Cardiovascular response of individuals with spinal cord injury to dynamic functional electrical stimulation under orthostatic stress

date: 2013 Jan;21(1):37-46.
author: Yoshida T.
publication: IEEE Trans Neural Syst Rehabil Eng.
PubMed ID: 22899587

Abstract

In this pilot study, we examined how effectively functional electrical stimulation (FES) and passive stepping mitigated orthostatic hypotension in participants with chronic spinal cord injury (SCI). While being tilted head-up to 70 (°) from the supine position, the participants underwent four 10-min conditions in a random sequence: 1) no intervention, 2) passive stepping, 3) isometric FES of leg muscles, and 4) FES of leg muscles combined with passive stepping. We found that FES and passive stepping independently mitigated a decrease in stroke volume and helped to maintain the mean blood pressure. The effects of FES on stroke volume and mean blood pressure were greater than those of passive stepping. When combined, FES and passive stepping did not interfere with each other, but they also did not synergistically increase stroke volume or mean blood pressure. Thus, the present study suggests that FES delivered to lower limbs can be used in individuals with SCI to help them withstand orthostatic stress. Additional studies are needed to confirm whether this use of FES is applicable to a larger population of individuals with SCI.

Comparison of orthostatic reactions of patients still unconscious within the first three months of brain injury on a tilt table with and without integrated stepping. A prospective, randomized crossover pilot trial.

date: 2008 Dec;22(12):1034-41
author: Luther MS
publication: Clin Rehabil
PubMed ID: 19052242

Abstract

OBJECTIVE:

To determine whether passive leg movement during tilt table mobilization reduces the incidence of orthostatic dysfunction in mobilization of patients being comatose or semi-comatose early after brain injury.

DESIGN:

Randomized crossover pilot trial using sequential testing.

SETTING:

Neurorehabilitation hospital.

SUBJECTS:

Nine patients still unconscious within the first three months of brain injury (5 men, 4 women; age 51 +/- 20 years).

INTERVENTION:

Patients were subjected once to a conventional tilt table and once to a tilt table with an integrated stepping device.

MAIN OUTCOME MEASURE:

The number of syncopes/presyncopes (orthostatic hypotension, tachypnoea, increased sweating) during interventions.

RESULTS:

One patient had presyncopes on both devices, six patients had presyncopes on the conventional tilt table but not on the tilt table with integrated stepping, and two patients did not exhibit presyncopal symptoms on either device. There were significantly more incidents on the tilt table without than on the one with an integrated stepping device (P < 0.05) at tilts of 50 or 70 degrees respectively.

CONCLUSION:

Patients tolerate greater degrees of head-up tilt better with simultaneous leg movement.

Investigation of robotic-assisted tilt-table therapy for early-stage spinal cord injury rehabilitation.

date: 2013;50(3):367-78.
author: Craven CTD.
publication: J Rehabil Res Dev
PubMed ID: 23881763

Abstract

Damage to the spinal cord compromises motor function and sensation below the level of injury, resulting in paralysis and progressive secondary health complications. Inactivity and reduced energy requirements result in reduced cardiopulmonary fitness and an increased risk of coronary heart disease and cardiovascular complications. These risks may be minimized through regular physical activity. It is proposed that such activity should begin at the earliest possible time point after injury, before extensive neuromuscular degeneration has occurred. Robotic-assisted tilt-table therapy may be used during early-stage spinal cord injury (SCI) to facilitate stepping training, before orthostatic stability has been achieved. This study investigates whether such a stimulus may be used to maintain pulmonary and coronary health by describing the acute responses of patients with early-stage (<1 yr) motor-complete SCI (cSCI) and motor-incomplete SCI (iSCI) to passive, active, and electrically stimulated robotic-assisted stepping. Active participation was found to elicit an increased response from iSCI patients. The addition of electrical stimulation did not consistently elicit further increases. Extensive muscle atrophy was found to have occurred in those patients with cSCI, thereby limiting the potential effectiveness of electrical stimulation. Active participation in robotic-assisted tilt-table therapy may be used to improve cardiopulmonary fitness in iSCI patients if implemented as part of a regular training program.

