Search Results (32)

Background/Objectives: Optimal activation of the quadriceps femoris, particularly the vastus medialis, while minimizing excessive activation of the vastus lateralis, is crucial for treating knee injuries like ACL ruptures and patellofemoral pain syndrome. Restoring proper muscle balance may enhance rehabilitation outcomes, but effective strategies for modulating muscle activity remain unclear. High-velocity low-amplitude hip manipulation has shown potential to influence neuromuscular function, yet its impact on quadriceps activation during knee extension has not been well studied. Therefore, the main aim of this study is to examine the effects of a single session of high-velocity low-amplitude hip manipulation on quadriceps femoris muscle activation and maximum voluntary contraction during knee extension. Methods: This study utilizes a randomized controlled design. Thirty physically active men and women (mean age: 21.9 ± 1.7 years) were randomly assigned to either an experimental group (n = 15; receiving hip joint manipulation) or a control group (n = 15; undergoing a sham intervention). Participants in the intervention group received a treatment involving hip manipulation and short-duration traction. Muscle activity of the rectus femoris, vastus lateralis, and vastus medialis was assessed using surface electromyography before and after the intervention, while muscle performance was measured by evaluating isometric knee extension strength in the lower limb. The isometric strength test was conducted in a seated position with the knee flexed at 60 degrees in Biodex System 4. Results: This study finds that the experimental group had significantly higher vastus lateralis mean amplitude (p = 0.020; effect size = 0.186) and vastus medialis mean amplitude (p < 0.001; effect size = 0.577) of electromyography root mean square electromyography compared to the control group. The experimental group also showed greater vastus medialis max amplitude (p < 0.001; effect size = 0.435). No significant differences were noted for rectus femoris mean amplitude (p = 0.078; effect size = 0.110), vastus lateralis max amplitude (p = 0.363; effect size = 0.031), rectus femoris max amplitude (p = 0.069; effect size = 0.117), or median frequency of the raw electromyography signal across muscle groups. Conclusions: In conclusion, high-velocity low-amplitude hip manipulation significantly enhances vastus medialis activation, highlighting its potential to improve quadriceps balance. These findings support the incorporation of hip manipulation into rehabilitation protocols. Full article

Grasping objects, from simple tasks to complex fine motor skills, is a key component of our daily activities. Our approach to facilitate the development of advanced prosthetics, robotic hands and human–machine interaction systems consists of collecting and combining surface electromyography (EMG) signals and contextual data of individuals performing manipulation tasks. In this context, the identification of patterns and prediction of hand grasp types is crucial, with cylindrical grasp being one of the most common and functional. Traditional approaches to grasp prediction often rely on unimodal data sources, limiting their ability to capture the complexity of real-world scenarios. In this work, grasp prediction models that integrate both EMG signals and contextual (task- and product-related) information have been explored to improve the prediction of cylindrical grasps during reaching movements. Three model architectures are presented: an EMG processing model based on convolutions that analyzes forearm surface EMG data, a fully connected model for processing contextual information, and a hybrid architecture combining both inputs resulting in a multimodal model. The results show that context has great predictive power. Variables such as object size and weight (product-related) were found to have a greater impact on model performance than task height (task-related). Combining EMG and product context yielded better results than using each data mode separately, confirming the importance of product context in improving EMG-based models of grasping. Full article

