Electromyography Research Articles

BIOMECHANICAL ASSESSMENT OF SCAPULAR PLANE ELEVATION EXERCISE WITH DIFFERENT MODES OF RESISTANCE IN SUBJECTS WITH AND WITHOUT IMPINGEMENT SYNDROME.

Background: Strengthening the rotator cuff and scapular stabilizers is usually prescribed for subjects with shoulder pain and is done either using dumbbells or TheraBand. The resistance offered by elastic Theraband increases with increase in change from initial length and therefore the resistance offered by TheraBand, and dumbbell differs across the range of motion. Objectives: The purpose of the study is to evaluate the scapular kinematics and activity of prime mover (Anterior Deltoid) while using two different modes of resistance (TheraBand v/s dumbbell) in subjects with and without impingement syndrome. Methods: Twenty-two asymptomatic subjects and 12 subjects with impingement syndrome were included. 3D motion sensors were attached over the humerus, scapulae and trunk to capture movements of the shoulders as the subject performed scapular elevation without load, with yellow Theraband or 2 Kg Dumbbell. Simultaneous electromyography (EMG) activity of anterior Deltoid was measured and analyzed as percentage of maximum voluntary contraction. Results: During arm elevation, scapular Upward rotation was significantly greater at 90° with TheraBand® as compared to unloaded. It was also greater at 120° as compared to unloaded and dumbbell conditions (p<0.001) during elevation and lowering phase. Scapula upward rotation was significantly lesser at 30° with TheraBand® as compared to other conditions. Conclusion: This study found significant downward rotation and anterior tilt of scapula with TheraBand during lowering phase of exercise as compared to dumbbell and unloaded. The alterations of kinematics may help therapists make informed decisions while making exercise prescriptions.

Characteristics, Relationships, and Differences in Muscle Activity and Impact Load Attenuation During Tennis Forehand Stroke with Different Grips

In forehand strokes with different grips in tennis, the forearm muscle activities, the distribution and attenuation of the impact loads, and the effects of the muscles on the impact load attenuation exhibited different characteristics. This study aimed to explore these characteristics by analyzing electromyography (EMG) and acceleration data, and comparing the differences between the Eastern and Western grips. Fourteen level II or above tennis players (ten males, aged 22.4 ± 3.6 years; four females, aged 19.8 ± 2.0 years) were recruited and instructed to perform forehand strokes using the Eastern and Western grips, respectively. The EMG of eight forearm muscles and the acceleration data at the ulnar and radial sides of the wrist and elbow were collected. The root mean square (RMS), the peaks of the impact load, the amplitude of impact load attenuation (AC), and the jerk value (Jerk) were calculated. The cross-correlation coefficients and time delays of EMG–EMG, EMG–AC, and EMG–jerk were obtained using the cross-correlation method. The results showed that in the Eastern grip group (group E), the RMS of the flexor carpi ulnaris (FCU) was significantly greater than that in the Western grip group (group W). In group E, the peaks of impact load, AC, and Jerk on the Y axis of the wrist ulnar side were all significantly higher than those in group W. The activity of the extensor digitorum commonis (EDC) had significantly different effects on the amplitude and rate of impact load attenuation at specific locations in different grips, especially at the elbow (p < 0.05). The conclusion indicated that the FCU exhibited higher levels of EMG activity in the Eastern grip. This grip responded to greater impact loads with more substantial and rapid attenuation on the wrist ulnar side. Furthermore, the EDC appeared to contribute more to the amplitude of impact load attenuation in the Western grip and to have a more significant influence on the rate of impact load attenuation in the Eastern grip, especially at the elbow. These results suggest that tennis players and coaches should pay more attention to improving the strength of the EDC and FCU, which can improve sports performance and comfort, as well as prevent sports injuries.

