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.
1. Participant Recruitment
<ol>
	<li>Perform a pre-screening evaluation with potential participants.
	<ol>
		<li>Thoroughly explain the details of the training protocol including the length of study (24 weeks), times per week (bi-weekly) and length of sessions (NMES-RT: 30 min and FES-LEC: 45-60 min). 
		NOTE: NMES-RT is conducted for the first 12 weeks, followed by 12 weeks of FES-LEC.</li>
		<li>Describe the medical requirements to the potential participant including: male or female with SCI, American Spinal Injury Classification (AIS) A, B or C (those with an AIS &#34;C&#34; classification who are unable to stand up and walk), 18 to 65-year old, greater than 1-year post-injury, body mass index (BMI) &#8804; 30 kg/m2, motor complete or incomplete C5-L2 level of injury.</li>
		<li>Describe the medical restrictions to the potential participant including: a diagnosis of cardiovascular disease, uncontrolled type II diabetes mellitus or those on insulin, uncontrolled hypertension, pressure sores stage 3 or greater, urinary tract infection or symptoms, osteoporosis with T-Score -2.5, and pregnancy for women with SCI.</li>
	</ol>
	</li>
</ol>
2. NMES-RT
<ol>
	<li>Ensure the participant voids his/her bladder and measure the resting blood pressure and heart rate. While participant is seated in wheelchair, instruct the participant to take off his/her shoes. Then, place a pillow behind the calf to cushion the leg during knee flexion. Apply ankle weights (0-26 lbs.) to the participant&#39;s ankles (Figure 1). 
	NOTE: The initial 2 sessions are conducted without ankle weights to ensure the participant can lift his/her leg against gravity.</li>
	<li>Apply two 7.5 cm x 12.7 cm adhesive carbon electrodes bilaterally on the skin over the knee extensor muscle group.
	<ol>
		<li>Place the distal electrode ~1/3 the distance between the patella and inguinal fold and medial to the midline of the quadriceps. Place the electrode longitudinally and parallel to the midline axis running from the hip to the knee joints (Figure 2).</li>
		<li>Place the proximal electrode laterally and adjacent to the inguinal fold over the vastus lateralis muscle. Place the electrode longitudinally and parallel to the midline axis (Figure 2).</li>
	</ol>
	</li>
	<li>Set a portable stimulator to a frequency of 30 Hz and a biphasic rectangular pulse width of 450 &#181;s and 50 &#181;s interpulse interval19,20,21,22,23,24,37,38,39. Connect the cables from the stimulator to each electrode. 
	NOTE: The polarity of the electrodes does not influence the stimulation pattern as long as the electrodes are positioned correctly.</li>
	<li>Beginning with the right leg, gradually increase the current until a noticeable visible tension is recognized in the knee extensor muscle group. Continue to slowly ramp the current to evoke full knee extension (max. 200 mA). Allow the leg to remain extended for 3-5 s to evoke maximum tension in the activated motor units.</li>
	<li>Gradually decrease the current until it&#39;s below 50% of the target current required to extend the leg and move leg eccentrically back to the starting position. Record the current amplitude necessary to evoke full leg extension.</li>
	<li>Complete unilateral training including 4 sets of 10 repetitions per leg and alternate between right and left legs. Allow the leg to rest 3-5 s between each repetition and 3 min between sets. If participant does not reach full knee extension, record the %range of motion and increase the time between repetitions. 
	NOTE: Muscle fatigue is defined as two consecutive repetitions with a range of motion &#8804; 25%.</li>
	<li>Attempt each of the four sets, but if participant experiences muscle fatigue, end the current set and continue training on the opposite leg. If full knee extension is achieved without muscle fatigue for 2 consecutive training sessions, add 2 lbs. of ankle weights the following week of training.</li>
</ol>
3. FES-LEC
<ol>
	<li>Measure the participant&#39;s resting blood pressure and heart rate. Position the participant in front of the FES ergometer bike (Table of Materials) seated in his/her personal power or manual wheelchair (Figure 3a, Figure 3b).</li>
