Transcutaneous auricular vagus nerve stimulation modulates masseter muscle activity, pain perception, and anxiety levels in university students: a double-blind, randomized, controlled clinical trial.

Introduction: Chronic anxiety is a statemarked by sustained activation of the masseter muscle, manifesting in both mental and physical strain. This prolonged tension can significantly impact mental wellbeing and cognitive abilities, posing a risk for a range of health complications. This double-blind, randomized, controlled clinical trial investigated the impact of transcutaneous auricular vagus nerve stimulation (TAVNS) on masseter muscle activity, pressure pain threshold (PPT), and anxiety levels in university students with elevated anxiety. Methods: Forty-two participants meeting inclusion criteria were randomly assigned to either active TAVNS or sham TAVNS groups. Various parameters, including masseter muscle electromyographic (EMG) signals, PPT, and Beck Anxiety Inventory (BAI) scores, were assessed before pretreatment, immediately after the intervention week, and 2 weeks follow-up. Results: Active TAVNS significantly reduced both left and right masseter activation during resting mandibular position, persisting for 2 weeks post-intervention. Additionally, TAVNS induced a lasting decrease in both left and right masseter PPT, indicative of altered pain perception. Notably, BAI scores showed a substantial reduction, emphasizing TAVNS as a potential intervention for anxiety, with effects maintained at the 2-week follow-up. Discussion: This study provides comprehensive insights into the multifaceted effects of TAVNS on physiological and psychological aspects associated with anxiety in university students. The promising results underscore TAVNS as a potential neuromodulatory intervention for anxiety-related conditions, warranting further research and clinical exploration. Clinical Trial Registration: https://ensaiosclinicos.gov.br/rg/RBR-4s4kt2r.

Is pilates better than other exercises at increasing muscle strength? A systematic review.

Our objective was to verify the effectiveness of Pilates method compared against other exercise modalities for muscle strength increase, balance and flexibility. Method: Databases used and its respective results were: CENTRAL (n = 456), CINAHL (n = 291), EMBASE (n = 313), PEDro (n = 176), PUBMED (n = 236), SCIELO (n = 98), SPORTDiscus (n = 197) e Web of Science (n = 150). It included randomized controlled studies using Pilates and others exercise modalities that measured muscle strength. Results: Eleven studies were included for analysis. The mean methodological quality score of these studies, evaluated by the PEDro scale, was 6 ± 1. For the primary outcome, not being observed this difference for dynamic force (SMD = -0.29; 95%IC -0.69; 0.10), isometric (SMD = 0.20; 95%IC -0.06; 0.47) or resistance (SMD = -0.19; 95%IC -0.46; 0.07). For secondary outcomes, there was no difference for balance and flexibility. Conclusion: In conclusion, there is very low to low evidence that there is no difference between Pilates and other exercise modalities for dynamic strength, isometric strength, resistance strength, balance and flexibility.

Long-Term Effects of a Kinematic Bikefitting Method on Pain, Comfort, and Fatigue: A Prospective Cohort Study.

The purpose of this study is to analyze the long-term riders' subjective responses to a standardized bikefitting method on their bicycles. Eighty-six amateur mountain bikers had their riding posture and bicycle components ergonomically adjusted through a 3D kinematic bikefitting method. Validated subjective scales (Feeling, OMNI, and Numerical Rating Pain Scale) were used to assess their overall riding comfort and fatigue along with localized pain for six body parts. Data were collected just before intervention (baseline or pre), immediately after (or post), and 30, 60, 90, and 120 days after the bikefit session. A Student's t-test comparing before bikefit and after 120 days showed significant (p < 0.05) reduction in localized pain for all six body parts and riding comfort along with a large effect size effect (d = 1.18) for riding comfort. Although initially reduced, fatigue scores gradually increased over the months, showing a high correlation (r = 0.946) with increased monthly training volume. In conclusion, overall riding discomfort and pain were significantly decreased after a standardized kinematic bikefit session even after 120 days post intervention. However, fatigue scores began to rise after 30 days, showing a high correlation with increasing monthly training volume.

Strength Level of Professional Elite Soccer Players after the COVID-19 Lockdown Period: A Retrospective Double-Arm Cohort Study.

