Reduced Muscle Activity Research Articles

Motor Strategies Learned during Pain Are Sustained upon Pain-free Reexposure to Task

Pain affects movement planning and execution, and may interfere with the ability to learn new motor skills. Variations among previous studies suggest task-specific effects of pain on the initial acquisition and subsequent retention of motor strategies. The present study assessed how acute pain in the anterior deltoid muscle affects movement accuracy of fast arm-reaching movements during force field perturbations and upon immediate pain-free repetition of the same task. Despite having slower initial rate of improvement, individuals who experienced pain during training achieved the same final performance as pain-free controls. However, pain altered the strategy of muscle activation adopted to perform the task, which involved less activity of the shoulder and arm muscles. Strikingly, motor strategies developed during the first exposure to the force field were retained upon reexposure to the same perturbation after resolution of pain. Although reduced muscle activation may be interpreted as metabolically efficient, it reduces joint stability and can have negative consequences for joint integrity. These results demonstrate that alternative motor strategies developed in the presence of pain can be maintained when training is resumed after resolution of pain. This effect could have deleterious consequences if it applies when learning motor skills in sports training and rehabilitation.

Influence of experimental pain on the spatio-temporal activity of upper trapezius during dynamic lifting – An investigation using Bayesian spatio-temporal ANOVA

High-density surface electromyography (HDsEMG) provides a detailed analysis of a muscle’s spatial distribution of activity. We applied a Bayesian spatio-temporal statistical method to quantify how acute nociception and task repetition alters the upper trapezius instantaneous spatial distribution of activity during dynamic muscular contractions. Ten male adults performed repeated lifting of a 1 kg box between shelves positioned at hip and shoulder heights with a cycle time of 3 s for 50 cycles under four conditions: baseline, isotonic and hypertonic saline injections (nociception) to the right upper trapezius, and 15 min post injection. Activity of the right upper trapezius was measured using a 64-channel surface electrode grid. Statistical inference was performed using Integrated Nested Laplace Approximations (INLA), and significance was determined by a non-zero crossing of the Bayesian 95% credible intervals (CrI). The maximal decrease in activity after nociception was −38.1 µV [95% CrI −40.9 to −35.3] at 30% of the lift cycle when compared to baseline. The maximal reduction in muscle activity between the early and later phases of lifting in the presence of nociception was by 10.4 µV [95% CrI 8.2–12.6]. A more holistic understanding of muscle behaviour is achieved using spatio-temporal inference than traditional reductionist methods.

Evaluation of Biofeedback Usefulness in Masticatory Muscle Activity Management—A Systematic Review

Temporomandibular disorders (TMD) have multifactorial and complex etiology. Regardless of their etiology, all those conditions may result in centrally mediated chronic muscle pain, myalgia, myofascial pain, myofibrotic contracture, myosistis, myospasm, headache and a variety of neck, shoulder, upper back and lower back pain. Biofeedback (BF) is one of methods that has been used for more than 50 years in rehabilitation to facilitate normal movement patterns after injuries. Some studies suggest that biofeedback may be an effective treatment option for patients with different muscle disorders. The aim of this study was to evaluate the efficiency of biofeedback in masticatory muscle activity management in the light of current medical literature. The authors followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines for this systematic review. The authors searched the MEDLINE, Scopus, Web of Science, CINAHL databases to identify relevant publications. Finally 10 papers were included. Most of the selected studies showed a significant correlation between biofeedback usage and reduction of masticatory muscle activity. By analyzing qualified studies, it can be concluded that biofeedback can be an effective tool in masticatory muscle activity management.

Muscle Synergies During Repetitive Stoop Lifting With a Bioelectrically-Controlled Lumbar Support Exoskeleton.

Lower back problems are common in the world, which leads to the development of various lumbar support exoskeletons to alleviate this problem. In general, previous studies evaluating lumbar support devices quantified assistance by reporting the reduction in back muscle activity and perceived fatigue. However, despite the beneficial effects of such devices, the effects of using such exoskeletons on muscle coordination are not well-studied. In this study, we examined the short-term change in muscle coordination of subjects using a bioelectrically-controlled lumbar support exoskeleton in a fatiguing stoop lifting task with muscle synergy analysis. Results indicate that muscle coordination changes were dominated by changes in timing coefficients, with minimal change in muscle synergy vectors. Analysis on muscle coordination changes would be useful to design future generations of exoskeletons.

