Respiratory muscle training improves exercise tolerance and respiratory muscle function/structure post-stroke at short term: A systematic review and meta-analysis

BackgroundPrevious reviews relating to the effects of respiratory muscle training (RMT) after stroke tend to focus on only one type of training (inspiratory or expiratory muscles) and most based the results on poor-quality studies (PEDro score ≤4).ObjectivesWith this systematic review and meta-analysis, we aimed to determine the effects of RMT (inspiratory or expiratory muscle training, or mixed) on exercise tolerance, respiratory muscle function and pulmonary function and also the effects depending on the type of training performed at short- and medium-term in post-stroke.MethodsDatabases searched were MEDLINE, PEDro, CINAHL, EMBASE and Web of Science up to the end of April 2020. The quality and risk of bias for each included study was examined by the PEDro scale (including only high-quality studies) and Cochrane Risk of Bias tool.ResultsNine studies (463 patients) were included. The meta-analysis showed a significant increase in exercise tolerance [4 studies; n = 111; standardized mean difference [SMD] = 0.65 (95% confidence interval 0.27–1.04)]; inspiratory muscle strength [9 studies; n = 344; SMD = 0.65 (0.17–1.13)]; inspiratory muscle endurance [3 studies; n = 81; SMD = 1.19 (0.71–1.66)]; diaphragm thickness [3 studies; n = 79; SMD = 0.9 (0.43–1.37)]; and peak expiratory flow [3 studies; n = 84; SMD = 0.55 (0.03–1.08)] in the short-term. There were no benefits on expiratory muscle strength and pulmonary function variables (forced expiratory volume in 1 s) in the short-term.ConclusionsThe meta-analysis provided moderate-quality evidence that RMT improves exercise tolerance, diaphragm thickness and pulmonary function (i.e., peak expiratory flow) and low-quality evidence for the effects on inspiratory muscle strength and endurance in stroke survivors in the short-term. None of these effects are retained in the medium-term. Combined inspiratory and expiratory muscle training seems to promote greater respiratory changes than inspiratory muscle training alone.     

Whole body vibration improves maximum voluntary isometric contraction of knee extensors in patients with chronic kidney disease: A randomized controlled trial

Background: Whole body vibration (WBV) training improves maximum voluntary isometric contraction (MVIC) of knee extensors, postural balance, functional capacity, and quality of life (QOL) in several diseases. The objective was to assess the efficacy of WBV training in patients with chronic kidney disease (CKD) on hemodialysis (HD) in the interdialytic period. Method: A randomized, controlled trial study with concealed allocation, intention-to-treat analysis, and triple blinding. Sixteen patients with CKD of both genders aged over 40 years were allocated in two groups, the WBV group or the sham group, training 2 times a week for 12 weeks. The primary outcome was knee extensor muscle strength, and the secondary outcomes were quadriceps thickness, distance walked, balance, and QOL. Results: The WBV group improved MVIC of knee extensors with a difference between groups in improvement of 117.29 N (95% CI, 32.25–202.24) at the end of training. The other outcomes were not different between groups. Practical applications: The WBV program has shown to be effective and may be able to help in prescribing the appropriate training program for CKD. Conclusion: WBV training improves MVIC of knee extensors in patients with CKD on HD in the interdialytic period. WBV training could be considered in the management of patients with CKD.     

Association between vertebral fragility fractures,muscle strength and physical performance: A cross-sectional study

