Neuromuscular Parameters Research Articles

Continuous Identification of Driver Model Parameters via the Unscented Kalman Filter

Advanced Driver-Assistance Systems (ADAS) have become an essential part of modern cars. Among the solutions proposed, haptic shared control of the steering wheel is increasingly being studied. A fundamental question is how drivers adapt their behavior to these systems. This article proposes to use the Unscented Kalman Filter (UKF) to identify the variation over time in the psychological and neuromuscular parameters of a driver structured model. The goal here is to understand how the driver adapts to changes, whether regarding the behavior of the steering system, the visibility or the road conditions. The LPV system considered for identification is known as the cybernetic driver model. Two experiments carried out respectively with Simulink© and on a driving simulator provide the data. The methodology proposed for tuning the UKF is studied from the results obtained with those data. A multi-UKF strategy is also considered. The methodology reveals useful when a compromise between rapidity and precision has to be achieved for parameters estimation. It opens the way to a detailed analysis of the driver’s parameter variations within the multi-UKF framework.

Chronic Non-specific Low Back Pain and Motor Control During Gait.

Background: Chronic non-specific low back pain (LBP) poses a major socioeconomic problem, although the mechanisms are not yet clear. Impaired motor control is one of the mechanisms being discussed.Objectives: The purpose of this review is to provide an overview of motor control parameter differences between individuals with and without non-specific LBP during gait.Methods: A literature search on Medline, SportDiscus, PsychInfo, PsychArticels, EMBASE, and Scopus was performed. Twenty-nine articles comparing healthy adults and adults with chronic non-specific LBP in neuromuscular and/or biomechanical parameters during walking or running were examined. Data extraction and quality assessment were independently performed by two persons. Among others, we extracted population, conditions, outcome measures, and results.Results: The results showed that persons with and without non-specific LBP differed in several parameters of motor control, which was indicated by a lower movement amplitude of the pelvis, more in-phase coordination, lower ground reaction forces, higher stride-to-stride variability and a higher activity in ES in the LBP group.Conclusion: Despite no strong evidence for any of the parameters, a combination of biomechanical and neuromuscular parameters provides a conclusive explanation. Impaired motor control during walking is reflected in higher activity of the erector spinae, which leads to a stiffened lumbar-pelvic region. Different acquisition and processing of data renders making comparisons difficult, whereby standards for future research are necessary.

Badminton preferentially decreases explosive over maximal voluntary torque in both the plantar flexors and extensors

We assessed changes in maximal and explosive plantar flexion (PF) and dorsi flexion (DF) torque, and thus the maximal and explosive DF/PF ratio, in response to successive badminton matches (2 × 35, 15 minutes of rest) in 16 juniors (10 males, 6 females) International‐level badminton players before (Pre), immediately after the first (Post‐1) and second (Post‐2) match as well as after resting for 12 hours. For both PF and DF, maximal voluntary torque decreased from Pre to Post‐2 (~7%‐9%; P < 0.05). Compared with Pre, PF explosive voluntary torque decreased by ~4%‐13% at Post‐1 (P < 0.05), with further reductions ranging from −15% to −25% within the 0‐100 ms epoch after contraction (P < 0.001) at Post‐2. Decrements of similar magnitude in DF explosive voluntary torque occurred at Post‐1 (ranging −7% to −27%) and Post‐2 (ranging −3% to −28%) relative to Pre (P < 0.05). All neuromuscular parameters were fully recovered after 12 hours of rest. Explosive DF/PF ratios during the very initial phase of contraction (up to 50 ms from onset) were lower compared with the maximal DF/PF ratio, with no effect of time (all P < 0.05). In badminton, explosive torque indices should be included to more accurately reflect acute fatigue induced by successive badminton matches.