	<li>Apply adhesive carbon electrodes to the knee extensor, knee flexor and gluteus maximus muscle groups bilaterally.
	<ol>
		<li>For knee extensors, place the distal electrode (7.5 x 12.7 cm) on the skin 1/3 the distance between the patella and inguinal fold, over the vastus medialis muscle. Place the proximal electrode laterally and adjacent to the inguinal fold over the vastus lateralis muscle (Figure 4a).</li>
		<li>For knee flexors, place the distal electrode (7.5 x 10 cm) on the skin 2-3 cm above the popliteal fossa. Place the proximal electrode 20 cm above the popliteal fossa (Figure 4b). To prevent movement of the distal electrode, apply an elastic wrap to secure positioning of the electrode (Figure 3a).</li>
		<li>For gluteus maximus, instruct the participant to lean forward towards the ergometer. Place two electrodes (5 x 9 cm) parallel and on the bulk of the muscle belly; allow ~two fingers width of separation between the electrodes.</li>
	</ol>
	</li>
	<li>With the participant seated in his/her wheelchair and centered in front of the ergometer, connect the cables from the stimulator to each of the 12 electrodes. Check the front and back of the ergometer to make sure the participant is correctly centered.</li>
	<li>Ensure that the participant&#39;s wheelchair is locked and gently place the participant&#39;s feet (wearing tennis shoes) inside the pedals (Figure 6). Secure the lower leg to the ergometer using the elastic straps wrapped in a fabric covering. Secure the participant&#39;s feet in place with the two crossing elastic straps and Velcro located on each petal (Figure 5).</li>
	<li>After strapping the legs to the ergometer, passively move the legs so observe the cycling pattern. If the legs are too compressed or hyperextended, adjust the height of the bike and recheck the position by passively moving the leg.</li>
	<li>Secure the participant&#39;s wheelchair to the ergometer using the two extendable hooks located at the base of the ergometer. Connect the hooks to a stable structure underneath the wheelchair (Figure 5). Place two wooden breaks underneath the wheels of the wheelchair, to prevent any movement of chair during cycling.</li>
	<li>Set the stimulation frequency to 33.3 Hz, pulse duration to 350 &#181;s and the current amplitude to 140, 100, 100 mA for the knee extensor, knee flexor and gluteus maximus muscle groups, respectively.</li>
	<li>Set the cycle parameters as follows: target speed of 40-45 revolutions per minute (RPM); adjustable motor torque starting at 10 Nm; resistance of 1.0, 1.5 and 2.0 Nm for exercise stages I, II and III.</li>
	<li>Set the interval training parameters as follows: 3 min &#34;warm up&#34; phase; three 10-min exercise stages (stimulation on); a 2-min resting phase following each exercise stage; and 3 min &#34;cool down&#34; phase.</li>
	<li>Based on the level of injury (above or below T4), measure the blood pressure and heart rate every 2 to 5 min to prevent the occurrence of any symptoms of autonomic dysreflexia.</li>
	<li>If blood pressure remains elevated, stop the ergometer and instruct the participant to void his/her bladder or rest if they have already voided. In addition, check to ensure the participant is seated properly to reduce any pressure points and check that the shoes or any straps are not overly-tightened. Monitor blood pressure closely every 2 min. If blood pressure recovers, resume training; if blood pressure remains unrecovered, end the session and instruct the participant to see his/her primary care physician. 
	NOTE: It is vital to ensure that participants consistently take their blood pressure medication, if any, and void their bladder before FES-cycling.</li>
	<li>Record the participant&#39;s heart rate, speed, power, distance, resistance and % stimulation every 30 s.</li>
	<li>If participant completes an entire exercise session without fatigue (speed &#60; 18 RPM during active cycling), decrease the servo motor torque assistance by 1 Nm the following session, otherwise keep all parameters the same.</li>
	<li>If participant completes two exercise training sessions without fatigue or the use of servo motor assistance during exercise stages, increase the resistance by 0.5 Nm in each exercise stage.</li>
</ol>