BackgroundFew studies have investigated the association between vertebral fragility fractures and lower limb muscle strength and physical performance in women with low bone mass.ObjectivesTo explore whether the presence of vertebral fracture is independently associated with poor physical performance and decreased lower limb muscle strength. To understand whether lower limb muscle strength is associated with physical performance in women with vertebral fracture.MethodsOlder women with low bone mass were divided into 2 groups: no vertebral fracture (NF) and presence of vertebral fragility fracture (VFF). Physical performance was evaluated using the Five Times Sit to Stand (5TSS) test, the Timed Up and Go (TUG) test and a 5m walk test (5MWT). Lower limb muscle strength was assessed using an isokinetic dynamometer.ResultsWe included 94 women with low bone mass (mean age 71.6 [SD 5.7] years, time since menopause 24.4 [7.1] years, mean BMI 27.5 [5.1] kgm^?2). VFF was only associated with low peak hip abductor torque (p = 0.001) after adjustments. In the VFF group (n= 47), each 1 Nmkg^?1 increase: in knee extensor torque was associated with improved 5MWT (p = 0.005), TUG (p = 0.002) and 5TSS (p = 0.005) performances; in knee flexor torque was associated with improved 5MWT speed (p = 0.003) and TUG time (p = 0.006); in hip abductor torque was associated with improved 5MWT speed (p = 0.003); and in hip extensor torque with improved TUG time (p = 0.046).ConclusionVFF was associated with reduced hip abductor strength in older women. However, the number of vertebral fractures influenced the association. Additionally, lower limb muscle strength was associated with physical performance, regardless of the clinical characteristics of the fractures. Therefore, strength and power training programs for the lower limbs could improve physical performance.     

Early neuromuscular electrical stimulation reduces the loss of muscle mass in critically ill patients – A within subject randomized controlled trial

PurposeTo investigate the effect of Neuromuscular Electrical Stimulation (NMES) on muscle thickness, strength and morphological and molecular markers of the quadriceps.Materials and methodsAdult critically ill patients with an expected prolonged stay received unilateral quadriceps NMES sessions for 7 consecutive days. Before and after the intervention period, quadriceps thickness was measured with ultrasound. After the intervention period, strength was assessed in cooperative patients and muscle biopsies were taken. Multivariable regression was performed to identify factors affecting muscle thickness loss.ResultsMuscle thickness decreased less in the stimulated leg (−6 ± 16% versus −12 ± 15%, p = 0.014, n = 47). Strength was comparable. Opioid administration, minimal muscle contraction and more muscle thickness loss in the non-stimulated muscle were independently associated with better muscle thickness preservation. Stimulated muscles showed a shift towards larger myofibers and higher MyHC-I gene expression. NMES did not affect gene expression of other myofibrillary proteins, MuRF-1 or atrogin-1. Signs of myofiber necrosis and inflammation were comparable for both muscles.ConclusionsNMES attenuated the loss of muscle mass, but not of strength, in critically ill patients. Preservation of muscle mass was more likely in patients receiving opioids, patients with a minimal muscle contraction during NMES and patients more prone to lose muscle mass.Trial registrationclinicaltrials.gov NCT02133300     

Evaluating the relationship between quadriceps muscle quality captured using ultrasound with clinical severity in women with knee osteoarthritis

BackgroundInfiltration of muscle with non-lean tissue, such as fat, reduces muscle quality. Ultrasound captures muscle quality through measurement of echogenicity. Given the potential implications of quadriceps muscle quality on physical function, particularly in knee osteoarthritis, the purpose of this study was to investigate the relationship between echogenicity, muscle thickness and subcutaneous fat thickness with the clinical severity of osteoarthritis.MethodsThirty-one women with clinical knee osteoarthritis participated. Rectus femoris and vastus lateralis echogenicity, muscle thickness and subcutaneous fat thickness were measured from ultrasound images of the most symptomatic knee. Clinical severity of osteoarthritis was characterized with pain, self-reported function, six-minute walk test, and knee extensor strength. Correlation coefficients were calculated between muscle and fat architecture outcomes (muscle quality, muscle and fat thicknesses) and osteoarthritis clinical severity outcomes.FindingsData from 25 women were of sufficient quality for analysis. Echogenicity (muscle quality) related to the six-minute walk test for both rectus femoris (r = −0.52, p = 0.02) and vastus lateralis (r = −0.74, p = 0.004), with poorer muscle quality related to lower mobility. Subcutaneous fat thickness was related to the six-minute walk test (rectus femoris, r = −0.61, p = 0.0012; vastus lateralis, r = −0.73, p = 0.003) and strength (rectus femoris, r = −0.46, p = 0.02; vastus lateralis, r = −0.59, p = 0.03). Muscle thickness was not related to any severity outcomes.InterpretationMuscle quality, rather than thickness, is associated with mobility performance in women with knee osteoarthritis. Thus, interventions for osteoarthritis that specifically target muscle quality, rather than size, should be explored.     

