Category: Weight Bearing & FES (Functional Electrical Stimulation)

Posted on by

Effect of dynamic weight bearing on neuromuscular activation after spinal cord injury.

date: 2007 Jun;86(6):499-506
author: Edwards LC, Layne CS.
publication: Am J Phys Med Rehabil
PubMed ID:17515690

Abstract

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.

Posted on by

Physiologic responses to electrically assisted and frame-supported standing in persons with paraplegia

date: 2003 Winter;26(4):384-9.
author: Jacobs PL1, Johnson B, Mahoney ET.
publication: J Spinal Cord Med.
pubmed_ID:14992341

assisted

Abstract

BACKGROUND:

Systems of functional electrical stimulation (FES) have been demonstrated to enable some persons with paraplegia to stand and ambulate limited distances. However, the energy costs and acute physiologic responses associated with FES standing activities have not been well investigated.

OBJECTIVE:

To compare the physiologic responses of persons with paraplegia to active FES-assisted standing (AS) and frame-supported passive standing (PS).

METHODS:

Fifteen persons with paraplegia (T6-T11) previously habituated to FES ambulation, completed physiologic testing of PS and AS. The AS assessments were performed using a commercial FES system (Parastep-1; Altimed, Fresno, Calif); the PS tests used a commercial standing frame (Easy Stand 5000; Altimed, Fresno, Calif). Participants also performed a peak arm-cranking exercise (ACE) test using a progressive graded protocol in 3-minute stages and 10-watt power output increments to exhaustion. During all assessments, metabolic activity and heart rate (HR) were measured via open-circuit spirometry and 12-lead electrocardiography, respectively. Absolute physiologic responses to PS and AS were averaged over 1-minute periods at 5-minute intervals (5, 10, 15, 20, 25, and 30 minutes) and adjusted relative to peak values displayed during ACE to determine percentage of peak (%pk) values. Absolute and relative responses were compared between test conditions (AS and PS) and across time using two-way analysis of variance.

RESULTS:

The AS produced significantly greater values of VO2 (43%pk) than did PS (20%pk). The mean HR responses to PS (100-102 beats per minute [bpm] throughout) were significantly lower than during AS, which ranged from 108 bpm at 5 minutes to 132 bpm at test termination.

CONCLUSION:

Standing with FES requires significantly more energy than does AS and may provide a cardiorespiratory stress sufficient to meet minimal requirements for exercise conditioning.

Posted on by — Leave a comment

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.

Posted on by — Leave a comment

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.

Posted on by — Leave a comment

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.