The authors have nothing to disclose.

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&lt;br/&gt; PALS3X4&lt;br/&gt; E7300</td><td>7.5&#039; x 12.7&#039;&lt;br/&gt; 7.5&#039; x 10&#039;&lt;br/&gt; 5&#039; x 9&#039;</td></tr><tr><td>TheraTouch 4.7 stimulator</td><td>Richmar (Chattanooga, TN, USA 37406)</td><td>400-082</td><td>41.28&#039; x 39.37&#039; x 17.78&#039; (8.91 kg)&lt;br/&gt; power: 110 VAC at 60 Hz / 220VAC at 50 Hz&lt;br/&gt; power consumption: 110 Watts</td></tr><tr><td>Red &amp;amp; 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&#039; x 49&#039; x 92-103&#039; (39 kg)&lt;br/&gt; 16 channel&lt;br/&gt; speed: 15 &amp;ndash; 55 rev/min</td></tr><tr><td>elastic NuStim wraps (2)</td><td>Fabrifoam (Exton, PA, USA 19341)</td><td>PP108666</td><td>36&quot;</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 ...

paradigms-lower-extremity-electrical-stimulation-training-after

Research

JoVE Journal

Behavior

12.6K Views.  Hunter Holmes McGuire VAMC. Dwarslaesie is een traumatische medische aandoening die leiden verhoogde risico's van chronische secundaire stofwisselingsziekten tot kan. Hier voorgesteld hebben we een protocol met behulp van oppervlakte neuromusculaire elektrische stimulatie-resistentie opleiding in combinatie met functionele elektrische stimulatie-lagere extremiteiten fietsen als een strategie ter verbetering van verscheidene van deze medische problemen.

Video: Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury

A Murine Model of Muscle Training by Neuromuscular Electrical Stimulation

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional capacity. Transcutaneous surface stimulation of skeletal muscle involves a current flow between a cathode and an anode, thereby inducing excitement of the motor unit and the surrounding muscle fibers. 
NMES is an attractive modality to evaluate skeletal muscle adaptive responses for several reasons. First, it provides a reproducible experimental model in which physiological adaptations, such as myofiber hypertophy and muscle strengthening6, angiogenesis7-9, growth factor secretion9-11, and muscle precursor cell activation12 are well documented. Such physiological responses may be carefully titrated using different parameters of stimulation (for Cochrane review, see 13). In addition, NMES recruits motor units non-selectively, and in a spatially fixed and temporally synchronous manner14, offering the advantage of exerting a treatment effect on all fibers, regardless of fiber type. Although there are specified contraindications to NMES in clinical populations, including peripheral venous disorders or malignancy, for example, NMES is safe and feasible, even for those who are ill and/or bedridden and for populations in which rigorous exercise may be challenging. 
Here, we demonstrate the protocol for adapting commercially available electrodes and performing a NMES protocol using a murine model. This animal model has the advantage of utilizing a clinically available device and providing instant feedback regarding positioning of the electrode to elicit the desired muscle contractile effect. For the purpose of this manuscript, we will describe the protocol for muscle stimulation of the anterior compartment muscles of a mouse hindlimb.

A murine model of neuromuscular electrical stimulation (NMES), a safe and inexpensive clinical modality, to the anterior compartment muscles is described. This model has the advantage of modifying a readily available clinical device for the purpose of eliciting targeted and specific muscle contractions in mice.

Neuromuscular electrical stimulation (NMES) is a common clinical modality that is widely used to restore1, maintain2 or enhance3-5 muscle functional ...

