Name: paradigms of lower extremity electrical stimulation training after spinal cord injury
Uploaded: 2018-02-01T14:00:00
Description: Watch this Scientific Journal Video about Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury at JoVE.com

We would like to thank the participants who devoted the time and effort to participate in the previous studies. We would like to thank Hunter Holmes McGuire Research Institute and Spinal Cord Injury Services and Disorders for providing the environment to conduct clinical human research trials. Ashraf S. Gorgey is currently supported by the Department of Veteran Affairs, Veteran Health Administration, Rehabilitation Research and Development Service (B7867-W) and DoD-CDRMP (W81XWH-14-SCIRP-CTA).

The training protocol described in this manuscript is registered with clinicaltrials.gov identifier (NCT01652040). The training program involves NMES-RT with ankle weights and FES-LEC. All necessary equipment is listed in Table 2. The study protocol and informed consent were reviewed and approved by the Richmond VAMC Institutional Review Board (IRB) and Virginia Commonwealth University (VCU) IRB. All study procedures were explained in-detail to each participant before beginning the trial.
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The current study demonstrated two different paradigms of electrical stimulation. One paradigm is focused on implementing progressive loading to the trained muscle to evoke skeletal muscle hypertrophy and the other paradigm is primarily intended to enhance cardio-metabolic performance via enhancing aerobic capacity. The study ensured to compare both paradigms and to highlight the pros and cons of each.
NMES-RT is proven to be effective in restoring muscle size and evoking hypertrophy in person...

It is estimated that approximately 282,000 persons in the U.S. are currently living with spinal cord injury (SCI)1. On average, there are roughly 17,000 new cases annually, primarily caused by motor vehicle crashes, acts of violence, and sporting activities1. SCI results in partial or total interruption of neural transmission across and below the level of injury2, leading to sub-lesional sensory and/or motor loss. After injury, activity of skeletal muscle below the level of injury is greatly reduced, leading to a rapid decline in lean mass and concomitant infiltration of ectopic adipose tissue, or intramuscular fat (IMF). Studies have shown that lower extremity skeletal muscle experiences significant atrophy within the first few weeks of injury, continuing throughout the end of the first year3,4. As soon as 6 weeks post-injury, individuals with complete SCI experienced an 18-46% decrease in sub-lesional muscle size compared to age and weight-matched abled-bodied controls. By 24 weeks post-injury, skeletal muscle cross-sectional area (CSA) could be as low as 30 to 50%3. Gorgey and Dudley showed that skeletal muscle continues to atrophy by 43% of the original size 4.5 months post-injury and noted a three times greater amount of IMF in persons with incomplete SCI compared to abled-bodied controls4. Loss of metabolically active lean mass results in a reduction in basal metabolic rate (BMR)2,6, which accounts for &#8764;65-70% of the total daily energy expenditure; such reductions in BMR can lead to a detrimental energy imbalance and increasing adiposity after injury2,7,8,9,10,18. Heightened adiposity has been linked to the development of chronic secondary conditions including hypertension, type II diabetes mellitus (T2DM) and cardiovascular disease2,10,11,12,13,14,15,16,17,18. Moreover, persons with SCI may suffer from malnutrition and reliance on a high fat diet. Dietary fat intake may account for 29 to 34% of the fat mass in persons with SCI, which is likely a factor explaining increasing adiposity and the escalating prevalence of obesity within the SCI population12,13.
Neuromuscular electrical stimulation evoked resistance training (NMES-RT) was designed to induce hypertrophy of paralyzed skeletal muscle19,20,21,22,23,24. Following twelve weeks of twice-weekly NMES-RT, skeletal muscle CSA of the whole thigh, knee extensor and knee flexor muscle groups increased by 28%, 35% and 16%, respectively22. Dudley et al. showed that 8 weeks twice-weekly of NMES-RT restored knee extensor muscle size to 75% of the original size at six weeks post-injury19. Moreover, Mahoney et al. utilized the same protocol and noted a 35% and 39% increase in the right and left rectus femoris muscles after 12 weeks of NMES-RT20.
Functional electrical stimulation-lower extremities cycling (FES-LEC) is a common rehabilitation technique used to exercise lower extremity muscle groups after SCI25,26. Unlike NMES-RT, FES-LEC relies on stimulation of 6 muscle groups, which may result in increased hypertrophy and improvements in the cardiometabolic profile10,25,26,27,28. Dolbow et al. found that total body lean mass increased by 18.5% following 56 months of FES-LEC in an individual with SCI27. Following twelve months of thrice-weekly FES-LEC, a 60-year old female with paraplegia experienced a 7.7% increase in total body lean mass and a 4.1% increase in leg lean mass28. Routine use of functional electrical stimulation (FES) is associated with improvement in risk factors of cardiometabolic conditions after SCI10,25,26.
Ideal candidates for electrical stimulation training will have either motor complete or incomplete injuries, with intact peripheral motor neurons and limited lower extremity sensation. The current manuscript, describes a combined approach using NMES-RT and FES-LEC designed to improve outcomes of electrical stimulation training in persons with chronic SCI. The process of NMES-RT using ankle weights will be outlined, while highlighting key steps within the protocol and the overall benefit the intervention provides to persons with chronic SCI. The second aim is to describe the process of FES-LEC designed to maximize the overall cardiometabolic effect of intervention. Previous work has affirmed our rational that a combined training protocol may evoke greater outcomes following 24 weeks of electrical stimulation training20,21,22,23,24,25,26,31,32,33,34,35,36.

