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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.

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.

Studies have described the use of electrophysical agents (EPA) by physical therapists worldwide. However, the use of EPA by Brazilian physical therapists remains undetermined. This study aims to describe the availability, use, and perception about EPA by orthopedic and sports physical therapists in Brazil. Professionals of the area were invited to answer an online questionnaire. Demographic data and information regarding the availability, use and perception about EPA in their current clinical practice were asked. Out of 376 physical therapists included in this study, 89% declared to use EPA in clinical practice. Sensory electrotherapy with pulsed current (TENS), therapeutic ultrasound, excitomotor electrotherapy with pulsed current (FES/NMES), and cryotherapy are available for more than 3/4 of interviewees. Scientific articles and clinical experience, respectively, are the most influential factors for the choice of EPA. Ultrasound is the most frequently used EPA, followed by TENS, cryotherapy, photobiomodulation, hot packs, and FES/NMES. The top-five most useful EPA in clinical practice chosen by physical therapists are: (1) ultrasound; (2) photobiomodulation; (3) TENS; (4) cryotherapy; and (5) FES/NMES. In conclusion, EPA are widely used by orthopedic and sports physical therapists in Brazil. Therapeutic ultrasound, TENS, FES/NMES, photobiomodulation, cryotherapy, and hot packs are the most used EPA in clinical practice of these physiotherapists. RESUMO Estudos têm descrito a utilização de agentes eletrofísicos (AE) por fisioterapeutas ao redor do mundo. No entanto, o uso de AE por fisioterapeutas brasileiros permanece inexplorado. O objetivo deste estudo é descrever o acesso, a utilização e a percepção sobre os AE de fisioterapeutas ortopédicos e esportivos no Brasil. Os profissionais foram convidados a responder um questionário on-line. Foram solicitados dados demográficos e informações sobre o acesso, utilização e percepção dos profissionais sobre os AE na prática clínica. Dentre os 376 fisioterapeutas incluídos, 89% declararam ser usuários de AE na prática clínica. Eletroterapia sensorial com corrente pulsada (TENS), ultrassom terapêutico, eletroterapia excitomotora com corrente pulsada (FES/NMES) e crioterapia são acessíveis para mais de 3/4 dos participantes. Artigos científicos e experiência clínica são os fatores de maior influência na escolha por AE. O ultrassom é o AE mais frequentemente utilizado, seguido por Tens, crioterapia, fotobiomodulação, bolsas quentes e FES/NMES. Os cinco AE elencados pelos fisioterapeutas como mais úteis na prática clínica são: (1) ultrassom; (2) fotobiomodulação; (3) TENS; (4) crioterapia; e (5) FES/NMES. Em conclusão, os AE são largamente usados pelos fisioterapeutas ortopédicos e esportivos no Brasil. Ultrassom terapêutico, TENS, FES/NMES, fotobiomodulação, crioterapia e bolsas quentes são os AE mais usados na prática clínica desses fisioterapeutas. RESUMEN Los estudios ya han descrito el uso de agentes electrofísicos (AE) por fisioterapeutas en todo el mundo. Todavía no se ha explorado el uso de los AE por fisioterapeutas brasileños. El presente estudio tuvo como objetivo describir el acceso, el uso y la percepción sobre los AE por fisioterapeutas ortopédicos y deportivos en Brasil. Se invitó a los profesionales para responder a un cuestionario en línea. Se solicitaron los datos demográficos e informaciones sobre el acceso, el uso y la percepción de profesionales sobre los AE en la práctica clínica. Entre los 376 fisioterapeutas incluidos, el 89% declararon utilizar los AE en la práctica clínica. La electroterapia sensorial con corriente pulsada (TENS), el ultrasonido terapéutico, la electroterapia excitomotora con corriente pulsada (FES/NMES) y la crioterapia son accesibles para más de 3/4 de los participantes. Los artículos científicos y la experiencia clínica son los factores que más influyeron en la elección de los AE. El ultrasonido es el AE más utilizado, seguido de Tens, crioterapia, fotobiomodulación, bolsas calientes y FES/NMES. Los cinco AE más útiles en la práctica clínica enumerados por los fisioterapeutas fueron: (1) ultrasonido; (2) fotobiomodulación; (3) TENS; (4) crioterapia; y (5) FES/NMES. Los AE son ampliamente utilizados por los profesionales de la ortopedia y el deporte en Brasil. El ultrasonido terapéutico, TENS, FES/NMES, fotobiomodulación, crioterapia y bolsas calientes son los AE más utilizados en la práctica clínica por estos fisioterapeutas.

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.