The clinical use of spinal manipulation to treat musculoskeletal conditions has nearly tripled in the United States since 1980, and it is currently recommended by most global clinical guidelines as a conservative treatment for musculoskeletal pain, despite a lack of knowledge concerning its mechanisms of action. This overview highlights evidence of direct neuromuscular responses to high-velocity, low-amplitude spinal manipulation (HVLA-SM) as delivered by chiropractic, osteopathic, and physical therapy clinicians, with an intent to foster greater interprofessional dialogue and collaborative research to better address current gaps in mechanistic knowledge of the neuromuscular response to HVLA-SM. Three databases (PubMed, CINAHL Ultimate (EBSCO), EMBASE (Elsevier)) were searched from 2000 to December 2024 with specific search terms related to thrust HVLA-SM and the neuromuscular response. To focus strictly on neuromuscular responses related to HVLA-SM, this literature overview excluded articles using non-HVLA-SM manual therapy techniques (i.e., massage, non-thrust joint mobilization, and/or combined HVLA-SM with other forms of treatment such as exercise or non-thrust joint mobilization) and studies in which patient-centered outcomes (i.e., pain scores) were the primary outcomes of the HVLA-SM interventions. Pediatric studies, animal studies, and studies in languages other than English were also excluded. One-hundred and thirty six articles were identified and included in this overview. Neuromuscular findings related to HVLA-SM in the areas of electromyography (EMG), muscle thickness, muscle strength, reflexes, electroencephalogram (EEG), and evoked potential were often mixed; however, evidence is beginning to accumulate either in favor of or opposed to particular neuromuscular responses to HVLA-SM as larger and more scientifically rigorous studies are being performed. Recurrent limitations of many HVLA-SM-related studies are small sample sizes, leading to a lack of generalizability, and the non-standardization of HVLA-SM delivery, which has prevented researchers from arriving at definitive conclusions regarding neuromuscular responses to HVLA-SM. Discussions of future neuromuscular research needs related to HVLA-SM are included for clinicians and researchers inside and outside of the field of manual therapy, to advance this field. Full article

Surface electromyography (sEMG) signals reflect the local electrical activity of muscle fibers and the synergistic action of the overall muscle group, making them useful for gesture control of myoelectric manipulators. In recent years, deep learning methods have increasingly been applied to sEMG gesture recognition due to their powerful automatic feature extraction capabilities. sEMG signals contain rich local details and global patterns, but single-scale convolutional networks are limited in their ability to capture both comprehensively, which restricts model performance. This paper proposes a deep learning model based on multi-scale feature fusion—MS-CLSTM (MS Block-ResCBAM-Bi-LSTM). The MS Block extracts local details, global patterns, and inter-channel correlations in sEMG signals using convolutional kernels of different scales. The ResCBAM, which integrates CBAM and Simple-ResNet, enhances attention to key gesture information while alleviating overfitting issues common in small-sample datasets. Experimental results demonstrate that the MS-CLSTM model achieves recognition accuracies of 86.66% and 83.27% on the Ninapro DB2 and DB4 datasets, respectively, and the accuracy can reach 89% in real-time myoelectric manipulator gesture prediction experiments. The proposed model exhibits superior performance in sEMG gesture recognition tasks, offering an effective solution for applications in prosthetic hand control, robotic control, and other human–computer interaction fields. Full article

(1) Background: Activation of the gluteus medius (GM) muscle while minimizing the involvement of the tensor fascia latae (TFL) is crucial in treating many lower limb and lumbar spine injuries. Previous studies have demonstrated the effectiveness of joint manipulations in regulating muscle activity. The main objective of this study was to evaluate the effects of hip joint manipulation (HJM) on the muscle strength and activity (GM and TFL) of hip abductors in asymptomatic young participants. (2) Methods: The study followed a double-blind randomized controlled design. Thirty healthy, physically active women and men, free from spinal and lower limb injuries, voluntarily participated. The participants were allocated to two groups: those allocated to the HJM intervention and those in the control group receiving a sham intervention. They were assessed before and after the intervention using surface electromyography to measure muscle activation (EMG_RMS) of the GM and TFL during maximal voluntary isometric hip abduction. (3) Results: HJM resulted in a significant increase in EMG_RMS amplitude solely within the GM muscle (p < 0.01); (4) Conclusions: This study suggests that HJM may increase EMGRMS amplitude in the GM muscle; however, the effects are neither statistically nor clinically significant when compared to the control group for most of the muscles analyzed. Full article

