The effect of electromyography triggered electrical stimulation to abdominal muscles on sitting balance, respiratory functions, and abdominal muscle thickness in complete spinal cord injury: a randomized controlled trial.

Complete thoracic spinal cord injury (SCI) results in a loss of innervation to the abdominal muscles, which affects trunk stability and performance of activities of daily living from a sitting position. Respiratory function is also affected, leading to frequent pulmonary complications. Given the importance of trunk stability and respiratory function, we investigated the effects of electromyography triggered electrical stimulation (EMG-ES) applied to the abdominal muscles on sitting balance, respiratory functions and abdominal muscle thickness in individuals with complete thoracic SCI. This randomized controlled study included 34 participants with complete thoracic SCI who were randomly allocated to the experimental group ( n  = 17) and the control group ( n  = 17). During the 4-week intervention period, the experimental group received EMG-ES to their abdominal muscles, while the control group received isometric abdominal exercises three times per week. Both groups continued with their routine rehabilitation program (active or passive range of motion exercises, stretching, and balance coordination exercises). The primary outcome measures were the modified functional reach test (mFRT) and trunk control test (TCT). Secondary outcome measures included a pulmonary function test (PFT) and the bilateral abdominal muscle thicknesses using ultrasonography. At the end of the study, the experimental group showed significantly greater improvements in both primary outcomes. The mean difference in pre-post changes between the groups for the mFRT area was 242.8 cm² [95% confidence interval (CI): 181.3-329.8; effect size 0.92; P  < 0.001] and 5.0 points for TCT (95% CI: 3.9-6.0; effect size 0.98, P  < 0.001). The increase in the abdominal muscle thickness was also significantly greater in the experimental group ( P  < 0.001) without significant differences in the PFT ( P  > 0.05). We conclude that adding EMG-ES of abdominal muscles may further improve sitting balance and abdominal muscle thickness in individuals with complete thoracic SCI.

Synergistic difference in the effect of stretching on electromechanical delay components.

This study investigated the synergistic difference in the effect of stretching on electromechanical delay (EMD) and its components, using a simultaneous recording of electromyographic, mechanomyographic, and force signals. Twenty-six healthy men underwent plantar flexors passive stretching. Before and after stretching, the electrochemical and mechanical components of the EMD and the relaxation EMD (R-EMD) were calculated in gastrocnemius medialis (GM), lateralis (GL) and soleus (SOL) during a supramaximal motor point stimulation. Additionally, joint passive stiffness was assessed. At baseline, the mechanical components of EMD and R-EMD were longer in GM and GL than SOL (Cohen's d from 1.78 to 3.67). Stretching decreased joint passive stiffness [-22(8)%, d = -1.96] while overall lengthened the electrochemical and mechanical EMD. The mechanical R-EMD components were affected more in GM [21(2)%] and GL [22(2)%] than SOL [12(1)%], with d ranging from 0.63 to 1.81. Negative correlations between joint passive stiffness with EMD and R-EMD mechanical components were found before and after stretching in all muscles (r from -0.477 to -0.926; P from 0.007 to <0.001). These results suggest that stretching plantar flexors affected GM and GL more than SOL. Future research should calculate EMD and R-EMD to further investigate the mechanical adaptations induced by passive stretching in synergistic muscles.

Serious Game with Electromyography Feedback and Physical Therapy in Young Children with Unilateral Spastic Cerebral Palsy and Equinus Gait: A Prospective Open-Label Study.

The clinical effects of a serious game with electromyography feedback (EMGs_SG) and physical therapy (PT) was investigated prospectively in children with unilateral spastic cerebral palsy (USCP). An additional aim was to better understand the influence of muscle shortening on function. Thirty children with USCP (age 7.6 ± 2.1 years) received four weeks of EMGs_SG sessions 2×/week including repetitive, active alternating training of dorsi- and plantar flexors in a seated position. In addition, each child received usual PT treatment ≤ 2×/week, involving plantar flexor stretching and command strengthening on dorsi- and plantar flexors. Five-Step Assessment parameters, including preferred gait velocity (normalized by height); plantar flexor extensibility (XV1); angle of catch (XV3); maximal active ankle dorsiflexion (XA); and derived coefficients of shortening, spasticity, and weakness for both soleus and gastrosoleus complex (GSC) were compared pre and post treatment (t-tests). Correlations were explored between the various coefficients and gait velocities at baseline. After four weeks of EMGs_SG + PT, there was an increase in normalized gait velocity from 0.72 ± 0.13 to 0.77 ± 0.13 m/s (p = 0.025, d = 0.43), a decrease in coefficients of shortening (soleus, 0.10 ± 0.07 pre vs. 0.07 ± 0.08 post, p = 0.004, d = 0.57; GSC 0.16 ± 0.08 vs. 0.13 ± 0.08, p = 0.003, d = 0.58), spasticity (soleus 0.14 ± 0.06 vs. 0.12 ± 0.07, p = 0.02, d = 0.46), and weakness (soleus 0.14 ± 0.07 vs. 0.11 ± 0.07, p = 0.005, d = 0.55). At baseline, normalized gait velocity correlated with the coefficient of GSC shortening (R = -0.43, p = 0.02). Four weeks of EMGs_SG and PT were associated with improved gait velocity and decreased plantar flexor shortening. A randomized controlled trial comparing EMGs_SG and conventional PT is needed.

