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Context: Pulsed current and kilohertz frequency alternating current are 2 types of neuromuscular electrical stimulation (NMES) currents often used by clinicians during rehabilitation. However, the low methodological quality and the different NMES parameters and protocols used in several studies might explain their inconclusive results in terms of their effects in the evoked torque and the discomfort level. In addition, the neuromuscular efficiency (ie, the NMES current type that evokes the highest torque with the lowest current intensity) has not been established yet. Therefore, our objective was to compare the evoked torque, current intensity, neuromuscular efficiency (evoked torque/current intensity ratio), and discomfort between pulsed current and kilohertz frequency alternating current in healthy people. Design: A double-blind, randomized crossover trial. Methods: Thirty healthy men (23.2 [4.5] y) participated in the study. Each participant was randomized to 4 current settings: 2 kilohertz frequency alternating currents with 2.5 kHz of carrier frequency and similar pulse duration (0.4 ms) and burst frequency (100 Hz) but with different burst duty cycles (20% and 50%) and burst durations (2 and 5 ms); and 2 pulsed currents with similar pulse frequency (100 Hz) and different pulse duration (2 and 0.4 ms). The evoked torque, current intensity at the maximal tolerated intensity, neuromuscular efficiency, and discomfort level were evaluated. Results: Both pulsed currents generated higher evoked torque than the kilohertz frequency alternating currents, despite the similar between-currents discomfort levels. The 2 ms pulsed current showed lower current intensity and higher neuromuscular efficiency compared with both alternated currents and with the 0.4 ms pulsed current. Conclusions: The higher evoked torque, higher neuromuscular efficiency, and similar discomfort of the 2 ms pulsed current compared with 2.5-kHz frequency alternating current suggests this current as the best choice for clinicians to use in NMES-based protocols.

Increasing age appears to influence several morphologic changes in major tendons. However, the effects of aging on the cross-sectional area (CSA) of different ankle tendons are much less understood. Furthermore, potential differences in specific tendon regions along the length of the tendons have not been investigated in detail. Sixty healthy adult participants categorized by age as young (n = 20; mean ± SD age = 22.5 ± 4.5 years), middle-age (n = 20; age = 40.6 ± 8. 0 years), or old (n = 20; age = 69.9 ± 9.1 years), from both sexes, were included. The tendon CSA of tibialis anterior (TA), tibialis posterior (TP), fibularis (FT), and Achilles (AT) was measured from T1-weighted 1.5 T MR images in incremental intervals of 10% along its length (from proximal insertion) and compared between different age groups and sexes. The mean CSA of the AT was greater in the middle-age group than both young and old participants (p 0.01) and large effect sizes were observed for these differences (Cohen's d 1). Furthermore, there was a significant difference in CSA in all three groups along the length of the different tendons. Region-specific differences between groups were observed in the distal portion (90% and 100% of the length), in which the FT presented greater CSA comparing middle-age to young and old (p 0.05). In conclusion, (1) great magnitude of morpho-structural differences was discovered in the AT; (2) there are region-specific differences in the CSA of ankle tendons within the three groups and between them; and (3) there were no differences in tendon CSA between sexes.

Neuromuscular electrical stimulation (NMES) can be delivered in a conventional form (CONVNMES) and using relatively wide-pulses and high-frequencies (WPHFNMES). WPHFNMES is proposed to reduce contraction fatigability and generate larger contractions with less discomfort than CONVNMES; however, there are no systematic reviews to guide the selection of NMES types. This systematic review compared the effects of CONVNMES versus WPHFNMES on contraction fatigability, strength adaptations, and perceived discomfort in clinical and non-clinical populations. Eight studies were included. When averaged across all non-clinical participants in individual short- and long-term studies, there was either no difference between CONVNMES and WPHFNMES for all outcomes or WPHFNMES produced more fatigability. In a subset of non-clinical participants (“responders”), however, WPHFNMES reduced contraction fatigability during a single session. Long-term studies found no differences between protocols for strength adaptations in non-clinical participants and those with multiple sclerosis. We concluded that WPHFNMES reduces contraction fatigability only in the short-term studies and in non-clinical responder participants and may exacerbate fatigability in non-responders. This review was registered in the prospective international registry of systematic reviews/PROSPERO (Registration Number: CRD42020153907). Novelty: WPHF NMES may reduce fatigue in some participants and exacerbate fatigue in others. There were no differences in long-term studies between WPHF and CONV NMES on strength adaptations. Future high-quality research is needed to optimize outcomes of NMES-based programs.

IntroductionThe handheld dynamometer has been validated to measure muscle strength in different muscle groups. However, to date, it has not been tested in individuals who experience pain induced by hip osteoarthritis. The current study aimed to evaluate the intra- and inter-rater reliability, agreement, and minimal detectable change of the Lafayette handheld dynamometer, model 1165, to assess the peak force (Pk) and average peak force (Af) of hip muscles in individuals with symptomatic hip osteoarthritis.MethodsTwenty participants with hip osteoarthritis (mean ± SD age: 58.7±15.3 years; body mass index: 28.8±4.2 kg/m2) and a pain intensity on the Visual Analogue Scale0020 ≥ 4 (8.05±1.2) were recruited to participate in this study. Pk and Af of hip flexors (seated position), abductors and adductors (supine position), and extensors (prone position) were collected in a single day by two independent raters, each one obtaining test and retest in randomly ordered separate sessions.ResultsThe intra-rater intraclass correlation coefficient (ICC) was classified as good (>0.75) or excellent (≥0.90) for all muscle groups, and all inter-rater ICCs were classified as excellent. Rater A had a lower standard error of measurement compared to rater B, ranging from 0.15 to 0.58 kilogram-force (Kgf) compared with 0.34 to 1.25 kg, respectively. However, the inter-rater comparison showed a minimal detectable change < 10% for all Pk and Af measures (except Af for the abductor muscle group). Finally, the inter-rater Bland-Altman analysis demonstrated good agreement for abductors, adductors, and extensors.ConclusionDespite pain and dysfunction related to hip osteoarthritis, the handheld dynamometer was shown to be a reliable tool to assess hip muscle strength, with good to excellent intra- and inter-rater ICCs, satisfactory agreement, and small values for minimal detectable change.

Background. COVID-19 patients may present sequelae, such as neuromuscular electrophysiological disorders (NED), that can be assessed using the stimulus electrodiagnostic test (SET). However, little is known about the reliability and agreement of the SET in post-COVID-19 patients. Objective. We aimed to verify the intra–inter-rater reliability and agreement of SET measurements in the rectus femoris, vastus medialis, vastus lateralis, tibialis anterior, and gastrocnemius lateralis (GL) in post-COVID-19 participants. Methods. We designed an observational prospective study to evaluate 20 (10 males and 10 females) post-COVID-19 patients, age: 44.95 ± 11.07 years, weight: 87.99 ± 19.08 kg, height: 1.69 ± 0.09 m. Two independent raters took two evaluations using the SET on selected muscles. The intra-class correlation coefficient (ICC) and 95% limits of the agreement defined the quality and magnitude of the measures. Results. For intra-rater reliability, all measurements presented correlations classified as high or very high (ICC: 0.71–1.0). For inter-rater reliability, the rheobase, chronaxie, accommodation, and accommodation index presented high or very high correlations, except for the accommodation index of the GL (ICC = 0.65), which was moderate. Conclusion. The reliability of the SET obtained by independent raters was very high, except for the GL accommodation, which presented moderate ICC. Therefore, the SET is a reliable tool for evaluating NED in post-COVID-19 patients.

Background The cross-sectional area (CSA) records make an essential measurement for determining the mechanical properties of tendons, such as stress and strength. However, there is no consensus regarding the best method to record the CSA from different tendons. Purpose To determine intra- and inter-rater reliability for CSA measures from magnetic resonance imaging (MRI) of the following tendons: tibialis anterior; tibialis posterior; fibularis longus and brevis; and Achilles. Material and Methods We designed an observational study with repeated measures taken from a convenience sample of 20 participants diagnosed with acute or chronic ankle sprain. Two independent raters took three separate records from the CSA of ankle tendon images of each MRI slice. The intra-class correlation coefficient (ICC) and 95% limits of agreement (LoA) defined the quality (associations) and magnitude (differences), respectively, of intra- and inter-rater reliability on the measures plotted by the Bland–Altman method. Results Data showed very high intra- and inter-rater correlations for measures taken from all tendons analyzed (ICC 0.952–0.999). It also revealed an excellent agreement between raters (0.12%–2.3%), with bias no higher than 2 mm2 and LoA in the range of 4.4–7.9 mm2. The differences between repeated measures recorded from the thinnest tendons (fibularis longus and brevis) revealed the lowest bias and narrowest 95% LoA. Conclusion Reliability for the CSA of ankle tendons measured from MRI taken by independent rates was very high, with the smallest differences between raters observed when the thinnest tendon was analyzed.

