In this study, a surface electromyography (sEMG) and blood oxygen signal real-time monitoring system is designed to explore the changes of physiological signals during muscle fatigue, so as to detect muscle fatigue. The analysis method of sEMG and the principle of blood oxygen detection are respectively introduced, and the system scheme is expounded. The hardware part of the system takes STM32 as the core. Conditioning module composition; blood oxygen signal acquisition is based on near infrared spectroscopy (NIRS), specifically including light source, light source driving, photoelectric conversion, signal conditioning and other modules. The system software part is based on the real-time uC/OS-III software system. The characteristic parameters of sEMG were extracted by isometric contraction local muscle fatigue experiment; the relative changes of oxyhemoglobin (HbO₂) and deoxyhemoglobin (Hb) were calculated in the forearm blocking experiment, thereby verifying that the system collects two signals effectiveness.
Muscle, Skeletal ; Oxygen ; Electromyography ; Muscle Fatigue/physiology* ; Computers

Based on the joint analysis of EMG spectrum and amplitude method (JASA), a study on muscle fatigue assessment of spinal surgical instruments based on surface EMG signals was carried out, and a comparative evaluation of the operating comfort before and after the optimization of spinal surgical instruments was completed. A total of 17 subjects were recruited to collect the surface EMG signals of their brachioradialis and biceps. Five surgical instruments before and after optimization were selected for data comparison, and the operating fatigue time proportion of each group of instruments under the same task was calculated based on the RMS and MF eigenvalues. The results showed that when completing the same operation task, the operation fatigue time of the surgical instruments before optimization was significantly higher than that after optimization (P<0.05); there was no significant difference in the fatigue status of brachioradialis and biceps when operating the same instrument (P>0.05). These results provide objective data and reference for the ergonomic design of surgical instruments and fatigue damage protection.
Humans ; Muscle Fatigue/physiology* ; Muscle, Skeletal ; Electromyography ; Ergonomics

Aiming at the human-computer interaction problem during the movement of the rehabilitation exoskeleton robot, this paper proposes an adaptive human-computer interaction control method based on real-time monitoring of human muscle state. Considering the efficiency of patient health monitoring and rehabilitation training, a new fatigue assessment algorithm was proposed. The method fully combined the human neuromuscular model, and used the relationship between the model parameter changes and the muscle state to achieve the classification of muscle fatigue state on the premise of ensuring the accuracy of the fatigue trend. In order to ensure the safety of human-computer interaction, a variable impedance control algorithm with this algorithm as the supervision link was proposed. On the basis of not adding redundant sensors, the evaluation algorithm was used as the perceptual decision-making link of the control system to monitor the muscle state in real time and carry out the robot control of fault-tolerant mechanism decision-making, so as to achieve the purpose of improving wearing comfort and improving the efficiency of rehabilitation training. Experiments show that the proposed human-computer interaction control method is effective and universal, and has broad application prospects.
Humans ; Exoskeleton Device ; Muscle Fatigue ; Muscles ; Algorithms ; Electric Impedance

At present, fatigue state monitoring of upper limb movement generally relies solely on surface electromyographic signal (sEMG) to identify and classify fatigue, resulting in unstable results and certain limitations. This paper introduces the sEMG signal recognition and motion capture technology into the fatigue state monitoring process and proposes a fatigue analysis method combining an improved EMG fatigue threshold algorithm and biomechanical analysis. In this study, the right upper limb load elbow flexion test was used to simultaneously collect the biceps brachii sEMG signal and upper limb motion capture data, and at the same time the Borg Fatigue Subjective and Self-awareness Scale were used to record the fatigue feelings of the subjects. Then, the fatigue analysis method combining the EMG fatigue threshold algorithm and the biomechanical analysis was combined with four single types: mean power frequency (MPF), spectral moments ratio (SMR), fuzzy approximate entropy (fApEn) and Lempel-Ziv complexity (LZC). The test results of the evaluation index fatigue evaluation method were compared. The test results show that the method in this paper has a recognition rate of 98.6% for the overall fatigue state and 97%, 100%, and 99% for the three states of ease, transition and fatigue, which are more advantageous than other methods. The research results of this paper prove that the method in this paper can effectively prevent secondary injury caused by overtraining during upper limb exercises, and is of great significance for fatigue monitoring.
Electromyography/methods* ; Fatigue ; Humans ; Muscle Fatigue ; Muscle, Skeletal ; Upper Extremity