Effects of photobiomodulation on pain, lactate and muscle performance (ROM, torque, and EMG parameters) of paretic upper limb in patients with post-stroke spastic hemiparesis-a randomized controlled clinical trial.

The objective of the study was to investigate the impact of photobiomodulation (PBM) on the paretic upper limb in post-stroke patients with spastic hemiparesis and to understand the potential of PBM as a long-term non-invasive therapy for reducing the side effects caused by spasticity in the hemiparetic upper limb after a stroke. This is a double-blind randomized clinical trial constituted of 27 participants, being Control group (CG = 12 healthy individuals) and PBM group (PBMG = 15 post-stroke individuals). In the CG, the baseline blood lactate (BL) was evaluated, followed by the evaluation of the IC torque of the biceps and triceps muscles, with the isokinetic dynamometer associated with surface electromyography (EMG) and, subsequently, a new measurement of BL. The PBMG received 10 sessions of treatment with PBM (780 nm, Power: 100 mV, Power Density: 3.18 W/cm2, Energy: 4 J, Fluency: 127.4 J/cm2, Time: 40 s per point and 1.280 s total, Spot: 0.0314 cm2, 32 Points: 16 points (brachial biceps) and 16 points (brachial triceps) applied with contact at 90°, Total Energy: 64 J), which in the pre-treatment evaluation measured BL, the visual analogue scale (VAS) of pain; torque and EMG of the same muscles in the IC, subsequently, a new measurement of VAS and BL, and measurement of range of motion (ROM) during the reaching movement. At the conclusion of the ten sessions, all participants underwent a reassessment, wherein all tests originally administered during the initial evaluation were repeated. Subsequently, the data were analyzed using the Shapiro-Wilk normality test. For related data, the paired t-test was used for normal distributions and the Wilcoxon test for non-normal data. For unrelated data, the t test was used for normal distributions and the Mann-Whitney test for non-normal data. Muscle torque was higher for the CG, with a significant difference (CGxPBMG = p < 0.0001). There was no significant difference between the EMG values of the CG in relation to the Pre-PBM phase and with the Post-PBM phase of the PBMG (p > 0.05). On the other hand, there was a 38% reduction in pain reported by hemiparetic patients (p = 0.0127) and a decrease in BL in the PBMG. Post-PBM ROM increased by 46.1% in the elbow extension of the paretic limb. In conclusion, Photobiomodulation (PBM) demonstrated significant improvements in muscle performance, reducing fatigue and pain levels, and enhancing range of motion in post-stroke patients with spastic hemiparesis. These findings support the potential integration of PBM into rehabilitation protocols, but further research and clinical trials are needed to validate and expand upon these promising outcomes.

Changes in the excitability of anterior horn cells in a mental rotation task of body parts.

INTRODUCTION/AIMS: Mental rotation (MR), a tool of implicit motor imagery, is the ability to rotate mental representations of two- or three-dimensional objects. Although many reports have described changes in brain activity during MR tasks, it is not clear whether the excitability of anterior horn cells in the spinal cord can be changed. In this study, we examined whether MR tasks of hand images affect the excitability of anterior horn cells using F-wave analysis. METHODS: Right-handed, healthy participants were recruited for this study. F-waves of the right abductor pollicis brevis were recorded after stimulation of the right median nerve at rest, during a non-MR task, and during an MR task. The F-wave persistence and the F/M amplitude ratio were calculated and analyzed. RESULTS: Twenty participants (11 men and 9 women; mean age, 29.2 ± 4.4 years) were initially recruited, and data from the 18 that met the inclusion criteria were analyzed. The F-wave persistence was significantly higher in the MR task than in the resting condition (p = .001) or the non-MR task (p = .012). The F/M amplitude ratio was significantly higher in the MR task than in the resting condition (p = .019). DISCUSSION: The MR task increases the excitability of anterior horn cells corresponding to the same body part. MR tasks may have the potential for improving motor function in patients with reduced excitability of the anterior horn cells, although this methodology must be further verified in a clinical setting.