Effect of foot strike patterns and angles on the biomechanics of side-step cutting

ObjectivesThe study aimed to determine how foot strike patterns and cutting angles affect lower extremity (LE) kinematics, kinetics, and muscle activity during side-step cutting.MethodsTwenty male college sport athletes participated in this research. Three-dimensional motion analysis featuring ground reaction force (GRF) and electromyography (EMG) of the dominant leg was used. LE kinematics, kinetics, and EMG data parameters were obtained during a 45° and 90° side-step cutting involving rearfoot strikes (RFS) and forefoot strikes (FFS).ResultsThe significant foot strike pattern × angle interactions were observed for the ankle eversion range of motion (ROM) at the loading phase. Cutting of 90° had greater knee flexion ROM, knee valgus ROM, and knee varus moment compared to that of 45°. RFS cutting had greater knee flexion, hip flexion, knee valgus, knee varus moment, knee varus moment, and ankle eversion ROM. FFS cutting produced a lower vertical GRF, lateral GRF, and a loading rate. Both vastus medialis and vastus lateralis muscle activities were remarkably greater during cutting of 90° than 45°. At the loading phase, semitendinosus, biceps femoris, and the lateral head of gastrocnemius muscle activities during FFS cutting were considerably greater than those during RFS cutting.ConclusionThe FFS pattern can better protect the anterior cruciate ligament (ACL) and improve the flexibility of athletes by increasing the plantarflexion torque of the ankle. The injury risk also increases with the larger cutting angle. The EMG activities of semitendinosus and biceps femoris are vital for the stability of knee joint during side-step cutting, which helps reduce ACL stress during buffering.

Biomechanical perspectives on college students’ psychological well-being and their impact on academic performance

Academic performance among college students is prejudiced by a complex interplay of psychological well-being, physical activity, and biomechanical health. While previous research has often focused on individual factors such as mental health or physical activity, there is a growing need for an integrative approach to understand how these elements interact and collectively impact academic performance. This study aims to explore these relationships among 126 students from four universities in China, using a comprehensive methodology that includes psychological assessments (GHQ-28, PSS, MHI), wearable activity trackers for physical activity and sleep monitoring, and biomechanical evaluations through motion capture and electromyography (EMG). The study adopts a multi-faceted analytical approach, including hierarchical regression, path analysis, and latent variable modelling. Hierarchical regression revealed that psychological factors alone explained 21.1% of the variance in GPA (R2 = 0.211), while adding biomechanical and physical activity factors increased the explanatory power to 35.0% (R2 = 0.350). Path analysis indicated that psychological well-being had a direct negative effect on academic performance (β = −0.41, p < 0.001) and an indirect effect mediated through physical activity (indirect β = −0.089, p = 0.0021). Latent variable modelling demonstrated that psychological well-being, physical activity, and biomechanical health constructs collectively explained 52% of the variance in academic performance.

Assessment of trunk and shoulder muscle asymmetries during two-armed kettlebell swings: implications for training optimization and injury prevention

IntroductionGreater side-to-side asymmetry can indicate impaired skill, reduced power production, and an increased risk of injury. Bilateral differences highlight the presence of asymmetries that should be assessed to understand their impact on both injury risk and performance enhancement.ObjectiveThis study aimed to assessment muscle activation and bilateral asymmetry in major trunk and shoulder muscles during a two-armed kettlebell swing exercise.MethodsTwenty-seven participants (age: 24.2 ± 2.6 years; body mass: 82.9 ± 7.7 kg; height: 176.9 ± 7.0 cm) were included in the study. Electromyographic (EMG) data were collected bilaterally from twelve muscles (six muscles per side: anterior deltoid [AD], posterior deltoid [PD], erector spinae longissimus [ESL], erector spinae iliocostalis [ESI], external oblique [EO], and rectus abdominis [RA]).ResultsResults indicated that asymmetry indices for the AD, ESL, ESI, and RA muscles during the upward propulsion phase fell within the determined threshold of 15%. However, the asymmetry indices for the PD and EO muscles exceeded this threshold by 3.36% and 2.62%, respectively. The findings suggest that trunk muscle asymmetries during the kettlebell swing are generally less pronounced than those of the shoulder muscles, particularly during the float phase.ConclusionThese results provide valuable insights into bilateral muscle asymmetry during a two-armed kettlebell swing, which can inform the development of targeted training programs. The methods and findings of this study may further contribute to understanding the effects of muscle balance, symmetry, and injury mechanisms in dynamic movements.

Musculoskeletal mimics for lumbosacral radiculopathy. Part 1: Theoretical considerations.