The Nordic hamstring exercise (NHE) is effective at decreasing hamstring strain injury risk. Limited information is available on the in vivo mechanics of the bicep femoris long head (BF_LH) during the NHE. Therefore, the purpose of this study was to observe kinematic, neuromuscular and in-vivo mechanics of the BF_LH during the NHE. Thirteen participants (24.7 ± 3.7 years, 79.56 ± 7.89 kg, 177.40 ± 12.54 cm) performed three repetitions of the NHE at three horizontal planes (0°, 20° and −20°). Dynamic ultrasound of the dominant limb BF_LH, surface electromyography (sEMG) of the contralateral hamstrings and sagittal plane motion data were simultaneously collected. Repeated measures analysis of variance with Bonferroni post hoc corrections were used on the in vivo mechanics and the kinematic and sEMG changes in performance of the NHE. Likely differences in ultrasound waveforms for the BF_LH were determined. Significant and meaningful differences in kinematics and in vivo mechanics between NHE variations were observed. Non-significant differences were observed in sEMG measures between variations. Changes to the NHE performance angle manipulates the lever arm, increasing or decreasing the amount of force required by the hamstrings at any given muscle length, potentially changing the adaptive response when training at different planes and providing logical progressions ore regressions of the NHE. All NHE variations result in a similar magnitude of fascicle lengthening, which may indicate similar positive adaptations from the utilization of any variation. Full article

Surface electromyography (sEMG) has emerged as a valuable tool for assessing muscle activity in various clinical and research settings. This review focuses on the application of sEMG specifically in the context of paraspinal muscles. The paraspinal muscles play a critical role in providing stability and facilitating movement of the spine. Dysfunctions or alterations in paraspinal muscle activity can lead to various musculoskeletal disorders and spinal pathologies. Therefore, understanding and quantifying paraspinal muscle activity is crucial for accurate diagnosis, treatment planning, and monitoring therapeutic interventions. This review discusses the clinical applications of sEMG in paraspinal muscles, including the assessment of low back pain, spinal disorders, and rehabilitation interventions. It explores how sEMG can aid in diagnosing the potential causes of low back pain and monitoring the effectiveness of physical therapy, spinal manipulative therapy, and exercise protocols. It also discusses emerging technologies and advancements in sEMG techniques that aim to enhance the accuracy and reliability of paraspinal muscle assessment. In summary, the application of sEMG in paraspinal muscles provides valuable insights into muscle function, dysfunction, and therapeutic interventions. By examining the literature on sEMG in paraspinal muscles, this review offers a comprehensive understanding of the current state of research, identifies knowledge gaps, and suggests future directions for optimizing the use of sEMG in assessing paraspinal muscle activity. Full article

Surface electromyography (sEMG) signals are the sum of action potentials emitted by many motor units; they contain the information of muscle contraction patterns and intensity, so they can be used as a simple and reliable source for grasping mode recognition. This paper introduces the InRes-ACNet (inception–attention–ACmix-ResNet50) model, a novel deep-learning approach based on ResNet50, incorporating multi-scale modules and self-attention mechanisms. The proposed model aims to improve gesture recognition performance by enhancing its ability to extract channel feature information within sparse sEMG signals. The InRes-ACNet model is evaluated on the NinaPro DB1 and NinaPro DB5 datasets; the recognition accuracy for these datasets can reach 87.94% and 87.04%, respectively, and recognition accuracy can reach 88.37% in the grasping mode prediction of an electromyography manipulator. The results show that the fusion of multi-scale modules and self-attention mechanisms endows a strong ability for the task of gesture recognition based on sparse sEMG signals. Full article