Electrically induced and voluntary activation of physiologic muscle pump: a comparison between spinal cord-injured and able-bodied individuals.

date: 2002 Dec;16(8):878-85.
author: Faghri PD.
publication: Clin Rehabil
PubMed ID:12501950

Abstract

OBJECTIVE:

To evaluate the central haemodynamic responses during position changes from supine to sitting and during 30 min of standing between able-bodied and spinal cord-injured subjects. Also to assess the effects of the physiologic muscle pump in both groups during 30 min of standing.

DESIGN:

A repeated measure design. Both groups were tested on two different days under two conditions of 30 min of stationary standing and 30 min of dynamic standing (voluntary activation of the lower leg muscles in able-bodied and FES-induced activation of these muscles in spinal cord injured). The order of testing was random.

SETTING:

Rehabilitation hospital.

SUBJECTS:

Fifteen healthy able-bodied and 14 healthy spinal cord-injured subjects.

MAIN OUTCOME MEASURED:

Stroke volume, cardiac output, heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure and total peripheral resistance during supine-pre sitting, sitting-pre standing and during 30 min of standing.

RESULTS:

Significant reductions (p < 0.05) in systolic blood pressure, diastolic blood pressure and mean arterial pressure were found when spinal cord-injured subjects moved from sitting to standing during stationary standing; these values were maintained during dynamic standing. These values were maintained during both standing sessions in able-bodied subjects. During 30 min of stationary standing, there were significant reductions in stroke volume, cardiac output in both able-bodied and spinal cord-injured while their total peripheral resistance increased (p < 0.05). During 30 min of dynamic standing, both groups maintained their haemodynamics at pre-standing values with the exception of significant reduction in stroke volume at 30 min of standing.

CONCLUSION:

FES-induced activation of the physiologic muscle pump during change in position from sitting to standing prevented orthostatic hypotension in spinal cord-injured subjects. During standing it had equal or even greater effect on improving blood circulation when compared with voluntary activation in able-bodied subjects. The use of FES during standing and tilting in spinal cord-injured individuals may prevent orthostatic hypotension and circulatory hypokinesis and improve tolerance to tilting and standing.

The effects of lower-extremity functional electric stimulation on the orthostatic responses of people with tetraplegia.

date: 2005 Jul;86(7):1427-33.
author: Chao CY.
publication: Arch Phys Med Rehabil
PubMed ID:16003676

 

Abstract

OBJECTIVE:

To determine whether application of functional electric stimulation (FES) to lower-limb muscles during postural tilting improves orthostatic tolerance in people with tetraplegia.

DESIGN:

A crossover design.

SETTING:

A rehabilitation hospital.

PARTICIPANTS:

Sixteen acute and chronic subjects with tetraplegia (15 men, 1 woman) with complete motor function loss at the C3-7 levels were recruited. Time since injury ranged from 2 to 324 months (mean, 118.9+/-104.2 mo).

INTERVENTION:

Subjects were tested on a progressive head-up tilting maneuver with and without the application of FES at 0 degrees , 15 degrees , 30 degrees , 45 degrees , 60 degrees , 75 degrees , and 90 degrees continuously for up to 1 hour. FES was administered to 4 muscle groups including the quadriceps, hamstrings, tibialis anterior, and gastrocnemius muscles bilaterally at an intensity that provided a strong, visible, and palpable contraction. This was to produce a muscle pumping mechanism during the tilting maneuver.

MAIN OUTCOME MEASURES:

Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, perceived presyncope score, and the overall duration of orthostatic tolerance, that is, the time that subjects could tolerate the tilting maneuver without developing severe hypotension or other intolerance symptoms.

RESULTS:

When the tilt angle was increased, the subjects’ SBP and DBP tended to decrease, whereas the heart rate tended to increase in both testing conditions. Adding FES to tilting significantly attenuated the drop in SBP by 3.7+/-1.1 mmHg (P = .005), the drop in DBP by 2.3+/-0.9 mmHg (P = .018), and the increase in heart rate by 1.0+/-0.5 beats/min (P = .039) for every 15 degrees increment in the angle of the tilt. FES increased the overall mean standing time by 14.3+/-3.9 min (P = .003).