The diagnosis of lumbosacral radiculopathy includes the exclusion of common musculoskeletal conditions that can cause similar symptoms. Neurology and physiatry physicians use history taking and physical examination findings to develop a differential diagnosis. Appropriate diagnostic testing is then utilized to narrow down this differential diagnosis to determine a working hypothesis of the cause of a patient's symptoms, leading to a treatment plan. There are stark limitations of patient symptoms and physical examination findings in making the diagnosis of lumbosacral radiculopathy and added value of a combination of symptoms and signs to distinguish patients with lumbosacral radiculopathy from patients with mimic disorders. Diagnostic tests have variable strengths and limitations in helping to confirm this diagnosis, contrasting the high sensitivity and lower specificity of magnetic resonance imaging (MRI) with the high specificity but lower sensitivity of electromyography (EMG). Further complexity is added to the task of making a diagnosis and setting a treatment plan by the fact that these disorders are common and interact with each other; they are present concomitantly in up to 25% of patients presenting for electrodiagnostic evaluation. A companion paper will review common musculoskeletal mimics of lumbosacral radiculopathy and provide tools to anchor testing for those conditions to the traditional neurological evaluation of lumbosacral radiculopathy.

Hip Flexor Muscle Activation During Common Rehabilitation and Strength Exercises

Background/Objectives: The iliopsoas muscle plays an essential role in lumbopelvic and hip anterior stability, which is particularly important in the presence of limited osseous acetabular coverage anteriorly as in hip dysplasia and/or hip micro-instability. The purpose of this systematic review is to (1) describe iliopsoas activation levels during common rehabilitation exercises and (2) provide an evidence-based exercise progression for strengthening the iliopsoas based on electromyography (EMG) studies. Methods: In total, 109 healthy adult participants ranging from ages 20 to 40 were included in nine studies. PubMed, CINAHL, and Embase databases were systematically searched for EMG studies of the psoas, iliacus, or combined iliopsoas during specific exercise. The Modified Downs and Black Checklist was used to perform a risk of bias assessment. PROSPERO guidelines were followed. Results: Nine studies were included. Findings suggest that the iliopsoas is increasingly activated in ranges of hip flexion of 30–60°, particularly with leg lowering/raising exercises. Briefly, >60% MVIC activity of the iliopsoas was reported in the active straight leg raise (ASLR) in ranges around 60° of hip flexion, as well as with supine hip flexion and leg lifts. In total, 40–60% MVIC was found in exercises including the mid-range of the ASLR around 45° of hip flexion and lifting a straight trunk while in a hip flexed position. Conclusions: The findings suggest that exercises in increased hip flexion provide greater activation of the iliopsoas compared to exercises where the trunk is moving on the lower extremity. Iliopsoas activation can be incrementally progressed from closed to open kinetic chain exercises, and eventually to the addition of external loads. The proposed exercise program interprets the results and offers immediate translation into clinical practice.

Effects of Extrinsic and Intrinsic Motivation on Selective Activation of Shoulder Girdle Muscles During the Barbell Bench Press Exercise

Background/Objectives: This study aimed to investigate the effects of intrinsic and extrinsic motivation on selective muscle activation of the shoulder girdle during the barbell bench press. Specifically, this research focused on how attentional focus on individual muscles, such as the anterior deltoid (AD), pectoralis major (PM), and triceps brachii long (TBL), could influence their electromyographic (EMG) activity during the exercise. Methods: Twelve male participants, with at least five years of strength training experience, performed bench press exercises under two conditions: with extrinsic motivation (no specific focus on muscle activity) and with intrinsic motivation (internal focus on specific muscles). Surface electromyography (sEMG) was used to measure muscle activity during three sets of bench presses at 60% of one repetition maximum (1RM). Participants were instructed to focus on the activation of specific muscles in a randomized sequence. Results: The intrinsic motivation condition significantly increased muscle activation compared to extrinsic motivation. Electromyographic activity of the AD, PM, and TBL muscles was notably higher when participants focused their attention on these muscles. AD activation increased from 71.78 ± 11.13%MVC (extrinsic) to 88.03 ± 8.84%MVC (intrinsic) (p = 0.0019), while PM and TBL activation also demonstrated significant increases under intrinsic focus. Conclusions: The study concludes that intrinsic motivation, or an internal focus on specific muscle activation, can significantly enhance EMG activity in target muscles during the bench press exercise. This finding has important implications for resistance training and rehabilitation, where focused muscle activation can be utilized to improve training outcomes and muscle engagement.