General anesthetics were first used over 170 years ago; however, the mechanisms of how general anesthetics induce loss of consciousness (LOC) remain unclear. Ciprofol, a novel intravenous anesthetic, has been developed by incorporating cyclopropyl into the chemical structure of propofol. This modification offers the benefits of rapid onset and minimal injection pain. Recent studies have revealed that the glutamatergic neurons of the lateral habenula (LHb) play a crucial role in modulating the LOC induced by propofol and sevoflurane. Nevertheless, the specific involvement of LHb in the anesthetic effects of ciprofol remains uncertain. Here, using targeted recombination in active populations (TRAP) combined with electroencephalogram/electromyography recordings and the righting reflex behavioral test, our study revealed that intravenous infusion of ciprofol for 1 h could lead to the induction of c-Fos expression in the LHb in mice. The combination of TRAP and gene ablation, aimed at selectively ablating ciprofol-activated neurons in the LHb, has been shown to facilitate the emergence of ciprofol anesthesia and decrease the proportion of delta waves during the emergence phase. Chemogenetic inhibition of these neurons produced a comparable effect, whereas chemogenetic activation resulted in the opposite outcome. Chemogenetic activation of ciprofol-activated neurons in the LHb delays the emergence of anesthesia and induces a deep hypnotic state during the emergence phase. Taken together, our findings suggest that LHb ciprofol-activated neurons modulate the state of consciousness and could potentially be targeted to manipulate consciousness during ciprofol anesthesia. Full article

The forces applied during a spinal manipulation produce a neuromuscular response in the paraspinal muscles. A systematic evaluation of the factors involved in producing this muscle activity provides a clinical insight. The purpose of this study is to quantify the effect of treatment factors (manipulation sequence and manipulation site) and response factors (muscle layer, muscle location, and muscle side) on the neuromuscular response to spinal manipulation. The surface and indwelling electromyographies of 8 muscle sites were recorded during lumbar side-lying manipulations in 20 asymptomatic participants. The effects of the factors on the number of muscle responses and the muscle activity onset delays were compared using mixed-model linear regressions, effect sizes, and equivalence testing. The treatment factors did not reveal statistical differences between the manipulation sequences (first or second) or manipulation sites (L3 or SI) in the number of muscle responses (p = 0.11, p = 0.28, respectively), or in muscle activity onset delays (p = 0.35 p = 0.35, respectively). There were significantly shorter muscle activity onset delays in the multifidi compared to the superficial muscles (p = 0.02). A small effect size of side (d = 0.44) was observed with significantly greater number of responses (p = 0.02) and shorter muscle activity onset delays (p < 0.001) in the muscles on the left side compared to the right. The location, layer, and side of the neuromuscular responses revealed trends of decreasing muscle response rates and increasing muscle activity onset delays as the distance from the manipulation site increased. These results build on the body of work suggesting that the specificity of manipulation site may not play a role in the neuromuscular response to spinal manipulation—at least within the lumbar spine. In addition, these results demonstrate that multiple manipulations performed in similar areas (L3 and S1) do not change the response significantly, as well as contribute to the clinical understanding that the muscle response rate is higher and with a shorter delay, the closer it is to the manipulation. Full article

In this work, we evaluate the relationship between human manipulability indices obtained from motion sensing cameras and a variety of muscular factors extracted from surface electromyography (sEMG) signals from the upper limb during specific movements that include the shoulder, elbow and wrist joints. The results show specific links between upper limb movements and manipulability, revealing that extreme poses show less manipulability, i.e., when the arms are fully extended or fully flexed. However, there is not a clear correlation between the sEMG signals’ average activity and manipulability factors, which suggests that muscular activity is, at least, only indirectly related to human pose singularities. A possible means to infer these correlations, if any, would be the use of advanced deep learning techniques. We also analyze a set of EMG metrics that give insights into how muscular effort is distributed during the exercises. This set of metrics could be used to obtain good indicators for the quantitative evaluation of sequences of movements according to the milestones of a rehabilitation therapy or to plan more ergonomic and bearable movement phases in a working task. Full article