Background: Low-frequency electrical stimulation (LFES) is an adjuvant method for heart failure (HF) patients with restrictions to start an exercise. However, the impact on molecular changes in circulating is unknown. We investigated the effects of 10 weeks of home-based LFES on plasma cytokines profile, redox biomarkers, metalloproteinases (MMPs) activity, and exercise performance in HF patients. Methods: Twenty-four HF patients (52.45 ± 9.15 years) with reduced ejection fraction (HFrEF) (EF < 40%), were randomly assigned to a home-based LFES or sham protocol. Plasma cytokines profile was assessed through interleukins, interferon-gamma, and tumor necrosis factor levels. Oxidative stress was evaluated through ferric reducing antioxidant power, thiobarbituric acid-reactive substances, and inducible nitric oxide synthase. The MMPs activity were analyzed by zymography. Cardiorespiratory capacity and muscle strength were evaluated by cardiopulmonary test and isokinetic. Results: LFES was able to increase the active-MMP2 activity post compared to pre-training (0.057 to 0.163, p = 0.0001), while it decreased the active-MMP9 (0.135 to 0.093, p = 0.02). However, it did not elicit changes in cytokines, redox biomarkers, or exercise performance (p > 0.05). Conclusion: LFES protocol is a promising intervention to modulate MMPs activity in HFrEF patients, although with limited functional effects. These preliminary responses may help the muscle to adapt to future mechanical demands dynamically.

Background: Although mat Pilates (MP) has become popular, the effects of MP in hypertensive women (HW) are not entirely clear. Here, we investigated the effects of 16 weeks of MP training contrasted with MP supplemented with aerobic exercise (MP+AE) and compared with a non-intervention group on autonomic modulation, cardiorespiratory fitness, strength, flexibility, performance of functional tasks, QOL, anthropometric variables, clinical BP, and heart rate. Methods: This is a three-arm, secondary analysis of an RCT. Sixty HW, aged 30 to 59 years, were allocated into: MP only (MP), MP+AE on a treadmill (MP+AE), and Control Group, without exercises. Assessments were performed before and after 16 weeks of training. Results: The ANOVA shows differences in between-group comparisons in the SDNN, rMSSD, and SD1 in the heart rate variability analysis, with increases in rMSSD, SDNN, and SD1 only in the MP, and this result was not found in the MP+AE group (p < 0.05). Differences were observed in the between-group comparisons in time in the cardiorespiratory exercise test (CPX), flexibility, and the waist-to-hip ratio, with changes in the MP+AE, differences in QOL, and increments in the MP and MP+AE (p < 0.05). Conclusions: MP increased the indices that reflect vagal and global cardiac autonomic modulation. MP+AE improved the CPX performance, flexibility, QOL, and anthropometric variables. These results suggest that MP supplemented or not with AE has promising effects in HW.

The extracellular matrix (ECM) is a 3-dimensional network of molecules that play a central role in differentiation, migration, and survival for maintaining normal homeostasis. It seems that ECM remodeling is required for adipose tissue expansion. Despite evidence indicating that ECM is an essential component of tissue physiology, adipose tissue ECM has received limited attention. Hence, there is great interest in approaches to neutralize the harmful effects of ECM enlargement. This review compiles and discusses the current literature on adipose tissue ECM remodeling in response to different dietary patterns and exercise training. High-calorie diets result in substantial adipose tissue ECM remodeling, which in turn could lead to fibrosis (excess deposition of collagens, elastin, and fibronectin), inflammation, and the onset of metabolic dysfunction. However, combining a nutritionally balanced diet with exercise is a remarkable potential strategy for lipolytic activity, preventing rapid ECM expansion in different adipose tissue depots. Despite the distinct exercise modalities (aerobic or resistance exercise) reversing adipose tissue fibrosis in animal models, the beneficial effect on humans remains controversial. Defining molecular pathways and specific mechanisms that mediate the positive effects on adipose tissue, ECM is essential in developing optimized interventions to improve health and clinical outcomes.

The present study aimed to determine the association between neuromuscular function, motor function impairment, and muscle and tendon structures in individuals with spinal cord injury (SCI) compared to a control (non-disabled) population.A cross-sectional study with a control group.Center of Adapted Sports Training and Special Physical Education.Fifteen individuals with SCI and motor function impairments participated in the study. A paired non-disabled group was recruited for comparison.Not applicable.Muscle (biceps brachii, rectus femoris, vastus lateralis, vastus medialis, and tibialis anterior) and tendon (quadriceps and patellar tendons) structures were assessed by ultrasound imaging (thickness, pennation angle, fascicle length, and echogenicity). Neuromuscular electrophysiological disorders were also assessed using electrodiagnosis techniques (stimulus non-responsivity and chronaxie) in the same muscles.Except for the biceps brachii muscle, muscle thickness, pennation angle, and fascicle length were lower (Neuromuscular disorders occur in association with muscle and tendon maladaptation in individuals with chronic SCI. A higher prevalence of electrophysiological disorders suggests an acquired polyneuromyopathy for muscles with motor function impairment even though the muscle was innerved, in addition to widespread muscle atrophy.

Kilohertz-frequency alternating current (KFAC) is used to minimize muscle atrophy and muscle weakness and improve muscle performance. However, no systematic reviews have evaluated the best KFAC parameters for this purpose. We investigated the effects of the carrier frequency, burst duty cycles, and burst durations on evoked torque, perceived discomfort, and muscle fatigue. A search of eight data sources by two independent reviewers resulted in 13 peer-reviewed studies being selected, following the PRISMA guidelines, and rated using the PEDro Scale to evaluate the methodological quality of the studies. The majority of studies showed that carrier frequencies up to 1 kHz evoked higher torque, while carrier frequencies between 2.5 kHz and 5 kHz resulted in lower perceived discomfort. In addition, most studies showed that shorter burst duty cycles (10% to 50%) induced higher evoked torque and lower perceived discomfort. Methodological quality scores ranged from 5 to 8 on the PEDro scale. We conclude that KFAC develops greater evoked torque for carrier frequencies between 1 kHz and 2.5 kHz and burst duty cycles below 50%. Lower perceived discomfort was generated using KFACs between 2.5 kHz and 5 kHz and burst duty cycles below 50%.

This study investigated the acute effects of seated and supine knee extension exercise on muscle swelling, torque, and work output. Twelve resistance-trained men performed two isokinetic concentric-only knee-extension training protocols at different hip positions in a counter-balanced order. They completed the knee extension exercise in the seated (hip angle at 85°) and supine (hip angle at 180°) positions. The torque and work output were assessed during each set. Moreover, muscle thickness of the middle and proximal vastus lateralis and rectus femoris were evaluated before and after each protocol and used as an indicator of muscle swelling. Middle rectus femoris and proximal vastus lateralis thickness increased significantly (p=0.01) with no difference between exercise variations. However, the middle vastus lateralis thickness increased (p=0.01) only after the seated knee extension exercise (~7%). Knee extensors’ peak torque and work output were approximately 8% higher (p=0.04) in the seated when compared to the supine hip position. There was a similar decrease in torque and work output throughout both protocols (p=0.98). In conclusion, seated knee extension exercises produced greater torque, work output, and muscle swelling in the vastus lateralis when compared to the supine knee extension exercise.

Context: Neuromuscular electrical stimulation is widely used to induce muscular strength increase; however, no study has compared Russian current (RC) with pulsed current (PC) effects after a training program. Objectives: We studied the effects of different neuromuscular electrical stimulation currents, RC, and PC on the neuromuscular system after a 6-week training period. Design: Blinded randomized controlled trial. Setting: Laboratory. Patients: A total of 27 male soccer players (age 22.2 [2.2] y, body mass 74.2 [10.0] kg, height 177 [0] cm, and body mass index 23.7 [2.9] kg/cm2 for the control group; 22.1 [3.1] y, 69.7 [5.7] kg, 174 [0] cm, and 23.0 [2.5] kg/cm for the PC group; and 23.0 [3.4] y, 72.1 [10.7] kg, 175 [0] cm, and 23.5 [3.4] kg/cm for the RC group) were randomized into 3 groups: (1) control group; (2) RC (2500 Hz, burst 100 Hz, and phase duration 200 μs); and (3) PC (100 Hz and 200 μs). Intervention: The experimental groups trained for 6 weeks, with 3 sessions per week with neuromuscular electrical stimulation. Main Outcome Measures: Maximal voluntary isometric contraction and evoked torque, muscle architecture, sensory discomfort (visual analog scale), and electromyographic activity were evaluated before and after the 6-week period. Results: Evoked torque increased in the RC (169.5% [78.2%], P P P P P P > .05). For all these variables, there was no difference between the RC and PC (P > .05). Conclusion: Despite the widespread use of RC in clinical practice, RC and PC training programs produced similar neuromuscular adaptations in soccer players. Nonetheless, as PC generated less perceived discomfort, it could be preferred after several training sessions.