BACKGROUND: It is well known that periods of inactivity generate a loss of muscle strength, a fundamental component of sports performance in soccer. However, little information is available on the decrease in strength levels in professional soccer players after the quarantine lockdown that occurred during the COVID-19 pandemic. AIM: To compare the isokinetic peak torque profiles of professional soccer players from different teams before and after the quarantine period generated by COVID-19. METHODS: A retrospective observational study was performed using data collected from two different professional elite-level soccer teams just before and immediately after the COVID-19 quarantine period. One team gave individual instructions to its players for conditioning maintenance at home during the quarantine period, while the other team used regular video calls to maintain the player's conditioning status on home training. The main outcomes were the mean peak torque of knee extensors and flexors, from concentric and eccentric contractions of each playing position. Analysis. A two-way ANOVA analysis was used to compare peak torque before and after the quarantine period and between both teams' strategies, showing a statistically significant reduction in eccentric knee flexor peak torque from the team that did not have remote monitoring. CONCLUSIONS: Remote monitoring programs are recommended so that athletes are less affected by the deleterious effects of confinement.

Association between Concentric and Eccentric Isokinetic Torque and Unilateral Countermovement Jump Variables in Professional Soccer Players.

Isokinetic tests have been highly valuable to athletic analysis, but their cost and technical operation turn them inaccessible. The purpose of this study was to verify the correlation between unilateral countermovement jump variables and isokinetic data. Thirty-two male professional soccer players were subjected to the isokinetic testing of both knee extensors and flexors in concentric and eccentric muscle contractions. They also executed unilateral countermovement vertical jumps (UCMJ) to compare maximum height, ground reaction force, and impulse power with isokinetic peak torque. Data analysis was conducted through Pearson correlation and linear regression. A high correlation was found between dominant unilateral extensor concentric peak torque and the UCMJ maximum height of the dominant leg. The non-dominant leg jump showed a moderate correlation. No other variable showed statistical significance. Linear regression allowed the generation of two formulae to estimate the peak torque from UCMJ for dominant and non-dominant legs. Although few studies were found to compare our results, leading to more studies being needed, a better understanding of the unilateral countermovement jump may be used in the future as a substitute to the expensive and technically demanding isokinetic testing when it is unavailable, allowing the assessment of lower limb physical asymmetries in athletic or rehabilitation environments.

Discomfort, pain and fatigue levels of 160 cyclists after a kinematic bike-fitting method: an experimental study.

OBJECTIVE: To analyse rider's subjective responses after a standardised bicycle ergonomic adjustment method. METHODS: Experimental study of 160 healthy, amateur mountain bikers analysed previously and 30 days after a bike-fitting session. The main outcome measures were subjective comfort level (Feeling Scale, FEEL), fatigue (OMINI Scale) and pain (Visual Analogue Scale, VAS). RESULTS: All variables demonstrated statistical significance between groups pre and post bike-fit session (p<0001). FEEL, OMNI and VAS-knee demonstrated large effect sizes (d=1.30; d=1.39 and d=0.86, respectively). VAS-hands, VAS-neck and VAS-back indicated moderate effect size (d=0.58; d=0.52 and d=0.43, respectively). VAS-groin and VAS-ankle indicated a small size effect (d=0.46 and d=0.43, respectively). CONCLUSIONS: Overall discomfort, fatigue and pain in healthy mountain biker adults improved according to all three scales. The major improvements in pain levels were detected on the knee, hands, back and neck compared with presession values. Groin and ankle pain had smaller improvements but were still significant. Future clinical trials should address the bias effects of this experimental study.

Validation of a 3D Camera System for Cycling Analysis.

BACKGROUND: Kinematic analysis aimed toward scientific investigation or professional purposes is commonly unaffordable and complex to use. OBJECTIVE: The purpose of this study was to verify concurrent validation between a cycling-specific 3D camera and the gold-standard 3D general camera systems. METHODS: Overall, 11 healthy amateur male triathletes were filmed riding their bicycles with Vicon 3D cameras and the Retul 3D cameras for bike fitting analysis simultaneously. All 18 kinematic measurements given by the bike fitting system were compared with the same data given by Vicon cameras through Pearson correlation (r), intraclass correlation coefficients (ICC), standard error measurements (SEM), and Bland-Altman (BA) analysis. Confidence intervals of 95% are given. RESULTS: A very high correlation between cameras was found on six of 18 measurements. All other presented a high correlation between cameras (between 0.7 and 0.9). In total, six variables indicate a SEM of less than one degree between systems. Only two variables indicate a SEM higher than two degrees between camera systems. Overall, four measures indicate bias tendency according to BA. CONCLUSIONS: The cycling-specific led-emitting 3D camera system tested revealed a high or very high degree of correlation with the gold-standard 3D camera system used in laboratory motion capture. In total, 14 measurements of this equipment could be used in sports medicine clinical practice and even by researchers of cycling studies.

