The Influence of Stress and Energy Level on Learning Muscle Relaxation During Gross-Motor Task Performance Using Electromyographic Feedback

The aim was to investigate the influence of mood on learning muscle relaxation. Self-reported mood (assessed by the Stress-Energy Checklist) at baseline was related to learning muscle relaxation induced by electromyographic feedback training during performance of a gross-motor task. Feedback training was provided either intermittently (Intermittent Feedback Task, IF, n=12) or continuously (Continuous Feedback Task, CF, n=9). Results reveal a negative correlation between the learning effect at short-term and energy dimension for the IF Task. It can be concluded that mood experienced prior to a learning task is relevant for the learning effect and this effect may be dependent on the schedule of feedback used.     

Analysis on the activation of the VMO and VLL muscles during semisquat exercises with and without hip adduction in individuals with patellofemoral pain syndrome

Objective: The purpose of this study was to investigate the effect of hip adduction on the activity of the Vastus Medialis Obliquus (VMO) and Vastus Lateralis Longus (VLL) muscles during semisquat exercises.

Methods: Twenty female subjects, divided into two groups comprising healthy and patellofemoral pain syndrome (PFPS) subjects (ten volunteers for each group), performed three double-leg semisquat exercise trials with maximum hip adduction isometric contraction (DLSS-HA) and three double-leg semisquat exercise trials without hip adduction (DLSS). The normalized electromyographic muscle data were analysed using Repeated Measure ANOVA (p  0.05).

Results: The electrical activity of both VMO and VLL muscles was significantly greater during DLSS-HA exercise than during DLSS (p = 0.0002) for both groups. Additionally, an independent Repeated Measure ANOVA revealed that the electric activity of the VLL muscle was significantly greater (p = 0.0149) than that of the VMO muscle during DLSS exercises only for the PFPS group. However, no differences were found during DLSS-HA exercises.

Conclusions: Although there was no preferential VMO muscle activation, the association of hip adduction with squat exercise promoted a greater balance between the medial and lateral portions of the quadriceps femoris muscle and could be indicated for the conservatory treatment of PFPS patients. The association of isometric hip adduction with isometric semisquat exercises produced a more overall quadriceps activity and could be indicated for clinical rehabilitation or muscle strengthening programs.     

Psychophysiological Assessment of Compulsive Gamblers' Arousal to Gambling Cues: A Pilot Study

Psychophysiological assessments measuring heart rate, systolic and diastolic blood pressure, and skin resistance level were conducted on 7 male compulsive gamblers and on 7 age and gender matched controls while both groups performed mental arithmetic and listened to individualized tapes of the gamblers' preferred form of gambling and an individualized fear tape. Heart rate responses of the gamblers to the 2 gambling audiotapes were significantly greater than those found for the controls whereas the groups did not differ on mental arithmetic or the fear provoking scene, confirming some degree of cue-specific arousal in gamblers. The other physical responses did not yield such strong results. If physiological arousal provides the motivational basis for gambling and is maintained on an intermittent schedule of reinforcement, the findings may have implications for the treatment of compulsive gambling.     

Surface electromyography in animal biomechanics: A systematic review

The study of muscle activity using surface electromyography (sEMG) is commonly used for investigations of the neuromuscular system in man. Although sEMG has faced methodological challenges, considerable technical advances have been made in the last few decades. Similarly, the field of animal biomechanics, including sEMG, has grown despite being confronted with often complex experimental conditions. In human sEMG research, standardised protocols have been developed, however these are lacking in animal sEMG. Before standards can be proposed in this population group, the existing research in animal sEMG should be collated and evaluated. Therefore the aim of this review is to systematically identify and summarise the literature in animal sEMG focussing on (1) species, breeds, activities and muscles investigated, and (2) electrode placement and normalisation methods used. The databases PubMed, Web of Science, Scopus, and Vetmed Resource were searched systematically for sEMG studies in animals and 38 articles were included in the final review. Data on methodological quality was collected and summarised. The findings from this systematic review indicate the divergence in animal sEMG methodology and as a result, future steps required to develop standardisation in animal sEMG are proposed.     