Context: Although stretching exercises are commonly used in clinical and athletic practice, there is a lack of evidence regarding the methodological variables that guide the prescription of stretching programs, such as intensity. Objective: To investigate the acute effects of different stretching intensities on the range of motion (ROM), passive torque, and muscle architecture. Design: Two-group pretest–posttest design. Setting: Laboratory. Participants: Twenty untrained men were allocated into the low- or high-intensity group. Main Outcome Measures: Subjects were evaluated for initial (ROMinitial) and maximum (ROMmax) discomfort angle, stiffness, viscoelastic stress relaxation, muscle fascicle length, and pennation angle. Results: The ROM assessments showed significant changes, in both groups, in the preintervention and postintervention measures both for the ROMinitial (P P = .02). There were no significant differences for stiffness and viscoelastic stress relaxation variables. The pennation angle and muscle fascicle length were different between the groups, but there was no significant interaction. Conclusion: Performing stretching exercises at high or low intensity acutely promotes similar gains in flexibility, that is, there are short-term/immediate gains in ROM but does not modify passive torque and muscle architecture.

RESUMO O objetivo deste estudo foi identificar, a partir de uma revisão sistemática, variáveis clínicas, instrumentais e demográficas associadas com maior risco de queda em indivíduos com esclerose múltipla (EM), com base em dados prospectivos. A pesquisa foi conduzida nas bases de dados Medline, Web of Science, Bireme e CINAHL, utilizando os descritores “esclerose múltipla”, “quedas”, “quedas acidentais”, “risco de quedas”, “controle postural” e “equilíbrio”, seguido de buscas manuais. Foram considerados elegíveis estudos de coorte prospectivos, com período mínimo de acompanhamento das quedas de três meses, que avaliassem a associação de determinada variável demográfica, clínica ou instrumental em relação a maior risco de queda em indivíduos com EM. A escala de Newcastle-Ottawa modificada foi utilizada para avaliação da qualidade metodológica dos estudos incluídos. Foram identificados 357 estudos, 12 dos quais foram incluídos na revisão sistemática, com total de 1.270 pacientes incluídos. Destes, 740 (58,26%) pacientes apresentaram um ou mais episódios de queda, 396 (31,18%) apresentaram episódios de queda recorrentes (2≥quedas no período estipulado), e 530 (41,74%) não apresentaram nenhum episódio. Com exceção da espasticidade e do impacto da dupla tarefa na velocidade da marcha, todas as variáveis investigadas apresentaram resultados conflitantes quanto às suas associações a maior risco de quedas. São necessários mais estudos que apresentem homogeneidade dos fenótipos clínicos de indivíduos com EM, além da utilização de instrumentos de avaliação validados, a fim de estabelecer uma associação robusta de outras variáveis clínicas, instrumentais e demográficas com maior risco de queda. RESUMEN El objetivo de este estudio fue identificar, a partir de una revisión sistemática, variables clínicas, instrumentales y demográficas asociadas con un mayor riesgo de caída en individuos con esclerosis múltiple (EM), con base en datos prospectivos. La búsqueda se realizó en las bases de datos: Medline, Web of Science, Bireme y CINAHL, utilizando los descriptores “esclerosis múltiple”, “caídas”, “caídas accidentales”, “riesgo de caídas”, “control postural” y “equilibrio”, seguido de búsquedas manuales. Se consideraron elegibles los estudios de cohorte prospectivos con un período de seguimiento mínimo de caídas de tres meses, que evaluaron la asociación de una variable demográfica, clínica o instrumental en relación con el mayor riesgo de caídas en individuos con EM. La escala modificada de Newcastle-Ottawa se utilizó para evaluar la calidad metodológica de los estudios incluidos. Se identificaron 357 estudios, 12 de los cuales se incluyeron en la revisión sistemática, con un total de 1.270 pacientes incluidos. De estos, 740 (58,26%) pacientes tuvieron uno o más episodios de caída, 396 (31,18%) presentaron episodios de caída recurrentes (2≥caídas en el período estipulado), y 530 (41,74%) no presentaron ningún episodio. Con excepción de la espasticidad y del impacto de la doble tarea en la velocidad de la marcha, todas las variables investigadas presentaron resultados conflictivos en cuanto a sus asociaciones a mayor riesgo de caídas. Se requieren más estudios que presenten homogeneidad de los fenotipos clínicos de pacientes con EM, además del uso de instrumentos de evaluación validados, para establecer una asociación robusta de otras variables clínicas, instrumentales y demográficas con mayor riesgo de caída. ABSTRACT The objective of this study was to identify demographic, clinical, and instrumental variables associated with falls in people with multiple sclerosis (MS), via systematic review, based on prospective data. The search was conducted in these databases: Medline, Web of Science, Bireme e CINAHL via a search strategy that combined the descriptors “multiple sclerosis”, “falls”, “accidental falls”, “fall risk”, “postural control” and “balance”, followed by manual search. Eligibility criteria were prospective cohort studies with a minimum 3-month follow-up of falls that assessed the association of a demographic, clinical or instrumental variable in relation to a higher fall risk in people with MS. The modified Newcastle-Ottawa Quality Assessment Scale was used for study quality assessment. A total of 357 studies were identified, of which 12 were included in the systematic review and 1,270 patients were included. In this study, 740 (58.26%) patients were classified as fallers, 396 (31.18%) patients had recurrent falls (2≥falls within the stipulated period) and 530 patients (41.74%) were classified as non-fallers. Except for spasticity and dual task cost in gait speed, all investigated variables showed conflicting results regarding their association with a higher fall risk. More studies with clinical homogeneity phenotypes of MS individuals and using validated assessment instruments are necessary to establish a robust association of other clinical, instrumental, and demographic variables with a higher fall risk.

Exercise interventions have been recommended for people with non-specific low back pain. The literature is scarce regarding the effects of exercise on muscle strength, endurance, and electrical activity of lumbar extensor muscles. Electronic searches were carried out from May 2020 until August 2020 in the following databases: PUBMED, CENTRAL, EMBASE, PEDro, SPORTDiscus, Scielo, and LILACS. Only randomized controlled trials with passive and active control groups were included. The methodological quality of the included studies was performed using the Physiotherapy Evidence Database Scale. Eight studies, involving 508 participants, were included in metanalytical procedures. Exercise interventions demonstrated superior effects on muscle activity (Electromyography) when compared with active controls (p p = 0.0340) and active controls (p = 0.0276). Exercise interventions demonstrated superior effects on muscle strength (Machine) when compared with passive controls (p = 0.0092). Exercise interventions can improve muscle strength, endurance, and electrical activity in people with non-specific low back pain.

A força de preensão manual (FPM) é considerada componente fundamental na análise da força muscular do público idoso. No entanto, dados que mostrem a sua relação com a força muscular global (FMG) ainda são inconclusivos. O objetivo do presente estudo foi investigar se a força de preensão manual relativa (FPMR) é representativa da FMG em idosas. Participaram do estudo 39 mulheres idosas (idade 69,02 ± 6,16 anos, estatura 1,55 ± 0,06 m, índice de massa corporal (IMC) 27,51 ± 4,10 kg/m², gordura 38,80 ± 6,28 %). Para mensuração da força muscular absoluta as participantes foram submetidas aos testes de 10 repetições máximas (RM), nos exercícios supino máquina, remada fechada, cadeira flexora, cadeira extensora e leg press horizontal e 1 RM foi estimada. A FPM absoluta foi avaliada utilizando um dinamômetro hidráulico de preensão manual. Para calcular a FPMR, a maior leitura foi dividida pelo IMC e massa magra dos membros superiores avaliado pelo DXA. O mesmo procedimento foi utilizado para o cálculo da força muscular relativa dos membros superiores e inferiores. Os resultados demonstraram que a FPMR apresentou correlação moderada e significativa com a força muscular relativa na cadeira flexora, supino máquina e remada fechada, porém, com os outros exercícios não houve correlação. Com isso, os dados do presente estudo demonstram que embora a FPMR tenha apresentado correlação moderada e significativa com a força muscular relativa dos membros superiores e inferiores, ainda é recomendada precaução ao afirmar que a FPMR é representativa da FMG em idosas.