Exercise intolerance, a hallmark of patients with heart failure (HF), is associated with muscle weakness. However, its causative microcirculatory and muscle characteristics among those with preserved or reduced ejection fraction (HFpEF or HFrEF) phenotype is unclear. The musculoskeletal abnormalities that could result in impaired peripheral microcirculation are sarcopenia and muscle strength reduction in HF, implying lowered oxidative capacity and perfusion affect transport and oxygen utilization during exercise, an essential task from the microvascular muscle function. Besides that, skeletal muscle microcirculatory abnormalities have also been associated with exercise intolerance in HF patients who also present skeletal muscle myopathy. 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 (echo intensity was rectus femoris muscle, while the muscle thickness parameter was measured on rectus femoris and quadriceps femoris) in heart failure patients with HFpEF and HFrEF phenotypes 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. We found phenotype differences among those with Weber C severity, with HFrEF patients reaching lower oxyhemoglobin (O2Hb, μM) (−10.9 ± 3.8 vs. −23.7 ± 5.7, p = 0.029) during exercise, while HFpEF reached lower O2Hb during the recovery period (−3.0 ± 3.4 vs. 5.9 ± 2.8, p = 0.007). HFpEF with Weber Class C also presented a higher echo intensity than HFrEF patients (29.7 ± 8.4 vs. 15.1 ± 6.8, p = 0.017) among the ultrasound-derived variables. Our preliminary study revealed more pronounced impairments in local microcirculatory dynamics in HFpEF vs. HFrEF patients during a muscle strength exercise, combined with muscle-skeletal abnormalities detected via ultrasound imaging, which may help explain the commonly observed exercise intolerance in HFpEF patients.

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.

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.

Background Resistance training has a positive impact on functional capacity and muscle mass in the elderly. However, due to physical limitations or a simple aversion against regular exercise, a majority of the elderly do not reach the recommended exercise doses. This led us to evaluate the effect of whole-body electromyostimulation (WB-EMS), a novel, time-efficient, and smooth training technology on physical function, fat-free mass, strength, falls-efficacy, and social participation of the elderly. Methods The present study is a randomized, parallel group clinical trial approved by the Ethics Committee of our Institution. Sixty-six volunteers (age ≥ 60 years) will be recruited from the geriatric outpatient department in a tertiary hospital and primary care units and randomized into two groups: WB-EMS group or active control group (aCG). The WB-EMS or aCG protocol will consist of 16 sessions for 8 consecutive weeks, twice per week. The primary outcomes will be maximal isometric knee extension (IKE), functional lower extremity strength, fat-free mass, gait speed, and risk of falls measured before and after intervention. The secondary outcomes will be social participation and falls-efficacy assessed before and after the intervention and at three and six months of follow-up. Participant’s satisfaction with and awareness of electrical stimulation therapy will also be assessed immediately after the 8-week intervention. Discussion Patients receiving WB-EMS exercises are believed to have better outcomes than those receiving conventional, more time-consuming resistance exercises. Hence, innovative, time-efficient, joint-friendly, and highly individualized exercise technologies (such as WB-EMS) may be a good choice for the elderly with time constraints, physical limitations, or little enthusiasm, who are exercising less than the recommended amounts for impact on muscle mass, strength, and function.

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.

O ambiente de terapia intensiva esta evoluindo em tecnologias para avaliacao e tratamento sendo uma das tecnicas mais atuais aplicadas neste ambiente o eletrodiagnostico. Esta e uma revisao sistematica desenvolvida com base nos resultados de pesquisa das principais bases de dados, seguindo o PRISMA. Neste foram incluidos somente artigos observacionais que utilizaram a tecnica de eletrodiagnostico em pacientes criticos, para os mais diferentes objetivos e desfechos. As bases de dados consultadas foram: MEDLINE (acessado via PubMed), Fisioterapia Evidence banco de dados (Pedro), Registro de Ensaios Controlados (CENTRAL Cochrane) e EMBASE alem de uma busca manual de referencias adicionais. Um total de 10 artigos foram encontrados, sendo que dois apresentaram-se repetidos e outros seis foram excluidos por nao contemplarem os criterios de inclusao obtendo-se ao final um total de dois artigos totalizando 33 pacientes. Um dos artigos apresentou resultados seguros, sem lesao muscular e o protocolo foi viavel para ser aplicado em terapia intensiva. O outro artigo que apos lesao cerebral traumatica os pacientes podem apresentar disturbios eletrofisiologicos, alem de atrofia muscular generalizada sendo evidenciados pela tecnica de eletrodiagnostico. Palavras-chave: Unidade de terapia intensiva; ventilacao mecânica; eletrodiagnostico cronaxia; musculo esqueletico; respiracao artificial

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.

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.

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.

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.