Comparison of synergy extrapolation and static optimization for estimating multiple unmeasured muscle activations during walking

BackgroundCalibrated electromyography (EMG)-driven musculoskeletal models can provide insight into internal quantities (e.g., muscle forces) that are difficult or impossible to measure experimentally. However, the need for EMG data from all involved muscles presents a significant barrier to the widespread application of EMG-driven modeling methods. Synergy extrapolation (SynX) is a computational method that can estimate a single missing EMG signal with reasonable accuracy during the EMG-driven model calibration process, yet its performance in estimating a larger number of missing EMG signals remains unknown.MethodsThis study assessed the accuracy with which SynX can use eight measured EMG signals to estimate muscle activations and forces associated with eight missing EMG signals in the same leg during walking while simultaneously performing EMG-driven model calibration. Experimental gait data collected from two individuals post-stroke, including 16 channels of EMG data per leg, were used to calibrate an EMG-driven musculoskeletal model, providing “gold standard” muscle activations and forces for evaluation purposes. SynX was then used to predict the muscle activations and forces associated with the eight missing EMG signals while simultaneously calibrating EMG-driven model parameter values. Due to its widespread use, static optimization (SO) applied to a scaled generic musculoskeletal model was also utilized to estimate the same muscle activations and forces. Estimation accuracy for SynX and SO was evaluated using root mean square errors (RMSE) to quantify amplitude errors and correlation coefficient r values to quantify shape similarity, each calculated with respect to “gold standard” muscle activations and forces.ResultsOn average, compared to SO, SynX with simultaneous model calibration produced significantly more accurate amplitude and shape estimates for unmeasured muscle activations (RMSE 0.08 vs. 0.15, r value 0.55 vs. 0.12) and forces (RMSE 101.3 N vs. 174.4 N, r value 0.53 vs. 0.07). SynX yielded calibrated Hill-type muscle–tendon model parameter values for all muscles and activation dynamics model parameter values for measured muscles that were similar to “gold standard” calibrated model parameter values.ConclusionsThese findings suggest that SynX could make it possible to calibrate EMG-driven musculoskeletal models for all important lower-extremity muscles with as few as eight carefully chosen EMG signals and eventually contribute to the design of personalized rehabilitation and surgical interventions for mobility impairments.

Functional and Aesthetic Lower Lip Reconstruction With Depressor Anguli Oris Muscle Flap and Reverse Superior Labial Artery Flap.

The lower lip is an important anatomical structure involved in daily activities such as eating, drinking, and speaking, as well as in facial expressions. Lower lip defects should be repaired to preserve lip function without disrupting the aesthetic harmony of the lips within the face. This goal is difficult for plastic surgeons because, for functional and aesthetic repair, it is necessary to replace the mucosa, muscle (especially contractile), and skin tissues present in the lip. Subtotal lower lip repair was performed using an innervated depressor anguli oris muscle flap and a desepithelialized reverse superior labial artery flap in seven male patients with a mean age of 63 years. A depressor anguli oris muscle flap was used to repair the orbicularis oris muscle defect. The desepithelialized part of the reverse superior labial artery flap was used for mucosal defect repair, whereas the remaining part was used for skin defect repair. Patients were followed up for an average of 15 months. Patient lips, epithelialization, sensation, and sphincter function were clinically evaluated. Electromyography (EMG) was performed at 6 and 12 months to evaluate the function of the depressor anguli oris muscle flap. All the reverse superior labial artery flaps survived without any loss. Trapdoor deformity developed in the flaps of two patients. The desepithelialized parts of the flaps were completely epithelialized (covered with mucosa) by approximately 6th week. In the EMG controls of the patients at 6 months, the depressor anguli oris muscle was contractible. Sensation regained in the operated lip during the follow-up period. The combination of an innervated depressor anguli oris muscle flap and a desepithelialized reverse superior labial artery flap is an important surgical option for the functional and aesthetic repair of subtotal lower lip defects.