This cross-sectional study aimed to compare the muscle microcirculation dynamics via near-infrared spectroscopy (NIRS) response during an isokinetic muscle strength test and ultrasound-derived parameters in heart failure patients with preserved or reduced ejection fraction phenotypes (HFpEF and HFrEF, respectively) and different functional severities (Weber Class A, B, and C). Twenty-eight aged-matched patients with HFpEF (n = 16) and HFrEF (n = 12) were assessed. Within HFpEF, Weber Class C patients presented a worse capability to reach a greater oxygen extraction during exercise than Classes A and B. Among those with Weber C severity, while HFrEF patients reached lower oxyhemoglobin (O2Hb, µM) (-10.9 ± 3.8 vs. -23.7 ± 5.7, p = 0.029) during exercise, HFpEF kept a lower O2Hb during the recovery period (-3.0 ± 3.4 vs. 5.9 ± 2.8, p = 0.007). Among the ultrasound-derived variables, HFpEF, Weber Class C, also presented a higher echo intensity than HFrEF patients (29.7 ± 8.4 vs. 15.1 ± 6.8, p = 0.017). Our study reveals more pronounced impairments in local microcirculatory dynamics in HFpEF vs. HFrEF patients during muscle strength exercise, combined with muscle-skeletal abnormalities detected via ultrasound imaging, which may help to explain the commonly observed exercise intolerance in HFpEF patients.

Objective: Does short-term cryotherapy improve pain, function and quality of life in people with knee osteoarthritis (OA)? Design: Randomised controlled trial with concealed allocation, blinded assessment of some outcomes, and intention-to-treat analysis. Participants: People living in the community with knee OA. Interventions: The experimental group received cryotherapy, delivered as packs of crushed ice applied to the knee with mild compression. The control group received the same regimen but with sham packs filled with sand. The interventions were applied once a day for 4 consecutive days. Outcome measures: Participants were assessed at baseline and on the day after the 4-day intervention period. The primary outcome was pain intensity according to a visual analogue scale. Secondary outcomes were baseline to post-intervention changes according to the Western Ontario and McMaster Universities Osteoarthritis, Knee injury and Osteoarthritis Outcome; Timed Up and Go test; and 30-Second Chair to Stand test. Results: Sixty participants were randomised into the experimental group (n = 30) or the control group (n = 30). Twenty-nine participants from each group completed the trial. The mean between-group difference in change in pain severity was −0.8 cm (95% CI −1.6 to 0.1), where negative values favour the experimental group. This result did not reach the nominated smallest worthwhile effect of 1.75 cm. The secondary outcomes had less-precise estimates, with confidence intervals that spanned worthwhile, trivial and mildly harmful effects. Conclusion: Short-term cryotherapy was not superior to a sham intervention in terms of relieving pain or improving function and quality of life in people with knee OA. Although cryotherapy is considered to be a widely used resource in clinical practice, this study does not suggest that it has an important short-term effect, when compared with a sham control, as a non-pharmacological treatment for people with knee osteoarthritis. Registration: NCT02725047. Key words: Osteoarthritis, Cryotherapy, Randomised trial, Knee, Physical therapy

Objective: This study evaluated the relationship between leg-length discrepancy (LLD) and plantar fasciitis (PF). Methods: A cross-sectional study was performed that measured the length of the lower limbs via a scanometry of patients with PF. Other risk factors such as body mass index (BMI), foot posture, and the presence of a plantar heel spur on foot X-ray were also evaluated. Results: Of the 54 participating patients, 44.4% were male with a mean age of 50.38 (23-73 years), 81.5% had pain in one foot, and 53.7% had plantigrade feet. We observed LLD in 88.9% of the sample, with a mean discrepancy of 0.749 cm (SD +/-0.63); 46.3% of the painful feet presented with spurs on X-ray. Conclusions: Approximately 90% of the patients presented with LLD, and the shorter limb was the affected side in most cases. Level of Evidence II; Prognostic Studies.

Objective: The aim of the present study was to verify the intra- and inter-rater reliability and agreement of the stimulus electrodiagnostic test (SET) measurements obtained by pen and square elect...

Muscle-tendon unit length plays a crucial role in quadriceps femoris muscle (QF) physiological adaptation, but the influence of hip and knee angles during QF neuromuscular electrical stimulation (NMES) is poorly investigated. We investigated the effect of muscle length on maximum electrically induced contraction (MEIC) and current efficiency. We secondarily assessed the architecture of all QF constituents and their tendon-aponeurosis complex (TAC) displacement to calculate a stiffness index. This study was a randomized, repeated measure, blinded design with a sample of twenty healthy men aged 24.0 ± 4.6. The MEIC was assessed in four different positions: supine with knee flexion of 60° (SUP60); seated with knee flexion of 60° (SIT60); supine with knee flexion of 20° (SUP20), and seated with knee flexion of 20° (SIT20). The current efficiency (MEIC/maximum tolerated current amplitude) was calculated. Ultrasonography of the QF was performed at rest and during NMES to measure pennation angle (θp) and fascicle length (Lf), and the TAC stiffness index. MEIC and current efficiency were greater for SUP60 and SIT60 compared to SUP20 and SIT20. The vastus lateralis and medialis showed lower θp and higher Lf at SUP60 and SIT60, while for the rectus femoris, in SUP60 there were lower θp and higher Lf than in all positions. The vastus intermedius had a similar pattern to the other vastii, except for lack of difference in θp between SIT60 compared to SUP20 and SIT20. The TAC stiffness index was greater for SUP60. We concluded that NMES generate greater torque and current efficiency at 60° of knee flexion, compared to 20°. For these knee angles, lengthening the QF at the hip did not promote significant change. Each QF constituent demonstrated muscle physiology patterns according to hip and/or knee angles, even though a greater Lf and lower θp were predominant in SUP60 and SIT60. QF TAC index stiffened in more elongated positions, which probably contributed to enhanced force transmission and slightly higher torque in SUP60. Our findings may help exercise physiologist better understand the impact of hip and knee angles on designing more rational NMES stimulation strategies.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier NCT03822221.

Introduction Neuromuscular electrical stimulation (NMES) is used by athletes to improve muscle performance. However, evidence on the use of NMES in long distance runners is scarce. As such, this study aimed to evaluate the effects of NMES on the muscle torque and sports performance of long-distance recreational runners. Methods This was a blinded randomized controlled trial. Data from 30 volunteers were analyzed. Participants were randomly allocated to an experimental (n = 15) or control group (n = 15). The experimental group was submitted to running training (RT) and a strengthening protocol with NMES (1 kHz, modulated in 2ms bursts, 50Hz modulated burst frequency and 10% duty cycle, 15 minutes totaling 18 contractions per sessions) for 6 weeks, with 3 sessions per week, while controls were submitted to RT alone. The following variables were analyzed: peak isometric (ISO), concentric (CON), and eccentric (ECC) torque of the quadriceps muscle in voluntary contractions, ventilatory anaerobic thresholds (VATs), maximal oxygen uptake (VO2max), and oxygen cost of transport (OCT). Results The NMES group obtained higher values of ISO, 21.04% (p = 0.001), CON, 21.97% (p = 0.001) and ECC, 18.74% (p = 0.001) peak torque and VAT1, 9.56% (p = 0.001), as well as a statistically significant improvement in oxygen cost of transport at VAT1 when compared to controls (p = 0.001). Conclusion NMES was effective in improving peak isometric, concentric and eccentric quadriceps muscle torque, in addition to being an interesting resource for enhancing sports performance in long-distance recreational runners and future clinical trials should be performed to compare the use of NMES to different forms of training over longer training periods.

