Low-intensity Electrical Stimulation Research Articles

Patient-reported outcomes during accelerating the en-masse retraction of the upper anterior teeth using low-intensity electrical stimulation: a randomized controlled trial

BackgroundLow-intensity electrical stimulation (LIES) is considered a relatively recent technology that has received little attention in orthodontics as a method of acceleration. This study aimed to evaluate patient-reported outcome measures when LIES is used to accelerate the en-masse retraction of the upper anterior teeth.Materials and methodsThe sample consisted of 40 patients (8 males, 32 females; mean age 21.1 ± 2.3 years), with Class II division I malocclusion who required extraction of the first premolars to retract upper anterior teeth. They were randomly assigned to the LIES group (n = 20) and the conventional en-masse retraction group (CER; n = 20). Patient responses regarding pain, discomfort, burning sensation, swelling, chewing difficulty, speech difficulty, and painkillers’ consumption were recorded at these nine assessment times: 24 h (T1), 3 days (T2), and 7 days (T3) after force application, then in the second month after 24 h (T4), 3 days (T5), and 7 days (T6) of force re-activation, and finally after 24 h (T7), 3 days (T8), and 7 days (T9) of force re-activation in the third month.ResultsThe mean values of pain perception were smaller in the LIES group than those in the CER group at all assessment times with no statistically significant differences between the two groups except during the second and third months (T5, T6, T8, and T9; P < 0.005). However, discomfort mean values were greater in the LIES group with significant differences compared to CER group during the first week of the follow-up only (T1, T2, and T3; P < 0.005). Burning sensation levels were very mild in the LIES group, with significant differences between the two groups at T1 and T2 only (P < 0.001). Speech difficulty was significantly greater in the LIES group compared to CER group at all studied times (P < 0.001). High levels of satisfaction and acceptance were reported in both groups, without any significant difference.ConclusionBoth the LIES-based acceleration of en-masse retraction of upper anterior teeth and the conventional retraction were accompanied by mild to moderate pain, discomfort, and chewing difficulty on the first day of retraction. These sensations gradually decreased and almost disappeared over a week after force application or re-activation.Trial registrationClinicalTrials.gov, ClinicalTrials.gov, NCT05920525. Registered 17 June 2023 - retrospectively registered, http://clinicaltrials.gov/study/NCT05920525?term=NCT05920525&rank=1.

Low-Intensity Electrical Stimulation Improved the Mineralization of Adipose-Derived Mesenchymal Stem Cells

Multipotent mesenchymal stromal cells (MSCs) derived from adipose tissue have been increasingly studied due their lessinvasive extraction surgery, self-renew and differentiation potential. The literature has not been reported the comparison of different sources of MSCs derived from distinct adipose tissues and the use of electrical stimulation (ES) for tooth and bone tissue regeneration. The present study evaluated in vitro cell viability by MTT, cell proliferation by CCK-8 and the osteogenic differentiation by alizarin red-S staining of MSCs from Wistar rats adipose tissue, abdominal (ABD) and inguinal (ING), submitted to ES therapy. ES was applied during 60s, 150s and 300s at 10µA-intensity 3x/week. The ES therapy was not cytotoxic at any time of the experimentation. MSCs from ING presented higher percentage of cell viability at 60s of ES than MSCs from ABD stimulated for 150s and 300s. Moreover, MSCs from ING presented higher proliferation rate than ABD at all three ES time-application. The use of ES therapy during the osteogenic differentiation contributed positively to improve the mineralization process. MSCs from ING presented 30% greater mineralization at 150s, and 50% at 300s, while ABD showed 50% greater at 60s of ES. In conclusion, MSCs from ING and ABD are able to increase cell proliferation and improve osteogenic mineralization, but with different responses depending on the ES stimuli at the same experimental condition, which reinforce the needing for further investigation on the use of MSCs derived from fat tissue and ES to optimize their use for cell proliferation and mineralization in regenerative medicine.

Electrical Stimulation Intensity to Induce Sensory Reweighting Dynamics While Standing on Balance Board.