Botulinum toxin for modulating the muscle strength of patients rehabilitated with zygomatic implants

Objective: To measure the intensity of muscle strength and electrical activity of masseter and anterior temporal muscles based on BTX-A therapy in patients rehabilitated with total prostheses on zygomatic implants. Material and Methods: The object of the study was a sample of 20 individuals subjected to zygomatic implant surgery and rehabilitated with implant-supported prostheses, in order to obtain electromyographic data using an eight-channel module (EMG System do Brasil). The data were collected for three consecutive months: prior to the application (single dose) of BTX-A (30 U/ masseter muscle; 10 U/temporal muscle) and after 30 and 90 days of therapeutic treatment. Result: All muscle groups studied showed reduction of muscle electrical activity during voluntary contraction after 30 days of treatment (around 47%) (p < 0.001), which progressively reverted after 90 days of treatment. The anterior temporal muscles presented similar motor behavior, with activity reduction of 39% (p < 0.05). There was a reduction of 17.68% (p < 0.05) in mandibular force and an increase of 14.22% (p < 0.05) in mouth opening after 30 days of BTX-A administration. Conclusions: The results suggest that BTX-A significantly reduces muscle activity, in either the recruitment of motor units or muscle tone, in the first three months of therapeutic treatment. This therapy may also be useful as a preventive method for the failure of zygomatic implant-supported prostheses.KeywordsElectromyography; Dental implants; Prostheses on implants; Botulinum toxin.Keywords: Electromyogra phy; Dental implants; Prostheses on implants; Botulinum toxin.

Whole-body vibration impedes the deterioration of postural control in patients with multiple sclerosis

ObjectiveThe current study aimed to investigate if whole-body vibration (WBV) might attenuate the processing functional and neuromuscular degeneration of postural control in patients with MS. DesignPerformance in postural control was assessed before and after 6 weeks of a control (CON) and a WBV intervention period. SettingLaboratory at the University of Freiburg & home-based training ParticipantsOut of 29 interested participants, 15 subjects with severe MS fit inclusion criteria. Main outcome measuresCentre of pressure displacement (COP), muscle activity and co-contraction indices of m. soleus (SOL), gastrocnemius medialis (GM), tibialis anterior (TA), biceps (BF) and rectus femoris (RF) as well as SOL H/M-ratios. ResultsAfter CON, COP was significantly enhanced with reduced muscle activity in RF and diminished shank muscle co-contraction. After WBV, no changes were observed in COP and neuromuscular control. However, over time, TA activity was reduced, but with no changes in muscle activation of SOL, GM and BF or H/M-ratios. ConclusionsAfter CON, MS patients experienced substantial deteriorations in postural control which have previously been associated with greater postural instability. No further disease-associated deteriorations were observed following the intervention. Thus, WBV might alleviate neurodegeneration of postural control in people with MS.

Reduced muscle activity variability in lumbar extensor muscles during sustained sitting in individuals with chronic low back pain.

The purpose of this study was to investigate muscle activity variability within and between the right and left side of lumbar muscles in patients with chronic low back pain (cLBP) compared to healthy controls (HCs) during sustained quiet sitting. Surface electromyographic (EMG) signals were collected bilaterally from the lumbar muscles with 2 high density surface EMG grids of 9x14 electrodes. Root mean square values (RMS) over 1-sec epochs of all bipolar EMG leadings were obtained. Between-sides alternating activation was computed, as well as temporal- and spatial variability within the electrode grids through the coefficient of variation and correlations between RMS distributions. The subjective influence of sitting was evaluated by the rating of perceived exertion and the amount of LBP on a numeric pain rating scale. Compared to HCs, the patients with cLBP had lower temporal (p = 0.03) and similar spatial muscle activity variability during sitting, despite a more variable sitting position. This did not result in increased muscle fatigue indicated by EMG, but the patients with cLBP reported higher levels of RPE during- and more LBP after the sitting and as a consequence ended the sitting earlier than HCs (p < 0.01). Present findings lend support to the presence of less tolerance for low-level static muscle load in patients with cLBP.