Acute lateral ankle sprain (LAS) is the most prevalent acute sports trauma. Ankle muscle atrophy and tendon volume decrease have not been analyzed concomitantly with functional impairment and pain following LAS. The objective of the present study was to investigate muscle cross-section area (CSA), tendon CSA and volume, ankle function, and pain in individuals who suffered an acute LAS.A series of cases, cross-sectional study with 20 participants who suffered moderate (grade II) and severe (grade III) acute LAS was undertaken. CSA for muscles (Tibialis Posterior, Fibularis, and Soleus) and tendons (Tibialis Anterior, Tibialis posterior, Fibularis, and Achilles), and volume were measured by magnetic resonance imaging (MRI) less than 48 h (baseline) and 6-weeks after the acute LAS. Ankle function (Cumberland Ankle Instability Tool [CAIT] and Foot and Ankle Outcome Score [FAOS]), ankle mechanical instability (Anterior Drawer Test [ADT]), and pain were also assessed.All tendons and muscles showed a significant reduction in CSA and volume between baseline and 6-weeks (P.001). A significant decrease in ankle function was observed 6 weeks after the LAS, along with a reduction in pain and mechanical instability (P = .001). Regarding sprain magnitude, the only difference observed was greater atrophy in muscle CSA in participants with grade III ankle sprain.Patients with acute LAS showed atrophy of ankle muscles and decreased tendon volume and CSA, followed by function impairments at 6-week follow-up.IV, Case series study.

Objective The purpose of this study was to determine the effects of mat Pilates (MP) versus MP plus aerobic exercise (AE) compared with the effects of no intervention on ambulatory blood pressure (BP) in women with hypertension. Methods This 3-arm, parallel-group randomized clinical trial assessed 60 women who had hypertension and were 30 to 59 years old. The intervention lasted 16 weeks, and the participants were allocated into 3 groups: MP only (MP group), MP with alternating bouts of AE on a treadmill (MP + AE group), and control group (CG) with no exercises. Primary outcomes were the effects of the interventions on ambulatory BP assessed in the 24-hour, awake, and asleep periods of analysis. Results A 2-way analysis of variance did not reveal statistically significant differences in between-group comparisons in the 24-hour period of analysis for systolic BP (CG vs MP = 3.3 [95% CI = −7.1 to 13.8]; MP vs MP + AE = 0.7 [95% CI = −4 to 5.4]; CG vs MP + AE = 4.0 [95% CI = −5.2 to 13.4]), diastolic BP (CG vs MP = 2.2 [95% CI = −5.6 to 10.0]; MP vs MP + AE = 1.1 [95% CI = −4.3 to 6.5]; CG vs MP + AE = 3.3 [95% CI = −3.8 to 10.4]), and heart rate (CG vs MP = 3.4 [95% CI = −2 to 8.8]; MP vs MP + AE = 2.0 [95% CI = −3.4 to 7.5]; CG vs MP + AE = 5.4 [95% CI = −0.8 to 11.8]). The awake and asleep periods of analyses also showed similar behavior and did not reveal statistically significant between-group differences. Furthermore, in the responsiveness analysis based on the minimal clinically important difference, no differences were observed between groups. Conclusion The magnitudes of the decrease in systolic BP during the 24-hour period of analysis were −3 and −5.48 mm Hg for the MP and MP + AE groups, without differences for responsiveness between groups. The results suggest that MP supplemented with AE or not may be an alternative adjuvant treatment for women who have hypertension and are using antihypertension medication. Impact Sixteen weeks of MP training reduced ambulatory BP in women who had hypertension. The MP + AE group displayed a BP reduction similar to that of the MP group. A reduction in ambulatory BP can decrease the risk of cardiovascular disease.

The Pilates method has become a popular exercise modality. However, there is little information on the energy expenditure (EE) and aerobic metabolism involved in a Pilates session. This study aimed to compare the EE of three different types of Pilates sessions. Thirty-three sedentary women (22.03 ± 3.32 years old) performed three Pilates sessions: (1) a traditional session (TS): single set, low volume of repetitions, and long rest interval; (2) non-traditional session (NSS): single set, a high volume of repetitions, and short rest interval; and (3) non-traditional session (NMS): multiple sets and short rest interval. In each session, EE per minute (EE/min), total EE (TEE), oxygen consumption (V’O2), respiratory exchange ratio (RER), and metabolic equivalent were determined via a gas analyzer. Heart rate (HR) was measured via a HR monitor. Repeated measures two-way ANOVA (time × session) followed by Tukey test were used to compare differences in each variable for the sessions (P ≤ 0.05). When compared to the TS session, the non-traditional sessions resulted in greater EE/min, TEE, V’O2, RER, and mean HR (P

Background Transcutaneous electrical nerve stimulation and interferential current have been widely used in clinical practice. However, a systematic review comparing their effects on pain relief has not yet been performed. Objectives To investigate the effects of transcutaneous electrical nerve stimulation and interferential current on acute and chronic pain. Methods We use Pubmed, Embase, LILACS, PEDro and Cochrane Central Register of Controlled Trials as data sources. Two independent reviewers that selected studies according to inclusion criteria, extracted information of interest and verified the methodological quality of the studies made study selection. The studies were selected if transcutaneous electrical nerve stimulation and interferential current were used as treatment and they had pain as the main outcome, as evaluated by a visual analog scale. Secondary outcomes were the Western Ontario Macmaster and Rolland Morris Disability questionnaires, which were added after data extraction. Results Eight studies with a pooled sample of 825 patients were included. The methodological quality of the selected studies was moderate, with an average of six on a 0–10 scale (PEDro). In general, both transcutaneous electrical nerve stimulation and interferential current improved pain and functional outcomes without a statistical difference between them. Conclusion Transcutaneous electrical nerve stimulation and interferential current have similar effects on pain outcome The low number of studies included in this meta-analysis indicates that new clinical trials are needed.

The aim of the study was to evaluate the effects of 6 weeks training with different neuromuscular electrical stimulation (NMES) currents (medium alternated and low-frequency pulsed current) on muscle architecture and neuromuscular performance of competitive athletes. A double-blind controlled and randomized experimental study was carried out with 33 athletes (22.2±2.6 yrs, 74.7±9.8 kg, 176.8±6.0 cm), divided into 3 groups: mid-frequency current (MF, n=12), pulsed current (PC, n=11) and the control group (CG, n=10). Quadriceps maximal voluntary peak torque (PT) and corresponding vastus lateralis electromyographic activity, evoked torque (PT-NMES), vastus lateralis muscle thickness, fascicle length, pennation angle, and level of discomfort were assessed before and after the interventions. NMES training was performed 3 times per week and consisted of 18 sessions, 15 min/session, 6 s duration in each contraction interspersed with 18 s rest. After the training period, muscle thickness increased in the MF and PC groups (p0.05). Quadriceps NMES training applied through alternated or pulsed currents produced similar effects in architecture and neuromuscular performance in competitive athletes.

In this study we investigated fatigue origins induced by low-frequency pulsed current (PC) and medium-frequency current (MF) neuromuscular electrical stimulation (NMES) after a clinical-like session.Eleven healthy men randomly underwent 2 NMES sessions, PC and MF, on quadriceps muscle (15-minute duration, 6 seconds on and 18 seconds off). Maximal voluntary contraction (MVC), central activation ratio (CAR), vastus lateralis electromyographic activity (EMG), and evoked contractile properties were determined before and after the sessions. Evoked torque and discomfort during the sessions were also measured.Both currents produced decreases in MVC, EMG, and evoked contractile properties after the sessions. No difference was found between currents for all variables (P 0.05). Evoked torque during sessions decreased (P 0.05). No difference was observed in mean evoked torque and discomfort (P 0.05).Both currents induced similar neuromuscular fatigue. Clinicians can choose either PC or MF and expect similar treatment effects when the goal is to generate gains in muscle strength. Muscle Nerve 58: 293-299, 2018.

O objetivo do estudo foi observar o efeito do ultra-som terapêutico no desenvolvimento do edema de pata de ratos artrí­ticos, associado ao tratamento farmacológico por 21 dias. Ratos Holtzman machos adultos receberam injeção intradérmica na pata esquerda, contendo Micobacterium tuberculosis inativado para a indução da artrite. Os animais artrí­ticos foram submetidos a quatro diferentes tratamentos, um dia após a indução: grupo controle recebeu salina; os demais grupos receberam tratamento diário com ultra-som (freqüência de 1 MHz, recorte de 20%, intensidade média de 0,4 W/cm2), indometacina (1,5 mg/kg peso corporal) e ultrasom associado í indometacina. Os animais foram avaliados através da mensuração diária do volume da pata inoculada, a partir do deslocamento de volume em um sistema de volumetria. Os dados foram analisados por meio de ANOVA e pelo teste de Tukey (p

The calcaneal tendon (CT) is the most commonly injured tendon in the human body. Moreover, with advancing age, the amount of damage increases further. Resistance training (RT) could be used to minimize such damages. The aim of the present study was to obtain the identification, detailed protein cataloging and biochemical characterization based on the effects of the aging process and the RT in CT of rats. The analysis by liquid chromatography tandem-mass spectrometry showed 142 distinct proteins, however, only 29 proteins met the inclusion criteria and were analyzed. Aging causes a reduction in the abundance of seven proteins related to extracellular matrix organization, biological regulation and cellular processes. However, RT promoted the positive regulation of proteins important for the maintenance of healthy tendons: seven proteins in young trained and two in older trained group. This study contributes to a better understanding of molecular aspects of the tendon. The down regulation of proteins linked to mechanical function and extracellular matrix remodeling of the tendon during aging can contribute to the increase of injury and weakness in the tendon. Nevertheless, RT proved to be a tool to prevent these adverse effects during aging by increasing proteins involved in the functionality of the tendon.