CONCLUSIONS:

An FES-induced leg muscle contraction is an effective adjunct treatment to delay orthostatic hypotension caused by tilting; it allows people with tetraplegia to stand up more frequently and for longer durations.

Orthostatic hypotension following spinal cord injury: impact on the use of standing apparatus

date: 2009;24(3):237-42
author: Chelvarajah R.
publication: NeuroRehabilation
PubMed ID19458431

 

Abstract

INTRODUCTION:

Upright posture confers numerous medical and social benefits to a spinal cord injured (SCI) patient. Doing so is limited by symptoms of orthostatic hypotension. This is a common secondary impairment among tetraplegic sufferers.

OBJECTIVE:

Establish the proportion of SCI patients who are restricted from using standing apparatus, such as standing frames and standing wheelchairs, because of inducing symptomatic orthostatic hypotension or the fear of developing these disabling symptoms.

STUDY DESIGN:

Survey conducted by Internet-accessible electronic questionnaire. Questionnaire validated for reliability and accuracy.

RESULTS:

293 respondents. Mean age 44.6; 76% male. Median time from injury: 7 years. 38% suffered with orthostatic hypotension; majority were complete injuries and all (except one – T12) were T5 or above level. 52% replied that they were using standing wheelchairs or frames. Of these, 59 (20% of total) stated that orthostatic hypotension symptoms were limiting the use of their upright apparatus. Of those who did not use standing wheelchairs or frames, 16 (5.5% of total) reported that this was because of the fear of worsening their orthostatic hypotension.

CONCLUSION:

Orthostatic hypotension restricts standing apparatus use in a large proportion (a total of 25.5% of respondents in this survey) of SCI patients.

Weight bearing through lower limbs in a standing frame with and without arm support and low-magnitude whole-body vibration in men and women with complete motor paraplegia

date: 2012 Apr;91(4):300-8. doi
author: Bernhardt KA
publication: Am J Phys Med Rehabil
PubMed ID:22407161

Abstract

OBJECTIVE:

The aim of the study was to determine the proportion of body weight borne through the lower limbs in persons with complete motor paraplegia using a standing frame, with and without the support of their arms. We also examined the effect of low-magnitude whole-body vibration on loads borne by the lower limbs.

DESIGN:

Vertical ground reaction forces (GRFs) were measured in 11 participants (six men and five women) with paraplegia of traumatic origin (injury level T3-T12) standing on a low-magnitude vibrating plate using a standing frame. GRFs were measured in four conditions: (1) no vibration with arms on standing frame tray, (2) no vibration with arms at side, (3) vibration with arms on tray, and (4) vibration with arms at side.

RESULTS:

GRF with arms on tray, without vibration, was 0.76 ± 0.07 body weight. With arms at the side, GRF increased to 0.85 ± 0.12 body weight. With vibration, mean GRF did not significantly differ from no-vibration conditions for either arm positions. Oscillation of GRF with vibration was significantly different from no-vibration conditions (P < 0.001) but similar in both arm positions.

CONCLUSIONS:

Men and women with paraplegia using a standing frame bear most of their weight through their lower limbs. Supporting their arms on the tray reduces the GRF by approximately 10% body weight. Low-magnitude vibration provided additional oscillation of the load-bearing forces and was proportionally similar regardless of arm position.

Mobility aids and transport possibilities 10-45 years after spinal cord injury

date: 2004 Dec;42(12):699-706
author: Biering-Sorensen F.
publication: Spinal Cord.
PubMed ID15289807

Abstract

STUDY DESIGN:

A cross-sectional survey with retrospective data.

OBJECTIVE:

Follow-up information on the use of mobility aids and transportation possibilities in a chronic traumatic spinal cord injury (SCI) population.

SETTING:

Clinic for Para- and Tetraplegia at Rigshospitalet, University hospital, Denmark (CPT). The uptake area is East Denmark with a population of 2.5 million inhabitants.

METHODS:

Survey on date of birth, gender, time of SCI, cause of SCI, neurological level and functional classification from medical files were combined with information concerning mobility aids and transport possibilities at the time of follow-up from a mailed questionnaire.

