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Nutrients Jun 2024Handgrip strength (HGS) is an indicator of muscular strength, used in the diagnosis of sarcopenia, undernutrition, and physical frailty as well as recovery. Typically,... (Review)
Review
BACKGROUND
Handgrip strength (HGS) is an indicator of muscular strength, used in the diagnosis of sarcopenia, undernutrition, and physical frailty as well as recovery. Typically, the maximum HGS value is used; however, recent evidence suggests the exploration of new indicators provided based on the force-time curve to achieve a more comprehensive assessment of muscle function. Therefore, the objective was to identify indicators of the HGS profile beyond maximum HGS, based on force-time curves, and to systematize knowledge about their applications to various types of samples, health issues, and physical performance.
METHODS
A systematic review was performed including studies whose participants' HGS was assessed with a digital or adapted dynamometer. The outcome measures were HGS profile indicators calculated from the force-time curve.
RESULTS
a total of 15 studies were included, and the following indicators were identified: grip fatigue, fatigability index, fatigue rate, fatigue resistance, time to 80% maximal voluntary contraction, plateau coefficient of variability, time to maximum value, T-90%, release rate, power factor, grip work, average integrated area, endurance, cycle duration, time between cycles, maximum and minimum force-velocity, rate of grip force, final force, inflection point, integrated area, submaximal control, and response time.
CONCLUSIONS
Various indicators based on the force-time curve can be assessed through digital or adapted dynamometers. Future research should analyze these indicators to understand their implications for muscle function assessment, to standardize evaluation procedures, to identify clinically relevant measures, and to clarify their implications in clinical practice.
Topics: Humans; Hand Strength; Muscle Strength Dynamometer; Female; Male; Muscle Fatigue; Aged; Muscle, Skeletal; Muscle Strength; Middle Aged; Sarcopenia; Time Factors; Adult
PubMed: 38931305
DOI: 10.3390/nu16121951 -
Frontiers in Nutrition 2024Coaches and athletes are increasingly interested in understanding athletes' serum vitamin D levels, their impact on strength, physical performance, and athletic...
Effects of vitamin D3 supplementation on strength of lower and upper extremities in athletes: an updated systematic review and meta-analysis of randomized controlled trials.
BACKGROUND
Coaches and athletes are increasingly interested in understanding athletes' serum vitamin D levels, their impact on strength, physical performance, and athletic outcomes. Previous meta-analyses were reported with limited sample size and no significant overall effect was found. Hence, it is crucial to conduct a thorough and up-to-date systematic examination and meta-analysis to elucidate the potential advantages of supplementing with vitamin D3 in enhancing muscle strength for athletes.
METHODS
We performed a thorough investigation, spanning three databases (PubMed, EBSCO, and Cochrane Library), seeking randomized controlled trials (RCTs) in all languages. These trials delved into the influence of vitamin D3 supplementation on the changes of pre- and post-intervention muscle strength in healthy athletes. Our systematic examination and meta-analysis took into account serum 25(OH)D levels exceeding 30 ng/mL as a marker of adequacy.
RESULTS
Ten RCTs, comprising 354 athletes (185 in the vitamin D3 group and 169 in the placebo group), fulfilled the inclusion criteria. During the study, 36 athletes were lost to follow-up, leaving 318 athletes (166 in the vitamin D3 group and 152 in the placebo group) with documented complete results. In comparison with the placebo group, there is a significant increase between the changes of pre- and post-intervention serum 25(OH)D levels among athletes following a period of vitamin D3 supplementation (MD 14.76, 95% CI: 8.74 to 20.77, < 0.0001). Overall effect of four strength measurements including handgrip, one repetition maximum Bench Press (1-RM BP), vertical jump, and quadriceps contraction was not significantly improved (SMD 0.18, 95% CI: -0.02 to 0.37, = 0.08), but there was a significant increase in quadriceps contraction (SMD 0.57, 95% CI: 0.04 to 1.11, = 0.04).
CONCLUSION
This updated meta-analysis indicates the potential benefits of vitamin D supplementation for enhancing muscle strength in athletes when analyzing its quantitatively synthesized effects. With limited available studies for the quantitative synthesis, it cannot warrant significant overall enhancements in muscle strength when athletes attain adequate serum 25(OH)D levels through supplementation.
