Effect of neuromuscular electrical stimulation on the recovery of people with COVID-19 admitted to the intensive care unit: A narrative review.

The rehabilitation of patients with COVID-19 after prolonged treatment in the intensive care unit is often complex and challenging. Patients may develop a myriad of long-term multiorgan impairments, affecting the respiratory, cardiac, neurological, digestive and musculoskeletal systems. Skeletal muscle dysfunction of respiratory and limb muscles, commonly referred to as intensive care unit acquired weakness, occurs in approximately 40% of all patients admitted to intensive care. The impact on mobility and return to activities of daily living is severe. Furthermore, many patients experience ongoing symptoms of fatigue, weakness and shortness of breath, in what is being described as "long COVID". Neuromuscular electrical stimulation is a technique in which small electrical impulses are applied to skeletal muscle to cause contractions when voluntary muscle contraction is difficult or impossible. Neuromuscular electrical stimulation can prevent muscle atrophy, improve muscle strength and function, maintain blood flow and reduce oedema. This review examines the evidence, current guidelines, and proposed benefits of using neuromuscular electrical stimulation with patients admitted to the intensive care unit. Practical recommendations for using electrical muscle stimulation in patients with COVID-19 are provided, and suggestions for further research are proposed. Evidence suggests NMES may play a role in the weaning of patients from ventilators and can be continued in the post-acute and longer-term phases of recovery. As such, NMES may be a suitable treatment modality to implement within rehabilitation pathways for COVID-19, with consideration of the practical and safety issues highlighted within this review.

Effectiveness of neuromuscular electrical stimulation for reducing oedema: A systematic review.

OBJECTIVE: This systematic review aimed to assess the clinical impact of neuromuscular electrical stimulation as a treatment modality for patients with oedema. DATA SOURCES AND STUDY SELECTION: PubMed was searched up to July 2018 for randomized and non-randomized clinical trials comparing neuromuscular electrical stimulation vs no stimulation following the formation of oedema. A modified Downs and Black checklist was used to evaluate the quality of the evidence. DATA SYNTHESIS: Initial searches yielded 150 results. Removal of duplicates reduced this number to 97 results. Seventy-five studies were excluded following a review of titles and abstracts. Full-text screening eliminated 15 studies. A final total of 7 studies met the inclusion criteria. Six studies supported the use of neuromuscular electrical stimulation for oedema reduction, and one study did not find an effect, but reported inter-group variance. CONCLUSION: The results of this systematic review support the use of neuromuscular electrical stimulation for ameliorating the abnormal accumulation of interstitial fluid, which is clinically shown as oedema. Neuromuscular electrical stimulation is effective in a number of rehabilitation settings and patient groups, for treatment of both upper and lower limb oedema. However, further trials are needed to reinforce these findings.

Training and orthotic effects related to functional electrical stimulation of the peroneal nerve in stroke.

OBJECTIVE: To examine the evidence for a training effect on the lower limb of functional electrical stimulation. DESIGN: Cohort study. PATIENTS: A total of 133 patients >6 months post-stroke. METHODS: Training and orthotic effects were determined from walking speed over 10 m, associated minimal and substantial clinically important differences (i.e. >0.05 and >0.10 m/s), and Functional Ambulation Category (FAC), ranging from household walking to independent walking in the community. RESULTS: An overall significant (p < 0.01) training effect was found that was not a clinically important difference (0.02 m/s); however, "community" FAC (≥ 0.8 m/s) and "most limited community walkers" FAC (0.4-0.58 m/s), but not "household walkers" (< 0.4 m/s), benefitted from a clinically important difference. A highly significant (p< 0.001), substantial clinically important orthotic effect (0.10 m/s) was found. In terms of overall improvement of one or more FACs, 23% achieved this due to a training effect, compared with 43% due to an orthotic effect. CONCLUSION: The findings suggest that functional electrical stimulation provides a training effect in those who are less impaired. Further work, which optimizes the use of the device for restoration of function, rather than as an orthotic device, will provide greater clarity on the effectiveness of functional electrical stimulation for eliciting a training effect.

Effectiveness of functional electrical stimulation on walking speed, functional walking category, and clinically meaningful changes for people with multiple sclerosis.