Electromyographic analysis of shoulder-complex muscles performing overhead presses with dumbbell, kettlebell, and bottom-up kettlebell.

INTRODUCTION: Kettlebell exercises, specifically the bottom-up grip, have become increasingly popular in training programs. The purpose of this research was to determine if a bottom-up kettlebell grip favorably alters the electromyography (EMG), activity in the medial deltoid (MD), serratus anterior (SA), and lower trapezius (LT), muscles compared to using a dumbbell or traditional kettlebell grip during overhead shoulder presses. METHODS: Twenty-eight healthy, male, Division III collegiate baseball players (mean age = 19.8 ± 1.28 years) performed five overhead presses of equal weight, 11.34 kg (25 lbs), using a dumbbell (DB), kettlebell w/traditional grip (KB), and kettlebell held with a bottom-up grip (KBU). RESULTS: For the MD, there was significantly greater EMG activity using the DB compared to KBU, but no significant differences between the DB and KB, or KB and KBU. For the SA, greater EMG activity was noted using the KBU compared to KB, and KBU compared to DB, but no differences between KB and DB. For the LT, greater EMG activity was noted using the DB compared to KB, but no differences between DB and KBU, or KB and KBU. CONCLUSION: The KBU press only elicited greater EMG activity in the SA. The DB elicited greater EMG activity in both the MD and LT. Shoulder-complex EMG activity varies with different types of overhead presses using equivalent loads.

Effect of verbal instructions on trunk muscle activity during volitional preemptive abdominal contraction.

OBJECTIVE: This study investigated the effect of Verbal Instruction (VI) strategies on trunk muscle contraction among healthy subjects. The effect of three VI Abdominal Drawing-In Maneuver (ADIM) and two VI Abdominal Bracing Maneuver (ABM) strategies on left Internal (LIO) and External Oblique (LEO) and bilateral superficial Multifidi (sMf) activation was examined. DESIGN: Within-subjects, repeated measure design. METHODS: Surface EMG (sEMG) measured LIO, LEO, and sMf activity in 28 subjects (mean age 23.5 ± 5.5 years). Testing included five supine hook-lying and five quiet standing conditions. RESULTS: One-way ANOVAs demonstrated no significant main effect for ADIM or ABM in supine or standing (p > .05). Muscle activation amplitudes during VPAC conditions demonstrated higher mean values for standing versus supine (p < .05) except for two conditions involving LEO. Friedman Tests for dominant strategy demonstrated a significant main effect for ADIM-VI and ABM-VI strategies. Post-hoc testing generally showed the dominant strategy to be significantly higher versus others. CONCLUSION: No single preferred VI cue for ADIM or ABM was observed. Each subject's dominant strategy dictated the most suitable VI. Standing was preferred for LIO and sMf activation, whereas position did not change LEO activation. Non-significant correlations between all muscle pairings during all ADIM and ABM strategies were observed. These findings may suggest the need for healthcare providers who understand the intricacies of trunk stability to teach and monitor VPAC with either ADIM or ABM options.

Use of electromyographic biofeedback in rehabilitation following anterior cruciate ligament reconstruction: a systematic review and meta-analysis.

BACKGROUND: Rehabilitation following anterior cruciate ligament (ACL) reconstruction surgery is essential to regain functionality and return to previous activity level. Electromyographic biofeedback may be an effective intervention for rehabilitation of patients following ACL surgery. OBJECTIVE: To synthesize the available evidence on the effect of electromyographic biofeedback in the treatment of quadriceps strength following ACL surgery. DESIGN: Systematic review with meta-analysis. DATA SOURCES: PubMed, EMBASE, CENTRAL and Epistemonikos were searched. ELIGIBILITY CRITERIA: Randomized clinical trials with patients undergoing ACL reconstruction surgery comparing biofeedback with a standard rehabilitation control group. DATA EXTRACTION AND DATA SYNTHESIS: Two authors selected articles and performed data extraction. The analysed outcomes were strength, function, pain, knee extension and balance. The risk of bias of individual studies was assessed using the Cochrane Risk of Bias Tool. Results were combined through random-effects meta-analysis, reporting mean differences. RESULTS: Eight articles were included in the qualitative analysis, and four articles were included in the quantitative analysis. The interventions lasted between 4 and 12 weeks. Three studies evaluated the effect of biofeedback on quadriceps strength; of these, two studies showed a significant difference in favour of the biofeedback group. In addition, biofeedback was found to improve knee extension [standardized mean difference - 1.3, 95% confidence interval (CI) - 1.74 to -0.86] and balance (one study). There was no significant difference in Lysholm score (mean difference -6.21, 95% CI -17.51 to 5.08; I2 =59%) or pain between the biofeedback group and the control group. CONCLUSION: Electromyographic biofeedback in knee rehabilitation could be useful following ACL reconstruction surgery. KEY MESSAGES: SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO (CRD42020193768).