Lean muscle volume of the thigh has a stronger relationship with muscle power than muscle strength in women with knee osteoarthritis

BackgroundThigh lean muscle and intramuscular fat have been implicated in the impairment of physical function observed in people with knee osteoarthritis. We investigated the relationships of quadriceps and hamstrings intramuscular fat fraction and lean muscle volume with muscle power and strength, controlling for neuromuscular activation, and physical performance in women with knee OA.MethodsWomen (n = 20) 55 years or older with symptomatic, radiographic knee osteoarthritis underwent a 3.0T magnetic resonance imaging scan of the thigh of their most symptomatic knee. Axial fat-separated images were analyzed using software to quantify intramuscular fat and lean muscle volumes of the quadriceps and hamstrings. To quantify strength and power of the knee extensors and flexors, participants performed maximum voluntary isometric contraction and isotonic knee extensions and flexions, respectively. Electromyography of the quadriceps and hamstrings was measured. Participants also completed five physical performance tests.FindingsQuadriceps and hamstrings lean muscle volumes were related to isotonic knee extensor (B = 0.624; p = 0.017) and flexor (B = 1.518; p = 0.032) power, but not knee extensor (B = 0.001; p = 0.615) or flexor (B = 0.001; p = 0.564) isometric strength. Intramuscular fat fractions were not related to isotonic knee extensor or flexor power, nor isometric strength. No relationships were found between intramuscular fat or lean muscle volume and physical performance.InterpretationMuscle power may be more sensitive than strength to lean muscle mass in women with knee osteoarthritis. Thigh lean muscle mass, but neither intramuscular nor intermuscular fat, is related to knee extensor and flexor power in women with knee osteoarthritis.     

Impact of two different pulmonary rehabilitation methods in children with down syndrome

PurposeTo investigate and compare the effect of proprioceptive neuromuscular facilitation of respiratory muscles with that of inspiratory muscle training as a preventive measure on respiratory muscle strength, chest expansion, spirometry, and functional capacity in children with Down syndrome.MethodsForty-five Down syndrome participants with an age ranged from 10 to 13 years were enrolled. There were distributed into three groups. The study group A (n = 15) underwent proprioceptive neuromuscular facilitation of respiratory muscles while study group B (n = 15) underwent inspiratory muscle training. Third group C (n = 15) was a control group. The three groups received aerobic exercises using the bicycle ergometer for 20 min, 5 times/week for 12 successive weeks. The treatment program for both study groups was conducted for 20–30 min, 5 times/week for 12 successive weeks. Measurements of respiratory muscle strength (MIP, MEP), chest expansion, spirometry test (VC, FEV1, PEFR, MVV) and 6 min walk test were measured pre and post treatment.ResultsThe post treatment mean values of all investigated variables were significantly increased in both study groups with higher effect to group underwent proprioceptive neuromuscular facilitation of respiratory muscles.ConclusionBoth proprioceptive neuromuscular facilitation of respiratory muscles and inspiratory muscle training are effective in children with Down syndrome on improving respiratory muscle strength, chest expansion, spirometry and functional capacity with superior effect of proprioceptive neuromuscular facilitation.     