In human postural control, maladaptation of sensory reweighting to sudden environmental changes is one of the main causes of postural instability. Providing sensory cues for body motion by means of stimulation could induce the sensory reweighting dynamics. In this paper, we aimed to investigate the intensity level of electrical stimulation to induce sensory reweighting dynamics while standing on a balance board under three conditions: no stimulation (control), electrotactile stimulation (ETS) at a low-intensity level, and electrical muscle stimulation (EMS) at a high-intensity level. A total of 30 participants (ten for each condition) controlled their posture to keep the board horizontal in a balance-board task, which included a pre-test without stimulation, a stimulation test, and a post-test without stimulation. The EMS and ETS groups received electrical stimulation to the tibialis anterior or soleus muscles based on the board tilt. Before and after the balance-board task, participants performed static standing with their eyes open and also with their eyes closed to evaluate the visual reweighting. In the EMS group, the visual reweighting showed a strong negative correlation with the balance-board sway ratio between the pre- and stimulation tests, indicating that EMS induced a tendency that requires visual up-weighting to improve postural balance. However, there were no significant correlations between either parameter in the control and ETS groups. These results suggest that high-intensity electrical stimulation at the level of directly contracting muscles may be effective in reliably inducing sensory reweighting dynamics, while low-intensity electrical stimulation may be insufficient.Clinical relevance- These findings will be helpful for designing stimulus conditions to reliably induce the reweighting during balance training, and for establishing a new balance training method utilizing EMS to induce visual up-weighting.

Modulation of reflex responses of the anterior and posterior bellies of the digastric muscle in freely moving rats.

Chewing and licking are primarily activated by central pattern generator (CPG) neuronal circuits in the brainstem and when activated trigger repetitive rhythmic orofacial movements such as chewing, licking and swallowing. These CPGs are reported to modulate orofacial reflex responses in functions such as chewing. This study explored the modulation of reflex responses in the anterior and posterior bellies (ant-Dig and post-Dig, respectively) of the digastric muscle evoked by low-intensity trigeminal stimulation in conscious rats. The ant-Dig and post-Dig reflexes were evoked by using low-intensity electrical stimulation applied to either the right or left inferior alveolar nerve. Peak-to-peak amplitudes and onset latencies were measured. No difference was observed between threshold and onset latency for evoking ant-Dig and post-Dig reflexes, suggesting that the latter was also evoked disynaptically. The peak-to-peak amplitude of both reflexes was significantly reduced during chewing, licking and swallowing as compared to resting period and was lowest during the jaw-closing phase of chewing and licking. Onset latency was significantly largest during the jaw-closing phase. Inhibitory level was similar between the ant-Dig and post-Dig reflex responses and between the ipsilateral and contralateral sides. These results suggest that both the ant-Dig and post-Dig reflex responses were significantly inhibited, probably due to CPG activation during feeding behaviours to maintain coordination of jaw and hyoid movements and hence ensure smooth feeding mechanics.

Engineering diabetic human skin equivalent for in vitro and in vivo applications

The prevalence of diabetes is increasing worldwide. Diabetes contributes to 70% of all non-traumatic lower-limb amputations, which are directly caused by diabetic foot ulcers (DFU) that are difficult to heal. Non-healing diabetic ulcers represent one of modern society’s most difficult medical challenges. One of the promising initiatives to treat DFU is the grafting of autologous skin or stimulating the skin cells at the edge of the wound to proliferate and close the wound. The present study was to engineer a diabetic human skin equivalent (DHSE) that contains fibroblasts and keratinocytes extracted from the skin collected from diabetic patients. The DHSE was used to investigate whether exposure to low-intensity electrical stimulation (ES) could promote diabetic cell activity. The ES was generated by a direct current (DC) electric field of 20 or 40 mV/mm. We demonstrated that the fibroblasts and keratinocytes could be extracted from older diabetics, cultured, and used to engineer DHSE. Interestingly, the exposure of DHSE to ES led to a structural improvement through tissue stratification, increased Ki-67 expression, and the deposition of basement membrane proteins (laminin and type IV collagen). The DHSE exposed to ES showed a high level of keratin 5 and 14 expressions in the basal and supra-basal layers. The keratinocyte proliferation was supported by an increased secretion of the keratinocyte growth factor (FGF-7). Exposure to ES decreased the activity of metalloproteinases (MMP) 2 and 9. In conclusion, we extracted keratinocytes and fibroblasts from the skin of diabetic-old donors. These cells were used to engineer skin equivalents and demonstrate that ES can promote diabetic wound healing. This DHSE can be a promising tool for various in vitro studies to understand the wound healing mechanisms under chronic inflammatory conditions such as diabetes. The DHSE could also be used as an autologous substrate to cover the DFU permanently.