MATERIAL:

Individuals with traumatic SCI before 1 January 1991 were still in regular follow-up at CPT, and with sufficient medical record. A total of 279 were included, out of which 236 answered the questionnaire. Of the 193 men and 43 women injured from 1956 to 1990 the response rate was 84.6%. Age at the time of follow-up was 50.5 years in mean, and follow-up time was 24.1 years in mean. In all, 126 were paraplegic and 110 tetraplegic. Responders and nonresponders were comparable.

RESULTS:

In all, 3.4% used no special mobility aids at all. In total, 49 used crutches or rolling walkers and 26 lower extremities bracing, but mostly in combination with a wheelchair. Standing frame and stand-up wheelchair were used by men only. Manual wheelchair was used by 83.5% and electrical wheelchair by 27%, and the latter more by the tetraplegics. In all, 9.3% had neither a manual nor an electrical wheelchair. Overall, 86.4% had a passenger van or another car. Women used a car less often. Passenger vans were more often used by tetraplegics.

CONCLUSION:

Nearly all SCI participants had mobility aids of some sort, and 90.7% had either a manual or an electrical wheelchair or both. Most had a passenger van or another type of car for transportation. These facilities are important for the individuals to obtain an independent living.

Does regular standing improve bowel function in people with spinal cord injury? A randomised crossover trial

date: 2015 Jan;53(1):36-41. doi:
author: Kwok S.
publication: Spinal Cord.
PubMed ID:25366527

Abstract

STUDY DESIGN:

A randomised crossover trial.

OBJECTIVES:

To determine the effects of a 6-week standing programme on bowel function in people with spinal cord injury.

SETTING:

Community, Australia and the United Kingdom.

METHODS:

Twenty community-dwelling people with motor complete spinal cord injury above T8 participated in a 16-week trial. The trial consisted of a 6-week stand phase and a 6-week no-stand phase separated by a 4-week washout period. Participants were randomised to one of two treatment sequences. Participants allocated to the Treatment First group stood on a tilt table for 30 min per session, five times per week for 6 weeks and then did not stand for the next 10 weeks. Participants allocated to the Control First group did the opposite: they did not stand for 10 weeks and then stood for 6 weeks. Participants in both groups received routine bowel care throughout the 16-week trial. Assessments occurred at weeks 0, 7, 10 and 17 corresponding with pre and post stand and no-stand phases. The primary outcome was Time to First Stool. There were seven secondary outcomes reflecting other aspects of bowel function and spasticity.

RESULTS:

There were three dropouts leaving complete data sets on 17 participants. The mean (95% confidence interval) between-intervention difference for Time to First Stool was 0 min (-7 to 7) indicating no effect of regular standing on Time to First Stool.

CONCLUSION:

Regular standing does not reduce Time to First Stool. Further trials are required to test the veracity of some commonly held assumptions about the benefits of regular standing for bowel function

Monitoring standing wheelchair use after spinal cord injury: a case report.

date: 2005 Feb 4;27(3):142-6
author: Shields RK.
publication: Disabil Rehabil
PubMed ID:15823996

Abstract

PURPOSE:

An important issue in spinal cord injury (SCI) research is whether standing can yield positive health benefits. However, quantifying dose of standing and establishing subject compliance with a standing protocol is difficult. This case report describes a method to monitor dose of standing outside the laboratory, describes the standing patterns of one subject, and describes this subject’s satisfaction with the standing protocol.

METHOD:

A man with T-10 complete paraplegia agreed to have his commercially available standing wheelchair instrumented with a custom-designed logging device for a 2-year period. The micro-controller-based logger, under custom software control, was mounted to the standing wheelchair. The logger recorded date, duration, angle of standing, and start/stop times.

RESULTS:

The client exceeded a suggested minimum dosage of standing per month (130.4% of goal), choosing to stand for short bouts (mean = 11.57 min) at an average angle of 61 degrees, on an average 3.86 days per calendar week. He was generally very satisfied with the standing device and provided subjective reports of improved spasticity and bowel motility.

CONCLUSION:

This case report describes a standing and surveillance system that allow quantification of standing dose. Future controlled studies are needed to evaluate whether standing can be beneficially affect secondary complications after SCI.