Quadriceps strengthening exercises may not change pain and function in knee osteoarthritis

It is believed that Quadriceps strength training may reduce pain and improve functional activity in patients with knee osteoarthritis (OA). This improvement is generally attributed to an increase in quadriceps strength. This study investigated whether quadriceps muscle strength increases with decreasing pain, improving functional activity in knee OA. Twenty-four patients with knee OA participated in an 8-week treatment protocol including traditional physical therapy and strength training 3 sessions per week. Measurements were conducted before and after the intervention and included the peak torque of quadriceps muscle, pain by visual analogue scale (VAS), short Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and functional activity by the 2 minute walking test (2MWT) and time up & go test (TUGT). After the intervention, analysis of data illustrated that changes in quadriceps muscle strength correlated with changes in VAS (r² = 0.310, p = 0.005), WOMAC (r² < 0.278, p < 0.008) and 2MWT (r² < 0.275, p < 0.009) significantly, although the correlation slope was negligible. No correlation was found between muscle strength and TUGT. However, the strength training significantly improved quadriceps muscle strength (p = 0.013), pain and functional activity (p = 0.000). This study showed that reduction in pain and improvement in functional activity occurs independently from an increase in quadriceps muscle strength in knee OA. It seems that increased quadriceps muscle strength may not be a cause of improvement in pain and functional activity in knee OA.     

Effects of an elastic resistance band exercise program on kinetics and muscle activities during walking in young adults with genu valgus: A double-blinded randomized controlled trial

BackgroundThis double-blinded randomized-controlled-trial aimed to identify the effects of an elastic band resistance training on walking kinetics and muscle activities in young adults with genu valgus.MethodsForty-two male young adults aged 22.5(2.7) years with genu valgus were randomly allocated to two experimental groups. The intervention group (n = 21) conducted a 14-weeks elastic band resistance training. The control group was passive during the intervention period and received the same treatment after the post-tests. Pre and post training, ground reaction forces and lower limb muscle activities were recorded during walking.FindingsResults revealed significant group-by-time interactions for peak medial ground reaction force and time-to-peak for posterior ground reaction force in favor of the intervention group (p < 0.012; d = 0.83–3.76). Resistance training with elastic bands resulted in significantly larger peak medial ground reaction force (p < 0.001; d = 1.45) and longer time-to-peak for posterior ground reaction force (p < 0.001; d = 1.85). Finding showed significant group-by-time interactions for peak positive free moment amplitudes in favor of the intervention group (p < 0.001; d = 1.18–2.02). Resistance training resulted in a lower peak positive free moment amplitude (p = 0.001; d = 1.46). With regards to muscle activities, the analysis revealed significant group-by-time interactions for rectus femoris and gluteus medius activities during the push-off phase in favor of the intervention group (p < 0.038; d = 0.68–0.89). Resistance training induced higher rectus femoris (p = 0.038; d = 0.84) and gluteus medius (p = 0.007; d = 0.54) activities.InterpretationThis study proved the effectiveness of resistance training using elastic bands on kinetics and muscle activities during walking in male adults with genu valgus disorder. Given that this training regime is low cost, effective, and easy-to-administer, we suggest that it should be implemented as a rehabilitative or preventive means for young adults with genu valgus.     

Assessment of muscle mass using ultrasound with minimal versus maximal pressure compared with computed tomography in critically ill adult patients

BackgroundPreserved skeletal muscle mass identified using computed tomography (CT) predicts improved outcomes from critical illness; however, CT imaging have few limitations such that it involves a radiation dose and transferring patients out of the intensive care unit. This study aimed to assess in critically ill patients the relationship between muscle mass estimates obtained using minimally invasive ultrasound techniques with both minimal and maximal pressure compared with CT images at the third lumber vertebra level.MethodsAll patients were treated in a single Australian intensive care unit. Eligible patients had paired assessments, within a 72-h window, of muscle mass by ultrasound (quadriceps muscle layer thickness in centimetres, with maximal and minimal pressure) and CT axial cross-sectional area (cm²). Data are presented as mean (standard deviation), median (interquartile range), and frequencies [n (%)].ResultsThirty-five patients [mean (standard deviation) age = 55 (16) years, median (interquartile range) body mass index = 27 (25–32) kg/m², and 26 (74%) men] contributed 41 paired measurements. Quadriceps muscle thickness measured using the maximal pressure technique was a strong independent predictor of lumbar muscle cross-sectional area. Within a multivariate mixed linear regression model and adjusting for sex, age, and body mass index, for every 1 cm increase in quadriceps muscle layer thickness, the lumbar muscle cross-sectional area increased by 35 cm² (95% confidence interval = 11–59 cm²). Similar univariate associations were observed using minimal pressure; however, as per multivariate analysis, there was no strength in this relationship [8 cm² (95% confidence interval = –5 to 22 cm²)].ConclusionUltrasound assessment of the quadriceps muscle using maximal pressure reasonably predicts the skeletal muscle at the third lumbar vertebra level of critically ill patients. However, there is substantial uncertainty within these regression estimates, and this may reduce the current utility of this technique as a minimally invasive surrogate for CT assessment of skeletal muscle mass.     