Medicine

Treating Low Back Pain in Failed Back Surgery Patients with Multicolumn-lead Spinal Cord Stimulation

Failed back surgery syndrome (FBSS) refers to persistent, chronic pain following spinal surgery. Spinal cord stimulation with dorsal epidural leads can be used to treat back and leg pain in FBSS patients. This paper presents a detailed protocol for using spinal cord stimulation with surgical leads in FBSS patients. In our department, with the patient under general anesthesia, we place the lead in the epidural space by means of a small laminectomy at the 10th thoracic level. Placement of the lead is followed by a 1 month trial period with an externalized lead. If pain relief is greater than 50% at the end of this 1 month stimulation trial (required by Belgian reimbursement criteria), an internal pulse generator is then placed under the skin and connected to the lead in a second surgical procedure. We have demonstrated that using this technique in rigorously selected FBSS patients can significantly improve back pain, leg pain, patient activity, and quality of life for a sustained period of time.

This paper presents a method that uses spinal cord stimulation with a multicolumn lead to treat neuropathic low back pain in failed back surgery patients.

Failed back surgery syndrome (FBSS) refers to persistent, chronic pain following spinal surgery. Spinal cord stimulation with dorsal epidural leads can be ...

Breathing-controlled Electrical Stimulation (BreEStim) for Management of Neuropathic Pain and Spasticity

Electrical stimulation (EStim) refers to the application of electrical current to muscles or nerves in order to achieve functional and therapeutic goals. It has been extensively used in various clinical settings. Based upon recent discoveries related to the systemic effects of voluntary breathing and intrinsic physiological interactions among systems during voluntary breathing, a new EStim protocol, Breathing-controlled Electrical Stimulation (BreEStim), has been developed to augment the effects of electrical stimulation. In BreEStim, a single-pulse electrical stimulus is triggered and delivered to the target area when the airflow rate of an isolated voluntary inspiration reaches the threshold. BreEStim integrates intrinsic physiological interactions that are activated during voluntary breathing and has demonstrated excellent clinical efficacy. Two representative applications of BreEStim are reported with detailed protocols: management of post-stroke finger flexor spasticity and neuropathic pain in spinal cord injury.

Breathing-controlled Electrical Stimulation BreEStim for Management of Neuropathic Pain and Spasticity

The purpose is to present a new method, breathing-control electrical stimulation (BreEStim) for management of neuropathic pain and spasticity.

Electrical stimulation (EStim) refers to the application of electrical current to muscles or nerves in order to achieve functional and therapeutic goals. ...

Training Persons with Spinal Cord Injury to Ambulate Using a Powered Exoskeleton

Powered exoskeletons have become available for overground ambulation in persons with paralyses due to spinal cord injury (SCI) who have intact upper extremity function and are able to maintain upright balance using forearm crutches. To ambulate in an exoskeleton, the user must acquire the ability to maintain balance while standing, sitting and appropriate weight shifting with each step. This can be a challenging task for those with deficits in sensation and proprioception in their lower extremities. This manuscript describes screening criteria and a training program developed at the James J. Peters VA Medical Center, Bronx, NY to teach users the skills needed to utilize these devices in institutional, home or community environments. Before training can begin, potential users are screened for appropriate range of motion of the hip, knee and ankle joints. Persons with SCI are at an increased risk of sustaining lower extremity fractures, even with minimal strain or trauma, therefore a bone mineral density assessment is performed to reduce the risk of fracture. Also, as part of screening, a physical examination is performed in order to identify additional health-related contraindications. 
Once the person has successfully passed all screening requirements, they are cleared to begin the training program. The device is properly adjusted to fit the user. A series of static and dynamic balance tasks are taught and performed by the user before learning to walk. The person is taught to ambulate in various environments ranging from indoor level surfaces to outdoors over uneven or changing surfaces. Once skilled enough to be a candidate for home use with the exoskeleton, the user is then required to designate a companion-walker who will train alongside them. Together, the pair must demonstrate the ability to perform various advanced tasks in order to be permitted to use the exoskeleton in their home/community environment.