Evaluation of the impact of shockwave therapy on the functioning of a patient with a lower calcaneal spur

Introduction. A common cause of heel pain is the presence of a calcaneal spur. This condition may disrupt the posterior superficial fascia chain and can also lead to problems in distant areas of the body. Among the physical methods used, shockwave therapy is often applied. The aim of the study was to assess the effectiveness of shockwave therapy and its effect on the tension of the gastrocnemius muscle, which is part of the posterior fascia chain. Materials and Methods. A 52-year-old female patient diagnosed with a left lower calcaneal spur underwent a series of six radial shockwave therapy sessions, performed twice a week. The method for assessing the therapy’s effectiveness involved measuring pain on the Visual Analogue Scale (VAS) and changes in tissue temperature before, immediately after, and five minutes post-therapy. Electromyographic (EMG) examination was used to assess the tension of the gastrocnemius muscle. Results. An average decrease in temperature was observed immediately after the treatment (from 25.3°C to 24.45°C). After five minutes, the temperature increased to 27.05°C compared to the initial measurement. The resting tension of the gastrocnemius muscle, as measured by EMG, decreased as follows: channel 1: from 0.6 µV to 0.4 µV, channel 2: from 4.3 µV to 3.2 µV. Pain decreased from a level of 7 to 2 on the VAS scale. Conclusions. Shockwave therapy is an effective solution for alleviating pain in the case of a calcaneal spur. The reduction of resting tension in the gastrocnemius muscle leads to a decrease in elevated tension within the posterior myofascial chain, which may help reduce the risk of secondary pathologies in distant areas along the chain.

Characteristics of Human Postactivation Effect of Skeletal Muscles Using Spectral and Non-Linear Parameters of the Surface Electromyogram

Postactivation effect (PAE, postactivation phenomenon) is a specific type of involuntary muscle tone (tonic automatism) which is generated in the “tonogenic” structures of the brain, presumably without the “sensory copy” and “motor command” mechanisms. In this regard, the electromyogram (EMG) signal of PAE may have a simpler temporal signal structure compared to PAE-inducing voluntary activity. The purpose of this work is to characterize the temporal structure and complexity of surface EMG (sEMG) of the human deltoid and biceps brachii muscles using fractal (D) and correlation dimensions (Dc). It was found that in deltoid muscles the value of D was 1.78–1.81 both during PAE and voluntary effort (p 0.05). Dc (approximately 4.0–4.2) also did not differ between PAE and voluntary effort, although the average frequency of the sEMG spectrum during PAE was 15–16 Hz (p 0.05) higher compared to voluntary effort. In biceps brachii muscles, the D value was 1.8 during PAE and 1.62 during voluntary effort (p 0.05). Dc values did not differ between PAE and voluntary contraction (4–4.8). Thus, despite the supposed difference in the central organization of PAE and voluntary effort, the temporal structure of their sEMG did not differ, indicating that isometric voluntary effort and involuntary tone in the form of PAE share a common principle of sEMG signal generation. At the same time, the differences in the frequency of the sEMG spectrum indicate that the organization of sEMG signal during PAE is specific on the level of the motoneuron pool.

Analysis of anticipatory and compensatory postural adjustment in women of different age groups using surface electromyography.

Postural balance is crucial for daily activities, relying on the coordination of sensory systems. Balance impairment, common in the elderly, is a leading cause of mortality in this population. To analyze balance, methods like postural adjustment analysis using electromyography (EMG) have been developed. With age, women tend to experience reduced mobility and greater muscle loss compared to men. However, few studies have focused on postural adjustments in women of different ages using EMG of the lower limbs during laterolateral and anteroposterior movements. This gap could reveal a decrease in muscle activation time with aging, as activation time is vital for postural adjustments. This study aimed to analyze muscle activation times in women of different ages during postural adjustments. Thirty women were divided into two groups: young and older women. A controlled biaxial force platform was used for static and dynamic balance tests while recording lower limb muscle activity using EMG. Data analysis focused on identifying muscle activation points and analyzing postural adjustment times. Results showed significant differences in muscle activation times between the two groups across various muscles and platform tilt conditions. Younger women had longer muscle activation times than older women, particularly during laterolateral platform inclinations. In anteroposterior movements, older women exhibited longer activation times compared to their laterolateral performance, with fewer differences between the groups. Overall, older women had shorter muscle activation times than younger women, suggesting a potential indicator of imbalance and increased fall risk.