Effects of a low-intensity dynamic-resistance training protocol using an isokinetic dynamometer on muscular strength and aerobic capacity after coronary artery bypass grafting

ObjectiveStudy the effect of muscle strength training on muscle strength, maximal oxygen uptake (VO₂max), hemodynamic and anthropometric parameters as well as quality of life after coronary artery bypass grafting (CABG).MethodsAfter CABG surgery, 32 patients were randomized into two groups. The first group was to perform aerobic-type training with a cycle ergometer (AT = 16). The second group was to perform low-intensity muscle strength training of the quadriceps and hamstrings using an isokinetic dynamometer (i.e. 20 to 30% of peak torque) (ST = 16). Before and after the strength training program we conducted a stress test, evaluation of isokinetic force production, 6-minute walking test, body impedance analysis (BIA) and SF-36 quality of life test.ResultsCompared to the AT group, the ST group showed better results with improved quadriceps strength (48.2% vs. 8.2%), VO₂max (P < .001) and diastolic blood pressure at rest (P = 0.01). Quality of life improved in both groups.ConclusionThe dynamic-resistance muscle strength training protocol using isokinetic dynamometer can safely (i.e. without clinical symptoms or changes to the ECG and arterial blood pressure) improve muscle strength and VO₂max without any major risks in patients post-CABG. These findings should encourage additional studies to validate the relevance of these strength training modalities in rehabilitation centers.     

Impact of resistance training on the 6-minute walk test in individuals with chronic obstructive pulmonary disease: A systematic review and meta-analysis

ObjectiveThe aim of this systematic review was to assess functional improvement, measured by the 6-minute walk test (6MWT) after the application of a resistance training (RT) protocol in people with chronic obstructive pulmonary disease (COPD).Materials and MethodsThe search involved the databases ClinicalTrials.gov, Cochrane Central Register of Controlled Trials, EMBASE, PubMed and Scopus from the beginning of inception to September 1, 2019. Randomized controlled trials evaluating the functional impact of RT were included. The quality of the trials was assessed with the Physiotherapy Evidence Database (PEDro) scale. Calculations were performed according to mean difference (MD) for differences between pre- and post-intervention in 6MWT distance and according to the standardized mean difference (SMD) for post-treatment results of the 6MWT and quadriceps muscle strength (QMS) improvement.ResultsIn total, 23 studies (690 patients) met the inclusion criteria. Meta-analysis was used to compute the best improvement on the 6MWT with an analysis of improvement pre- versus post-treatment (MD 37.3, 95% confidence interval [CI] 9.8; 64.8, I² = 86%, p = 0.008) versus post-treatment alone, intervention versus control group (MD 15.5, 95% CI -7.7; 38.6, I^2 = 71%, p = 0.19). QMS was significantly improved (SMD 2.9, 95% CI 1.1; 4.7, I^2 = 91%, p = 0.002).ConclusionThe results of the meta-analysis show a significant improvement in walking ability and performance measured by the 6MWT and an improvement in QMS for people with COPD responding to the therapy. The main limitation of this review is the significant heterogeneity across the study results. Furthermore, the statistical significance does not totally coincide with the clinical significance. RT is recommended to reduce muscle dysfunction and seems useful when combined with endurance training.     