Validity of judo-specific tests to assess neuromuscular performance of judo athletes

ABSTRACT Uchi-komi Fitness Test (UFT) is a specific judo test that evaluates physiological fitness of judo athletes in similar conditions to judo matches. Neuromuscular parameters obtained by generic and judo-specific tests would aid to get more information about its criterion validity. This study aimed to analyse the relationship between UFT and shoulder external (PTEX) and internal (PTINT) rotation torque, handgrip strength (HGS) and vertical jumps (VJs) performance. The relationship between UFT and Judogi grip strength test (JGST) was also investigated. Eighteen male judo athletes participated in this study. Athletes performed neuromuscular tests (VJ, PTEX, PTINT and HGS) and judo-specific tests (JGST and UFT). Pearson’s correlation was used with the level set at p < 0.05. Significant correlation was found between UFT and all VJ variables (r = 0.50–0.72, p < 0.004), UFT a + b (two first series of UFT) and PTEX (r = 0.49, p = 0.033), UFT and PTINT (r = 0.47, p = 0.044). Also, UFT was correlated to JGST (r = 0.50–0.72, p < 0.044, respectively). We conclude that muscle power of lower limbs, PTEX and PTINT was related to UFT. Strength-endurance in the upper limbs (JGST) was also related to the UFT performance.

Effects of resistance training on neuromuscular parameters in elderly with type 2 diabetes mellitus: A randomized clinical trial.

This study is a randomized controlled clinical trial that verified the resistance training efficacy on neuromuscular parameters, with muscle quality as primary outcome. Forty-four elderly with diabetes type 2 (69.7 ± 6.9 years; 26 men) were randomly allocated to a 12-weeks resistance training group (RTG, 3 times a week), or an active control group with stretching classes (CG, once a week). Primary and secondary outcomes were assessed at baseline and after 12 weeks, as follow: quadriceps muscle thickness and rectus femoris muscle quality, maximal knee extension strength, rapid strength, functional performance, visceral adipose tissue, glycemic control, lipid profile and quality of life. Generalized estimating equations were used to analyses based on intention-to-treat and per-protocol approaches, which showed the same results. Among all outcomes measured there were improvements in the knee extension strength (P < 0.001) and quadriceps muscle thickness (P < 0.001) for RTG. The muscle quality did not improve for both groups (P = 0.98). For the secondary outcomes there were no improvements for functional performance, rapid strength, glycemic control, quality of life, visceral adipose tissue and lipid profile in both groups, with exception of triglyceride level reduction for RTG (P = 0.04).The resistance training program is an efficacious strategy for improve the neuromuscular health in elderly with T2DM, considering increases in lower limb strength and muscle mass, but the same was not found for muscle quality, rapid strength, functional performance and quality of life. Furthermore, the training program did not induce significant reduction in glycated hemoglobin values of patients who already had suitable glycemic control.

Countermovement Jump Analysis Using Different Portable Devices: Implications for Field Testing

The aim of this study was to analyze the concurrent validity, test–retest reliability, and capacity to detect changes of four different portable devices used to measure a wide range of neuromuscular parameters derived from countermovement jump (CMJ). An accelerometric device (Myotest), a jump mat (Ergojump), an optical device (Optojump), and a smartphone app (MyJump) were simultaneously examined for concurrent validity against gold-standard measures (motion-capture system and a force platform). Twenty-two CMJ-derived variables were collected from 15 healthy male subjects (n = 60 CMJs). Contraction time (CT) and eccentric duration (EccD) measurements obtained from the Myotest were moderately to largely associated with and not different from force platform measurements (r = 0.31 to 0.64, ES = 0.11 to 0.18) and showed moderate test-retest reliability (intraclass correlation coefficient (ICC) = 0.92 to 0.97, coefficient of variation (CV) = 3.8 to 8.0%). Flight time (FT) and jump height (JH) from Ergojump, Optojump, and MyJump showed moderate to strong associations with gold-standard measurements (r = 0.57 to 0.98) and good test–retest reliability (ICC = 0.54 to 0.97, CV = 1.8 to 4.2). However, all portable devices underestimated JH (ES = 1.25 to 2.75). Independent of the instrument used, the analyzed CMJ variables showed good capacity to detect changes (standard error of measurement (SEM) < smallest worthwhile change (SWC)), with the exception of rate of force and rate of power development parameters, which showed marginal capacity (SEM > SWC). The Myotest is preferable to measure temporal parameters during ground contact, whereas Ergojump, Optojump, and MyJump devices may be preferable to measure FT and JH, with the Optojump being the most accurate.