Strength development according with age and position: a 10-year study of 570 soccer players.

BACKGROUND/AIM: The purpose of this study was to compare the isokinetic peak torque profiles from the quadriceps and hamstrings muscles during concentric and eccentric contractions in elite Brazilian soccer players across different field positions and age categories. Our hypothesis was that soccer players from different field positions are subjected to different ageing-related effects on their isokinetic peak torque. METHODS: This is a retrospective study based on professional elite-level soccer players between the years 2009 and 2019. It included 570 adult males who played for at least 5 years on first or second Brazilian divisions. Playing positions were divided as: goalkeepers, defenders, sidebacks, midfielders and forwards. Age categories were also divided as: G1 (17-20 years old), G2 (21-24 years old), G3 (25-28 years old), G4 (29-32 years old) and G5 (33 years old or more). RESULTS: The results indicate a moderate effect of age (F(4545)=8.197; p<0.001; η2=0.057) and a small effect of playing position (F(4545)=2.993; p<0.05; η2=0.021) on torque of concentric extensors; mainly from midfielders and goalkeepers with 29 years or more. CONCLUSIONS: Soccer players from different field positions are subjected to different ageing related effects on their muscular performance during their career special attention should be given to these players to avoid reduction in physical performance.

Concentric and eccentric isokinetic hamstring injury risk among 582 professional elite soccer players: a 10-years retrospective cohort study.

BACKGROUND/AIM: Different authors have tried to correlate the peak isokinetic torque values with the incidence of soccer match injuries. However, due to the wide variety of assessment testing protocols, such an inference becomes difficult. This study aimed to verify the capacity of an isokinetic test to establish injury risk reference values for hamstring strain injuries. METHODS: A retrospective cohort study based on isokinetic data and clinical records from the last 10 years was conducted in 582 Brazilian elite-professional soccer players, who were subjected to the same isokinetic test protocol, machine, and tester. A Multivariate Logistic Regression Analysis for Complex Data Sampling was used to generate injury risk statistical indexes. RESULTS: Multivariate regression analysis of both legs provided important data to identify the cut-off values of Concentric Peak Torque (181.82 Newton/*metres), Concentric Work (236.23 watts) and Concentric Power (130.11 joules). CONCLUSIONS: The injury risk indexes indicate that an increase of just one Newton unit in CPT (Concentric Peak Torque) and CJ (Concentric Power) above those cut-off values, can reduce the risk of future injuries by 2% and 2.7%, respectively.

Heart rate and lower limb muscle activity on cycle ergometer / Frequência cardíaca e atividade muscular dos membros inferiores em cicloergômetro / Frecuencia cardíaca y actividad muscular de los miembros inferiores en cicloergómetro

ABSTRACT Introduction: Muscle activity in the pedal stroke movement on a cycle ergometer can be measured by surface electromyography, as an effective and improved method for studying muscle action and objectively determining the different action potentials of the muscles involved in specific movements. Heart rate behavior is an important factor during exercise with load. Objective: To identify heart rate behavior and pattern of muscle activity of the rectus femoris and vastus medialis in healthy subjects in the pedaling dynamic at different loads, submaximal test, on an instrumented cycle ergometer. Methods: 20 healthy adults were evaluated. Heart rate measurement was performed, together with electromyographic analysis, in the time domain, of the rectus femoris and vastus medialis muscles during incremental exercise of the lower limbs on the cycle ergometer. Results: Heart rate behavior presented significant difference for p≥0.05 in relation to increased loads. The EMG signal intensity from the vastus medialis muscle (normalized RMS value) in each quadrant of the pedaling cycle showed significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants III and IV. In the rectus femoris (RF) muscle, there was significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants I, II and III. Conclusion: An increase in heart rate proportional to the increase in load was observed, as well as an increase in the amplitude of the electromyographic signal proportional to the increase in load. It was possible to identify the pattern of muscle activation in the studied quadrants during pedal stroke movements, independent of load. Level of evidence III; Study of non-consecutive patients; without uniform application of the "gold" standard reference.