<table>
	<tbody>
		<tr>
			<td>adhesive carbon electrodes (2 of each)</td>
			<td>Physio Tech (Richmond, VA, USA 23233)</td>
			<td>PT3X5 
			PALS3X4 
			E7300</td>
			<td>7.5&#39; x 12.7&#39; 
			7.5&#39; x 10&#39; 
			5&#39; x 9&#39;</td>
		</tr>
		<tr>
			<td>TheraTouch 4.7 stimulator</td>
			<td>Richmar (Chattanooga, TN, USA 37406)</td>
			<td>400-082</td>
			<td>41.28&#39; x 39.37&#39; x 17.78&#39; (8.91 kg) 
			power: 110 VAC at 60 Hz / 220VAC at 50 Hz 
			power consumption: 110 Watts</td>
		</tr>
		<tr>
			<td>Red &#38; White Lead Cords (2)</td>
			<td>Richmar (Chattanooga, TN, USA 37406)</td>
			<td>A1717</td>
			<td>2.0 m</td>
		</tr>
		<tr>
			<td>RT300-SL FES Ergometer</td>
			<td>Restorative Therapies, Inc. (Baltimore, MD, USA 21231)</td>
			<td>RT300-SL</td>
			<td>80&#39; x 49&#39; x 92-103&#39; (39 kg) 
			16 channel 
			speed: 15 &#8211; 55 rev/min</td>
		</tr>
		<tr>
			<td>elastic NuStim wraps (2)</td>
			<td>Fabrifoam (Exton, PA, USA 19341)</td>
			<td>PP108666</td>
			<td>36&#34;</td>
		</tr>
		<tr>
			<td>wooden wheelchair break (2)</td>
			<td>n/a</td>
			<td>n/a</td>
			<td>n/a</td>
		</tr>
		<tr>
			<td>pillow/cushion</td>
			<td>n/a</td>
			<td>n/a</td>
			<td>standard</td>
		</tr>
		<tr>
			<td>ankle weights</td>
			<td>n/a</td>
			<td>n/a</td>
			<td>2-26 lb.</td>
		</tr>
	</tbody>
</table>

paradigms of lower extremity electrical stimulation training after spinal cord injury

Skeletal muscle atrophy, increased adiposity and reduced physical activity are key changes observed after spinal cord injury (SCI) and are associated with numerous cardiometabolic health consequences. These changes are likely to increase the risk of developing chronic secondary conditions and impact the quality of life in persons with SCI. Surface neuromuscular electrical stimulation evoked resistance training (NMES-RT) was developed as a strategy to attenuate the process of skeletal muscle atrophy, decrease ectopic adiposity, improve insulin sensitivity and enhance mitochondrial capacity. However, NMES-RT is limited to only a single muscle group. Involving multiple muscle groups of the lower extremities may maximize the health benefits of training. Functional electrical stimulation-lower extremity cycling (FES-LEC) allows for the activation of 6 muscle groups, which is likely to evoke greater metabolic and cardiovascular adaptation. Appropriate knowledge of the stimulation parameters is key to maximizing the outcomes of electrical stimulation training in persons with SCI. Adopting strategies for long-term use of NMES-RT and FES-LEC during rehabilitation may maintain the integrity of the musculoskeletal system, a pre-requisite for clinical trials aiming to restore walking after injury. The current manuscript presents a combined protocol using NMES-RT prior to FES-LEC. We hypothesize that muscles conditioned for 12 weeks prior to cycling will be capable of generating greater power, cycle against higher resistance and result in greater adaptation in persons with SCI.

Ankle weights increased progressively for 22 participants, over 16 weeks of NMES-RT (Figure 6a). The average weights lifted by the participants was 19.6 &#177; 6.5 lb. (right leg) and 20 &#177; 6 lbs. (left leg) [8-24 lb.]. Current amplitude fluctuated throughout the trial for right and left legs (Figure 6b).
Progression of an individual with motor complete SCI followin...

Watch this Scientific Journal Video about Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury at JoVE.com

Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury

Spinal cord injury is a traumatic medical condition that may result in elevated risks of chronic secondary metabolic disorders. Here, we presented a protocol using surface neuromuscular electrical stimulation-resistance training in conjunction with functional electrical stimulation-lower extremities cycling as a strategy to ameliorate several of these medical problems.