Subject-specific calibration of neuromuscular parameters enables neuromusculoskeletal models to estimate physiologically plausible hip joint contact forces in healthy adults

In-vivo hip joint contact forces (HJCF) can be estimated using computational neuromusculoskeletal (NMS) modelling. However, different neural solutions can result in different HJCF estimations. NMS model predictions are also influenced by the selection of neuromuscular parameters, which are either based on cadaveric data or calibrated to the individual. To date, the best combination of neural solution and parameter calibration to obtain plausible estimations of HJCF have not been identified. The aim of this study was to determine the effect of three electromyography (EMG)-informed neural solution modes (EMG-driven, EMG-hybrid, and EMG-assisted) and static optimisation, each using three different parameter calibrations (uncalibrated, minimise joint moments error, and minimise joint moments error and peak HJCF), on the estimation of HJCF in a healthy population (n = 23) during walking. When compared to existing in-vivo data, the EMG-assisted mode and static optimisation produced the most physiologically plausible HJCF when using a NMS model calibrated to minimise joint moments error and peak HJCF. EMG-assisted mode produced first and second peaks of 3.55 times body weight (BW) and 3.97 BW during walking; static optimisation produced 3.75 BW and 4.19 BW, respectively. However, compared to static optimisation, EMG-assisted mode generated muscle excitations closer to recorded EMG signals (average across hip muscles R2 = 0.60 ± 0.37 versus R2 = 0.12 ± 0.14). Findings suggest that the EMG-assisted mode combined with minimise joint moments error and peak HJCF calibration is preferable for the estimation of HJCF and generation of realistic load distribution across muscles.

Neuromuscular responses of recreationally active women during a sustained, submaximal isometric leg extension muscle action at a constant perception of effort.

The purpose of the present study was to examine the fatigue-related patterns of responses for electromyography (EMG), mechanomyography (MMG), and force during a sustained, submaximal isometric leg extension muscle action anchored at RPE = 5. Ten women (23.1 ± 2.3year) performed two, maximal voluntary isometric contractions (MVIC) prior to and following an isometric muscle action that was sustained at RPE = 5 (OMNI-RES) for a maximal time-limit of 5min or until RPE = 5 could not be maintained (actual time-limit). EMG amplitude (AMP), EMG mean power frequency (MPF), MMG AMP, MMG MPF, and force values were determined every 5% of the actual or maximal time-limit. Regression analyses were used to examine the neuromuscular parameters and force vs. time relationships. The pretest MVIC (46.9 ± 8.9kg) was significantly (p = 0.003; d = 1.8) greater than posttest (36.4 ± 5.3kg) MVIC. The actual time-limit was 180 ± 90.9s (range 84.8-300s). The percent decline in force production during the sustained isometric muscle action was 34.7 ± 17.1%, and there was a significant negative, quadratic force vs. time relationship (p < 0.001; R= - 0.983). There was a significant positive, quadratic MMG AMP vs. time relationship (p < 0.001; R = 0.852), but no significant (p > 0.05) relationships for EMG AMP, EMG MPF, or MMG MPF vs. time. The current findings indicated that it was necessary to reduce force to maintain RPE = 5. The neuromuscular and force responses supported the RPE clamp model and suggested that force was initially regulated by anticipatory feedforward mechanisms and then altered by afferent feedback.

Acute effects of aerobic exercise performed with different volumes on strength performance and neuromuscular parameters