Electromyographic biofeedback therapy for improving limb function after stroke: A systematic review and meta-analysis.

BACKGROUND: Upper and lower limb impairment is common after stroke. Electromyographic biofeedback therapy is a non-invasive treatment, and its effectiveness in functional rehabilitation of the limb after stroke still remains uncertain. OBJECTIVE: The objective of this study was to evaluate whether electromyographic biofeedback can improve upper and lower limb dysfunction in stroke patients. METHODS: PubMed, Embase, Cochrane Library, and Physiotherapy Evidence Database (PEDro) were searched from inception to 1st May 2022. Inclusion criteria were randomized controlled clinical trials of electromyographic biofeedback therapy interventions reporting changes in upper and lower limb function in post-stroke patients. Data were extracted by two independent reviewers and pooled in random-effects models using Review manager (RevMan) software. RESULTS: Our analyses included 10 studies enrolling a total of 303 participants. Electromyographic biofeedback therapy can effectively improve limb function after stroke (standardized mean difference [SMD], 0.44; 95% confidence interval [CI], 0.12-0.77; P = 0.008) and in subgroup analyses, the effect sizes of short-term effect (SMD, 0.33; 95% CI, 0.02-0.64; P = 0.04) was significant, but the long-term was not (SMD, 0.61; 95% CI, -0.11-1.33; P = 0.10). In addition, Electromyographic biofeedback therapy can improve the active range of motion of shoulder (SMD, 1.49; 95% CI, 2.22; P<0.0001) and wrist joints (SMD, 0.77; 95% CI, 0.13-1.42; P = 0.02) after stroke. CONCLUSION: In this meta-analysis, electromyographic biofeedback therapy intervention can improve upper and lower limb function in patients with stroke. Short-term (less than one month) improvement after electromyographic biofeedback therapy was supported, while evidence for long-term (more than one month) benefits was lacking. Range of motion in the glenohumeral and wrist joints were improved. Stronger evidence for individualized parameters, such as optimal treatment parameters and intervention period, is needed in the future. SYSTEMATIC REVIEW REGISTRATION: [https://www.crd.york.ac.uk/prospero/display_record.php?recordID=267596], identifier [CRD42022354363].

First-in-human demonstration of floating EMG sensors and stimulators wirelessly powered and operated by volume conduction.

BACKGROUND: Recently we reported the design and evaluation of floating semi-implantable devices that receive power from and bidirectionally communicate with an external system using coupling by volume conduction. The approach, of which the semi-implantable devices are proof-of-concept prototypes, may overcome some limitations presented by existing neuroprostheses, especially those related to implant size and deployment, as the implants avoid bulky components and can be developed as threadlike devices. Here, it is reported the first-in-human acute demonstration of these devices for electromyography (EMG) sensing and electrical stimulation. METHODS: A proof-of-concept device, consisting of implantable thin-film electrodes and a nonimplantable miniature electronic circuit connected to them, was deployed in the upper or lower limb of six healthy participants. Two external electrodes were strapped around the limb and were connected to the external system which delivered high frequency current bursts. Within these bursts, 13 commands were modulated to communicate with the implant. RESULTS: Four devices were deployed in the biceps brachii and the gastrocnemius medialis muscles, and the external system was able to power and communicate with them. Limitations regarding insertion and communication speed are reported. Sensing and stimulation parameters were configured from the external system. In one participant, electrical stimulation and EMG acquisition assays were performed, demonstrating the feasibility of the approach to power and communicate with the floating device. CONCLUSIONS: This is the first-in-human demonstration of EMG sensors and electrical stimulators powered and operated by volume conduction. These proof-of-concept devices can be miniaturized using current microelectronic technologies, enabling fully implantable networked neuroprosthetics.

Effects of ankle exoskeleton assistance and plantar pressure biofeedback on incline walking mechanics and muscle activity in cerebral palsy.

Ankle dysfunction affects more than 50 % of people with cerebral palsy, resulting in atypical gait patterns that impede lifelong mobility. Incline walking requires increased lower limb effort and is a promising intervention that targets lower-limb extensor muscles. A concern when prescribing incline walking to people with gait deficits is that this exercise may be too challenging or reinforce unfavorable gait patterns. This study aims to investigate how ankle exoskeleton assistance and plantar pressure biofeedback would affect gait mechanics and muscle activity during incline walking in CP. We recruited twelve children and young adults with CP. Participants walked with ankle assistance alone, biofeedback alone, and the combination while we assessed ankle, knee, and hip mechanics, and plantar flexor and knee extensor activity. Compared to incline walking without assistance or biofeedback, ankle assistance alone reduced the peak biological ankle moment by 12 % (p < 0.001) and peak soleus activity by 8 % (p = 0.013); biofeedback alone increased the biological ankle moment (4 %, p = 0.037) and power (19 %, p = 0.012), and plantar flexor activities by 9 - 27 % (p ≤ 0.026); assistance-plus-biofeedback increased biological ankle and knee power by 34 % and 17 %, respectively (p ≤ 0.05). The results indicate that both ankle exoskeleton assistance and plantar pressure biofeedback can effectively modify lower limb mechanics and muscular effort during incline walking in CP. These techniques may help in establishing personalized gait training interventions by providing the ability to adjust intensity and biomechanical focus over time.