Training a person with paralysis to ambulate using a powered exoskeleton may present challenges. The goals are to present the candidate selection criteria and the training procedures for exoskeletal-assisted walking and other mobility skills that can be progressed as the participant's skill level improves.

Powered exoskeletons have become available for overground ambulation in persons with paralyses due to spinal cord injury (SCI) who have intact upper ...

Bioengineering

Standing Neurophysiological Assessment of Lower Extremity Muscles Post-Stroke

Transcranial magnetic stimulation (TMS) is a common tool used to measure the behavior of motor circuits in healthy and neurologically impaired populations. TMS is used extensively to study motor control and the response to neurorehabilitation of the upper extremities. However, TMS has been less utilized in the study of lower extremity postural and walking-specific motor control. The limited use and the additional methodological challenges of lower extremity TMS assessments have contributed to the lack of consistency in lower extremity TMS procedures within the literature. Inspired by the decreased ability to record lower extremity TMS motor evoked potentials (MEP), this methodological report details steps to enable post-stroke TMS assessments in a standing posture. The standing posture allows for the activation of the neuromuscular system, reflecting a state more akin to the system's state during postural and walking tasks. Using dual-top force plates, we instructed participants to equally distribute their weight between their paretic and non-paretic legs. Visual feedback of the participants' weight distribution was provided. Using image guidance software, we delivered single TMS pulses via a double-cone coil to the participants' lesioned and non-lesioned hemispheres and measured the corticomotor response of the paretic and non-paretic tibialis anterior and soleus muscles. Performing assessments in the standing position increased the TMS response rate and allowed for the use of the lower stimulation intensities compared to the standard sitting/resting position. Utilization of this TMS protocol can provide a common approach to assess the lower extremity corticomotor response post-stroke when the neurorehabilitation of postural and gait impairments are of interest.

This protocol describes the process for performing a neurophysiological assessment of the lower extremity muscles, tibialis anterior and soleus, in a standing position using TMS in people post-stroke. This position provides a greater probability of eliciting a post-stroke TMS response and allows for the use of reduced stimulator power during neurophysiological assessments.

Transcranial magnetic stimulation (TMS) is a common tool used to measure the behavior of motor circuits in healthy and neurologically impaired ...

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Execution of Sit-to-Stand (SitTS) in incomplete spinal cord injury (SCI) patients involves motor function in both upper and lower extremities. The use of arm support, in particular, is a significant assistive factor while executing SitTS movement in SCI population. In addition, the application of functional electrical stimulation (FES) onto quadriceps and gluteus maximus muscles is one of the prescribed management for incomplete SCI to improve muscle action for simple lower limb movements. However, the relative contribution of upper and lower extremities during SitTS has not been thoroughly investigated. Two motor incomplete SCI paraplegics performed repetitive SitTS to fatigue exercise challenge. Their performance was investigated as a mixed-method case-control study comparing SitTS with and without the assistance of FES. Three sets of SitTS tests were completed with 5-min resting period allocated in between sets, with mechanomyography (MMG) sensors attached over the rectus femoris muscles bilaterally. The exercise was separated into 2 sessions; Day 1 for voluntary SitTS and Day 2 for FES-assisted SitTS. Questionnaires were conducted after every session to gather the participants&#39; input about their repetitive SitTS experience. The analysis confirmed that a SitTS cycle could be divided into three phases; Phase 1 (Preparation to stand), Phase 2 (Seat-off), and Phase 3 (Initiation of hip extension), which contributed to 23% &#177; 7%, 16% &#177; 4% and 61% &#177; 6% of the SitTS cycle, respectively. The contribution of arms and legs during SitTS movement varied in different participants based on their legs&#39; Medical Research Council (MRC) muscle grade. In particular, the applied arm forces start to increase clearly when the leg forces start to decline during standing. This finding is supported by the significantly reduced MMG signal indicating leg muscle fatigue and their reported feeling of tiredness.

