 20 degrees head-down positions. The study population was divided into 2 groups of cervical spinal cord injured patients: group I included 13 patients with C6 or C7 lesions; group II included 14 patients with C4 or C5 lesions. The mean time between injury and data collection was 47 days. Several trends were identified: (1) the neurologic level of lesion in quadriplegics appears relatively unimportant in determining cardiopulmonary response to postural change; (2) the use of assistive compressive devices does not improve pulmonary ventilatory parameters during postural change, although such devices do help maintain cardiovascular parameters; and (3) the abdominal corset appears more effective than pneumatic leg splints in maintaining blood pressure at pretilt levels. A tidal volume of 350ml to 400ml is most easily maintained by placing patients in a supine position and eschewing assistive compressive devices. Because the pneumatic devices proved successful in helping quadriplegic patients maintain cardiovascular stability during postural changes, therapeutic modalities, such as tilt table treatments, may be initiated at an earlier stage in the rehabilitation process.
Moving the arms to activate the legs.
date: 07/01/2006
author: Ferris DP, Huang HJ, Kao PC.
publication: Exerc Sport Sci Rev. 2006 Jul;34(3):113-20.
pubmed_ID: 16829738
Recent studies on neurologically intact individuals and individuals with spinal cord injury indicate that rhythmic upper limb muscle activation has an excitatory effect on lower limb muscle activation during locomotor-like tasks. This finding suggests that gait rehabilitation therapy after neurological injury should incorporate simultaneous upper limb and lower limb rhythmic exercise to take advantage of neural coupling.