OBJECTIVE: To investigate the effect of M3P (containing Deer antler, Cordyceps sinensis, Rhodiola rosea, and Panax ginseng); an herbal remedy with the function of tonifying Kidney (Shen) and invigorating Spleen (Pi), replenishing qi and nourishing blood; on fatigue alleviation, endurance capacity and toxicity. METHODS: Swimming with weight-loading of 24 male ICR mice was used to evaluate the endurance capacity, and fatigue-related plasma biomarkers were determined. Mice were randomly assigned to control or M3P treatment groups with 6 mice for each group and were orally administered with M3P everyday for 8 weeks at doses 0, 10, 33 or 100 mg/kg. Swimming time to exhaustion was measured in a specialized water tank. Lliver and kidney functions, body weight, and hematological profile were determined to evaluate the safety and toxicity after long-term M3P administration. RESULTS: M3P supplementation 100 mg/kg significantly increased swimming endurance time up to approximate 2.4 folds of controls (P<0.05). The plasma concentrations of cortisol and hepatic glycogen content were significantly increased in mice received M3P (P<0.05, P<0.01 respectively). The lactic acid level and blood glucose were not changed after M3P treatment (P>0.05). The liver and kidney functions muscle damage biomarker creatine, body weight, and hemograms were not altered in M3P supplementation (P>0.05). CONCLUSION M3P supplementation may improve swimming endurance accompanied by increasing hepatic glycogen content and serum cortisol level without major toxicity.
Animals ; Body Weight ; Deer ; Dietary Supplements ; Fatigue/drug therapy* ; Hydrocortisone ; Liver Glycogen ; Male ; Mice ; Mice, Inbred ICR ; Muscle, Skeletal ; Swimming/physiology*

The automatic recognition technology of muscle fatigue has widespread application in the field of kinesiology and rehabilitation medicine. In this paper, we used surface electromyography (sEMG) to study the recognition of leg muscle fatigue during circuit resistance training. The purpose of this study was to solve the problem that the sEMG signals have a lot of noise interference and the recognition accuracy of the existing muscle fatigue recognition model is not high enough. First, we proposed an improved wavelet threshold function denoising algorithm to denoise the sEMG signal. Then, we build a muscle fatigue state recognition model based on long short-term memory (LSTM), and used the Holdout method to evaluate the performance of the model. Finally, the denoising effect of the improved wavelet threshold function denoising method proposed in this paper was compared with the denoising effect of the traditional wavelet threshold denoising method. We compared the performance of the proposed muscle fatigue recognition model with that of particle swarm optimization support vector machine (PSO-SVM) and convolutional neural network (CNN). The results showed that the new wavelet threshold function had better denoising performance than hard and soft threshold functions. The accuracy of LSTM network model in identifying muscle fatigue was 4.89% and 2.47% higher than that of PSO-SVM and CNN, respectively. The sEMG signal denoising method and muscle fatigue recognition model proposed in this paper have important implications for monitoring muscle fatigue during rehabilitation training and exercise.
Electromyography ; Memory, Short-Term ; Muscle Fatigue ; Neural Networks, Computer ; Recognition, Psychology

Robots are being used to assist the recovery of walking ability for patients with neurologic disorders. This study aimed to evaluate the feasibility and functional improvement of training with robot-assisted gait training (RAGT) using the Morning Walk®, an end-effector type robot using footplates and saddle seat support. A total of 189 individuals (65.1% men, 34.9% women; mean age, 53.2 years; age range: 5–87 years) with brain lesions, spinal cord injuries, Parkinson's disease, peripheral neuropathies, and pediatric patients were involved in this retrospectively registered clinical trial. Each participant performed 30 minutes of RAGT, five times a week, for a total of 24 sessions. Failure was defined as an inability to complete all 24 sessions, and the reasons for discontinuation were analyzed. Parameters of Medical Research Council scales and Functional Ambulation Categories were analyzed before and after RAGT training. Among the 189 patients, 22 (11.6%) failed to complete the RAGT. The reasons included decreased cooperation, musculoskeletal pain, saddle seat discomfort, excessive body-weight support, joint spasticity or restricted joint motion, urinary incontinence from an indwelling urinary catheter, and fatigue. Comparison between the pre- and post-training motor and ambulatory functions showed significant improvement. The result of the study indicates that the Morning Walk® is feasible and safe and useful for functional improvement in patients with various neurologic disordersTRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0003627
Brain ; Fatigue ; Female ; Gait ; Humans ; Information Services ; Joints ; Male ; Muscle Spasticity ; Musculoskeletal Pain ; Nervous System Diseases ; Parkinson Disease ; Peripheral Nervous System Diseases ; Retrospective Studies ; Spinal Cord Injuries ; Urinary Catheters ; Urinary Incontinence ; Walking ; Weights and Measures