Acute Effects of Low-Intensity Electrical Stimulation on Segmental Arterial Stiffness.

Electrical muscle stimulation (EMS) has traditionally been employed to improve muscle strength and glucose uptake. EMS may also reduce arterial stiffness, but little is known about whether low-intensity EMS reduces systemic and/or regional arterial stiffness. This study aimed to examine the effects of low-intensity EMS of the lower limbs on segmental arterial stiffness. Fourteen healthy subjects participated in experiments under two different protocols (control resting trial (CT) and electrical stimulation trial (ET)) in random order on separate days. The EMS was applied to the lower limbs at 4 Hz for 20 min at an intensity corresponding to an elevation of approximately 15 beats/min in pulse rate (10.7 ± 4.7% of heart rate reserve). Arterial stiffness was assessed by cardio-ankle vascular index (CAVI), CAVI0, heart-ankle pulse wave velocity (haPWV), brachial-ankle pulse wave velocity (baPWV), heart-brachial pulse wave velocity (hbPWV), and carotid-femoral pulse wave velocity (cfPWV). In both trials, each parameter was measured at before (Pre) and 5 min (Post 1) and 30 min (Post 2) after trial. After the experiment, CT did not cause significant changes in any arterial stiffness parameters, whereas ET significantly reduced CAVI (from Pre to Post 1: −0.8 ± 0.5 unit p < 0.01), CAVI0 (from Pre to Post 1: −1.2 ± 0.8 unit p < 0.01), haPWV (from Pre to Post 1: −47 ± 35 cm/s p < 0.01), and baPWV (from Pre to Post 1: −120 ± 63 cm/s p < 0.01), but not hbPWV or cfPWV. Arm diastolic blood pressure (BP) at Post 2 was slightly but significantly increased in the CT compared to Pre or Post 1, but not in the ET. Conversely, ankle diastolic and mean BPs at Post 1 were significantly reduced compared to Pre and Post 2 in the ET (p < 0.01). These findings suggest that low-intensity EMS of the lower limbs reduces arterial stiffness, but only in sites that received EMS.

Accurate Neurosurgery for the Establishment of the Electric Kindling Model of Epilepsy in Mice

This article describes in detail the essential stereotaxic neurosurgery to develop the electric experimental kindling model in mice. To date, available literature describing the methodology of the kindling model is very poor and usually neglects many relevant details about the neurosurgery, such as the manufacture of the electrodes, accurate stereotaxic coordinates of the amygdala nuclei, and the general surgery procedures (e.g., anesthesia, postsurgical recovery, fit survival of the animal’s). The electric kindling model produces a progressive development of generalized tonic-clonic seizures, which can be assessed by electroencephalography and behavioral responses. The seizures displayed are produced by a repeated low-intensity electrical stimulation in specific regions of the brain that is achieved through the previous implantation of electrodes. In this study, the aim was to implant the electrodes in basolateral amygdaloid nucleus (BLA). In order to successfully establish the kindling experimental model, neurosurgery to place the electrodes is an essential step to develop the epileptogenic phenomenon. It crucial that the surgery is carried out with exceptional exactitude, because in that way the experimental model represents an accurate and valid tool to study and understand epilepsy and the results obtained can be used to develop further strategies in epilepsy clinical research.