International audience; Purpose: The aim of this study was to evaluate the safety and feasibility of a neuromuscular electrical stimulation (NMES) protocol based on neuromuscular excitability and applied in numerous muscle groups of critical ill patients.Materials and methods: We performed a prospective observational study using an NMES applied daily and bilaterally into 5 muscle groups in lower limbs for 3 consecutive days. The characteristics of NMES were 90 contractions per muscle, pulse width equal to chronaxie, and a pulse frequency of 100 Hz. We assessed safety with central venous oxygen saturation, serum lactate, and creatine phosphokinase measurements. To evaluate feasibility, we recorded the time spent for the entire NMES protocol and the number of NMES sessions completed.Results: Eleven male patients finished the study. There were no significant changes observed in creatine phosphokinase from baseline up to 96 hours: 470 (+/- 270) IU/L and 455 (+/- 240) IU/L (P > .99). Central venous oxygen saturation and serum lactate had the same pattern with no significant variations (P =.23 and P =.8, respectively). The time spent during the whole procedure and the number of complete NMES sessions performed were 107 +/- 24 minutes and 84 sessions (85%), respectively.Conclusions: We demonstrated that NMES chronaxie-based protocol is safe and feasible.

Aging process is characterized by a decline in the organism functionality, especially in the decrease of muscle function, which also affects tendons. On the other hand, the resistance training (RT) has been used as an important tool to increase muscle and tendineous function during aging. Thus, this study aim has been to verify the effects of RT on the biomechanical properties of three different aged rat tendons. For this purpose, 20 wistar rats have been divided into four groups (5 rats per group): young sedentary (YS), trained (YT), old sedentary (OS) and old trained (OT). The RT has been performed through climb protocol for 12 weeks. After RT, the calcaneal tendon (CT), superficial flexor tendon (SFT) and deep flexor tendon (DFT) have been used for analysis. The results indicate that the RT in aged rats can prevent tendon function decrease (p

Background Even thought Neuromuscular electrical stimulation (NMES) has been widely used as a non-pharmacological intervention in patients with knee osteoarthritis (OA) to improve muscle strength and function, prior research has shown conflicting results regarding NMES effectiveness in knee OA treatment. Objectives The aim of this systematic review and meta-analysis was to investigate the effectiveness of NMES in muscle strengthen, pain, and function in individuals with knee OA. Methods Only randomized controlled trials (RCTs) were included in this study. Two authors independently performed the study selection. We use Pubmed, Embase, LILACS, PEDro and Cochrane Central Register of Controlled Trials as data sources. The main outcome evaluated was muscle strength. Function and pain were assessed as secondary outcomes using the Western Ontario Macmaster (WOMAC) questionnaire and Timed get up and go (TUG) test. The methodological quality was assessed using PEDro scale. Results A total of 23,215 were initially identified. After selection of titles and abstracts, studies were selected for the full-text analysis, ten studies were included with a total sample size of 622 patients. The methodological quality of the selected studies was moderate, with a mean score of 5.5 on a 0-10 scale (PEDro). The following analysis were performed: Legend All measurements were standardized in N/m. A homogeneity in the data (Chi² = 5.01; I² = 0%) was identified, with a significant difference in favor of NMES (Z = 4.52, p = 0.01). NMES - Neuromuscular electro stimulation. Legend A heterogeneity in the data was identified (Chi² = 4.80, I² = 58%), with no significant difference in favor of NMES (Z = 1.04, p = 0.30). Legend A homogeneity in the data (Chi² = 4.04; I² = 26%) was identified, with a significant difference in favor of NMES (Z = 4.56, p = 0.01). N Legend Data homogeneity (Chi² = 5.03; I² = 21%) was identified, with no significant difference in favor of NMES (Z = 0.07, p = 0.95). NMES - Neuromuscular electro stimulation. Legend Data homogeneity (Chi² = 12.29; I² = 84%) was identified, with no significant difference in favor of NMES (Z = 0.90, p = 0.37). Legend A homogeneity in the data (Chi² = 0.51; I² = 0%) was identified, with no significant difference in favor of NMES associated with exercise (Z = 0.97, p = 0.33). Conclusion NMES increased muscle strength in patients with OA compared to the active control group. However, the evidence to date did not demonstrate effects for pain control nor improvement in physical function. References [1] Elboim-Gabyzon M, Rozen N, Laufer Y. 2013 Does neuromuscular electrical stimulation enhance the effectiveness of an exercise programme in subjects with knee osteoarthritis? A randomized controlled trial. Clinical Rehabilitation.27(3):246-257. [2] De Oliveira Melo M, Aragao FA, Vaz MA. 2013Neuromuscular electrical stimulation for muscle strengthening in elderly with knee osteoarthritis - A systematic review. Complementary Therapies in Clinical Practice.19(1):27-31. Acknowledgement This research was supported by University of Brasilia. Disclosure of Interests None declared

Sarcopenia is a complex multifactorial process, some of which involves fat infiltration. Intramyocellular lipid (IMCL) accumulation is postulated to play a role on sarcopenia during aging, which is believed to be due alterations in glucose homeostasis in the skeletal muscle. Sarcopenia, along with intramuscular lipids, is associated with physical inactivity. Resistance training (RT) has been indicated to minimize the age-induced muscle skeletal adaptations. Thus, we aimed to investigate the effects of RT on mRNA levels of regulatory components related to intramyocellular lipid, glucose metabolism and fiber size in soleus and gastrocnemius muscles of aged rats. Old male rats were submitted to RT (ladder climbing, progressive load, 3 times a week for 12 weeks). Age-induced accumulation of IMCL was attenuated by RT, which was linked to a PPARy-mediated mechanism, concomitant to enhanced regulatory components of glucose homeostasis (GLUT-4, G6PDH, Hk-2 and Gly-Syn-1). These responses were also linked to decreased catabolic (TNF-α, TWEAK/Fn14 axis; FOXO-1, Atrogin-1 and MuRF1; Myostatin) and increased anabolic intracellular pathways (IGF-1-mTOR-p70S6sk-1 axis; MyoD) in muscles of trained aged rats. Our results point out the importance of RT on modulation of gene expression of intracellular regulators related to age-induced morphological and metabolic adaptations in skeletal muscle.

Electrically evoked muscle contraction has become a relevant therapeutic strategy in the rehabilitation practice and in the research field. In Intensive Care Unit (ICU), for instance, critical ill patients can present significant muscle weakness and neuromuscular electrophysiological disorders due to long periods of immobility. Neuromuscular Electrical Stimulation (NMES) has been shown an important tool to avoid such problems. However, in crically-ill patients with neuromuscular electrophysiological disorders the assessment of neuromuscular excitability is essential for improving NMES efficacy. Neuromuscular excitability has been assessed by Stimulus Electrodiagnosis Test (SET) which measures: rheobase, chronaxie and accommodation. However, SET is a time demanding procedure and depends on the subjective visual detection of each examiner. The objective of this work was to develop an equipment capable to automating SET, making it feasible accurate and reliable. Such equipment is capable of generating the electrical stimuli with the parameters necessary for SET, modify these parameters in real time and stop the stimulation when the contraction is detected. This detection is possible through a biofeedback system implemented using an accelerometer placed on the muscle in which contraction will occur due to electrostimulation. Through the workbench tests it was possible to generate biphasic electric stimuli up to 225 mA with load of 1 kΩ and monophasic up to 104 mA with load of 1 kΩ too. It was possible to vary the pulse width of the stimuli from 20 µs to 50 ms with steps of 20 µs. Tests performed on biofeedback algorithm showed it was capable to detect automatically voluntary muscle contractions.