PubMed: 38860160
DOI: 10.3389/fnut.2024.1381301 -
PloS One 2024Neuromuscular electrical stimulation (NMES) can improve physical function in different populations. NMES-related outcomes may be influenced by muscle length (i.e., joint...
Effect of muscle length on maximum evoked torque, discomfort, contraction fatigue, and strength adaptations during electrical stimulation in adult populations: A systematic review.
Neuromuscular electrical stimulation (NMES) can improve physical function in different populations. NMES-related outcomes may be influenced by muscle length (i.e., joint angle), a modulator of the force generation capacity of muscle fibers. Nevertheless, to date, there is no comprehensive synthesis of the available scientific evidence regarding the optimal joint angle for maximizing the effectiveness of NMES. We performed a systematic review to investigate the effect of muscle length on NMES-induced torque, discomfort, contraction fatigue, and strength training adaptations in healthy and clinical adult populations (PROSPERO: CRD42022332965). We conducted searches across seven electronic databases: PUBMED, Web of Science, EMBASE, PEDro, BIREME, SCIELO, and Cochrane, over the period from June 2022 to October 2023, without restricting the publication year. We included cross-sectional and longitudinal studies that used NMES as an intervention or assessment tool for comparing muscle lengths in adult populations. We excluded studies on vocalization, respiratory, or pelvic floor muscles. Data extraction was performed via a standardized form to gather information on participants, interventions, and outcomes. Risk of bias was assessed using the Revised Cochrane risk-of-bias tool for cross-over trials and the Physiotherapy Evidence Database scale. Out of the 1185 articles retrieved through our search strategy, we included 36 studies in our analysis, that included 448 healthy young participants (age: 19-40 years) in order to investigate maximum evoked torque (n = 268), contraction fatigability (n = 87), discomfort (n = 82), and muscle strengthening (n = 22), as well as six participants with spinal cord injuries, and 15 healthy older participants. Meta-analyses were possible for comparing maximal evoked torque according to quadriceps muscle length through knee joint angle. At optimal muscle length 50° - 70° of knee flexion, where 0° is full extension), there was greater evoked torque during nerve stimulation compared to very short (0 - 30°) (p<0.001, CI 95%: -2.03, -1.15 for muscle belly stimulation, and -3.54, -1.16 for femoral nerve stimulation), short (31° - 49°) (p = 0.007, CI 95%: -1.58, -0.25), and long (71° - 90°) (p<0.001, CI 95%: 0.29, 1.02) muscle lengths. At long muscle lengths, NMES evoked greater torque than very short (p<0.001, CI 95%: -2.50, -0.67) and short (p = 0.04, CI 95%: -2.22, -0.06) lengths. The shortest quadriceps length generated the highest perceived discomfort for a given current amplitude. The amount of contraction fatigability was greater when muscle length allowed greater torque generation in the pre-fatigue condition. Strength gains were greater for a protocol at the optimal muscle length than for short muscle length. The quality of evidence was very high for most comparisons for evoked torque. However, further studies are necessary to achieve certainty for the other outcomes. Optimal muscle length should be considered the primary choice during NMES interventions, as it promotes higher levels of force production and may facilitate the preservation/gain in muscle force and mass, with reduced discomfort. However, a longer than optimal muscle length may also be used, due to possible muscle lengthening at high evoked tension. Thorough understanding of these physiological principles is imperative for the appropriate prescription of NMES for healthy and clinical populations.