Skeletal muscle atrophy, increased adiposity and reduced physical activity are key changes observed after spinal cord injury (SCI) and are associated with ...

The overall goal of this rehabilitation intervention is to highlight different uses of surface neuromuscular electrical stimulation resistance training, and functional electrical stimulation lower extremity cycling, as strategies to ameliorate several of the health-related consequences of spinal cord injury. So this method can help to answer key questions in the area of rehabilitation, on how to effectively design an electrical stimulation protocols for persons who has spinal cord injury. The benefit of these techniques is to maximize cardio-metabolic benefits, and to increase muscle mass after a spinal cord injury.We would like to investigate this research question to improve rehabilitation protocols available for persons with spinal cord injury. Should an individual with the spinal cord injury who are new to this method may struggle because of pain, that may experience at the beginning of the training. However, these patients may likely to have intact sensation, and as they develop training and move on in their training, they are likely to develop used to the program, and they become more tolerant to electrical stimulation protocol.Demonstrating the neuro-muscular electric stimulation protocol is Refka Khalil. She is a research coordinator in our lab. Demonstrating the FAS cycling for lower extremity training is Robert Lester and Sally Abilmona.Both of them are research assistants in our lab. To begin, measure the participant's resting blood pressure and heart rate. With the participant seated in a wheelchair, instruct them to remove their shoes.Position a pillow behind the participant's calf, to support the legs during knee flexion. Then, secure ankle weights to the participant's ankles. Position the distal electrode approximately 1/3 the distance between the patella and inguinal fold.Next, position the proximal electrode over the vastus lateralis muscle, laterally and adjacent to the inguinal fold. Position the proximal electrode longitudinally, and parallel to the midline access of the hip and knee joints. Set the frequency of a portable stimulator to 30 hertz, with a biphasic rectangular pulse width of 450 microseconds, and an inter-pulse interval of 50 microseconds.Then, connect the stimulator cables to each electrode. Start with the right leg, and gradually increase the current until visible tension is observed in the knee extensor muscle group. Slowly ramp the current until the knee is fully extended.Keep the knee in this position for three to five seconds to achieve maximum tension in the motor units. Then, progressively decrease the current until it is below 50%of the current required to extend the leg, and return the leg to the starting position. Record the current amplitude needed to achieve full leg extension.Complete a training protocol consisting of four sets of 10 repetitions per leg, alternating between the right and left legs. If the participant cannot achieve full knee extension, record the percent range of motion, and allow the participant to take more time between repetitions. First, measure the participant's resting blood pressure and heart rate.Then, position the participant, seated in their personal wheelchair, in front of an FES ergometer bike. Add here the distal electrode of the knee extensors to the skin over the vastus medialis, approximately 1/3 the distance between the patella and inguinal fold. Next, position the proximal electrode over the vastus lateralis muscle laterally, and adjacent to the inguinal fold.Adhere the distal electrode for the knee flexors to the skin two to three centimeters above the popliteal fossa, and apply an elastic wrap to secure its positioning. Then, position the proximal electrode 20 centimeters above the popliteal fossa. Next, instruct the participant to lean forward in the direction of the ergometer.Adhere two electrodes parallel and on the bulk of the muscle belly of the gluteus maximus. Inspect the front and back of the ergometer to ensure that the participant is appropriately positioned, and connect the electrodes to the stimulator. Then ensure the participant's wheelchair is locked, and secure the participant's feet to the ergometer pedals.Next, passively move the participant's legs to observe their movement in the ergometer. Adjust the height of the bike if the participant's legs are compressed or hyper-extended. Use two hooks located at the base of the ergometer to secure the wheelchair to the ergometer.Then, place two wooden blocks under the wheels of the wheelchair to prevent movement during cycling. On the stimulator, set the appropriate stimulation frequency for each muscle group. Then, select the appropriate cycle and interval training parameters.While the participant is completing the training session, measure their blood pressure every two to five minutes. Finally, record the participant's heart rate, speed, power, distance, resistance, and percent stimulation every 30 seconds, until the training session is complete. As shown in this table, the results indicate that with FES-LEC, there is an increase in the percentage of current stimulation to offset for the increase flywheel resistance over the 12 weeks of training.Resistance progressed from 1.0 to 4.5 newton meters during the first stage, 1.6 to 5.5 newton meters during the second stage, and 2.1 to 5.5 newton meters during the third stage. Finally, power output increased by two to four times in each of the three stages between week one and week 12. Power progressed from four to 12 watts during the first stage, 5.4 to 11.24 watts during the second stage, and 2.6 to 11 watts during the third stage.The implication of this techniques extend towards therapy and rehab of person who has spinal cord injury because of the dramatic muscle atrophy he has experienced that lead to significant health-related consequences after spinal cord injury. This method is essential, and can provide insights in how to apply electrical stimulation to other clinical population, not only spinal cord injury with neurological disorders. It can also be applied to other systems, such as upper extremity, abdominal, and trunk muscles.

Research

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