A lower limb exoskeleton based on recognition of lower limb walking intention

Recognition of walking intention and assistance in the load-carrying driver’s walking capability are key challenging areas in lower limb exoskeletons. We present a lower limb exoskeleton called the unmanned technology research centre exoskeleton (UTRCEXO). It recognizes walking intention, including step initiation, step velocity (acceleration and deceleration), and step termination of drivers using only insole-type FSRs and three axis F/T sensors. UTRCEXO recognizes the driver’s intention of step initiation using insole-type FSRs and recognizes the intention of step velocity and step termination using three axis F/T sensors. UTRCEXO makes use of four DC motors, two at each knee and hip joint, to assist the driver. The the driver can carry a 20 kg payload comfortably with muscle activity reduction. In this paper, we evaluate muscle activity reduction in walking drivers equipped with UTRCEXO carrying a 20 kg payload.

Changes in the Flexion-Relaxation Response After Percutaneous Endoscopic Lumbar Discectomy in Patients with Disc Herniation

Previous studies of percutaneous endoscopic lumbar discectomy (PELD) to treat lumbar disc herniation (LDH) have shown good clinical results. However, limited information has been reported regarding postoperative improvement in back muscle function. We aimed to determine whether changes in neuromuscular patterns, assessed using the flexion-relaxation phenomenon (FRP), could be observed after PELD. A total of 30 patients participated in the present study. The patients' muscle functions were evaluated before and after PELD using surface electromyography and self-report measures. The evaluated action included 3 repetitions of a trunk flexion and extension movement. The association between the FRP measures and patient-reported outcomes was evaluated. At 4 weeks after PELD, the patients had significantly lower visual analog scale and Quebec Back Pain Disability Scale (QBPDS) scores and significantly increased gross range of motion. Also, we observed a reduction in erector spinae muscle activation at L3 in the maximum voluntary flexion phase. Normalized electromyographic root-mean-square values were significantly reduced in the maximum voluntary flexion phase and significantly increased in the extension phase. Postoperatively, 60% of the patients successfully achieved flexion-relaxation compared with 7% of the patients preoperatively. A significant correlation was found between the FRP measures and patient-reported outcomes, except for the Fear-Avoidance Beliefs Questionnaire scale. PELD for individuals with LDH appears to normalize paraspinal muscle activation during lumbar flexion-extension movement. The gross range of motion and disability-related limitations of physical activity also improved.

Comparison of pentobarbital‐phenytoin alone vs propofol prior to pentobarbital‐phenytoin for euthanasia in 436 client‐owned dogs

To report the incidence of adverse events during euthanasia of client-owned dogs administered either intravenous pentobarbital/phenytoin (PP) or PP after propofol delivery. Prospective, observational, multi-site study. Four hundred thirty-six dogs undergoing client-elected euthanasia over a 1-year period. Interventions included placement of an IV catheter and delivery of euthanasia agents (PP for the PP group, propofol followed by PP for the propofol group). Seven pre-determined adverse events were recorded: agonal breaths, urination, defecation, vocalization, muscle activity, dysphoria, and catheter complications. Euthanasia scores for each patient were defined as the sum of all adverse events (0-7) the patient exhibited. Two hundred thirty-six dogs were in the PP group and 200dogs were in the propofol group. No significant differences were detected in the dose of PP administered (166.9±105.6 mg/kg for PP group, 182.6±109.8 mg/kg for propofol group). Propofol dogs received 4.5±2.9 mg/kg propofol. The incidence of ≥ 1 adverse event was 35.2% in the PP group and 26.5% in the propofol group (P = 0.052). Mean euthanasia scores (0.47 PP group, 0.32 propofol group) were not significantly different (P = 0.08). Propofol significantly reduced the incidence of muscle activity (6% vs. 14%, odds ratio 0.39; P = 0.0079). There was no difference in the likelihood of the studied adverse events during client-elected euthanasia in dogs when propofol was used prior to PP. There was a significant reduction in perimortem muscle activity if propofol was given prior to PP.

A Follow-Up Study of the Effects of An Arm Support Exoskeleton on Physical Demands and Task Performance During Simulated Overhead Work