Short period of high-intensity inspiratory muscle training improves inspiratory muscle strength in patients with chronic kidney disease on hemodialysis: a randomized controlled trial

BackgroundChronic kidney disease is a complex disease that impacts multiple organs and systems (including musculoskeletal and cardiorespiratory) leading to reduction of functional capacity.ObjectiveThe aim of this study was to investigate the effect of a short period of high intensity inspiratory muscle training on maximum inspiratory pressure, functional capacity and endothelial function of chronic kidney disease patients on hemodialysis.MethodsThis randomized controlled trial enrolled 25 patients who were allocated into two groups: intervention (IMTG = 14) and control (CG = 11) groups. Intervention patients received the exercise protocol over a period of 5 weeks, 6 times per week, with each session consisting of 5 sets of 10 repetitions with an initial load of 50% progressing to 70% of maximum inspiratory pressure , measured weekly. The primary outcome was inspiratory muscle strength and the secondary outcomes were functional capacity and endothelial function evaluated before and after the training protocol.ResultsThe inspiratory muscle training induced a marked improvement in maximum inspiratory pressure which was evident after the training period (mean difference 19.0 cmH₂O – 95%CI 0.4–37.5; IMTG: 102 ± 25.7 cmH₂O vs CG: 83 ± 19.2; p = 0.046). The magnitude of maximum inspiratory pressure improvement was 33.5% at the end of the protocol for the IMTG. Functional capacity and endothelial function did not vary between or within groups.ConclusionA short period of high-intensity inspiratory muscle training for five weeks was able to improve inspiratory muscle strength of chronic kidney disease patients on hemodialysis (ClinicalTrials.gov registration NCT03082404).     

Does whole body vibration training improve heart rate variability in kidney transplants patients? A randomized clinical trial

BackgroundWhole-body vibration (WBV) is an exercise modality that can promote improvements in heart rate variability (HRV) with lower patient overload, and consequently reduce cardiovascular risk in renal transplant patients. The aim of this study was to evaluate the effects of a 12-week WBV training program of two weekly sessions on HRV.MethodsA double-blind, randomized controlled clinical trial with 12 kidney transplant recipients of both genders who underwent WBV training (35 Hz) twice a week for 12 weeks on alternate days (WBV Group) and training with sub-therapeutic WBV (8 Hz) (Sham Group). Variables were evaluated in time and frequency domains of HRV through the 24-h Holter monitor, heart rate (HR), blood pressure (BP) and maximum oxygen consumption (VO_2max) through an exercise stress test.ResultsThe delta between Sham and WBV groups showed an increase in the low frequency (Δ = 959.05 Hz; p = 0.01) and in the high frequency (Δ = 204.42 Hz; p = 0.04) of the HRV compared to Sham group. No changes in the ergometric variables were observed for any of the groups.ConclusionThe present study evidenced an increase in the low and high frequency of HRV in individuals who participated in the Sham WBV group. There was no improvement in the autonomic balance in the groups, in the other HRV parameters, or the exercise test after the WBV training period.     

Effect of gender on strength gains after isometric exercise coupled with electromyographic biofeedback in knee osteoarthritis: A preliminary study

ObjectiveThe objective of this trial was to evaluate the effect of gender on strength gains after five week training programme that consisted of isometric exercise coupled with electromyographic biofeedback to the quadriceps muscle.Materials and methodsForty-three (20 men and 23 women) patients with knee osteoarthritis (OA), were placed into two groups based on their gender. Both groups performed isometric exercise coupled with electromyographic biofeedback for five days a week for five weeks.ResultsBoth groups reported gains in muscle strength after five week training. However, the difference was found to be statistically insignificant between the two groups (P = 0.224).ConclusionThe results suggest that gender did not affect gains in muscle strength by isometric exercise coupled with electromyographic biofeedback in patients with knee OA.     