The aim of this study was to investigate the effects of multiple cold-water immersions (CWIs) on muscle function, markers of muscle damage, systemic inflammation and ECM degradation following exercise-induced muscle damage (EIMD). Thirty physically active males were randomly assigned to either a control (n = 15) or cold-water immersion (CWI) group (n = 15). The CWI group performed one immersion (10 °C for 20 min) at post-exercise and every 24 h for the following 72 h, while the control group remained in a seated position during these corresponding periods. Muscle strength, vertical jump height, muscle thickness, delayed-onset muscle soreness (DOMS), systemic creatine kinase (CK), C-reactive protein (CRP), inflammatory cytokines and matrix metalloproteinase-2 (MMP-2) activity were assessed at Pre, Post, 24, 48, 72, 96 and 168 h following EIMD. No significant time × group interaction was obtained for muscle strength, vertical jump height recovery and MMP-2 activity (p > 0.05). At 24 h, muscle thickness from the CWI group returned to baseline and was lower than the control (p = 0.04). DOMS returned to baseline at 168 h for the CWI group (p = 0.109) but not for the control (p = 0.008). At 168 h, CK showed a time-group difference with a greater peak for the control group (p = 0.016). In conclusion, multiple CWIs attenuated muscle damage, but not altered systemic inflammation and muscle function recovery.

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.

International audience; Erratum inCorrigendum to "Neuromuscular electrophysiological disorders and muscle atrophy in mechanically-ventilated traumatic brain injury patients: New insights from a prospective observational study" [J Crit Care 44 (2018) 87-94]. [J Crit Care. 2019]AbstractPURPOSE:It is unclear whether the muscular changes in mechanically-ventilated traumatic brain injury patients (TBI) are only associated with disuse or additionally to neuromuscular electrophysiological disorders (NED). The correlation between muscle atrophy and NED may affect functional outcomes and rehabilitation programs significantly.MATERIAL AND METHODS:An observational study was performed to investigate the presence of NED and muscle atrophy in TBI patients undergoing mechanical ventilation. NED was diagnosed by the stimulus electrodiagnosis test when chronaxie was ≥1000μs. The muscle structure (thickness and echogenicity) was assessed by B-mode ultrasound. Tibialis anterior (TA), rectus femoris (RF), and biceps brachialis (BB) muscles were analyzed. Patients were followed from the first day of admission in the intensive care unit (ICU) to the fourteenth day.RESULTS:Twenty-two patients were analyzed. An increase of 48% in NED from day 1 to day 14 was detected in TA (p=0.004). All muscles presented a significant decrease in thickness (~18%, p

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

Aging is a complex, multifactorial process characterized by the accumulation of deleterious effects, including biochemical adaptations of the extracellular matrix (ECM). The purpose of this study was to investigate the effects of 12 weeks of resistance training (RT) on metalloproteinase 2 (MMP-2) activity in skeletal muscles and, MMP-2 and MMP-9 activity in the blood circulation of young and old rats. Twenty-eight Wistar rats were randomly divided into four groups (n = 7 per group): young sedentary (YS); young trained (YT), old sedentary (OS), and old trained (OT). The stair climbing RT consisted of one training session every 2 other day, with 8–12 dynamic movements per climb. The animals were euthanized 48 h after the end of the experimental period. MMP-2 and MMP-9 activity was measured by zymography. There was higher active MMP-2 activity in the lateral gastrocnemius and flexor digitorum profundus muscles in the OT group when compared to the OS, YS, and YT groups (p ≤ 0.001). Moreover, there was higher active MMP-2 activity in the medial gastrocnemius muscle in the OT group when compared to the YS and YT groups (p ≤ 0.001). The YS group presented lower active MMP-2 activity in the soleus muscle than the YT, OS, OT groups (p ≤ 0.001). With respect to active MMP-2/9 activity in the bloodstream, the OT group displayed significantly reduced activity (p ≤ 0.001) when compared to YS and YT groups. In conclusion, RT up-regulates MMP-2 activity in aging muscles, while down-regulating MMP-2 and MMP-9 in the blood circulation, suggesting that it may be a useful tool for the maintenance of ECM remodeling.

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.

International audience; Objective To test the hypotheses that, as compared with pulsed current with the same pulse duration, kilohertz frequency alternating current would not differ in terms of evoked-torque production and perceived discomfort, and as a result, it would show the same current efficiency.Design A repeated-measures design with 4 stimuli presented in random order was used to test 25 women: (1) 500-microsecond pulse duration, (2) 250-microsecond pulse duration, (3) 500-microsecond pulse duration and low carrier frequency (1 kHz), (4) 250-microsecond pulse duration and high carrier frequency (4 kHz). Isometric peak torque of quadriceps muscle was measured using an isokinetic dynamometer. Discomfort was measured using a visual analog scale.Results Currents with long pulse durations induced approximately 21% higher evoked torque than short pulse durations. In addition, currents with 500 microseconds delivered greater amounts of charge than stimulation patterns using 250-microsecond pulse durations (P < 0.05). All currents presented similar discomfort. There was no difference on stimulation efficiency with the same pulse duration.Conclusions Both kilohertz frequency alternating current and pulsed current, with the same pulse duration, have similar efficiency for inducing isometric knee extension torque and discomfort. However, neuromuscular electrical stimulation (NMES) with longer pulse duration induces higher NMES-evoked torque, regardless of the carrier frequency. Pulse duration is an important variable that should receive more attention for an optimal application of NMES in clinical settings.