A versatile approach to determine instantaneous co-activation: Development,implementation and comparison to existing measures

Abstract

An adaptable method of computing muscle co-activity is presented. Instantaneous muscle activities from multiple muscles are reduced into commonality and activity level dimensions. Both dimensions are weighted independently and combined into a co-activation measure, Φ. Myoelectric data from relaxed and braced simulated rear vehicle impacts were used to compare Φ to two existing co-activity measures in muscle pair and multi-muscle cases, Φ showed greater sensitivity in the muscle pair case and could better discriminate the relaxed and braced conditions in the multi-muscle case than previous measures. The flexibility of Φ allowed tailoring to reflect the current purpose.     

基于支持向量机的表面肌电信号和加速度融合跌倒识别方法

目的:针对老人易跌倒和跌倒过后可能产生严重后果这一现实问题,通过将表面肌电信号和加速度融合,进一步优化采用支持向量机分类器下的包含跌倒在内的几种不同动作的分类效果。方法:提出基于表面肌电和加速度信号融合的跌倒识别算法,首先采集股直肌,股内侧肌,胫骨前肌和腓肠肌的表面肌电信号以及位于腰部的三轴加速度信号作为实验数据,然后利用滑动窗口法提取表面肌电和加速度信号的均方根值,最后针对人体日常活动和跌倒的运动特征,构建了支持向量机的分类器。结果:实验数据共计320组数据,包括3种日常活动和向前跌倒,其中160组数据作为训练集,另外160组数据作为测试集。对4种动作进行识别实验,算法的准确度为93.23%、灵敏度为92.4%、特异度为100%,达到了良好的分类效果。结论:基于支持向量机的表面肌电信号和加速度融合的跌倒识别算法分类效果良好,对于老人跌倒防护具有现实意义。     

Heterogeneity of muscle activation in relation to force direction: A multi-channel surface electromyography study on the triceps surae muscle

Several skeletal muscles can be divided into sub-modules, called neuromuscular compartments (NMCs), which are thought to be controlled independently and to have distinct biomechanical functions. We looked for distinct muscle activation patterns in the triceps surae muscle (TS) using surface electromyography (EMG) during voluntary contraction. Nine subjects performed isometric and isotonic plantar flexions combined with forces along pre-defined directions. Besides the forces under the ball of the foot, multi-channel surface EMG was measured with electrodes homogeneously distributed over the entire TS. Using principal component analysis, common (global) components were omitted from the EMG signals, thereby estimating muscle activity sufficiently accurate to track fine fluctuations of force during an isotonic contraction (r = 0.80 ± 0.09). A subsequent cluster analysis showed a topographical organization of co-activated parts of the muscle that was different between subjects. Low and negative correlations between the EMG activity within clusters were found, indicating a substantial heterogeneity of TS activation. The correlations between cluster time series and forces at the foot in specific directions differed substantially between clusters, showing that the differentially activated parts of the TS had specific biomechanical functions.     

The Influence of Voice Volume, Pitch, and Speech Rate on Progressive Relaxation Training: Application of Methods from Speech Pathology and Audiology

Vocal characteristics of therapists, including voice volume, pitch and timbre of speech, and rate of speech have been hypothesized to facilitate the therapeutic process, particularly during procedures like progressive relaxation training (PRT). Very little empirical work, however, has examined the relation between vocal characteristics and treatment process or outcome. The purpose of this study was to examine the role of vocal characteristics during a single session of PRT applying technological innovations devised for speech pathology and audiology settings for evaluating therapist's vocal characteristics. Forty-eight high anxious young adult women were randomly assigned to one of four conditions for training: PRT with the recommended therapist voice (RV) that decreased in tone, volume, and rate across the session, PRT with conversational therapist voice during the session (CV), a credible treatment control called systematic self-relaxation (SR), or no treatment control (NT). All subjects participated in a single PRT session during which heart rate, EMG, self-report measures of tension (SRT) and anxiety, and treatment credibility ratings were obtained. Results revealed significant reductions in SRT, self-reported anxiety, and heart rate for participants in all groups. Only the RV group displayed significant reductions in EMG when compared with the other three groups. Participants in the RV group also rated the therapist's voice as “more facilitating” of relaxation when compared to the CV group. These results suggest that methods employed for evaluating the quality of vocal characteristics in speech and audiology clinics may be useful for evaluating the quality of therapist's voice when conducting PRT.     