A Step Forward for Smart Clothes: Printed Fabric-Based Hybrid Electronics for Wearable Health Monitoring

Smart clothes equipped with flexible sensing systems provide a comfortable means to track health status in real time. Although these sensors are flexible and small, the core signal-processing units still rely on a conventional printed circuit board (PCB), making current health-monitoring devices bulky and inconvenient to wear. In this study, a printed fabric-based hybrid circuit was designed and prepared—with a series of characteristics, such as surface/sectional morphology, electrical properties, and stability—to study its reliability. Furthermore, to verify the function of the fabric-based circuit, simulations and measurements of the circuit, as well as the collection and processing of a normal adult’s electrophysiological signals, were conducted. Under 10,000 stretching and bending cycles with a certain elongation and bending angle, the resistance remained 0.27 Ω/cm and 0.64 Ω/cm, respectively, demonstrating excellent conductivity and reliability. Additionally, the results of the simulation and experiment showed that the circuit can successfully amplify weak electrocardiogram (ECG) signals with a magnification of 1600 times with environmental filtering and 50 Hz of industrial frequency interference. This technology can monitor human electrophysiological signals, such as ECGs, electromyograms (EMGs), and joint motion, providing valuable practical guidance for the unobtrusive monitoring of smart clothes.

Understanding the clinical management of co-occurring sleep-related bruxism and obstructive sleep apnea in adults: A narrative and critical review.

Sleep-related bruxism (SRB) is a motor oral behavior characterized by tooth grinding and jaw clenching activity, reported by 8%-12% of the adult general population and 3% of older individuals. The frequency of one of its biomarkers, rhythmic masticatory muscle activity (RMMA), remains elevated across ages. Obstructive sleep apnea (OSA) is associated with the brief and repetitive pause of breathing (apnea) and with transient reduction in oxygen (hypoxia). OSA is observed at all ages and in about 50% of older individuals with a male preponderance. SRB clinical assessment is based on self-reporting of tooth grinding sound, awareness of clenching, jaw pain or headache, and clinical observation of tooth damage. OSA clinical assessment is based on sleepiness and fatigue, snoring, sleep quality, and awareness of breathing cessation, plus clinical examination of anatomical factors (e.g., obesity, retrognathia, large tonsil, macroglossia), age, gender, and body mass. Although the literature does not support association or causality between these two conditions, the co-occurrence is reported in about 30%-50% of adults. To confirm a diagnosis of co-occurring SRB and OSA, home sleep testing (HST) may be indicated. A sleep test is performed using electromyography (EMG) of jaw muscle (masseter or temporalis) and cardio-respiratory variables (e.g., air flow, respiratory effort, oxygen level, heart rate). The management of co-occurring SRB and OSA for individuals with prosthodontic needs is challenging to prevent compromising the oro-pharyngeal space and breathing efficiency. OSA treatment in the presence of SRB includes continuous positive airway pressure (CPAP) use alone or with an occlusal splint or mandibular advancement device (MAD). In addition, the following may be considered: supine sleep correction device, myofuncional therapy, medications, and surgeries. All have limitations and risks. Individual variability suggests that phenotyping is mandatory to select the most efficient and personalized treatment.