OBJECTIVE: To determine the effectiveness of functional electrical stimulation (FES) on drop foot in patients with multiple sclerosis (MS), using data from standard clinical practice. DESIGN: Case series with a consecutive sample of FES users collected between 2008 and 2013. SETTING: Specialist FES center at a district general hospital. PARTICIPANTS: Patients with MS who have drop foot (N=187) (117 women, 70 men; mean age, 55y [range, 27-80y]; mean duration since diagnosis, 11.7y [range, 1-56y]). A total of 166 patients were still using FES after 20 weeks, with 153 patients completing the follow-up measures. INTERVENTIONS: FES of the common peroneal nerve (178 unilateral, 9 bilateral FES users). MAIN OUTCOME MEASURES: Clinically meaningful changes (ie, >.05m/s and >0.1m/s) and functional walking category derived from 10-m walking speed. RESULTS: An increase in walking speed was found to be highly significant (P<.001), both initially where a minimum clinically meaningful change was observed (.07m/s) and after 20 weeks with a substantial clinically meaningful change (.11m/s). After 20 weeks, treatment responders displayed a 27% average improvement in their walking speed. No significant training effect was found. Overall functional walking category was maintained or improved in 95% of treatment responders. CONCLUSIONS: FES of the dorsiflexors is a well-accepted intervention that enables clinically meaningful changes in walking speed, leading to a preserved or an increased functional walking category.

A feasibility study to investigate the effect of functional electrical stimulation and physiotherapy exercise on the quality of gait of people with multiple sclerosis.

OBJECTIVE: To examine the effect of Functional Electrical Stimulation (FES) for dropped foot and hip instability in combination with physiotherapy core stability exercises. METHODS: Twenty-eight people with secondary progressive multiple sclerosis and unilateral dropped foot participated in a randomized crossover trial. Group1 received FES for correction of dropped foot for six weeks with the addition of hip extension for a further six weeks. In weeks 12-18, FES was continued with the addition of eight sessions of core stability physiotherapy with home-based exercise. FES and home-based exercise were continued until weeks 19-24. Group 2 received the same physiotherapy intervention over the first 12 weeks, adding FES in the second 12 weeks. RESULTS: FES improved walking speed and Rivermead Observational Gait Analysis (ROGA) score, whereas physiotherapy did not. Adding gluteal stimulation further improved ROGA score. Both interventions reduced falls, but adding FES to physiotherapy reduced them further. FES had greater impact on Multiple Sclerosis Impact Scale, MSIS-29. CONCLUSION: The intervention was feasible. FES for dropped foot may improve mobility and quality of life and may reduce falls. Adding gluteal stimulation further improved gait quality. Adding physiotherapy may have enhanced the effect of FES, but FES had the dominant effect.

The long-term cost-effectiveness of the use of Functional Electrical Stimulation for the correction of dropped foot due to upper motor neuron lesion.

OBJECTIVE: Functional Electrical Stimulation (FES) for correction of dropped foot has been shown to increase mobility, reduce the incidence of falls and to improve quality of life. This study aimed to determine how long the intervention is of benefit, and the total cost of its provision. DESIGN: Retrospective review of medical records. PARTICIPANTS: One hundred and twenty-six people with spastic dropped foot (62 stroke, 39 multiple sclerosis, 7 spinal cord injury, 3 cerebral palsy, 15 others) who began treatment in the year 1999. METHOD: All received common peroneal nerve stimulation, producing dorsiflexion and eversion time to the swing phase of gait using a heel switch. Device usage, 10 m walking speed and Functional Walking Category (FWC) were recorded. RESULTS: The median time of FES use was 3.6 years (mean 4.9, standard deviation 4.1, 95% confidence interval 4.2-5.6) with 33 people still using FES after a mean of 11.1 years. People with stroke walked a mean of 45% faster overall, including a 24% training effect with 52% improving their FWC. People with multiple sclerosis did not receive a consistent training effect but walked 29% faster when FES was used with 40% increasing their FWC. The average treatment cost was £3,095 per patient resulting in a mean cost per Quality Adjusted Life Years of £15,406. CONCLUSION: FES is a practical, long-term and cost-effective treatment for correction of dropped foot.

The effects of functional electrical stimulation on walking in hereditary and spontaneous spastic paraparesis.