Reliability of knee extensor neuromuscular structure and function and functional tests’ performance

IntroductionThe aim of this study was to evaluate the intra and inter-rater and inter-analyzer reliability of neuromuscular variables and functional tests.MethodsCross-sectional crossover design. Two independent raters and analyzers evaluated twenty-two healthy subjects. Knee-extensor strength was assessed from three maximal voluntary isometric contractions. Muscle activation was obtained from the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) muscles. VL and RF muscles’ architecture [fascicle length (FL), pennation angle (PA), muscle thickness (MT)] was obtained at rest by ultrasound. The time from five sit-to-stand (STS) trials, and the distance from the 6-min walk test (6MWT) were obtained. Intraclass correlation coefficient was determined and classified as strong (r = 0.75–1.00), moderate (r = 0.40–0.74), and weak (r < 0.40).ResultsStrong intra-rater reliability values were observed for strength (r = 0.97), muscle activation [VL (r = 0.91); RF (r = 0.92); VM (r = 0.80)], VL [FL (r = 0.90); PA (r = 0.94); MT (r = 0.99)] and RF [MT (r = 0.85)] muscle architecture, STS (r = 0.95), and 6MWT (r = 0.98). Inter-rater reliability also presented strong values for strength (r = 0.97), muscle activation [VL (r = 0.94); RF (r = 0.79); VM (r = 0.78)], muscle architecture VL [PA (r = 0.81) and MT (r = 0.88)] and RF [MT (r = 0.80)], STS (r = 0.93), and 6MWT (r = 0.98). A moderate correlation VL muscle architecture [FL (r = 0.69)]. Inter-analyzer muscle architecture reliability presented strong VL [FL (r = 0.77); PA (r = 0.76); MT (r = 0.91)] and RF [MT (r = 0.99)].ConclusionThe high intra and inter-rater and inter-analyzer reliability values for most variables is evidence that they can be used for clinical evaluation. Muscle architecture might need a longer training period by different raters and analyzers to increase reliability.     

Muscular adaptations to fatiguing exercise with and without blood flow restriction

The purpose of this study was to determine the muscular adaptations to low‐load resistance training performed to fatigue with and without blood flow restriction (BFR). Middle‐aged (42–62 years) men (n = 12) and women (n = 6) completed 18 sessions of unilateral knee extensor resistance training to volitional fatigue over 6 weeks. One limb trained under BFR, and the contralateral limb trained without BFR [free flow (FF)]. Before and after the training, measures of anterior and lateral quadriceps muscle thickness (MTh), strength, power and endurance were assessed on each limb. The total exercise training volume was significantly greater for the FF limb compared with the BFR limb (P<0·001). Anterior quadriceps thickness and muscle function increased following the training in each limb with no differences between limbs. Lateral quadriceps MTh increased significantly more (P<0·05) in the limb trained under BFR (BFR: 3·50 ± 0·61 to 3·67 ± 0·62 cm; FF: 3·49 ± 0·73 to 3·56 ± 0·70 cm). Low‐load resistance training to volitional fatigue both with and without BFR is viable options for improving muscle function in middle‐aged individuals. However, BFR enhanced the hypertrophic effect of low‐load training and reduced the volume of exercise needed to elicit increases in muscle function.     

Proximal and distal muscle thickness is different in women with patellofemoral pain but is not associated with knee frontal plane projection angle

ObjectiveThe aim of this study was to compare proximal and distal muscle thickness between patellofemoral pain (PFP) and asymptomatic women (CG) and to verify the possible association between morphology and lower limb alignment during single leg-squat.MethodsThirty women (PFP, n = 15 and CG, n = 15) performed the following evaluations: (i) muscle thickness of external oblique (EO), gluteus medius (GMed), tensor fascia latae (TFL), peroneus (PER) and tibialis anterior (TA); (ii) knee frontal plane projection angle (FPPA) during single-leg squat.ResultsCompared with the CG, PFP showed: (1) smaller GMed (−10.02%; p = 0.04; effect size = 0.82), greater TFL (+18.44%; p = 0.02; effect size = 0.92) and PER (+14.23%; p = 0.02; effect size = 0.87) muscle thickness and greater knee FPPA during single-leg squat (+31.8%; p = 0.04; effect size = 1.12). No differences were observed in EO (+7.17%; p = 0.37; effect size = 0.34) and TA (−1.35%; p = 0.81; effect size = 0.12) muscle thickness. Additionally, we failed to observe significant associations between muscle morphology and knee FPPA in both groups.ConclusionPFP patients showed alterations in proximal and distal muscle thickness, despite the lack of association with poor lower limb alignment. Prospective studies are necessary to determine if differences in muscle morphology are the cause or the consequence of PFP and to confirm the absence of relationship with lower limb alignment.     