OCCUPATIONAL APPLICATIONSThis study supports that use of an arm-support exoskeleton (ASE) can lower the activity of shoulder and lower trunk muscles during an overhead drilling and a light assembly task, and also improve work quality in terms of the number of errors made during drilling. Integrating the findings from earlier studies, though, the current results suggest that such benefits of ASE use likely depend on the specific ASE and work tasks in which it is used. Further, a decrease in the number of drilling errors with the fixed drilling pace used here can be explained by a speed-accuracy tradeoff. In practice, this tradeoff has implied that when an ASE is provided, workers may need a reasonable training/acclimation period with an ASE, to develop a mental model and an optimal work strategy to adopt to their ASE-enhanced physical capacity without any adverse consequences.TECHNICAL ABSTRACT Background: Overexertion and bodily reaction remain leading causes of work-related musculoskeletal disorders. Occupational use of an exoskeleton has been recognized recently as an alternative intervention approach to reduce physical demands and fatigue experienced in a range of occupational tasks. Purpose: This study replicated many aspects of an earlier study of using an arm-support exoskeleton (ASE) during simulated overhead drilling and light assembly (Kim et al., 2018), and was complete to reexamine the beneficial effects of ASE and determine if a speed-accuracy tradeoff might explain the increase in the number of errors reported in the noted earlier study. Methods: In a controlled lab-based experiment, 12 gender-balanced participants performed a simulated overhead repetitive drilling (at 1 hole per 10 s) and a light assembly task at two different work heights, both with and without a commercial ASE. Activity of shoulder and lower trunk muscles, perceived discomfort, and drilling performance were measured. Results: Using the ASE reduced peak and median normalized muscle activity levels, respectively, by up to 52.5% and 60.6% for the shoulder, and ∼29% and ∼16% for the lower trunk. Reductions in shoulder muscle activity and perceived discomfort were often more substantial at the overhead work height. Using the ASE also led to fewer drilling errors (up to ∼92% reduction), especially with a heavier tool and/or at the overhead work height. Conclusions: This study supplements earlier evidence that supports the efficacy of ASE use in reducing physical demands of the upper extremity and the lower back during overhead work. However, the latter “secondary” benefit, beyond the specific ASE design focus, is likely conditional on the specific ASE design and the specific work task in which it is used. Effects of an ASE on drilling task performance were also task-specific, dependent on how task pacing is controlled and consistent with a traditional speed-accuracy tradeoff.

Application of multiple‐response optimization methods for the ergonomic evaluation of carpet weaving knife

AbstractThe aim of this study is to evaluate several weaving knife configurations in response to multiple criteria’s for optimum design. Nine different knife combinations were tested over ten female weavers in a field experiment. Three levels of blade width and angular orientations were taken as the independent variables. Output response about goniometry and electromyography were taken as dependent variables. Multivariate analysis was carried out to estimate the effect of independent variables on output responses. To tackle the difficulty of knife selection with several output responses, three multicriteria optimization approaches have been compared. Multivariate analysis of variance results showed that the effect of both blade width and angle were significant at wrist angles. Also, the magnitude of effect size on both blade width and the angle was highest for the wrist angles. Despite the same weighing criteria, a slight difference was evident between the ranks from optimization methods. The higher blade widths and smaller angular orientations should be recommended for reduction of wrist deviation and muscle activity during weaving. The best possible combination of knife evaluated using multicriteria optimization was 25 mm × 100°.

The Effect of Arm Support Exoskeletons in Realistic Work Activities: A Review Study

The use of arm-support exoskeletons could be a strategy to unload the shoulder in elevated arm work. In this paper the effects of these type of exoskeletons on objective parameters of shoulder load, subjective measures and performance measures were reviewed. The review resulted in eleven papers addressing ten arm-support exoskeletons. Seven of these exoskeletons were passive (spring-based) exoskeletons, one was an active exoskeleton mounted to the wall and two exoskeletons were equipped with a supernumerary limb (snl) attached to the waist. For the exoskeletons with a snl, the concept of transferring loads from the shoulder to the waist did not result in the expected reductions in shoulder muscle activity. The passive exoskeletons did show reduced levels of activity in the agonistic muscles (those involved in arm elevation), ranging from 16% to 130%, both in quasi-static tasks like overhead drilling and overhead assembly, but also in lifting and stacking tasks that involved elevation of the arms. However, the activity in antagonistic muscles was found to increase by up to 107%. The adoption of arm support exoskeletons in practice depends on whether the positive effects of lowered muscle activity would outweigh negative effects like increased antagonistic muscle activity and other potentially adverse effects regarding discomfort or usability. With regards to subjective experiences and performance related measures, mixed results were reported. The effectivity and subjective experience seem to be task-dependent. Therefore, it is important to consider the specific working environment and envisioned results, to select the exoskeleton that best suits the specific working conditions.