Instrumented assessment of lower and upper motor neuron signs in amyotrophic lateral sclerosis using robotic manipulation: an explorative study

BackgroundAmyotrophic lateral sclerosis (ALS) is a lethal progressive neurodegenerative disease characterized by upper motor neuron (UMN) and lower motor neuron (LMN) involvement. Their varying degree of involvement results in a clinical heterogenous picture, making clinical assessments of UMN signs in patients with ALS often challenging. We therefore explored whether instrumented assessment using robotic manipulation could potentially be a valuable tool to study signs of UMN involvement.MethodsWe examined the dynamics of the wrist joint of 15 patients with ALS and 15 healthy controls using a Wristalyzer single-axis robotic manipulator and electromyography (EMG) recordings in the flexor and extensor muscles in the forearm. Multi-sinusoidal torque perturbations were applied, during which participants were asked to either relax, comply or resist. A neuromuscular model was used to study muscle viscoelasticity, e.g. stiffness (k) and viscosity (b), and reflexive properties, such as velocity, position and force feedback gains (kv, kp and kf, respectively) that dominated the responses. We further obtained clinical signs of LMN (muscle strength) and UMN (e.g. reflexes, spasticity) dysfunction, and evaluated their relation with the estimated neuromuscular model parameters.ResultsOnly force feedback gains (kf) were elevated in patients (p = 0.033) compared to controls. Higher kf, as well as the resulting reflexive torque (Tref), were both associated with more severe UMN dysfunction in the examined arm (p = 0.040 and p < 0.001). Patients with UMN symptoms in the examined arm had increased kf and Tref compared to controls (both p = 0.037). Neither of these measures was related to muscle strength, but muscle stiffness (k) was lower in weaker patients (p = 0.012). All these findings were obtained from the relaxed test. No differences were observed during the instructions comply and resist.ConclusionsThis findings are proof-of-concept that instrumented assessment using robotic manipulation is a feasible technique in ALS, which may provide quantitative, operator-independent measures relating to UMN symptoms. Elevated force feedback gains, driving larger reflexive muscle torques, appear to be particularly indicative of clinically established levels of UMN dysfunction in the examined arm.

Assessment of small fiber neuropathy and distal sensory neuropathy in female patients with fibromyalgia.

We investigated sudomotor dysfunction, small fiber neuropathy (SFN), and their clinical significance in female fibromyalgia patients. Fibromyalgia patients and healthy controls (HCs) were recruited. Clinical and laboratory data were measured. Electrochemical skin conductance (ESC) values of hands and feet were assessed by SUDOSCAN. Additionally, several other methods were employed, including nerve conduction study (NCS), electromyography (EMG), and questionnaires. Spearman correlation coefficient was calculated to identify factors associated with ESC values of SUDOSCAN. Twenty-two female fibromyalgia patients and 22 female HCs were recruited. The fibromyalgia group had lower EQ5D and higher Toronto Clinical Neuropathy scores than the HC group. Most of the EMG/NCS findings of motor and proximal sensory nerves were comparable between the fibromyalgia and HC groups, whereas sensory nerve action potential amplitudes of distal sensory nerves were significantly lower in the fibromyalgia group. Mean ESC values of hands and feet were significantly lower in the fibromyalgia group than in the HC group (57.6 ± 16.2 vs. 68.8 ± 10.3 μS, p = 0.010 for hands, 64.9 ± 11.5 vs. 72.0 ± 8.2 μS, p = 0.025 for feet, respectively). Moderate to severe SFN was more common in the fibromyalgia group (68.2%) than in the HC group (68.2 vs. 50%, p = 0.019). Fibromyalgia disease duration was significantly correlated with the ESC values of hands/feet, and tricyclic antidepressant (TCA) responders had higher ESC values than non-responders. SFN was commonly detected in fibromyalgia patients who had normal EMG/NCS findings and was more severe in fibromyalgia patients with longer disease duration. SUDOSCAN may predict response to TCA therapy.

Cushing’s Myopathy in Dogs: Prevalence, Clinical Abnormalities, and Response to Treatment

A distinct myotonia is a muscle disorder that may occur secondary to excess corticosteroids (hyperadrenocorticism, HAC, or Cushing’s disease) and is associated with electrodiagnostic abnormalities on electromyography (EMG). Clinically these disorders cause muscle stiffness, weakness, atrophy, and/or contractures, which can severely limit the quality of life of those affected. To date, there are very few published data regarding the onset, development, and treatment of hyperadrenocorticism-associated myotonia/pseudomyotonia. This is a multi-institutional retrospective study describing the clinical signs, diagnosis, and treatment of HAC-associated myotonia/pseudomyotonia. We found that this disorder was and continues to be rare. It most commonly occurs in adult dogs with chronic steroid exposure secondary to pituitary-dependent HAC. No cases of adrenal dependent HAC were identified in this population. In addition to muscle stiffness, dermatologic disease and liver enzyme abnormalities were common. A wide variety of therapeutic strategies, including polypharmacy and physical rehabilitation, were implemented, with little success. Analgesics were the most frequently administered type of medication.