Nonlinear spatio-temporal filter to reduce crosstalk in bipolar electromyogram.

Objective.The wide detection volume of surface electromyogram (EMG) makes it prone to crosstalk, i.e. the signal from other muscles than the target one. Removing this perturbation from bipolar recordings is an important open problem for many applications.Approach.An innovative nonlinear spatio-temporal filter is developed to estimate the EMG generated by the target muscle by processing noisy signals from two bipolar channels, placed over the target and the crosstalk muscle, respectively. The filter is trained on some calibration data and then can be applied on new signals. Tests are provided in simulations (considering different thicknesses of the subcutaneous tissue, inter-electrode distances, locations of the EMG channels, force levels) and experiments (from pronator teres and flexor carpi radialis of 8 healthy subjects).Main results.The proposed filter allows to reduce the effect of crosstalk in all investigated conditions, with a statistically significant reduction of its root mean squared of about 20%, both in simulated and experimental data. Its performances are also superior to those of a blind source separation method applied to the same data.Significance.The proposed filter is simple to be applied and feasible in applications in which single bipolar channels are placed over the muscles of interest. It can be useful in many fields, such as in gait analysis, tests of myoelectric fatigue, rehabilitation with EMG biofeedback, clinical studies, prosthesis control.

A randomized controlled trial investigating the impact of a single flash cupping session on patients with chronic lower back pain using multichannel surface electromyographic assessment.

BACKGROUND: Chronic lower back pain (CLBP) is one of the most common disorders worldwide. Flash cupping has the ability to relieve CLBP; nevertheless, its impact on CLBP and the likely mechanism of action have not been studied. OBJECTIVE: The goal of this study was to assess the impact of a single, brief cupping session on CLBP and low back muscle activity using multichannel surface electromyography (sEMG). METHODS: In this randomized controlled trial, 24 patients with CLBP were enrolled and randomly assigned to the control group (treated by acupuncture) and cupping group (treated by acupuncture and flash cupping). Acupuncture was applied on the shen shu (BL23), dachang shu (BL25), and wei zhong (BL40) acupoints in both the groups. A brief cupping treatment was applied to the shen shu (BL23), qihai shu (BL24), dachang shu (BL25), guanyuan shu (BL26), and xiaochang shu (BL27) acupoints on both sides of the lower back in the cupping group. The numeric rating scale (NRS) was used to assess therapy efficacy for lower back pain (LBP) before and after treatment. Surface EMG data collected during symmetrical trunk flexion-extension movements were utilized to measure lower back muscle activity and the effectiveness of LBP therapy. RESULTS: There was no statistically significant difference (P= 0.63) in pain intensity between the two groups before and after treatment. There was a statistically significant difference (P= 0.04) between the control group and the cupping group in the sEMG topographic map parameter CoGx-To-Midline. CONCLUSION: This study established a connection between the action mechanism of flash cupping and enhanced horizontal synchronization of lower back muscular activity.

Laser acupuncture and photobiomodulation therapy in Bell's palsy with a duration of greater than 8 weeks: a randomized controlled trial.