Assessment of rabbit hemorrhagic disease in controlling the population of red fox: A measure to preserve endangered species in Australia

Predator's management requires a detailed understanding of the ecological circumstances associated with predation. Predation by foxes has been a significant contributor to the Australian native animal reduction. This paper mainly focuses on the dissemination of rabbit hemorrhagic disease in the rabbit population and its subsequences on red fox (Vulpes vulpes) population, by qualitative and quantitative analyses of a designed eco-epidemiological model with simple law of mass action and sigmoid functional response.Existence of solution has been analyzed and shown to be uniformly bounded. The basic reproduction number (R₀) is obtained and the occurrence of a backward bifurcation at R₀ = 1 is shown to be possible using central manifold theory. Global stability of endemic equilibrium is established by geometric approach. Criteria for diffusion-driven ecological instability caused by local random movements of European rabbits and red fox are obtained. Detailed analyses of Turing patterns formation selected by reaction-diffusion system under zero flux boundary conditions are presented. We found that transmission rate, self and cross-diffusion coefficients have appreciable influence on spatial spread of epidemics. Numerical simulation results confirm the analytical finding and generate patterns which indicate that population of red foxes might be controlled if rabbit hemorrhagic disease (RHD) is introduced into the rabbit population and thus ecological balance can be maintained.     

Combined Psychophysiological Assessment of ADHD: A Pilot Study of Bayesian Probability Approach Illustrated by Appraisal of ADHD in Female College Students

Manifestations of ADHD are observed at both psychological and physiological levels and assessed via various psychometric, EEG, and imaging tests. However, no test is 100% accurate in its assessment of ADHD. This study introduces a stochastic assessment combining psychometric tests with previously reported (Consistency Index) and newly developed (Alpha Blockade Index) EEG-based physiological markers of ADHD. The assessment utilizes classical Bayesian inference to refine after each step the probability of ADHD of each individual. In a pilot study involving six college females with ADHD and six matched controls, the assessment achieved correct classification for all ADHD and non-ADHD participants. In comparison, the classification of ADHD versus non-ADHD participants was < 85% for any one of the tests separately. The procedure significantly improved the score separation between ADHD versus non-ADHD groups. The final average probabilities for ADHD were 76% for the ADHD group and 8% for the control group. These probabilities correlated (r = .87) with the Brown ADD scale and (r = .84) with the ADHD-Symptom Inventory used for the screening of the participants. We conclude that, although each separate test was not completely accurate, a combination of several tests classified correctly all ADHD and all non-ADHD participants. The application of the proposed assessment is not limited to the specific tests used in this study--the assessment represents a general paradigm capable of accommodating a variety of ADHD tests into a single diagnostic assessment.     

Residual Pattern and Dietary Intake of Iprodione on Grapes under Egyptian Field Conditions: A Prelude to Risk Assessment Profile

Field experiments were conducted in two different locations in the Nile delta to determine the residue levels and dissipation rates of iprodione in grapes. Iprodione was applied in different rates (recommended dose and two times recommended dose) and spraying times. Analysis was carried out using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The dissipation rates of iprodione were described using first-order kinetics and the half-life ranged from 8.8 to 9.4 days. There was a sharp decrease in the amount of iprodione residues 10 days after application. At harvest time, the remaining residues of iprodione were below the Food and Agriculture Organization (FAO)/World Health Organization (WHO) maximum residue level (MRL) of 10 mg/kg when measured 14 days after final application. The exposure to iprodione was assessed and compared to acceptable daily intake (ADI). Based on grape consumption, the estimated daily intakes of iprodione ranged from 0.2% to 1.1% of the ADI, showing insignificant risk to consumers.     

Environmental Profile of a Community's Health (EPOCH): An Ecometric Assessment of Measures of the Community Environment Based on Individual Perception

BACKGROUND: Public health research has turned towards examining upstream, community-level determinants of cardiovascular disease risk factors. Objective measures of the environment, such as those derived from direct observation, and perception-based measures by residents have both been associated with health behaviours. However, current methods are generally limited to objective measures, often derived from administrative data, and few instruments have been evaluated for use in rural areas or in low-income countries. We evaluate the reliability of a quantitative tool designed to capture perceptions of community tobacco, nutrition, and social environments obtained from interviews with residents in communities in 5 countries. METHODOLOGY/ PRINCIPAL FINDINGS: Thirteen measures of the community environment were developed from responses to questionnaire items from 2,360 individuals residing in 84 urban and rural communities in 5 countries (China, India, Brazil, Colombia, and Canada) in the Environmental Profile of a Community's Health (EPOCH) study. Reliability and other properties of the community-level measures were assessed using multilevel models. High reliability (>0.80) was demonstrated for all community-level measures at the mean number of survey respondents per community (n?=?28 respondents). Questionnaire items included in each scale were found to represent a common latent factor at the community level in multilevel factor analysis models. CONCLUSIONS/ SIGNIFICANCE: Reliable measures which represent aspects of communities potentially related to cardiovascular disease (CVD)/risk factors can be obtained using feasible sample sizes. The EPOCH instrument is suitable for use in different settings to explore upstream determinants of CVD/risk factors.     