The purpose of this work was to validate an addition to a dynamic armrest design (DA) for use during inward–outward and fore–aft joystick manipulation. The design was validated compared to a stationary armrest (SA) and no armrest (NA) using surface electromyography (EMG) and a questionnaire. The DA was not successful in reducing muscle activation for inward–outward movements when compared to the SA. Furthermore, the addition of inward–outward dynamic portion negated the improvements seen with the fore–aft dynamic armrest design. Despite the lack of significant muscular activation findings, most participants preferred the DA to the SA or NA. However, unlike the fore–aft dynamic armrest, which was found to successfully reduce muscle activation in multiple muscles involved in joystick manipulation, results suggest that the horizontally dynamic support addition may not be necessary for inward and outward joystick movements. Full article

The multi-fingered dexterous robotic hand is increasingly used to achieve more complex and sophisticated human-like manipulation tasks on various occasions. This paper proposes a hybrid Surface Electromyography (SEMG) and Kinect-based human in-hand motion (HIM) capture system architecture for recognizing complex motions of the humans by observing the state information between an object and the human hand, then transferring the manipulation skills into bionic multi-fingered robotic hand realizing dexterous in-hand manipulation. First, an Adaptive Directed Acyclic Graph (ADAG) algorithm for recognizing HIMs is proposed and optimized based on the comparison of multi-class support vector machines; second, ten representative complex in-hand motions are demonstrated by ten subjects, and SEMG and Kinect signals are obtained based on a multi-modal data acquisition platform; then, combined with the proposed algorithm framework, a series of data preprocessing algorithms are realized. There is statistical symmetry in similar types of SEMG signals and images, and asymmetry in different types of SEMG signals and images. A detailed analysis and an in-depth discussion are given from the results of the ADAG recognizing HIMs, motion recognition rates of different perceptrons, motion recognition rates of different subjects, motion recognition rates of different multi-class SVM methods, and motion recognition rates of different machine learning methods. The results of this experiment confirm the feasibility of the proposed method, with a recognition rate of 95.10%. Full article

Background: To investigate the effectiveness of a specific manual therapy, Fascial Manipulation^® (FM), in comparison with conventional treatments in temporomandibular disorders (TMD) patients using a two-arm randomized controlled trial. Methods: The study consisted of 28 patients that were divided in two groups (Group 1: Fascial Manipulation^® vs. Group 2: conventional TMD treatment). The Verbal Rating Scale (VRS), RDC/TMD, electromyography (EMG) and Pression/Pain Evaluation on Masseter and Temporalis Muscle were assessed with different times. Results: In both groups, the improvement in pain was evident on the VRS scale (p < 0.0001) and pain-free opening (p < 0.001). In Group 1, the recovery of the function was faster; maximum unassisted opening T0 vs. T1 (p = 0.001). Conclusions: FM^® can be used as an effective method for facial pain, being a rapid, safe and cost-effective approach to reduce pain, gain function and mouth opening that can be used prior to occlusion stabilization appliances. Full article

Aiming at the lack of active willingness of patients to participate in the current upper limb exoskeleton rehabilitation training control methods, this study proposed a radial basis function (RBF) sliding mode impedance control method based on surface electromyography (sEMG) to identify the movement intention of upper limb rehabilitation. The proposed control method realizes the process of active and passive rehabilitation training according to the wearer’s movement intention. This study first established a joint angle prediction model based on sEMG for the problem of poor human–machine coupling and used the least-squares support vector machine method (LSSVM) to complete the upper limb joint angle prediction. In addition, in view of the problem of poor compliance in the rehabilitation training process, an adaptive sliding mode controller based on the RBF network approximation system model was proposed. In the process of active training, an impedance model was added based on the position loop control, which could dynamically adjust the motion trajectory according to the interaction force. The experiment results showed that the impedance control method based on the RBF could effectively reduce the interaction force between the human and machine to improve the compliance of the exoskeleton manipulator and achieve the purpose of stabilizing the impedance characteristics of the system. Full article