BACKGROUND: Performing cognitive tasks and muscular fatigue have been shown to increase muscle activity of the lower extremity during quiet standing. A common intervention to reduce muscular fatigue is to provide a softer shoe-surface interface. However, little is known regarding how muscle activity is affected by softer shoe-surface interfaces during static standing. The purpose of this study was to assess lower extremity muscular activity during erect standing on three different standing surfaces, before and after an acute workload and during cognitive tasks. METHODS: Surface electromyography was collected on ankle dorsiflexors and plantarflexors, and knee flexors and extensors of fifteen male participants. Dependent electromyography variables of mean, peak, root mean square, and cocontraction index were calculated and analyzed with a 2 × 2 × 3 within-subject repeated measures analysis of variance. RESULTS: Pre-workload muscle activity did not differ between surfaces and cognitive task conditions. However, greater muscle activity during post-workload balance assessment was found, specifically during the cognitive task. Cognitive task errors did not differ between surface and workload. CONCLUSIONS: The cognitive task after workload increased lower extremity muscular activity compared to quite standing, irrespective of the surface condition, suggesting an increased demand was placed on the postural control system as the result of both fatigue and cognitive task.
Ankle ; Electromyography ; Fatigue ; Humans ; Knee ; Lower Extremity ; Male ; Muscle Fatigue

BACKGROUND AND PURPOSE: This randomized controlled study examined the effect of repetitive transcranial magnetic stimulation (rTMS) on spasticity in patients with multiple sclerosis (MS). METHODS: This study included 16 patients with a history of MS and spasticity in the adductor hip muscles according to the Modified Ashworth Scale (MAS). The participants were randomized into the active group (n=10) and control group (n=6), in which active rTMS and sham rTMS were applied in 10 sessions, respectively. A physical therapy and rehabilitation program was applied along with rTMS sessions in both groups. The evaluation parameters were assessed at baseline and then 1 week and 1 month after applying rTMS. RESULTS: Statistical analyses with post-hoc correction revealed statistically significant improvements in the active group compared to the control group in the bilateral MAS score, Penn Spasm Frequency Scale score, patient satisfaction, amount of urine leakage, actual health status, perceived health status, energy and fatigue, role limitations due to physical problems, social function, overall quality of life, cognitive functioning, physical health composite score, mental health composite score, and total score on the Multiple Sclerosis Quality of Life-54 (MSQOL-54) (p<0.05). Statistically significant changes were detected in the MSQOL-54 social function and physical health composite scores of patients in the control group (p<0.05). CONCLUSIONS: Active rTMS combined with a physical therapy program reduced spasticity in MS patients compared to the control group that received only physical therapy. Further comprehensive and more advanced studies are needed to confirm the present findings.
Fatigue ; Hip ; Humans ; Mental Health ; Multiple Sclerosis ; Muscle Spasticity ; Muscles ; Patient Satisfaction ; Quality of Life ; Rehabilitation ; Social Problems ; Spasm ; Transcranial Magnetic Stimulation

Neuromyelitis optica spectrum disorder (NMOSD) is generally known as selective involvement of central nervous system. However, in recent years, some evidences have been found that NMOSD invades other peripheral organs. Especially, skeletal muscle involvement of NMOSD has been documented scantily and further studies must be required. Here, we describe a patient who first had generalized fatigue, mild weakness, and myalgia with increased level of serum creatine kinase and was finally diagnosed with myopathy associated with NMOSD.
Central Nervous System ; Creatine Kinase ; Fatigue ; Humans ; Muscle, Skeletal ; Muscular Diseases ; Myalgia ; Myotonia ; Myotonic Disorders ; Neuromyelitis Optica