Comparison of time-series models for predicting physiological metrics under sedation.

This study presents a comprehensive comparison of multiple time-series models applied to physiological metric predictions. It aims to explore the effectiveness of both statistical prediction models and pharmacokinetic-pharmacodynamic prediction model and modern deep learning approaches. Specifically, the study focuses on predicting the bispectral index (BIS), a vital metric in anesthesia used to assess the depth of sedation during surgery, using datasets collected from real-life surgeries. The goal is to evaluate and compare model performance considering both univariate and multivariate schemes. Accurate BIS prediction is essential for avoiding under- or over-sedation, which can lead to adverse outcomes. The study investigates a range of models: The traditional mathematical models include the pharmacokinetic-pharmacodynamic model and statistical models such as autoregressive integrated moving average (ARIMA) and vector autoregression (VAR). The deep learning models encompass recurrent neural networks (RNNs), specifically Long Short-Term Memory (LSTM) and Gated Recurrent Units (GRU), as well as Temporal Convolutional Networks (TCNs) and Transformer models. The analysis focuses on evaluating model performance in predicting the BIS using two distinct datasets of physiological metrics collected from actual surgical procedures. It explores both univariate and multivariate prediction schemes and investigates how different combinations of features and input sequence lengths impact model accuracy. The experimental findings reveal significant performance differences among the models: In univariate prediction scenarios for predicting BIS, the LSTM model demonstrates a 2.88% improvement over the second-best performing model. For multivariate predictions, the LSTM model outperforms others by 6.67% compared to the next best model. Furthermore, the addition of Electromyography (EMG) and Mean Arterial Pressure (MAP) brings significant accuracy improvement when predicting BIS. The study emphasizes the importance of selecting and building appropriate time-series models to achieve accurate predictions in biomedical applications. This research provides insights to guide future efforts in improving vital sign prediction methodologies for clinical and research purposes. Clinically, with improvements in the prediction of physiological parameters, clinicians can be informed of interventions if an anomaly is detected or predicted.

Evaluation of Split Hand Syndrome in Early Diagnosis of Amyotrophic Lateral Sclerosis by Nerve Conduction Study as a Diagnostic Tool

Background: Amyotrophic lateral sclerosis (ALS), a degenerative disease of the motor neurons that can present diversly. Needle electromyography (EMG) is the gold standard investigation for the diagnosis of ALS. Split hand syndrome (SHS) demonstrated by nerve conduction study (NCS); a noninvasive tool could be useful in diagnosing ALS. This study aimed to assess SHS by NCS in ALS. Methods: This diagnostic accuracy case-control study included 37 cases of ALS and 37 age and gender-matched controls. Compound muscle action potential (CMAP) and distal motor latency (DML) of median and ulnar nerves and the ratio of median and ulnar CMAP and DML were compared between study groups. The diagnostic validity testing of electrophysiological SHS was also done. Results: The mean age of the ALS and control groups were similar, 39.8±2.7 and 39.3±2.6 years, respectively. Sixteen (43.2%) ALS patients were in 30-59 years age group. Male-female ratio was 5.2. In the ALS group, median-ulnar CMAP ratio was lower and median-ulnar DML ratio was prolonged than the control. The diagnostic efficacy of median-ulnar CMAP ratio and DML ratio were calculated. A median-ulnar CMAP ratio cut-off value ≤1 showed 70% sensitivity, 97% specificity, 96% positive predictive value and 77% negative predictive value. A median-ulnar DML ratio cut-off value ≥1.5 showed 48% sensitivity, 89% specificity, 82% positive predictive value and 65% negative predictive value. Conclusion: NCS demonstrating SHS can be an important tool in the early diagnosis of ALS. J Bangladesh Coll Phys Surg 2024; 42: 350-354