Phase synchronized 6 Hz transcranial electric and magnetic stimulation boosts frontal theta activity and enhances working memory

Network-level synchronization of theta oscillations in the cerebral cortex is linked to many vital cognitive functions across daily life, such as executive functions or regulation of arousal and consciousness. However, while neuroimaging has uncovered the ubiquitous functional relevance of theta rhythms in cognition, there remains a limited set of techniques for externally enhancing and stabilizing theta in the human brain non-invasively. Here, we developed and employed a new phase-synchronized low-intensity electric and magnetic stimulation technique to induce and stabilize narrowband 6-Hz theta oscillations in a group of healthy human adult participants, and then demonstrated how this technique also enhances cognitive processing by assaying working memory. Our findings demonstrate a technological advancement of brain stimulation methods, while also validating the causal link between theta activity and concurrent cognitive behavior, which may ultimately help to not only explain mechanisms, but offer perspectives for restoring deficient theta-band network activity observed in neuropsychiatric diseases.

Twelve-Week Daily Gluteal and Hamstring Electrical Stimulation Improves Vascular Structure and Function, Limb Volume, and Sitting Pressure in Spinal Cord Injury: A Pilot Feasibility Study.

We examined the long-term effects of low-intensity electrical stimulation on (micro)vasculature and sitting pressure of a home-based, wearable electrical stimulation device in a pilot feasibility study. In a cohort observation before-after trial, nine middle-aged male (n = 8) and female (n = 1) individuals (48 ± 15 yrs) with American Spinal Injury Association A-C classified chronic (1-24 yrs) spinal cord injury underwent 12 wks of self-administered daily, low-intensity gluteal and hamstring electrical stimulation (50 Hz, 6 hrs [30-min electrical stimulation, 15-min rest]). Common femoral artery diameter and blood blow were determined with ultrasound, skin vascular function during local heating was assessed using Laser-Doppler flowmetry, thigh volume was estimated using leg circumferences and skinfolds, and interface sitting pressure was measured using pressure mapping. Resting common femoral artery diameter increased (0.73 ± 0.20 to 0.79 ± 0.22 cm, P < 0.001) and baseline common femoral artery blood flow increased (0.28 ± 0.12 to 0.40 ± 0.15 l/min, P < 0.002). Gluteal cutaneous vascular conductance showed a time*temperature interaction (P = 0.01) with higher conductance at 42°C after 12 wks. Ischial peak pressure decreased (P = 0.003) by 32 ± 23 mm Hg and pressure gradient decreased (23 ± 7 to 16 ± 6 mm Hg, P = 0.007). Thigh volume increased (+19%, P = 0.01). Twelve-week daily home-based gluteal and hamstring electrical stimulation is feasible and effective to improve (micro)vasculature and sitting pressure, and electrical stimulation may have clinical implications for ameliorating pressure ulcers and (micro)vascular complications in spinal cord injury.

Effects of combined treatment with blood flow restriction and low-current electrical stimulation on capillary regression in the soleus muscle of diabetic rats

The combined treatment of blood flow restriction and low intensity electrical stimulation attenuated type 2 diabetes (T2D)-associated capillary regression in the skeletal muscles. The treatment inhibits the T2D-associated increase in antiangiogenic factors via inhibition of intramuscular chronic hypoxia; it can inhibit intramuscular chronic hypoxia by enhancing proangiogenic factors. These results suggest that the combined treatment may be an effective therapeutic intervention for the prevention of T2D-associated capillary regression in the skeletal muscles.

Regulation of cell differentiation via synergistic self-powered stimulation and degradation behavior of a biodegradable composite piezoelectric scaffold for cartilage tissue