To investigate the efficacy of laser acupuncture and photobiomodulation therapy in alleviating symptoms among patients diagnosed with Bell's palsy with duration of greater than 8 weeks. The randomized controlled trial has been performed from May 2021 to April 2023. Patients were eligible who had Bell's palsy with duration of greater than 8 weeks on out-patient Department of Otorhinolaryngology in Beijing Tongren Hospital. The laser acupuncture group received class IV laser treatment for 3 times per weeks, a total of 72 times. The control group received the same treatment procedure except the laser parameter. The primary outcome measures comprised House-Brackmann facial nerve grading system and electroneurography. Secondary outcome measures comprised Sunnybrook facial grading system, electromyography, and the blink reflex. A total of 84 participants were included (42 control group, 42 laser acupuncture group). After treatment, House-Brackmann facial nerve grading system (OR, 0.11; 95% CI, 0.04-0.30; P < 0.001), and the pathologic numbers of electroneuronography were statistically different between the laser acupuncture group and control group, including orbicularis oculi (OR,0.08; 95% CI, 0.02-0.21; P < 0.001), Frontalis muscle (OR,0.14; 95% CI, 0.05-0.39; P < 0.001), Orbicularis oris (OR,0.13; 95% CI, 0.04-0.36; P < 0.001), Ala nasi muscle (OR,0.06; 95% CI, 0.02-0.18; P < 0.001). In secondary outcomes, Sunnybrook facial grading system, has significant difference between the two groups (20.26; 95% CI, 14.69 to 25.83; P < 0.01). Latency by ENoG, include orbicularis oculi (-0.61; 95% CI, -0.43 to -0.09; P < 0.001), frontalis muscle (-0.12; 95% CI, -0.21 to -0.03; P < 0.01), orbicularis oris (-0.28; 95% CI, -0.41 to -0.16; P < 0.001), and ala nasi muscle (-0.26; 95% CI, -0.38 to -0.16; P < 0.001). All amplitudes of MUAPs and durations by electromyography (EMG) showed statistically significant differences compared with the control group after treatment. For the frontalis muscle, the amplitude of MUAPs was -64.23 (95% CI, -80.89 to -47.56; P < 0.001) and duration was -1.18 (95% CI, -1.49 to -0.87; P < 0.001). For orbicularis oris, amplitude of MUAPs was -29.82 (95% CI, -55.03 to -4.62; P = 0.02) and duration was -0.57 (95% CI, -0.94 to -0.20; P < 0.001). For depressor angulli oris, amplitude of MUAPs was -47.06 (95% CI, -62.15 to -31.97; P < 0.001) and duration was -2.21 (95% CI, -2.69 to -1.72; P < 0.001). Blink reflex, including R1 (OR, 0.03; 95% CI, 0.01-0.16; P < .001), R2 (OR, 0.04; 95% CI, 0.004-0.29; P < .001), and R2 latency differences (OR, 0.15; 95% CI, 0.05-0.51; P < .001), have significant difference between the two groups, respectively. The findings suggest that laser acupuncture relieve symptoms for patients with Bell's palsy with a duration of greater than 8 weeks.Trial registration: ClinicalTrials.gov Identifier: NCT05846217.

Unique case study: Impact of single-session neuromuscular biofeedback on motor unit properties following 12 days of Achilles tendon surgical repair.

We explored the first evidence of a single-session neuromuscular biofeedback effect on motor unit properties, neuromuscular activation, and the Achilles tendon (AT) length 12 days after undergoing AT surgical repair. We hypothesized that immediate neuromuscular biofeedback enhances motor unit properties and activation without causing AT lengthening. After 12 days AT surgical repair, Medial Gastrocnemius (MG) motor unit decomposition was performed on a 58-year-old male before and after a neuromuscular biofeedback intervention (surface electromyography (sEMG) and ultrasonography), involving unressited plantar flexion. The analysis included motor unit population properties, sEMG amplitude, force paradigm, and AT length. There were increased MG motor unit recruitment, peak and average firing rate, coefficient of variation, and sEMG amplitude, and decreased recruitment and derecruitment threshold in the repaired AT limb. The non-injured limb increased the motor unit recruitment, and decreased the coefficient of variation, peak and average firing rate, inter-pulse interval, derecruitment threshold and sEMG amplitude. The AT length experienced -0.4 and 0.3 cm changes in the repaired AT and non-injured limb, respectively. This single-session neuromuscular biofeedback 12 days after AT surgery shows evidence of enhanced motor unit properties and activation without signs of AT lengthening when unresisted plantar flexion is performed in the repaired AT limb.

Electromyogram Power Spectrum and Cardiac Function Changes After Combined Aerobic Interval Training and Inspiratory Muscle Training in Chronic Heart Failure Patients.

Exercise intolerance and dyspnea are the major symptoms of patients with chronic heart failure (CHF) and are associated with a poor quality of life. In addition to impaired central hemodynamics, symptoms may be attributed to changes in peripheral skeletal muscles. This study aimed to evaluate the effects of aerobic interval training (AIT) combined with inspiratory muscle training (IMT) on cardiac and skeletal muscle function and on functional capacity and dyspnea in patients with CHF and inspiratory muscle weakness.Left ventricle ejection fraction was improved significantly after AIT and AIT & IMT with a high percentage of amelioration (17%, P < 0.042) in the combined group compared to the control group. Therefore, we showed a significant improvement in maximal voluntary isometric force, isometric endurance time, root mean square, and frequency median in both strength and endurance manipulations in the aerobic and combined group; however, the improvement was superior in the combined group compared to the control group. Significant amelioration was proved in functional capacity and dyspnea after all types of training but was performed at 18% higher in 6 minutes' walk test and 43% lower in dyspnea for the combined group compared to the control group.Combining AIT to IMT had optimized exercise training benefits in reversing the cardiac remodeling process and improving skeletal muscle function, functional capacity, and dyspnea in patients with CHF.