OBJECTIVES: To investigate in people with spastic paraparesis (SP): 1) the factors contributing to foot drop and reduced toe clearance while walking; 2) short-term effects of bilateral functional electrical stimulation (FES) of the common peroneal nerve. MATERIALS AND METHODS: Long term (>0.5 years) users of FES with SP were compared to matched controls (N = 11 per group). Ankle strength and plantarflexor stiffness and walking kinematics were objectively recorded. The effects of FES on: 1) perceived efficacy; 2) muscle torque and ankle motion; 3) clinical outcome measures and walking kinematics were assessed. Results were compared using an analysis of covariance. RESULTS: Ankle weakness and stiffness is higher among people with SP. Higher plantarflexor stiffness is associated with reduced swing phase dorsiflexion; higher toe clearance while walking is associated with increased hip flexion. FES increases dorsiflexor torque, improves toe clearance and dorsiflexion in swing phase, and significantly improves walking speed (p < 0.05). CONCLUSIONS: There are multiple causes of tripping in people with SP; FES reduces foot drop and improves walking speed.

Neuromuscular electrical stimulation for children with cerebral palsy: a review.

The aim of this review paper is to consider the application of neuromuscular electrical stimulation (NMES) to improve gait or upper limb function in children with cerebral palsy (CP). Although most NMES research has been directed at adults with neurological conditions, there is a growing body of evidence supporting its use in children with CP. In line with a recent meta-analysis, the use of electrical stimulation to minimise impairment and activity limitations during gait is cautiously advocated. A detailed commentary on one of the most common lower limb NMES applications, tibialis anterior stimulation (either with or without gastrocnemius stimulation) is given. Although there is a lack of randomised controlled trials and a predominance of mainly small studies, this review further concludes that the balance of available evidence is in favour of upper limb exercise NMES offering benefits such as increased muscle strength, range of motion and function in children with CP. The use of dynamic splinting with NMES has been shown to be more effective than either treatment on its own in improving function and posture. There is at present little published work to support the application of botulinum toxin type A to temporarily reduce muscle tone as an adjunct intervention to NMES in this population, although the presence of parallel applications to manage similar symptoms in other muscular disorders is noted.

The combined effect of Dynamic splinting and Neuromuscular electrical stimulation in reducing wrist and elbow contractures in six children with Cerebral palsy.

The aim of this pilot study was to investigate the feasibility of applying the combination of Dynamic splinting (DS) and Neuromuscular electrical stimulation (NMES) in order to improve wrist and elbow function, and range of motion, in children with upper limb contractures due to Cerebral palsy (CP). Six children aged seven to 16, with contractures at the wrist or elbow, were recruited. Following a 12-week baseline period all participants underwent a 12-week treatment period where DS was used for one hour per day and combined with NMES for the second half of the 1-h treatment. A 12-week follow-up period then ensued. Upper limb function was assessed with the Melbourne assessment, physical disability with the Paediatric Evaluation of Disability Index and the Activity Scale for Kids, and quality of life with the Pediatric Quality of Life Scale. Passive and active range of motion at the wrist and elbow were measured using manual and electrical goniometers. The technique of using combined NMES and DS was demonstrated to be feasible and compliance with the intervention was good. There was an increase in passive elbow extension in two participants treated for elbow contractures, although no accompanying change in upper limb function was demonstrated. Wrist range of movement improved in one participant treated for wrist contracture.

The effect of combined use of botulinum toxin type A and functional electric stimulation in the treatment of spastic drop foot after stroke: a preliminary investigation.

OBJECTIVE: To investigate the effect of combined botulinum toxin type A (BTX) and functional electric stimulation (FES) treatment on spastic drop foot in stroke. DESIGN: Nonblinded randomized controlled trial. SETTING: Hospitals. PARTICIPANTS: Consecutive sample of 21 ambulant adults within 1 year after stroke with a spastic drop foot, of whom 18 completed the study. INTERVENTIONS: The treatment group received BTX injections (Dysport) on 1 occasion into the medial and lateral heads of the gastrocnemius (200U each) and tibialis posterior (400U each) muscles and FES, used on a daily basis for 16 weeks to assist walking. Both groups continued with physiotherapy at the same rate. MAIN OUTCOME MEASURES: Walking speed, Physiological Cost Index, Modified Ashworth Scale, Rivermead Motor Assessment, and Medical Outcomes Study 36-Item Short-Form Health Survey. RESULTS: Walking speed increased over 12 weeks in both control (P=.020) and treatment groups (nonstimulated, P=.004; stimulated, P=.042). The baseline corrected (analysis of covariance) increase in mean walking speed at 12 weeks, relative to controls, was.04m/s (95% confidence interval [CI],.003-.090) without stimulation, and.09m/s (95% CI,.031-.150) with stimulation. CONCLUSIONS: Combined treatment effectively improved walking and function. A larger study is needed to quantify the treatment effect and to investigate its impact on quality of life.