Exposure Based Waiving in Environmental Risk Assessment: A Tiered Approach

The REACH legislation describes the “Exposure Based Waiving” (EBW) methodology, that allows reduction of animal tests and that facilitates the Chemical Safety Assessments. We introduced a tiered EBW decision strategy for the aquatic environment. Tier 0 in this strategy justifies waiving if it can be demonstrated that exposure of organisms to a chemical will be practically zero (i.e., if no environmental emissions during the full life-cycle of a chemical are to be expected. Tier 1 uses tabular data, derived from physical–chemical properties of a chemical and emission data, to identify whether the environmental exposure levels are less than the conservative toxicological reference value “Threshold of Toxicological Concern” (TTC). To this end, systematic exposure calculations have been carried out with a hypothetical chemical dataset, covering the full chemical spectrum for neutral organic substances. In tier 2, PEC and PNEC are to be assessed probabilistically in order to address the probability of effects. Following this strategy, risk can be shown to be sufficiently low, using minimal exposure and hazard data. Our tiered EBW concept is illustrated by a case study for the substance dibutylphthalate with the endpoint of fresh water aquatic risks.     

Association between the Functional Gait Assessment and spatiotemporal gait parameters in individuals with obesity compared to normal weight controls: A proof-of-concept study

Objectives:Obesity is a significant global health concern that involves motor impairment, including deficits in gait and balance. A simple tool would be useful to capture gait and balance impairment in obesity. We assessed whether the Functional Gait Assessment (FGA) captures impairment in individuals with obese BMI (≥30 kg/m²) and whether impairment was related to spatiotemporal gait parameters.Methods:Fourteen individuals with obese BMI and twenty individuals of normal weight underwent the FGA. Spatiotemporal gait parameters were collected while participants walked on a pressure sensitive walkway under five conditions: pre-baseline (flat ground walking), crossing small, medium, and high obstacles, and final-baseline (flat ground walking).Results:Individuals with obesity had lower scores on the FGA (p≤0.001) and showed less efficient spatiotemporal gait parameters than healthy controls, particularly when crossing over obstacles (all ps≤0.05). For participants with obesity, lower FGA scores were associated with decreased gait velocity, but only during obstacle crossing (p≤0.05).Conclusions:The FGA may be a useful tool to capture gait impairment in populations with obesity. Obstacles may help reveal meaningful gait impairments. To our knowledge, this is the first study to examine the FGA in individuals with obesity, and represents a proof-of-concept that motivates further validation studies.     

A Study on the Importance of Core Strength and Coordination Balance during Basketball Based on Biomechanics

When basketball players play against each other in a game, better coordinated balance can give them a better advantage. This paper briefly introduces the coordination balance and core strength of basketball players. Twenty basketball varsity members were selected from Chengdu College of University of Electronic Science and Technology of China as subjects for the test. The athletes were randomly divided into a control group and an experimental group. The control group received regular strength training, and the experimental group received core strength training in addition to regular training. Both groups underwent isometric muscle strength test, coordination and balance test and shooting percentage test before and after training. The results demonstrated that muscle group strength increased in the control group after conventional training, but the experimental group showed more significant improvement in muscle group strength after additional core strength training; the experimental group had better coordination and balance ability after core strength training; the experimental group had a significantly higher shooting percentage after core strength training due to the improvement of coordination and balance ability.     