The aim of the present study was to investigate the acute effect of the aerobic exercise volume on maximum strength and strength-endurance performance; and possible causes of strength decrements (i.e. central and peripheral fatigue). Twenty-one moderately trained men were submitted to a maximal incremental test to determine anaerobic threshold (AnT) and maximum dynamic strength (1RM) and strength-endurance (i.e. total volume load [TV]) tests to determine their baseline strength performance. Following, subjects performed six experimental sessions: aerobic exercise sessions (continuous running at 90% AnT) with different volumes (3 km, 5 km or 7 km) followed by 1RM or strength-endurance test in the 45° leg press exercise. Maximum voluntary isometric contraction (MVIC), voluntary activation (VA) level, contractile properties, and electromyographic activity (root mean square [RMS]) of the knee extensor muscles were assessed before and after aerobic exercises and after strength tests. TV was lower after 5 km and 7 km runs than in the control condition (12% and 22%, respectively). Additionally, TV was lower after 7 km than 3 km (14%) and 5 km (12%) runs. MVIC, VA, RMS, and contractile properties were reduced after all aerobic exercise volumes (∼8%, ∼5%, ∼11% and ∼6–14%, respectively). Additionally, MVIC, VA, and contractile properties were lower after strength tests (∼15%, ∼6%, ∼9–26%, respectively). In conclusion, strength-endurance performance is impaired when performed after aerobic exercise and the magnitude of this interference is dependent on the aerobic exercise volume; and peripheral and central fatigue indices could not explain the different TV observed.

Neuromuscular Parameters Predict the Performance in an Incremental Cycling Test.

The aim was to determine the predictive capacity of neuromuscular parameters on physiological predictors of performance related to pedaling power. The sample comprised fifty elite cyclists. On the same day, they were given a neuromuscular evaluation with tensiomyography (TMG) and then performed an effort test on a cycle ergometer until exhaustion. The TMG recorded the maximum radial muscle belly displacement, contraction time, delay time, derivative normalized response speed, and lateral symmetry. Peak power output (Wpeak·kg-1), effort time, maximum lactate concentration, power in the first lactate threshold, and power in the second lactate threshold were recorded in the effort test. Linear regression analysis was used to determine the explanatory capacity of neuromuscular parameters on potential cycling performance indicators. A higher Wpeak·kg-1 during a maximal incremental test on the cycle ergometer can be predicted moderately (R2=0.683; R2a=0.615; R=0.826; Std. Error=0.26017; p<0.001) by a longer rectus femoris contraction time and a greater radial muscle belly displacement of the vastus lateralis and vastus medialis as well as a slower normalized response speed of the biceps femoris. In conclusion, neuromuscular parameters can partially explain performance in a specific cycling test until exhaustion.

Different neuromuscular parameters influence dynamic balance in male and female football players.

To analyse the relationship between several parameters of neuromuscular performance with unilateral dynamic balance measured through the Y-Balance test, as well as to determine the possible sex-related differences. The Y-Balance test, isokinetic (concentric and eccentric) knee flexion and extension strength, isometric hip abduction and adduction strength, lower extremity joint range of motion (ROM) (hip, knee and ankle) and core stability were assessed in male (n = 88) and female (n = 44) professional football players. A stepwise multivariate linear least square regression with backward elimination analysis was carried out to identify a group of factors that were independently associated with balance performance in both sexes. Passive hip flexion and ankle dorsiflexion with knee flexed ROM were the main factors that retained a significant association to dominant (R2 = 23.1) and non-dominant (R2 = 33.5) balance scores for males. For females, core stability, hip abduction isometric peak torque, passive hip abduction and ankle dorsiflexion with knee flexed ROM variables retained a significant association with balance scores for both, dominant (R2 = 38.2) and non-dominant (R2 = 46.9) legs. Training interventions aimed at improving or maintaining unilateral dynamic balance in male football players should include, among other things, stretching exercises for the posterior chain of the lower extremity. However, females should also include exercises for strength and mobility of the hip abductors and core stability (especially in the frontal plane). This knowledge would allow clinicians and sport practitioners to develop more effective and tailored unilateral dynamic balance training interventions in male and female football players, possibly improving performance and reducing the risk of injury. III.

Computational model to investigate the relative contributions of different neuromuscular properties of tibialis anterior on force generated during ankle dorsiflexion.