The articular cartilage disorder at the junction mainly results from constantly repeated dynamic tension/compression effects with ageing and lack of intrinsic defect repairability. Therefore, the degradable piezoelectric scaffolds are very essential, which mimics the dynamic mechanical loading and optimizes the chondrocyte differentiation during the degradation. Here, a degradable aligned electrospun poly-L-lactic acid (PLLA) modified with graphene (rGO) and polydopamine (PDA) fibrous scaffolds with different orientations (0°, 90°) and surface morphologies (wrinkled and porous) was developed as a biocompatible and degradable piezoelectric scaffold with the self-powered tunable piezoelectricity to modulate cell behaviour and cell differentiation by tuning the degradation effect. The results show that the electrical output and mechanical properties of the composite fibrous scaffold can be improved by adding rGO and applying mechanical force along with the 90° orientation. With changing the degradation behavior, dynamic mechanical loading on the porous PLLA/rGO/PDA fibrous scaffold exhibits a significant increase in cell proliferation and secretion of extracellular matrix (ECM). More surprisingly, as extending the degradation periods to 21 days, a higher glycosaminoglycans (GAGs) synthesis was detected in prechondrogenic ATDC5 cells cultured on the degraded porous scaffold compared with that after 7 days’ culture. This indicated that long-term degradation favoured promoting cell differentiation of ATDC5 towards a chondrogenic phenotype due to dynamic mechanical loading, low-intensity electrical stimulation, and interconnected porous structural morphology. In contrast, on the wrinkled PLLA/rGO/PDA fibre with a high-intensity electrical stimulation, the ALP activity significantly increased after 21 days, inducing mineralization with the differentiation of ATDC5 into osteocytes. The modulation of the degraded environment and electrical stimulation of the piezoelectric scaffold offers an effective alternative to influence cell functions, significantly improving the ECM secretion and cell differentiation.

The role of oxidative stress in the susceptibility of noise-impaired cochleae to synaptic loss induced by intracochlear electrical stimulation

Intracochlear electrical stimulation (ES) generated by cochlear implants (CIs) is used to activate auditory nerves to restore hearing perception in deaf subjects and those with residual hearing who use electroacoustic stimulation (EAS) technology. Approximately 1/3 of EAS recipients experience loss of residual hearing a few months after ES activation, but the underlying mechanism is unknown. Clinical evidence indicates that the loss is related to the previous history of noise-induced hearing loss (NIHL). In this report, we investigated the impact of intracochlear ES on oxidative stress levels and synaptic counts in inner hair cells (IHCs) of the apical, middle and basal regions of guinea pigs with normal hearing (NH) and NIHL. Our results demonstrated that intracochlear ES with an intensity of 6 dB above the thresholds of electrically evoked compound action potentials (ECAPs) could induce the elevation of oxidative stress levels, resulting in a loss of IHC synapses near the electrodes in the basal and middle regions of the NH cochleae. Furthermore, the apical region of cochleae with NIHL were more susceptible to synaptic loss induced by relatively low-intensity ES than that of NH cochleae, resulting from the additional elevation of oxidative stress levels and the reduced antioxidant capability throughout the whole cochlea.

Influence of surface peripheral electrical stimulation on nerve regeneration after digital nerve neurorrhaphy: study protocol for a randomized clinical trial

We will study the influence of low intensity and frequency surface peripheral electrical stimulation (PES) on nerve regeneration of digital nerve injuries of the hand after its surgical repair in humans. Participants will be patients with acute traumatic peripheral nerve injury referred to the Hand Surgery Service of the General Hospital of the State of Bahia, a reference service in the state. These patients will undergo surgery followed by PES in the immediate postoperative period. After hospital discharge, they will be followed up on an outpatient basis by researchers, who will remotely supervise a physiotherapy program. Our hypothesis is that PES will positively influence the recovery of sensory function in patients undergoing neurorrhaphy of digital nerves of the hand. ReBEC registration: U1111-1259-1998 (12/18/2020)

Influence of surface peripheral electrical stimulation on nerve regeneration after digital nerve neurorrhaphy: study protocol for a randomized clinical trial

We will study the influence of low intensity and frequency surface peripheral electrical stimulation (PES) on nerve regeneration of digital nerve injuries of the hand after its surgical repair in humans. Participants will be patients with acute traumatic peripheral nerve injury referred to the Hand Surgery Service of the General Hospital of the State of Bahia, a reference service in the state. These patients will undergo surgery followed by PES in the immediate postoperative period. After hospital discharge, they will be followed up on an outpatient basis by researchers, who will remotely supervise a physiotherapy program. Our hypothesis is that PES will positively influence the recovery of sensory function in patients undergoing neurorrhaphy of digital nerves of the hand. ReBEC registration: U1111-1259-1998 (12/18/2020).