Management of musculoskeletal shoulder and neck pain through ergonomic intervention: a pre-post design analysis in hand screen printing industry

Hand screen printing process (HSP) is a highly labour intensive work involving repetitive and awkward motion without proper ergonomic tools. The main purpose of this study is to modify the design of the traditionally employed wooden squeegee and evaluate its effect on muscle activity during HSP process. Twenty hand screen printing industry workers participated in the study and printed the design on 30-metre length cloth using both traditional and modified squeegee. Surface electromyography (SEMG) is used to record the muscle activity of sternocleidomastoid (SCM), upper trapezius (bilateral) and infraspinatus (bilateral) muscles during HSP process. One way ANOVA and chi square test is performed using SPSS version 21.0 and the result showed that the data obtained using both traditional and modified squeegee are statistically significant. Introducing modified squeegee in HSP process reduces muscle activity of sternocleidomastoid (SCM), upper trapezius (bilateral) and infraspinatus (bilateral) muscles during HSP process thereby reduces the risk of neck and shoulder injuries.

Management of musculoskeletal shoulder and neck pain through ergonomic intervention: a pre-post design analysis in hand screen printing industry

Hand screen printing process (HSP) is a highly labour intensive work involving repetitive and awkward motion without proper ergonomic tools. The main purpose of this study is to modify the design of the traditionally employed wooden squeegee and evaluate its effect on muscle activity during HSP process. Twenty hand screen printing industry workers participated in the study and printed the design on 30-metre length cloth using both traditional and modified squeegee. Surface electromyography (SEMG) is used to record the muscle activity of sternocleidomastoid (SCM), upper trapezius (bilateral) and infraspinatus (bilateral) muscles during HSP process. One way ANOVA and chi square test is performed using SPSS version 21.0 and the result showed that the data obtained using both traditional and modified squeegee are statistically significant. Introducing modified squeegee in HSP process reduces muscle activity of sternocleidomastoid (SCM), upper trapezius (bilateral) and infraspinatus (bilateral) muscles during HSP process thereby reduces the risk of neck and shoulder injuries.

Reboxetine and hyoscine butylbromide improve upper airway function during nonrapid eye movement and suppress rapid eye movement sleep in healthy individuals.

Recent findings indicate that noradrenergic and antimuscarinic processes are crucial for sleep-related reductions in pharyngeal muscle activity. However, there are few human studies. Accordingly, this study aimed to determine if a combined noradrenergic and antimuscarinic intervention increases pharyngeal dilator muscle activity and improves airway function in sleeping humans. Genioglossus (GG) and tensor palatini electromyography (EMG), pharyngeal pressure, upper airway resistance, and breathing parameters were acquired in 10 healthy adults (5 female) during two overnight sleep studies after 4 mg of reboxetine (REB) plus 20 mg of hyoscine butylbromide (HBB) or placebo using a double-blind, placebo-controlled, randomized, cross-over design. Compared with placebo, peak and tonic GG EMG were lower (Mean ± SD: 83 ± 73 vs. 130 ± 75, p = 0.021 and 102 ± 102 vs. 147 ± 123 % wakefulness, p = 0.021, respectively) but the sleep-related reduction in tensor palatini was less (Median [25th, 75th centiles]: 53[45, 62] vs. 34[28, 38] % wakefulness, p = 0.008) with the drug combination during nonrapid eye movement (non-REM) sleep. These changes were accompanied by improved upper airway function including reduced pharyngeal pressure swings, airway resistance, respiratory load compensation, and increased breathing frequency during N2. REB and HBB significantly reduced rapid eye movement sleep compared with placebo (0.6 ± 1.1 vs. 14.5 ± 6.8 % total sleep time, p < 0.001). Contrary to our hypothesis, GG muscle activity (% wakefulness) during non-REM sleep was lower with REB and HBB. However, sleep-related reductions in tensor palatini activity were less and upper airway function improved. These findings provide mechanistic insight into the role of noradrenergic and antimuscarinic processes on upper airway function in humans and have therapeutic potential for obstructive sleep apnea. Australian New Zealand Clinical Trials Registry, https://www.anzctr.org.au, trial ID: ACTRN12616000469415.

Altered Neural Control Reduces Shear Forces and Ankle Impedance on a Slippery Surface.