This study describes a new model of the force generated by tibialis anterior muscle with three new features: single-fiber action potential, twitch force, and pennation angle. This model was used to investigate the relative effects and interaction of ten age-associated neuromuscular parameters. Regression analysis (significance level of 0.05) between the neuromuscular properties and corresponding simulated force produced at the footplate was performed. Standardized slope coefficients were computed to rank the effect of the parameters. The results show that reduction in the average firing rate is the reason for the sharp decline in the force and other factors, such as number of muscle fibers, specific force, pennation angle, and innervation ratio. The fast fiber ratio affects the simulated force through two significant interactions. This study has ranked the individual contributions of the neuromuscular factors to muscle strength decline of the TA and identified firing rate decline as the biggest cause followed by decrease in muscle fiber number and specific force. The strategy for strength preservation for the elderly should focus on improving firing rate. Graphical abstract Neuromuscular properties of Tibialis Anterior on force generated during ankle dorsiflexion.

Neuromuscular features in sprinters with cerebral palsy: case studies based on paralympic classification.

Despite the evolution of runner performance in athletes with cerebral palsy (CP), little is known about neuromuscular parameters of sprinters from different classes, especially related to power output, muscular imbalances and asymmetry indexes in lower limbs. The aim of this study was to assess muscle power, muscular imbalance and asymmetry in sprinters with CP. Four male sprinters with CP (age, 18 to 27 years; body mass, 58.5 to 72.8 kg; height, 161.5 to 174 cm) classified as T38, T37, T36, T35 according to International Paralympic Committee functional classification, performed vertical counter movement jump and squat jump on force plate and isokinetic torque evaluations in both limbs. The concentric peak torque (PT) was measured at 60°/sec, 120°/sec and 180°/sec and PT eccentric at 60°/sec and 120°/sec. The asymmetry indexes, conventional and functional ratios were assessed. the results showed that athletes with more severe impairments (T35 and T36) showed worse performance to muscle power, more muscular imbalance and higher asymmetry in PT between limbs (> 10%). The exception was T37 athlete, who presented the better performance for all variables. it is concluded that CP athletes with more severe impairments showed lower jumping performance and torque production of knee extensors and flexors, they showed greater asymmetries between limbs. Finally, considering the results of T37 athlete, it seems that the athletic training for a longer period can reverse part of the neuromuscular impairments caused by CP.

Time Course of Changes in Neuromuscular Parameters During Sustained Isometric Muscle Actions: Erratum.

Time Course of Changes in Neuromuscular Parameters During Sustained Isometric Muscle Actions: Erratum.

Influence of platinum harmonized textile on neuromuscular, systemic and subjective recovery.

The clothing manufacturer Venex Life-Science tracks the strategy to enhance recovery process through implementing platinum harmonized technology (PHT) into their Venex® Regeneration Wear. The proposed mechanisms of the regeneration wear are an increase of parasympathetic activity and an increase of the temperature due far-infrared radiation. The purpose of this study was to investigate potential effects of Venex regeneration wear on the recovery of neuromuscular, systemic and subjective parameters following exercise. In a randomized, single-blinded cross-over design, 13 strength-trained male participants performed two exercise sessions in one day. After the first exercise session and for 3 nights following the exercise day participants wore the Venex regeneration wear or a placebo product. Measures of isometric maximum voluntary contraction (MVC), voluntary activation (VA) and potentiated twitch torque (PTT) of the knee extensors, as well as maximum jump height during the Counter-Movement and Drop Jump, creatinkinase (CK) and subjective parameters (perceived pain, recovery condition and sleep quality) were obtained before and after each exercise session and 24, 48, and 72 hours after the first exercise session. MVC, PTT, CK and jump parameters changed over time during the exercise day as well as on the following days, however, there were no significant differences between treatments. Subjective parameters showed strong effect sizes (i. e. Cohen’s d > 0.6) in favor for Venex but no significant differences between treatments. Based on these findings, it is concluded that wearing a platinum harmonized textile following exercise did not improve neuromuscular and systemic recovery in a trained male population to a statistical noticeable extent. However, the findings for the subjective parameters suggest some potential for enhanced recovery that requires further research.