Microcirculation of skeletal muscle adapts differently to a resistive exercise intervention with and without superimposed whole‐body vibrations

Whole‐body vibration (WBV) training is commonly practiced and may enhance peripheral blood flow. Here, we investigated muscle morphology and acute microcirculatory responses before and after a 6‐week resistive exercise training intervention without (RE) or with (RVE) simultaneous whole‐body vibrations (20 Hz, 6 mm peak‐to‐peak amplitude) in 26 healthy men in a randomized, controlled parallel‐design study. Total haemoglobin (tHb) and tissue oxygenation index (TOI) were measured in gastrocnemius muscle (GM) with near‐infrared spectroscopy (NIRS). Whole‐body oxygen consumption (VO₂) was measured via spirometry, and skeletal muscle morphology was determined in soleus (SOL) muscle biopsies. Our data reveal that exercise‐induced muscle deoxygenation both before and after 6 weeks training was similar in RE and RVE (P = 0·76), although VO₂ was 20% higher in the RVE group (P<0·001). The RVE group showed a 14%‐point increase in reactive hyperaemia (P = 0·007) and a 27% increase in blood volume (P<0·01) in GM after 6 weeks of training. The number of capillaries around fibres was increased by 15% after 6 weeks training in both groups (P<0·001) with no specific effect of superimposed WBV (P = 0·61). Neither of the training regimens induced fibre hypertrophy in SOL. The present findings suggest an increased blood volume and vasodilator response in GM as an adaptation to long‐term RVE, which was not observed after RE alone. We conclude that RVE training enhances vasodilation of small arterioles and possibly capillaries. This effect might be advantageous for muscle thermoregulation and the delivery of oxygen and nutrients to exercising muscle and removal of carbon dioxide and metabolites.     

Feasibility and preliminary efficacy of a hypopressive exercise program on postmenopausal cancer survivors: A pilot study

BackgroundCancer-related fatigue (CRF) is a common symptom during and after cancer treatment that negatively affects the patient's quality of life. Exercise is one of the most effective non-pharmacological treatments for CRF. Multimodal exercise therapy programs that include hypopressive exercises, relaxation and myofascial release may be beneficial for CRF. The aim of this pilot study was to evaluate the feasibility and efficacy of a multimodal program on CRF and lower limb functional strength in postmenopausal women diagnosed with cancer.Methods7 postmenopausal women (age = 55.28 years; BMI = 26.05 kg/m2) who had a cancer diagnosis participated in a supervised and progressive 55-min class once per week for 12-weeks. CRF was measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Cancer Related Fatigue 12 and lower limb strength was assessed with the sit and stand test.ResultsNo adverse events were reported during the training period and all participants completed the exercise protocol. There was a significant increase (p = 0.01) in lower limb functional strength (pre: 19.60 (SD = 2.19) vs post: 24.60(SD = 2.19)) with an effect size of d = 2.28 and a decrease in CRF (p = 0.245) (pre: 29.36 ± 24.42; post: 17.85 ± 14.23) with a trivial effect size (d < 0.5).ConclusionsThese preliminary findings indicate that a supervised once per week multimodal program that includes hypopressive exercises for postmenopausal cancer survivors increased lower limb functional strength without exacerbating their CRF. These findings support further randomized trials of hypopressive training programs on patients with cancer.