Reduced center of mass acceleration during regular walking with electromyography biofeedback.

BACKGROUND: Regular walking in healthy adults is known to be kinematically stable, but it is unclear how to further kinematically stabilize regular walking. Electromyography biofeedback (EMG-BF) during walking improves walking ability in patients. However, the effect of EMG-BF on walking stability in healthy adults is unknown. Therefore, this study aimed to investigate whether EMG-BF enhances the stability of regular walking in healthy adults. RESEARCH QUESTION: Does the EMG-BF enhance the stability of regular walking in healthy adults? METHODS: Auditory biofeedback of single muscle activity was given to twelve participants during regular walking. The target muscles were the ankle plantar flexor, ankle dorsiflexor, and knee flexor. We compared the root mean square of the center of mass acceleration (RMS-CoMacc), which represents walking smoothness, between biofeedback conditions. RESULTS: We found that EMG-BF during regular walking partially reduced the RMS-CoMacc (p = 0.01). In particular, biofeedback of the ankle plantar flexor muscle reduced the RMS-CoMacc in both the anteroposterior and vertical directions. In the mediolateral RMS-CoMacc, no significant difference was found (p = 0.24). SIGNIFICANCE: Our study is novel because it is the first study to reveal the impact of EMG-BF on the stability of walking among healthy adults. It identifies the key muscles for EMG-BF, potentially leading to the development of a more effective EMG-BF system in the rehabilitation. Especially, biofeedback of the ankle plantar flexor muscle could improve walking stability in both the anteroposterior and vertical directions. The effect of EMG-BF for reducing the RMS-CoMacc during regular walking might depend on the target muscles of biofeedback.

Efficacy of game training combined with surface electromyography biofeedback on post-stroke dysphagia.

OBJECTIVE: To explore the efficacy of game training combined with surface electromyography biofeedback (sEMG-BF) in the treatment of dysphagia after early stroke. METHODS: Ninety patients with early post-stroke dysphagia (PSD), who were diagnosed and treated from March 2021 to December 2022, were divided randomly into a control group (30 cases), experimental group 1 (30 cases) and experimental group 2 (30 cases). The control group received routine swallowing rehabilitation and transcranial direct current stimulation. Experimental group 1 received sEMG-BF in conjunction with the care provided to the control group. Experimental group 2 received sEMG-BF and game training in addition to the care provided to the control group. Before and after treatment, all three patient groups were evaluated using the WADA water swallowing test, the Functional Oral Intake Scale (FOIS), sEMG and a tongue manometer test. RESULTS: Before treatment, there was no significant difference (P > 0.05) among the three groups of patients in terms of WADA water swallowing rating, FOIS score, submandibular muscle sEMG peak, swallowing time limit and maximum tongue pressure. After treatment, all three groups exhibited improvements in these indices compared with those before treatment (P < 0.05). Experimental group 1 showed greater improvement than the control group (P < 0.05), and experimental group 2 exhibited greater improvement than experimental group 1 and the control group (P < 0.05). CONCLUSION: Game training combined with sEMG-BF can significantly improve the swallowing function of patients with PSD.

Peripheral fatigue regulation during knee extensor exercise in type 1 diabetes and consequences on the force-duration relationship.

PURPOSE: This study aimed to examine if peripheral fatigue is adjusted during knee extensor (KE) exercise in order not to surpass a critical threshold patient with type 1 diabetes (T1D) and the consequences of this mechanism on the force-duration relationship. METHODS: Eleven T1D individuals randomly performed two different sessions in which they performed 60 maximum voluntary contractions (MVC; 3 s contraction, 2 s relaxation). One trial was performed in the non-fatigued state (CTRL) and another after fatiguing neuromuscular stimulation of the KE (FNMES). Peripheral and central fatigue were quantified by the difference between pre and post exercise in quadriceps voluntary activation (ΔVA) and potentiated twitch (ΔPtw). Critical torque (CT) was determined as the average force of the last 12 contractions, whereas W' was calculated as the area above the CT. RESULTS: Although FNMES led to a significant decrease in potentiated twitch (Ptw) before performing the 60-MVCs protocol (p < 0.05), ΔVA (∼ -7.5%), ΔPtw (∼ -39%), and CT (∼816 N) post-MVCs were similar between the two conditions. The difference in W' between CTRL and FNMES was correlated with the level of pre-fatigue induced in FNMES (r2 = 0.60). In addition, W' was correlated with ΔPtw (r2 = 0.62) in the CTRL session. CONCLUSION: Correlative results in the present study indicate that regulating peripheral fatigue mechanisms at a critical threshold limit W'. Additionally, peripheral fatigue during KE exercise is limited to an individual threshold in T1D patients.