Effectiveness of electric stimulation of the vastus medialis muscle in the rehabilitation of patients after total knee arthroplasty.

OBJECTIVE: To investigate the possible effect of electric muscle stimulation (EMS) of the vastus medialis on the walking speed, Hospital for Special Surgery (HSS) knee score, and Physiological Cost Index (PCI) of patients during rehabilitation after total knee arthroplasty (TKA). DESIGN: Prospective, randomized controlled trial. SETTING: Various departments at a district general hospital in the United Kingdom. PARTICIPANTS: Thirty patients with unilateral osteoarthritis of the knee admitted for elective TKA were randomly assigned to 1 of 2 groups (15 per group): control and treatment. Both groups received standard physical therapy. The treatment group also received EMS of the vastus medialis. INTERVENTION: EMS (40Hz, 300micros) of the vastus medialis muscle for 4 hours a day, starting on postoperative day 2, over the first 6 postoperative weeks. MAIN OUTCOME MEASURES: Changes in walking speed, HSS knee score, and effort of walking as measured by the PCI. RESULTS: A statistically significant increase in walking speed was observed in the treatment group in relation to the control group at both 6 weeks (P=.0002) and 12 weeks (P<.0001) postoperatively. No statistically significant difference was observed in relation to the PCI or the HSS knee score variables. CONCLUSIONS: Application of EMS after TKA resulted in a statistically significant improvement in patients' walking speed. There was also a carry-over effect after the discontinuation of treatment.

Control of leg-powered paraplegic cycling using stimulation of the lumbo-sacral anterior spinal nerve roots.

We investigated leg-powered cycling in a recumbent tricycle for a paraplegic using functional electrical stimulation (FES) with the lumbo-sacral anterior root stimulator implant (LARSI). A female complete T9 paraplegic had a stimulator for the anterior L2 to S2 spinal roots (bilaterally) implanted in 1994. She was provided with equipment for daily FES cycling exercise at home. The cycling controller applies a pattern of stimulation in each of 16 crank angle phases. A 7-bit shaft encoder measures the crank angle with adequate precision. Each pattern was originally chosen to give the greatest propulsive force in that position when there was no motion. However, dynamically, some reduction in co-contraction is needed; also the patterns are applied with a preset advance time. Maximal power is obtained with an advance of 250 ms, which compensates for muscle response delay and accommodates changes in cadence (from about 25 to 85 rpm). With this system, she has cycled 1.2 km at a time on gently undulating road. We found that spinal root stimulation gives sufficient control over the muscles in the legs to produce a fluid cycling gait. We propose that root stimulation for leg cycling exercise may be a practicable and valuable function for paraplegics following spinal cord injury.

A pilot study to investigate the combined use of botulinum neurotoxin type a and functional electrical stimulation, with physiotherapy, in the treatment of spastic dropped foot in subacute stroke.

The objective was to inform sample size calculations for a full randomized controlled trial (RCT). The design included an RCT pilot trial with a 16 week study period, including a 4 week baseline phase. The subjects were adults within 1 year of first stroke, ambulant with a spastic dropped foot. Twenty-one participants were recruited from the stroke services of 4 centers. For intervention all participants received physiotherapy; the treatment group also received botulinum neurotoxin Type A (BoNTA) intramuscular injections to triceps surae (800 U Dysport) and functional electrical stimulation (FES) of the common peroneal nerve to assist walking. The main outcome measure was walking speed. The result was a significant upward trend in median walking speed for both the control (p = 0.02) and treatment groups (nonstimulated p = 0.004, stimulated p = 0.042). Trend lines were different in location (p = 0.04 and p = 0.009, respectively). In conclusion, there is evidence of an additional, beneficial effect of BoNTA and FES. Sufficient information has been gained on the variability of the primary outcome measure to inform sample size calculations for a full RCT to quantify the treatment effect with precision.