Background and objectives: Osteoarthritis of the knee is considered the major cause of pain and dysfunction of the motor apparatus and mainly affects female individuals over 60 years. Electrotherapy presents a reasonable level of evidence for pain control and inconsistent results. Thus, this study aims to verify the efficacy of electroanalgesia, using different currents, for knee osteoarthritis. Subjects and methods: This is a randomized, triple-blind, placebo-controlled clinical trial. Individuals will be randomly divided into four groups, and subjected to four different types of currents: transcutaneous electric nerve stimulation in Group 1, bipolar interferential current in Group 2, Aussie in Group 3, and placebo in Group 4, presenting different modulations and 20 minutes of intervention each. Patients have been recruited since August 2017. The primary outcome measures will be analyzed in June 2020 and the study will finish in August 2020. Protocol version: 1.0. This study was approved by the Ethics Committee of University of Brasilia on July 18, 2017 (CAEE: 62256516.2.0000.0030). Outcome measures: Primary and secondary outcomes will be analyzed at baseline, 1, 3 and 6 months after the start of the study. The primary outcome is pain assessed by numerical verbal scale, pain-pressure threshold, and brief pain inventory. The secondary outcomes are function and quality of life (including Western Ontario and McMaster Universities Osteoarthritis Index, The Medical Outcomes Study 36-item Short-Form Health Survey, Timed Get-Up-and-Go test, 30-second Sit-to-Stand test, Stair-ascend test, 6-minute walk test, 40-meter fast-walk test). Discussion: We hope to provide evidence for finding suitable electroanalgesia on knee osteoarthritis. Trial registration: Registered in the Brazilian Clinical Trials Registry (ReBEC) (RBR-875zsw) on November 24, 2017.

This study investigated the effects of 5 and 15°C cold-water immersion on recovery from exercise resulting in exercise-induced muscle damage. 42 college-aged men performed 5×20 drop-jumps and were randomly allocated into one of 3 groups: (1) 5°C; (2) 15°C; or (3) control. After exercise, individuals from the cold-water immersion groups had their lower limbs immerged in iced water for 20 min. Isometric knee extensor torque, countermovement jump, muscle soreness, and creatine kinase were measured before, immediately after, 24, 48, 72, 96 and 168 h post-exercise. There was no between-group difference in isometric strength recovery (p=0.73). However, countermovement jump recovered quicker in cold-water immersion groups compared to control group (p

Objective: The purpose of this study was to evaluate the in vivo response of two different laser fluences (4 and 8 J/cm2) on molecular markers involved in muscle repair after a cryolesion of the tibialis anterior (TA) muscle. Study design: Forty-eight male Wistar rats were randomly distributed into six groups: control (C); normal/uninjured TA muscle treated with either 4 J/cm2 (L4J) or 8 J/cm2 (L8J) laser irradiation; injured TA muscle without treatment (IC); and injured TA muscle treated with either 4 J/cm2 (IL4J) or 8 J/cm2 (IL8J) laser irradiation. The injured region was irradiated daily for 5 consecutive days, starting immediately after the cryolesion was set using a GaAlAs laser (continuous wave; wavelength, 830 nm; tip area, 0.0028 cm2; power, 20 mW). The animals were euthanized on the sixth day after injury. The injured right TA muscles were removed for histological evaluation, zymography, and immunoblotting and biotin switch analyses. Nitrite and nitrate plasma levels were measured to evaluate the nitric oxide (NO) production. Results: After low-level laser therapy (LLLT), in both injured treatment groups (IL4J and IL8J) the injured area was reduced, the NO production decreased and the S-nitrosated COX-2 was lowered. Moreover, both laser fluences increased the activity and expression of MMP-2. Conclusion: These results suggest that LLLT, for both fluences, could be an efficient therapeutic approach to modulate molecules involved in injured muscle, accelerating regeneration process.

Stretching is a common method used to prevent muscle shortening and improve limited mobility. However, the effect of different time periods on stretching-induced adaptation of the extracellular matrix and its regulatory elements have yet to be investigated. We aimed to evaluate the expression of fibrillar collagens, sarcomerogenesis, metalloproteinase (MMP) activity and gene expression of the extracellular matrix (ECM) regulators in the soleus (SOL) muscle of rats submitted to different stretching periods. The soleus muscles were submitted to 10 sets of passive stretching over 10 (St 10d) or 15 days (St 15d) (1 min per set, with 30 seconds’ rest between sets). Sarcomerogenesis, muscle cross-sectional area (CSA), and MMP activity and mRNA levels in collagen (type I, III and IV), connective tissue growth factor (CTGF), growth factor-beta (TGF-β), and lysyl oxidase (LOX) were analyzed. Passive stretching over both time periods mitigated COL-I deposition in the SOL muscle of rats. Paradoxically, 10 days of passive stretching induced COL-I and COL-III synthesis, with concomitant upregulation of TGF-β1 and CTGF at a transcriptional level. These responses may be associated with lower LOX mRNA levels in SOL muscles submitted to 10 passive stretching sessions. Moreover, sarcomerogenesis was observed after 15 days of stretching, suggesting that stretching-induced muscle adaptations are time-dependent responses.

Accumulation of connective tissue, particularly extracellular matrix (ECM) proteins, has been observed in skeletal muscles with advancing age. Resistance training (RT) has been widely recommended to attenuate age-induced sarcopenia, even though its effects on the components that control ECM turnover in skeletal muscles remain to be elucidated. Thus, the aim of this study was to determine the effects of RT on connective tissue content and gene expression of key components of ECM in the skeletal muscles of aged rats. Young (3 mo.) and older (21 mo.) adult male Wistar rats were submitted to a RT protocol (ladder climbing with 65, 85, 95, and 100% load), 3 times a week for 12 weeks. Forty-eight hours post-training, the soleus (SOL) and gastrocnemius (GAS) muscles were dissected for histological and mRNA analysis. RT mitigated the age-associated increase of connective tissue content in both muscles, even though mRNA levels of COL-1 and−3 were elevated in older trained rats. Overall, RT significantly elevated the gene expression of key components of connective tissue deposition (TGFβ and CTGF; MMP-2 and-9; TIMP-1 and−2) in the GAS and SOL muscles of older rats. In conclusion, RT blunted the age-induced accumulation of connective tissue concomitant to the upregulation of genes related to synthesis and degradation of the ECM network in the SOL and GAS muscles of older rats. Although our findings indicate that RT plays a crucial role reducing connective tissue accumulation in aged hindlimb muscles, key components of ECM turnover were paradoxically elevated. The phenotypic responses induced by RT were not accompanied by the gene expression of those components related to ECM turnover.

Clara Maria Pinheiro-Dardis,1 Vânia Ortega Gutierres,1 Renata Pires Assis,1 Sabrina Messa Peviani,2 Gabriel Borges Delfino,2 João Luiz Quagliotti Durigan,3 Tania de Fátima Salvini,2 Amanda Martins Baviera,1 Iguatemy Lourenço Brunetti1 1São Paulo State University (UNESP), School of Pharmaceutical Sciences, Department of Clinical Analysis, Araraquara, São Paulo, Brazil; 2Federal University of São Carlos (UFSCar), Department of Physical Therapy, São Carlos, São Paulo, Brazil; 3Physical Therapy Division, University of Brasilia, Brasilia, Federal District, Brazil Background: The aim of this study was to evaluate the changes in biomarkers of skeletal muscle proteolysis (atrogin-1, muscle RING finger-1 protein [MuRF-1]) and inflammation (nuclear factor kappa-B) in skeletal muscles of rats under two catabolic conditions, diabetes mellitus (DM) and acute joint inflammation, and the effects of insulin therapy. Materials and methods: Male Wistar rats were divided into groups without diabetes – normal (N), saline (NS), or Ɩ-carrageenan (NCa) injection into the tibiotarsal joint – and groups with diabetes – diabetes (D), plus insulin (DI), saline (DS), or Ɩ-carrageenan (DCa) injection into the tibiotarsal joint, or Ɩ-carrageenan injection and treatment with insulin (DCaI). Three days after Ɩ-carrageenan injection (17 days after diabetes induction), tibialis anterior (TA) and soleus (SO) skeletal muscles were used for analysis. Results: DM alone caused a significant decrease in the mass of TA and SO muscles, even with low levels of atrogenes (atrogin-1, MuRF-1), which could be interpreted as an adaptive mechanism to spare muscle proteins under this catabolic condition. The loss of muscle mass was exacerbated when Ɩ-carrageenan was administered in the joints of diabetic rats, in association with increased expression of atrogin-1, MuRF-1, and nuclear factor kappa-B. Treatment with insulin prevented the increase in atrogin-1 (TA, SO) and the loss of muscle mass (SO) in diabetic-carrageenan rats; in comparison with TA, SO muscle was more responsive to the anabolic actions of insulin. Conclusion: Acute joint inflammation overcame the adaptive mechanism in diabetic rats to prevent excessive loss of muscle mass, worsening the catabolic state. The treatment of diabetic-carrageenan rats with insulin prevented the loss of skeletal muscle mass mainly via atrogin-1 inhibition. Under the condition of DM and inflammation, muscles with the prevalence of slow-twitch, type 1 fibers were more responsive to insulin treatment, recovering the ability to grow. Keywords: diabetes mellitus, inflammation, muscle proteolysis, atrogenes, creatine kinase, NF-κB, insulin