Arms contribution in Sit-To-Stand (SitTS) is determined by the legs' muscle condition. Several compensating strategies were discovered in efforts to achieve complete SitTS cycles. These findings triangulate the spinal cord injury (SCI) persons' biomechanical measures with their subjective feeling of load borne by both their limbs throughout the SitTS approaches.

Execution of Sit-to-Stand (SitTS) in incomplete spinal cord injury (SCI) patients involves motor function in both upper and lower extremities. The use of ...

Engineering

A Human-machine-interface Integrating Low-cost Sensors with a Neuromuscular Electrical Stimulation System for Post-stroke Balance Rehabilitation

A stroke is caused when an artery carrying blood from heart to an area in the brain bursts or a clot obstructs the blood flow to brain thereby preventing delivery of oxygen and nutrients. About half of the stroke survivors are left with some degree of disability. Innovative methodologies for restorative neurorehabilitation are urgently required to reduce long-term disability. The ability of the nervous system to reorganize its structure, function and connections as a response to intrinsic or extrinsic stimuli is called neuroplasticity. Neuroplasticity is involved in post-stroke functional disturbances, but also in rehabilitation. Beneficial neuroplastic changes may be facilitated with non-invasive electrotherapy, such as neuromuscular electrical stimulation (NMES) and sensory electrical stimulation (SES). NMES involves coordinated electrical stimulation of motor nerves and muscles to activate them with continuous short pulses of electrical current while SES involves stimulation of sensory nerves with electrical current resulting in sensations that vary from barely perceivable to highly unpleasant. Here, active cortical participation in rehabilitation procedures may be facilitated by driving the non-invasive electrotherapy with biosignals (electromyogram (EMG), electroencephalogram (EEG), electrooculogram (EOG)) that represent simultaneous active perception and volitional effort. To achieve this in a resource-poor setting, e.g., in low- and middle-income countries, we present a low-cost human-machine-interface (HMI) by leveraging recent advances in off-the-shelf video game sensor technology. In this paper, we discuss the open-source software interface that integrates low-cost off-the-shelf sensors for visual-auditory biofeedback with non-invasive electrotherapy to assist postural control during balance rehabilitation. We demonstrate the proof-of-concept on healthy volunteers.

A novel low-cost human-machine interface for interactive post-stroke balance rehabilitation system is presented in this article. The system integrates off-the-shelf low-cost sensors towards volitionally driven electrotherapy paradigm. The proof-of-concept software interface is demonstrated on healthy volunteers.

A stroke is caused when an artery carrying blood from heart to an area in the brain bursts or a clot obstructs the blood flow to brain thereby preventing ...

Neuroscience

Finite Element Modelling of a Cellular Electric Microenvironment

Clinical studies show electrical stimulation (ES) to be a potential therapy for the healing and regeneration of various tissues. Understanding the mechanisms of cell response when exposed to electrical fields can therefore guide the optimization of clinical applications. In vitro experiments aim to help uncover those, offering the advantage of wider input and output ranges that can be ethically and effectively assessed. However, the advancements in in vitro experiments are difficult to reproduce directly in clinical settings. Mainly, that is because the ES devices used in vitro differ significantly from the ones suitable for patient use, and the path from the electrodes to the targeted cells is different. Translating the in vitro results into in vivo procedures is therefore not straightforward. We emphasize that the cellular microenvironment's structure and physical properties play a determining role in the actual experimental testing conditions and suggest that measures of charge distribution can be used to bridge the gap between in vitro and in vivo. Considering this, we show how in silico finite element modelling (FEM) can be used to describe the cellular microenvironment and the changes generated by electric field (EF) exposure. We highlight how the EF couples with geometric structure to determine charge distribution. We then show the impact of time dependent inputs on charge movement. Finally, we demonstrate the relevance of our new in silico model methodology using two case studies: (i) in vitro fibrous Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT-PSS) scaffolds and (ii) in vivo collagen in extracellular matrix (ECM).