RESUMO Introdução: A atividade muscular no gesto motor da pedalada no cicloergômetro pode ser mensurada por meio da eletromiografia de superfície. A eletromiografia de superfície tem sido um método efetivo e aprimorado para estudar a ação muscular, determinando com objetividade os diferentes potenciais de ação dos músculos empenhados em movimentos específicos. O comportamento da frequência cardíaca tem relação importante durante o exercício com carga. Objetivo: Identificar o comportamento da frequência cardíaca e o padrão da atividade muscular do reto femoral e vasto medial em indivíduos saudáveis na dinâmica da pedalada em diferentes cargas, teste submáximo, no cicloergômetro instrumentado. Métodos: Foram avaliados 20 adultos saudáveis, realizando-se a mensuração da frequência cardíaca e a análise eletromiográfica no domínio do tempo dos músculos reto femoral e vasto medial durante o exercício incremental dos membros inferiores em cicloergômetro. Resultados: O comportamento da frequência cardíaca apresentou diferença significante para p ≥ 0,05 com relação ao incremento das cargas. A intensidade do sinal EMG do músculo vasto medial (valor RMS normalizado) em cada quadrante do ciclo da pedalada mostrou diferença significativa para p ≥ 0,05 com relação aos quadrantes I, II e IV e diferença significativa para p ≥ 0,05 com relação aos quadrantes III e IV. No músculo reto femoral (RF) verificou-se diferença significativa para p ≥ 0,05 com relação aos quadrantes I, II e IV e diferença significativa para p ≥ 0,05 com relação aos quadrantes I, II e III. Conclusão: Constatou-se aumento da frequência cardíaca proporcional ao incremento das diferentes cargas e também se evidenciou um aumento na amplitude do sinal eletromiográfico proporcional ao incremento da carga. Foi possível identificar o padrão da ativação dos músculos com relação ao ciclo da pedalada nos quadrantes estudados, independentemente do nível da carga. Nível de evidência III; Estudo de pacientes não consecutivos; sem padrão de referência "ouro" aplicado uniformemente.

RESUMEN Introducción: La actividad muscular en el gesto motor de la pedaleada en el cicloergómetro se puede medir por medio de la electromiografía de superficie. La electromiografía de superficie ha sido un método efectivo y mejorado para estudiar la acción muscular, determinando con objetividad los diferentes potenciales de acción de los músculos empeñados en movimientos específicos. El comportamiento de la frecuencia cardíaca tiene relación importante durante el ejercicio con carga. Objetivo: Identificar el comportamiento de la frecuencia cardíaca y el patrón de la actividad muscular del recto femoral y vasto medial en individuos en la dinámica de la pedaleada en el cicloergómetro instrumentado. Métodos: Se evaluaron 20 adultos saludables, realizándose la medición de la frecuencia cardíaca y el análisis electromiográfico en el dominio del tiempo de los músculos recto femoral y vasto medial durante el ejercicio incremental de los miembros inferiores en cicloergómetro. Resultados: El comportamiento de la frecuencia cardíaca presentó una diferencia significativa para p ≥ 0,05 con relación al incremento de las cargas. La intensidad de la señal EMG del músculo vasto medial (valor RMS normalizado) en cada cuadrante del ciclo de la pedaleada mostró diferencia significativa para p ≥ 0,05 con relación a los cuadrantes I, II y IV y diferencia significativa para p ≥ 0,05 con relación a los cuadrantes III y IV. En el músculo recto femoral (RF) se verificó diferencia significativa para p ≥ 0,05 con relación a los cuadrantes I, II y IV, y diferencia significativa para p ≥ 0,05 con relación a los cuadrantes I, II y III. Conclusión: Se constató aumento de la frecuencia cardíaca proporcional al incremento de las diferentes cargas y también se evidenció un aumento en la amplitud de la señal electromiográfica proporcional al incremento de la carga. Fue posible identificar el patrón de la activación de los músculos con relación al ciclo de la pedaleada en los cuadrantes estudiados, independientemente del nivel de la carga. Nivel de evidencia III; Estudio de pacientes no consecutivos; sin patrón de referencia "oro" aplicado uniformemente.

Diagnostic Validity of an Isokinetic Testing to Identify Partial Anterior Cruciate Ligament Injuries.