This study investigated the consequences of reduced ankle muscle activity on slippery surfaces. We hypothesized that reduced activation would reduce shear forces and ankle impedance to improve contact and reduce slip potential. Data were collected from unimpaired adults walking across non-slippery and slippery walkways. Set within the walkway was a robotic platform with an embedded force plate for collecting shear forces and estimating the mechanical impedance of the ankle; impedance was characterized by a model with stiffness, damping, and inertia. We found a significant reduction in shear force due to reduced muscle activity in late mid-stance. We found no significant difference in stiffness between the surfaces. However, the muscle activation changes that contributed to shear force modulation occurred in late mid-stance, where reliable impedance estimates could not be made due to the foot leaving the measurement platform. When impedance could be measured, we found that a change in muscle activity predicted a change in stiffness, providing indirect estimates that stiffness was likely reduced later in stance. These results suggest that reduced muscle activity on slippery surfaces serves to reduce shear forces, and possibly also stiffness, during late mid-stance. These results have implications for identifying and training likely fallers, and possibly for designing prosthetic systems that help prevent falls when walking across different terrains.

Muscle activity prevents the uncoupling of mitochondria from Ca2+ Release Units induced by ageing and disuse

In fast-twitch fibers from adult mice Ca2+ release units (CRUs, i.e. intracellular junctions of excitation-contraction coupling), and mitochondria are structurally linked to each other by small strands, named tethers. We recently showed that aging causes separation of a fraction of mitochondria from CRUs and a consequent impairment of the Ca2+ signaling between the two organelles. However, whether the uncoupling of mitochondria from CRUs is the result of aging per-se or the consequence of reduced muscle activity remains still unclear. Here we studied the association between mitochondria and CRUs: in a) extensor digitorum longus (EDL) muscles from 2 years old mice, either sedentary or trained for 1 year in wheel cages; and b) denervated EDL muscles from adult mice and rats. We analyzed muscle samples using a combination of structural (confocal and electron microscopy), biochemical (assessment of oxidative stress via western blot), and functional (ex-vivo contractile properties, and mitochondrial Ca2+ uptake) experimental procedures. The results collected in structural studies indicate that: a) ageing and denervation result in partial uncoupling between mitochondria and CRUs; b) exercise either maintains (in old mice) or restores (in transiently denervated rats) the association between the two organelles. Functional studies supported the hypothesis that CRU-mitochondria coupling is important for mitochondrial Ca2+ uptake, optimal force generation, and muscle performance. Taken together our results indicate that muscle activity maintains/improves proper association between CRUs and mitochondria.

Development of control for the ankle joint simulator applied to the problem on vertical posture balance of a human

The optimal ankle joint controller based on the model that describes the system of human vertical balance in response to small disturbances was developed. The method for optimization of the selection of control matrices was proposed, which leads to stabilization, taking into consideration the requirements of comfortable return of a human to the equilibrium position, minimization of the efforts of a simulator of the central nervous system (CNS). With a view to understanding the ways of functioning of the CNS, the operation of its departments responsible for stabilization was analyzed, which makes it possible to apply this knowledge to the problem of the balance of the vertical posture. The research is limited to the study of functioning of the ankle joint in terms of its influence on the posture stabilization. The merit of this research is the development of a methodological platform for further simulation of functioning of the ankle, knee and hip joints in totality and determining the optimal choice of the CNS management strategy. The research supports the hypothesis that at small disturbances in the sagittal plane, the key role in stabilization is played by the ankle joint. The law of the controller management was presented and its model implementation was carried out. To do this, we used the actual values of operating points, obtained based of the program platform of movements tracking Opti Flex Track 13 which simulates human movements in real time. The results are of value in the process of studying the vertical stabilization of a human. Simulation of operation of different muscle groups taken together is essential for rehabilitation of patients with CNS problems at reduced muscle activity. The results are useful for the design of a functional electrical CNS stimulation controller, development of the technical rehabilitation facilities for people who are at risk of falling

Transcranial Magnetic Stimulation: Potential Use in Obstructive Sleep Apnea and Sleep Bruxism.

The aim of this article is to introduce transcranial magnetic stimulation (TMS) to dental practitioners and to explain its use in obstructive sleep apnea (OSA) and sleep bruxism (SB). In these 2 sleep disorders, TMS has proven to be a useful tool to explore pathophysiological pathways and disease mechanisms, and in a more limited way, to recruit upper airway muscles in OSA and reduce muscle activity and pain intensity in SB. Although promising, research using TMS in these conditions is still very limited and future investigations should be conducted before its clinical application can be considered.