Arm cycling increases the short-latency reflex from ankle dorsiflexor afferents to knee extensor muscles.

Low-intensity electrical stimulation of the common peroneal nerve (CPN) evokes a short latency reflex in the heteronymous knee extensor muscles (referred to as the CPN reflex). The CPN reflex is facilitated at a heel strike during walking, contributing to body weight support. However, the origin of the CPN reflex increase during walking remains unclear. We speculate that this increase originates from multiple sources due to a body of evidence suggesting the presence of neural coupling between the arms and legs. Therefore, we investigated the extent to which the CPN reflex is modulated during rhythmic arm cycling. Twenty-eight subjects sat in an armchair and were asked to perform arm cycling at a moderate cadence using a stationary ergometer while performing isometric contraction of the knee extensors, such that the CPN reflex was evoked. The CPN reflex was evoked by stimulating the CPN [0.9-2.0× the motor threshold (MT) in the tibialis anterior muscle] at the level of the neck of the fibula. The CPN-reflex amplitude was measured from the vastus lateralis (VL). The biphasic reflex response in the VL was evoked within 27-45 ms following CPN stimulation. The amplitude of the CPN reflex increased during arm cycling compared with that before cycling. The modulation of the CPN reflex during arm cycling was detected only for CPN stimulation intensity around 1.2× MT. Furthermore, CPN-reflex modulation was not observed during the isometric contraction of the arm or passive arm cycling. Our results suggest the presence of neural coupling between the CPN-reflex pathways and neural systems generating locomotive arm movement.NEW & NOTEWORTHY Whether locomotive arm movements contribute to the control of the reflex pathway from ankle dorsiflexor afferents to knee extensor muscles [common peroneal nerve (CPN)-reflex] is an unresolved issue. The CPN reflex in the stationary leg was facilitated only by arm cycling, and not by passive or isometric motor tasks. Our results suggest that the arm locomotor system modulates the reflex pathway from ankle dorsiflexor afferents to the knee extensor muscles.

Microcurrent and adipose-derived stem cells modulate genes expression involved in the structural recovery of transected tendon of rats.

Tendon injuries are common and have a high incidence of re-rupture that can cause loss of functionality. Therapies with adipose-derived stem cells (ASC) and the microcurrent (low-intensity electrical stimulation) application present promising effects on the tissue repair. We analyzed the expression of genes and the participation of some molecules potentially involved in the structural recovery of the Achilles tendon of rats, in response to the application of both therapies, isolated and combined. The tendons were distributed in five groups: normal (N), transected (T), transected and ASC (C) or microcurrent (M) or with ASC, and microcurrent (MC). Microcurrent therapy was beneficial for tendon repair, as it was observed a statistically significant increase in the organization of the collagen fibers, with involvement of the TNC, CTGF, FN, FMDO, and COL3A1 genes as well as PCNA, IL-10, and TNF-α. ASC therapy significantly increased the TNC and FMDO genes expression with no changes in the molecular organization of collagen. With the association of therapies, a significant greater collagen fibers organization was observed with involvement of the FMOD gene. The therapies did not affect the expression of COL1A1, SMAD2, SMAD3, MKX, and EGR1 genes, nor did they influence the amount of collagen I and III, caspase-3, tenomodulin (Tnmd), and hydroxyproline. In conclusion, the application of the microcurrent isolated or associated with ASC increased the organization of the collagen fibers, which can result in a greater biomechanical resistance in relation to the tendons treated only with ASC. Future studies will be needed to demonstrate the biological effects of these therapies on the functional recovery of injured tendons.

Low-Intensity Electrical Stimulation to Improve the Neurological Aspect of Weakness in Individuals with Chronic Anterior Cruciate Ligament Lesion.