OBJECTIVE: To assess the diagnostic validity of an isokinetic testing to detect partial injuries on the anterior cruciate ligament (ACL). DESIGN: Prospective diagnostic study. SETTINGS: Orthopedic clinic, physiotherapy clinic, orthopedic hospital, and diagnostic/image clinic. PARTICIPANTS: Consecutive patients (n = 29) with unilateral knee complaint submitted to physical examination, magnetic resonance images (MRIs), and isokinetic testing prior to surgery of ACL reconstruction. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The isokinetic torque curves data from extensor and flexor muscles were converted to frequency domain by fast Fourier transformation and compared with healthy contralateral limb. Differences were categorized as unstable knees and these conclusions were compared with patient's physical examinations (doctor's conclusion on ACL integrity) and MRIs (as the radiologist conclusions on ACL integrity). After surgery, all intraoperatively confirmed partial injured patient's data were collected. The diagnostic accuracy measures to compare the conclusions of all 3 professionals included sensitivity, specificity, positive predictive value, negative predictive value, disease prevalence, positive likelihood ratio, and accuracy-all using a confidence interval of 95%. RESULTS: Compared with MRI, the sensitivity of isokinetic test for an ACL partial injury was 90.00%, specificity 83.33%, positive predictive value 52.94%, negative predictive value 97.56%, and accuracy 84.48%. Compared with physical examination, the sensitivity of isokinetic test for an ACL partial injury was 85.71%, specificity 78.43%, positive predictive value 35.29%, negative predictive value 97.56%, and accuracy 79.31%. CONCLUSIONS: This method of isokinetic data analysis through fast Fourier transformation can be used to improve diagnostic accuracy of a difficult detection injury. Even present, a partial ACL injury can produce a stable knee during isokinetic testing and could be used to detect candidates for conservative treatment based on strengthening exercises, reducing surgery risks, and financial and social impact on patient's life.

Validity and reliability of an instrumented leg-extension machine for measuring isometric muscle strength of the knee extensors.

CONTEXT: Isometric muscle strength of knee extensors has been assessed for estimating performance, evaluating progress during physical training, and investigating the relationship between isometric and dynamic/functional performance. OBJECTIVE: To assess the validity and reliability of an adapted leg-extension machine for measuring isometric knee extensor force. DESIGN: Validity (concurrent approach) and reliability (test and test-retest approach) study. SETTING: University laboratory. PARTICIPANTS: 70 healthy men and women aged between 20 and 30 y (39 in the validity study and 31 in the reliability study). MAIN OUTCOME MEASURE: Intraclass correlation coefficient (ICC) values calculated for the maximum voluntary isometric torque of knee extensors at 30°, 60°, and 90°, measured with the prototype and with an isokinetic dynamometer (ICC2,1, validity study) and measured with the prototype in test and retest sessions, scheduled from 48 h to 72 h apart (ICC1,1, reliability study). RESULTS: In the validity analysis, the prototype showed good agreement for measurements at 30° (ICC2,1 = .75, SEM = 18.2 Nm) and excellent agreement for measurements at 60° (ICC2,1 = .93, SEM = 9.6 Nm) and at 90° (ICC2,1 = .94, SEM = 8.9 Nm). Regarding the reliability analysis, between-days' ICC1,1 were good to excellent, ranging from .88 to .93. Standard error of measurement and minimal detectable difference based on test-retest ranged from 11.7 Nm to 18.1 Nm and 32.5 Nm to 50.1 Nm, respectively, for the 3 analyzed knee angles. CONCLUSIONS: The analysis of validity and repeatability of the prototype for measuring isometric muscle strength has shown to be good or excellent, depending on the knee joint angle analyzed. The new instrument, which presents a relative low cost and easiness of transportation when compared with an isokinetic dynamometer, is valid and provides consistent data concerning isometric strength of knee extensors and, for this reason, can be used for practical, clinical, and research purposes.

A utilização da estimulação elétrica nervosa transcutânea após cirurgias cardíacas / The use of transcutaneous electrical nerve stimulation after cardiac surgeries

Este trabalho tem como objetivos revisar e analisar as pesquisas sobre o uso da estimulação elétrica nervosa transcutânea (TENS) no pós-operatório de pacientes submetidos a cirurgias cardíacas. Foram encontrados 12 trabalhos com metodologias e resultados diferentes para grau de analgesia, consumo de medicamentos analgésicos e complicações pulmonares. Uma padronização nos parâmetros terapêuticos e metodologias é necessária para se avaliar melhor esta técnica terapêutica. Um grupo de parâmetros terapêuticos é recomendado ao final desta revisão.

The aim of this study was to review the literature about the use of transcutaneous electrical nerve stimulation (TENS) after cardiac surgeries. Twelve reports with different methods and results for analgesic effect, opioid consumption and postoperative pulmonary complication were encountered. Therapeutic parameters and methods standardization are needed to correctly evaluate this therapeutic technique. A therapeutic parameter group is suggested at the end of this review.