Background. The present study aimed to analyze the effects of physical training on an antioxidant canonical pathway and metalloproteinases activity in diaphragm muscle in a model of cigarette smoke-induced chronic obstructive pulmonary disease (COPD). Methods. Male mice were randomized into control, smoke, exercise, and exercise + smoke groups, which were maintained in trial period of 24 weeks. Gene expression of kelch-like ECH-associated protein 1; nuclear factor erythroid-2 like 2; and heme-oxygenase1 by polymerase chain reaction was performed. Metalloproteinases 2 and 9 activities were analyzed by zymography. Exercise capacity was evaluated by treadmill exercise test before and after the protocol. Results. Aerobic training inhibited diaphragm muscle wasting induced by cigarette smoke exposure. This inhibition was associated with improved aerobic capacity in those animals that were submitted to 24 weeks of aerobic training, when compared to the control and smoke groups, which were not submitted to training. The aerobic training also downregulated the increase of matrix metalloproteinases (MMP-2 and MMP-9) and upregulated antioxidant genes, such as nuclear factor erythroid-2 like 2 (NRF2) and heme-oxygenase1 (HMOX1), in exercise + smoke group compared to smoke group. Conclusions. Treadmill aerobic training protects diaphragm muscle wasting induced by cigarette smoke exposure involving upregulation of antioxidant genes and downregulation of matrix metalloproteinases.

To evaluate the effects of a single session of partial-body cryotherapy (PBC) on muscle recovery, 26 young men performed a muscle-damaging protocol that consisted of five sets of 20 drop jumps with 2-min rest intervals between sets. After the exercise, the PBC group (n = 13) was exposed to 3 min of PBC at −110 °C, and the control group (n = 13) was exposed to 3 min at 21 °C. Anterior thigh muscle thickness, isometric peak torque, and muscle soreness of knee extensors were measured pre, post, 24, 48, 72, and 96 h following exercise. Peak torque did not return to baseline in control group (P 0.05). Peak torque was also higher after PBC at 72 and 96 h compared with control group (P

Introduction: We studied the effects of different neuromuscular electrical stimulation (NMES) currents, 2 kHz-frequency alternating currents (KACs, Russian and Aussie) and 2 pulsed currents (PCs), on isometric knee extension torque and discomfort level, both in isolation and combined, with maximum voluntary contraction (MVC). Methods: Twenty-one women (age 21.6 ± 2.5 years) were studied. We evaluated torque evoked by NMES or NMES combined with maximum voluntary contraction of the quadriceps muscle of healthy women. Discomfort level was measured using a visual analog pain scale. Results: Despite comparable levels of discomfort, evoked torque was lower for Russian current compared with the other modalities (Russian 50.8%, Aussie 71.7%, PC500 76.9%, and PC200 70.1%; P

In elderly persons, weak tendons contribute to functional limitations, injuries, and disability, but resistance training can attenuate this age-related decline. We evaluated the effects of resistance training on the extracellular matrix (ECM) of the calcaneal tendon (CT) in young and old rats and its effect on tendon remodeling. Wistar rats aged 3 mo (young, n = 30) and 20 mo (old, n = 30) were divided into 4 groups: young sedentary, young trained, old sedentary (OS), and old trained (OT). The training sessions were conducted over a 12-wk period. Aging in sedentary rats showed down-regulation in key genes that regulated ECM remodeling. Moreover, the OS group showed a calcification focus in the distal region of the CT, with reduced blood vessel volume density. In contrast, resistance training was effective in up-regulating connective tissue growth factor, VEGF, and decorin gene expression in old rats. Resistance training also increased proteoglycan content in young and old rats in special small leucine-rich proteoglycans and blood vessels and prevented calcification in OT rats. These findings confirm that resistance training is a potential mechanism in the prevention of aging-related loss in ECM and that it attenuates the detrimental effects of aging in tendons, such as ruptures and tendinopathies.-Marqueti, R. C., Durigan, J. L. Q., Oliveira, A. J. S., Mekaro, M. S., Guzzoni, V., Aro, A. A., Pimentel, E. R., Selistre-de-Araujo, H. S. Effects of aging and resistance training in rat tendon remodeling.

Progressive fibrosis is a hallmark of the aging heart. Age-related fibrosis is modulated by endurance exercise training; however, little is known concerning the influence of resistance training (RT). Therefore we investigated the chronic effects of high-intensity RT on age-associated alterations of left ventricle (LV) structure, collagen content, matrix metalloproteinase-2 (MMP-2), and extracellular matrix-related gene expression, including transforming growth factor-β (TGF-β). Young adult (3 mo) and aged (21 mo) male Wistar rats were submitted to a RT protocol (ladder climbing with 65, 85, 95, and 100% load), three times a week for 12 wk. Forty-eight hours posttraining, arterial systolic and diastolic pressure, LV end-diastolic pressure (LVEDP) and dP/d t were recorded. LV morphology, collagen deposition, and gene expression of type I (COL-I) and type III (COL-III) collagen, MMP-2, tissue inhibitor of metalloproteinases-1 (TIMP-1), and TGF-β1 were analyzed by quantitative reverse transcriptase-PCR. MMP-2 content was assessed by zymography. Increased collagen deposition was observed in LV from aged rats. These parameters were modulated by RT and were associated with increased MMP-2 activity and decreased COL-I, TGF-β1, and TIMP-1 mRNA content. Despite the effect of RT on collagen accumulation, there was no improvement on LVEDP and maximal negative LV dP/d t of aged rats. Cardiomyocyte diameter was preserved in all experimental conditions. In conclusion, RT attenuated age-associated collagen accumulation, concomitant to the increase in MMP-2 activity and decreased expression of COL-I, TGF-β1, and TIMP-1 in LV, illustrating a cardioprotective effect of RT on ventricular structure and function. NEW & NOTEWORTHY We demonstrated the beneficial resistance-training effect against age-related left ventricle collagen accumulation in the left ventricle, which was associated with decreased type I collagen (COL-I), transforming growth factor-β1 (TGF-β1), and tissue inhibitor of metalloproteinases-1 (TIMP-1) gene expression and matrix metalloproteinase-2 (MMP-2) activity. Our findings suggest for the first time the potential effects of resistance training in modulating collagen accumulation and possibly fibrosis in the aging heart.

The aim of the present study was to compare the response of systolic blood pressure (SBP), mean blood pressure (MBP) and diastolic blood pressure (DBP) following combined training with 1 set or with 3 sets of resistance exercise (RE). Sixteen women with metabolic syndrome (MetS) were randomly assigned to perform two combined exercise protocols and a control session (CON): 1-set, 30 min of aerobic exercise (AE) at 65-70% of reserve heart rate and 1 set of 8-12 repetitions at 80% of 10-RM in six resistance exercises; 3-sets, same protocol but with 3 sets; and CON, 30 min of seated rest. The SBP, MBP and DBP were measured before and every 15 min during 90 min following the experimental sessions. The SBP displayed a decrease (P ≤ 0.05) during the 90 min following the RE session with 1-set and 3-set, while MBP was decreased (P ≤ 0.05) up to 75 min after 1-set and up to 30 min after the 3-set exercise session compared with pre-intervention values. There was a decrease in DBP only for the greatest individual decrease following 1-set (-6.1 mmHg) and 3-set (-4.9 mmHg) combined exercise sessions, without differences between them. The rate-pressure product and heart rate remained significantly higher (P ≤ 0.05) 75 min and 90 min after the combined exercise session with 1- and 3-sets compared with the CON, respectively. In conclusion, a low-volume RE combined with AE resulted in similar decrease of SBP when compared with RE with 3-sets in women with MetS, which could be beneficial in situations of limited time.