This paper presents a strategy for building finite element models of fibrous conductive materials exposed to an electric field (EF). The models can be used to estimate the electrical input that cells seeded in such materials receive and assess the impact of changing the scaffold's constituent material properties, structure or orientation.

Clinical studies show electrical stimulation (ES) to be a potential therapy for the healing and regeneration of various tissues. Understanding the ...

Activity-based Training on a Treadmill with Spinal Cord Injured Wistar Rats

Spinal cord injury (SCI) results in lasting deficits that include both mobility and a multitude of autonomic-related dysfunctions. Locomotor training (LT) on a treadmill is widely used as a rehabilitation tool in the SCI population with many benefits and improvements to daily life. We utilize this method of activity-based task-specific training (ABT) in rodents after SCI to both elucidate the mechanisms behind such improvements and to enhance and improve upon existing clinical rehabilitation protocols. Our current goal is to determine the mechanisms underlying ABT-induced improvements in urinary, bowel, and sexual function in SCI rats after a moderate to severe level of contusion. After securing each individual animal in a custom-made adjustable vest, they are secured to a versatile body weight support mechanism, lowered to a modified three-lane treadmill and assisted in step-training for 58 minutes, once a day for 10 weeks. This setup allows for the training of both quadrupedal and forelimb-only animals, alongside two different non-trained groups. Quadrupedal-trained animals with body weight support are aided by a technician present to assist in stepping with proper hind limb placement as necessary, while forelimb-only trained animals are raised at the caudal end to ensure no hind limb contact with the treadmill and no weight-bearing. One non-trained SCI group of animals is placed in a harness and rests next to the treadmill, while the other control SCI group remains in its home cage in the training room nearby. This paradigm allows for the training of multiple SCI animals at once, thus making it more time-efficient in addition to ensuring that our pre-clinical animal model mimics the clinical representation as close as possible, particularly with respect to the body weight support with manual assistance.

This protocol demonstrates our model of activity-based locomotor treadmill training for rats with spinal cord injury (SCI). Included is both quadrupedal and forelimb-only groups, in addition to two distinct types of non-trained control groups. Investigators are able to assess training effects on SCI rats using this protocol.

Spinal cord injury (SCI) results in lasting deficits that include both mobility and a multitude of autonomic-related dysfunctions. Locomotor training (LT) ...

Implantation and Control of Wireless, Battery-free Systems for Peripheral Nerve Interfacing

Peripheral nerve interfaces are frequently used in experimental neuroscience and regenerative medicine for a wide variety of applications. Such interfaces can be sensors, actuators, or both. Traditional methods of peripheral nerve interfacing must either tether to an external system or rely on battery power that limits the time frame for operation. With recent developments of wireless, battery-free, and fully implantable peripheral nerve interfaces, a new class of devices can offer capabilities that match or exceed those of their wired or battery-powered precursors. This paper describes methods to (i) surgically implant and (ii) wirelessly power and control this system in adult rats. The sciatic and phrenic nerve models were selected as examples to highlight the versatility of this approach. The paper shows how the peripheral nerve interface can evoke compound muscle action potentials (CMAPs), deliver a therapeutic electrical stimulation protocol, and incorporate a conduit for the repair of peripheral nerve injury. Such devices offer expanded treatment options for single-dose or repeated dose therapeutic stimulation and can be adapted to a variety of nerve locations.

This is a protocol for the surgical implantation and operation of a wirelessly powered interface for peripheral nerves. We demonstrate the utility of this approach with examples from nerve stimulators placed on either the rat sciatic or phrenic nerve.

Peripheral nerve interfaces are frequently used in experimental neuroscience and regenerative medicine for a wide variety of applications. Such interfaces ...

Paradigms of Lower Extremity Electrical Stimulation Training After Spinal Cord Injury

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