Effects of Thiazolidinediones on Stroke Recovery: A Case-Matched Controlled Study

Background and purpose Anti-inflammatory therapy decreases infarct size and enhances stroke recovery. Thiazolidinedione peroxisome proliferator-activated receptor (PPAR)gamma agonists have potent anti-inflammatory and insulin-sensitizing anti-diabetic actions. Methods Thirty stroke patients with type 2 diabetes admitted for acute inpatient stroke rehabilitation receiving pioglitazone or rosiglitazone were matched for age, sex, initial FIM^TM score and interval post-stroke with 30 stroke patients with type 2 diabetes not receiving thiazolidinediones. Relevant outcome variables were compared for both groups. Results The thiazolidinedione treated group showed significantly greater mean improvement in FIM^TM score compared to control group (25.6 ± 10.2 SD vs. 19.8 ± 10.5, respectively, P = 0.015). There was no significant difference in length of rehabilitation hospital stay (24.2 ± 7.6 vs. 25.1 ± 7.4 days, P = 0.657) or final discharge destination (home/institution, 19/11 versus 17/13, P = 0.792). Conclusions Use of thiazolidinediones was associated with enhanced functional recovery in stroke patients with type 2 diabetes. Special issue dedicated to John P. Blass.     

Lower Limb Muscle Forces in Table Tennis Footwork during Topspin Forehand Stroke Based on the OpenSim Musculoskeletal Model: A Pilot Study

Introduction: Footwork is one of the training contents that table tennis players and coaches focus on. This study aimed to gain a thorough understanding of the muscle activity of the table tennis footwork and creating a musculoskeletal model to investigate the muscle forces, joint kinematic, and joint kinetic characteristics of the footwork during topspin forehand stroke. Methods: Six male table tennis athletes (height: 171.98 ± 4.97 cm; weight: 68.77 ± 7.86 kg; experience: 10.67 ± 1.86 years; age: 22.50 ± 1.64 years) performed chasse step and one-step footwork to return the ball from the coach by topspin forehand stroke. The kinematics, kinetics, and muscle activity of the lower limb were recorded by the motion capture, force platform, and Electromyography (EMG) system. Statistical parametric mapping (SPM) analysis was used to investigate any difference between the chasse step and one-step footwork during the stroke. Results and Conclusion: The muscle force of the biceps femoris long head (p < 0.001), lateral gastrocnemius (p < 0.001), vastus lateralis (p < 0.001), vastus medial (p < 0.001), rectus femoris (p < 0.001), and tibia anterior (p < 0.001) of the chasse step were significantly greater than the one-step footwork during the early stroke phase (stance). At the end of the stroke phase (push-off), the muscle force of the biceps femoris long head (p < 0.001), medial gastrocnemius (p < 0.001), lateral gastrocnemius (p < 0.001), rectus femoris (p < 0.001), and tibias anterior (p < 0.001) in the chasse step footwork was significantly greater than the one-step footwork. The muscle force of the ankle plantar flexor and valgus muscle groups in the one-step was significantly greater than in the chasse step. Besides, the moment and angle of hip flexion (p = 0.001) and axial rotation (p = 0.009) were significantly greater for the chasse step than the one-step footwork, as well as the ankle plantarflexion angle (p < 0.001) and moment (p < 0.001) of the one-step footwork were significantly higher than the chasse step footwork. The results of this study can be applied to movement control and injury prevention in table tennis footwork.     

A Comparative Life Cycle Assessment Study of Polyethylene Based on Sugarcane and Crude Oil

A potential strategy for tackling the negative environmental impact of conventional plastics is to produce them from renewable resources. However, such a strategy needs to be assessed quantitatively, by life cycle assessment (LCA) for example. This screening LCA is intended to identify key aspects that influence the environmental impact of sugarcane low‐density polyethylene (LDPE) and compare these results against fossil‐based LDPE. The study showed that the major contributors to the environmental impact of sugarcane LDPE are ethanol production, polymerization, and long‐distance sea transport. The comparison between sugarcane‐ and oil‐based plastics showed that the sugarcane alternative consumes more total energy, although the major share is renewable. Moreover, for their potential impacts on acidification, eutrophication, and photochemical ozone creation, no significant difference between the two materials exists. However, with regard to global warming potential (GWP), the contribution of land use change (LUC) is decisive. Although the range of LUC emissions is uncertain, in the worst case they more than double the GWP of sugarcane LDPE and make it comparable to that of fossil‐based LDPE. LUC emissions can thus be significant for sugarcane LDPE, although there is need for a consistent LUC assessment method. In addition, to investigate the influence of methodological choices, this study performed attributional and consequential assessments in parallel. No major differences in key contributors were found for these two assessment perspectives.