Effect of M-wave Amplitude on Inter-evaluator Concordance and Number of Detected Innervation Zones in the Medial Gastrocnemius Using Multichannel Electromyography / Efecto de la Amplitud de la Onda M sobre la Concordancia entre Evaluadores y el Número de Zonas de Inervación Detectadas en el Gastrocnemio Medial Mediante Electromiografía Multicanal

SUMMARY: The Innervation Zones (IZ) correspond to clusters of neuromuscular junctions. The traditional method of locating IZs through voluntary muscle contractions may not be feasible in individuals with motor disorders. Imposed contractions by electrostimulation are an alternative. However, there is limited evidence regarding the factors that affect inter-evaluator concordance and the number of localized IZs when using imposed contraction. The main objective of this research was to determine the effect of the amplitude of compound motor action potentials (CMAPs) containing the M-wave on inter-evaluator agreement. As a secondary objective, was investigate the effect on the number of detected IZs. Twenty-four healthy volunteers (age: 21.2 ± 1.5years, weight: 67.4 ± 13.2kg, height: 1.68 ± 0.80m) participated in the study. Electrostimulation was applied to the tibial nerve to induce contraction of the medial gastrocnemius. The IZ were identified based on the M-wave recorded through multichannel electromyography. A receiver operating characteristic (ROC) analysis was conducted to assess sensitivity and specificity in detecting the IZs. Inter-rater agreement was evaluated using a two-way mixed effects test to determine the intraclass correlation coefficients (ICC). A p-value less than 0.05 was considered statistically significant. The ROC analysis revealed that for both evaluators, a specificity of 95% was achieved with an amplitude ≥30 %. The area under the ROC curve was 0.980 [0.964, 0.996], indicating a strong influence of CMAP amplitude on detection of IZs. The highest level of agreement (ICC = 0.788 [0.713, 0.844]) among the evaluators was observed with CMAP amplitudes equal to or greater than 80 % of the maximum M-wave. The findings of this study demonstrate that both the number and the inter-evaluator concordance for detecting IZs using imposed contractions are strongly influenced by the amplitude of the M-wave. Higher M-wave amplitudes were associated with improved concordance and increased IZ detection, making it crucial to standardize amplitude settings for reliable outcomes.

Las Zonas de Inervación (IZ) corresponden a grupos de uniones neuromusculares. El método tradicional para localizar IZs mediante contracciones musculares voluntarias puede no ser factible en personas con trastornos motores. Las contracciones impuestas mediante electro estimulación son una alternativa. Sin embargo, existe poca evidencia sobre los factores que afectan la concordancia entre evaluadores y el número de IZs localizadas al usar este tipo de contracciones. El objetivo de esta investigación fue determinar el efecto de la amplitud de los potenciales de acción motores compuestos (PAMCs) que contienen la onda M sobre la concordancia entre evaluadores. Como objetivo secundario, se investigó el efecto sobre el número de IZs detectadas. Veinticuatro voluntarios sanos (edad: 21.2 ± 1.5 años, peso: 67.4 ± 13.2 kg, altura: 1.68 ± 0.80 m) participaron en el estudio. Se aplicó electroestimulación al nervio tibial para inducir la contracción del gastrocnemio medial. Las IZs se identificaron según la onda M registrada mediante electromiografía multicanal. Se realizó un análisis de curva de las característica del receptor (ROC) para evaluar la sensibilidad y especificidad en la detección de las IZs. La concordancia entre evaluadores se evaluó utilizando una prueba de efectos mixtos de dos vías para determinar los coeficientes de correlación intraclase (ICC). Se consideró un valor de p menor que 0.05 como estadísticamente significativo. El análisis ROC reveló que para ambos evaluadores se logró una especificidad del 95% con una amplitud ≥30 %. El área bajo la curva ROC fue de 0.980 [0.964, 0.996], lo que indica una fuerte influencia de la amplitud del CMAP en la detección de las IZs. El nivel más alto de concordancia (ICC = 0.788 [0.713, 0.844]) entre los evaluadores se observó con amplitudes de CMAP iguales o mayores al 80 % de la onda M máxima. Los hallazgos de este estudio demuestran que tanto el número como la concordancia entre evaluadores para detectar IZs mediante contracciones impuestas están fuertemente influenciados por la amplitud de la onda M. Las amplitudes más altas de la onda M se asociaron con una concordancia mejorada y un aumento en la detección de IZs, lo que hace crucial estandarizar los ajustes de amplitud para obtener resultados confiables.