Purpose This study is aimed at investigating the effect of low-intensity electrical stimulation on the voluntary activation level (VA) and the cortical facilitation/inhibition of quadriceps in people with chronic anterior cruciate ligament lesion. Methods Twenty former athletes with unilateral ACL deficiencies (ACL group) and 20 healthy subjects (healthy control group) participated in the study. The quadriceps VA level, motor-evoked potential (MEP), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF) elicited by transcranial magnetic stimulation were tested before and after 30 minutes of low-intensity electrical stimulation (ES). Results Before ES, the quadriceps VA in the ACL lesion legs of the ACL group was lower compared to the legs of the healthy control group (P < 0.05). The MEP sizes in the ACL lesion legs and the healthy control were not significantly different. The ACL lesion legs showed lower SICI and higher ICF compared to the healthy control group (P < 0.05). After ES, the quadriceps VA level increased and the SICI-ICF was modulated only in the ACL lesion legs (P < 0.05) but not in the healthy controls. Conclusions Low-intensity ES can normalize the modulation of intracortical inhibition and facilitation, thereby ameliorating the activation failure in individuals with ACL lesion.

A Survey of Lower Limb Rehabilitation Systems and Algorithms Based on Functional Electrical Stimulation

Functional electrical stimulation is a method of repairing a dysfunctional limb in a stroke patient by using low-intensity electrical stimulation. Currently, it is widely used in smart medical treatment for limb rehabilitation in stroke patients. In this paper, the development of FES systems is sorted out and analyzed in a time order. Then, the progress of functional electrical stimulation in the field of rehabilitation is reviewed in details in two aspects, i.e., system development and algorithm progress. In the system aspect, the development of the first FES control and stimulation system, the core of the lower limb-based neuroprosthesis system and the system based on brain-computer interface are introduced. The algorithm optimization for control strategy is introduced in the algorithm. Asynchronous stimulation to prolong the function time of the lower limbs and a method to improve the robustness of knee joint modeling using neural networks. Representative applications in each of these aspects have been investigated and analyzed.

Transcranial Direct Current Stimulation in the Treatment of Facial Pain.

Non-invasive neuromodulation techniques such as transcranial direct current stimulation (tDCS) enable researchers and health care professionals to gain unique insight into brain functions and to treat a number of neurological and psychiatric conditions. Repeated applications of anodal tDCS over the primary motor cortex (M1) have been shown to produce long-lasting relief of neuropathic pain. tDCS is a technique that can induce and modulate brain plasticity and thus be suitable for treating diverse chronic pain conditions, disorders associated with substantial reorganization of central nervous system activity. The number of published basic research and clinical papers in this field is increasing exponentially, but the number of studies that include patients with facial pain is still limited, and there are no "gold standards" with regard to how to treat the various kinds of pain disorders. Pharmacoresistant facial pain is a substantial burden for the patient as manifested by its interference with daily functioning and reduced health status associated with pain severity. Without doubt, further trials are needed to optimize stimulation parameters and find effective protocols for this disorder. In addition, evaluation of the clinical effects of tDCS shows that low-intensity electrical stimulation techniques are exceptionally suitable for gaining further insight into the functional role of a given brain region, e.g. how brain processes emerge and can be altered in anatomically distributed, but functionally connected, brain networks.

Modulation of the rate of force development in hip abductor muscles by neuromuscular electrical stimulation during gait

Purpose/aim of the study: An increase of hip abductor muscle strength contributes to the increase in gait speed. It is known that the rate of force development (RFD), an indicator of muscle strength, is increased by the combined use of low-intensity neuromuscular electrical stimulation (NMES) to the glutaeus medius (GM) and low-load resistance training (RT). However, it is unclear whether low-intensity neuromuscular electrical stimulation of the glutaeus medius during walking also increases the rate of force development. The aim of this study was to clarify whether NMES to the GM during gait modulates the RFD of the hip abductor muscles in healthy adults.Materials and methods: Twenty-two healthy adults randomly received both gait with sub-motor threshold NMES and gait with sham NMES conditions. The RFD was assessed at pre- and post-intervention. A two-way repeated measures analysis of variance was used to analyse the effects of time and intervention.Results: Gait with sub-motor threshold NMES condition significantly increased the RFD in shorter time interval (0–50 and 0–100 ms) compared to gait with sham NMES condition.Conclusions: These findings suggest that the adding low-intensity NMES of the GM to gait is effective in increasing the RFD of the hip abductor muscles.