Bilateral extracephalic transcranial direct current stimulation improves endurance performance in healthy individuals

BackgroundTranscranial direct current stimulation (tDCS) has been used to enhance endurance performance but its precise mechanisms and effects remain unknown. ObjectiveTo investigate the effect of bilateral tDCS on neuromuscular function and performance during a cycling time to task failure (TTF) test. MethodsTwelve participants in randomized order received a placebo tDCS (SHAM) or real tDCS with two cathodes (CATHODAL) or two anodes (ANODAL) over bilateral motor cortices and the opposite electrode pair over the ipsilateral shoulders. Each session lasted 10 min and current was set at 2 mA. Neuromuscular assessment was performed before and after tDCS and was followed by a cycling time to task failure (TTF) test. Heart rate (HR), ratings of perceived exertion (RPE), leg muscle pain (PAIN) and blood lactate accumulation (ΔB[La−]) in response to the cycling TTF test were measured. ResultsCorticospinal excitability increased in the ANODAL condition (P < 0.001) while none of the other neuromuscular parameters showed any change. Neuromuscular parameters did not change in the SHAM and CATHODAL conditions. TTF was significantly longer in the ANODAL (P = 0.003) compared to CATHODAL and SHAM conditions (12.61 ± 4.65 min; 10.61 ± 4.34 min; 10.21 ± 3.47 min respectively), with significantly lower RPE and higher ΔB[La−] (P < 0.001). No differences between conditions were found for HR (P = 0.803) and PAIN during the cycling TTF test (P = 0.305). ConclusionOur findings demonstrate that tDCS with the anode over both motor cortices using a bilateral extracephalic reference improves endurance performance.

Resistance training and exercise tolerance during high-intensity exercise: moving beyond just running economy and muscle strength.

Resistance training and exercise tolerance during high-intensity exercise: moving beyond just running economy and muscle strength.

Análisis costo-efectividad de rocuronio y succinilcolina en tiroidectomías programadas

En el presente trabajo se realiza un análisis costo-efectividad de la succinilcolina y del rocuronio utilizados en la intubación de pacientes sometidos a tiroidectomía programada, mediante un estudio descriptivo prospectivo, donde se tuvo en cuentala calidad de intubación, los tiempos de latencia y de relajación muscular, necesidad de reversión farmacológica del bloqueo neuromuscular, parámetros hemodinámicos,reacciones adversas y costos directos e indirectos en 30 pacientes sometidos al procedimiento.El análisis económico evidenció la existencia de diferencias significativas entre los costos asociados al tiempo de latencia de la relajación muscular. En cuanto a los costos relacionados al bloqueo muscular, se observó que el grupo con succinilcolinapresentó unos costos totales de 10.972 ± 341,7 pesos colombianos, mientras que con rocuronio fueron de 63.088 ± 1.184 con valor P &lt; 0,0001. La succinilcolinamostró mayor costo-efectividad al presentar menor tiempo de latencia, mejores condiciones de intubación, no provocar cambios hemodinámicos clínicamente significativos y bajo costo al ser comparado con rocuronio.

Low-load high-velocity resistance exercises improve strength and functional capacity in diabetic patients

This study investigated the effects of low-load high-velocity resistance exercises on neuromuscular and functional outcomes in patients with Type 2 diabetes (T2D) during the early-phase of resistance training. Thirty participants with T2D performed 18 training sessions (6 weeks – 3x week) in one of two groups: low-load high-velocity exercises (LLHV, n=15, 62.1±10.5 years) or recreational activities (RA, n=15 56.7 ± 19.4 years). LLHV performed resistance exercises with 3x 8reps as fast as possible with 50-60% 1RM. RA performed light activities. Strength, power, and functional tests were assessed. There was significant increasing in the knee extension peak-torque at 60°/s (7.6%) and 180°/s (12.2%), rate of force development in the LLHV group (P<0.05), whereas there were no changes in the RA group. Significant increases in functional test were observed in the LLHV group (P<0.01) with no changes in the RA group. In conclusion, the LLHV induced marked improvements in neuromuscular parameters, as well as in the functional capacity of participants with T2D.

Effects of Sprint Training on Athletic Performance Related Physiological, Cardiovascular, and Neuromuscular Parameters

Effects of Sprint Training on Athletic Performance Related Physiological, Cardiovascular, and Neuromuscular Parameters