Topics: Humans; Torque; Adult; Muscle Fatigue; Muscle, Skeletal; Muscle Contraction; Electric Stimulation; Muscle Strength; Adaptation, Physiological; Electric Stimulation Therapy
PubMed: 38857245
DOI: 10.1371/journal.pone.0304205 -
Scientific Reports May 2024Whole-body vibration (WBV), a training method based on the stimulation of muscle contraction by mechanical vibration generated in a vibrating platform, is claimed to be... (Meta-Analysis)
Meta-Analysis
Whole-body vibration (WBV), a training method based on the stimulation of muscle contraction by mechanical vibration generated in a vibrating platform, is claimed to be effective in diabetes management. This meta-analysis evaluated WBV effects against other exercises, placebo, or no intervention in type-2 diabetes. Medline, Scopus, and Web of Science databases were systematically searched through June 2023. Randomized controlled trials reported the effect of WBV on glucose (hemoglobin A1C and fasting blood glucose), and lipid profiles (total cholesterol, triglycerides, high, and low-density lipoprotein) were included. Two researchers independently extracted the characteristics of the studies, participants, WBV intervention and comparisons, and the outcomes from the included articles. The Physiotherapy Evidence Database (PEDro) scale assessed trial quality. In this review, all articles had no high risk of bias according to the PEDro scale, with studies achieving optimal, excellent, and good scores. Network meta-analysis revealed that WBV was effective for reducing hemoglobin A1C when compared with conventional (mean difference: - 1.58%, 95%CrI: - 2.51, - 0.47) and resistance exercise (mean difference: - 1.32%, 95%CrI: - 1.96, - 0.33). WBV had also a desirable but insignificant effect on hemoglobin A1C compared to stretching and balance exercises, placebo, and no intervention. The current pairwise meta-analysis did not show that WBV favors fasting blood glucose and lipids. WBV may have potential advantages for glycemic control in type-2 diabetes. However, uncertainties in the findings remain due to the limited number of studies and their heterogeneity.
Topics: Humans; Diabetes Mellitus, Type 2; Vibration; Randomized Controlled Trials as Topic; Blood Glucose; Network Meta-Analysis; Lipids; Glycated Hemoglobin
PubMed: 38822020
DOI: 10.1038/s41598-024-63316-0 -
The Knee Jun 2024Anterior cruciate ligament reconstruction (ACLR) is a common orthopedic surgery procedure whose incidence has increased over the past few decades. Nevertheless, it is... (Review)
Review
BACKGROUND
Anterior cruciate ligament reconstruction (ACLR) is a common orthopedic surgery procedure whose incidence has increased over the past few decades. Nevertheless, it is believed that neuromuscular control remains altered from the early stages after ACLR to later years. Therefore, the aim of this study was to systematically evaluate the magnitude of co-contraction during functional tasks in subjects with unilateral ACLR.
METHODS
A systematic review design was followed. The search strategy was conducted in PubMed, Scopus, EBSCO, PEDro, Cochrane Library, and Web of Science databases from inception to March 2024. The inclusion criteria involved studies using electromyography (EMG) data to calculate muscle pair activation via the co-contraction index (CCI) in ACLR individuals during functional tasks. The Preferred Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and study quality was evaluated using National Institutes of Health (NIH) Study Quality Assessment Tools.
RESULTS
The search strategy found a total of 792 studies, of which 15 were included in this systematic review after reviewing the eligibility criteria. The magnitude of co-contraction was assessed in a total of 433 ACLR individuals and 206 controls during functional tasks such as hop, drop-land, step-up/step-down, and gait. Overall, approximately 79.6% of individuals who had undergone ACLR exhibited increased levels of co-contraction magnitude in the ACLR limb, while 8.5% showed low co-contraction levels.
CONCLUSIONS
The findings of the review suggest that, during functional tasks, most individuals who have undergone ACLR exhibit changes of co-contraction magnitude in the involved limb.
Topics: Anterior Cruciate Ligament Reconstruction; Humans; Electromyography; Anterior Cruciate Ligament Injuries; Muscle Contraction; Muscle, Skeletal
PubMed: 38781829
DOI: 10.1016/j.knee.2024.05.005 -
Journal of Bodywork and Movement... Apr 2024Various exercise programs are used to treat lateral abdominal muscle (LAM) impairments in people with low back pain. Factors comprising these programs include exercise... (Review)
Review
BACKGROUND
Various exercise programs are used to treat lateral abdominal muscle (LAM) impairments in people with low back pain. Factors comprising these programs include exercise type, session time, frequency, and program duration. However, specific clinical guidance about optimal exercise prescription is lacking.
OBJECTIVES
To perform a dose-response analysis on exercise prescription variables for LAM thickness and activation as measured by ultrasound imaging.
DESIGN
Systematic review METHOD: Databases were searched from their inception for studies examining the association between exercise interventions and LAM thickness/activation measured by ultrasound imaging in healthy individuals. Risk of bias was assessed using the Joanna Brigg's Institute critical appraisal tools. For each muscle, subgroup analyses were performed to determine the dose response of exercise prescription variables for LAM thickness and activation. Where there was insufficient data for subgroup analyses, data was narratively synthesised.
RESULTS
Fourteen studies comprising 395 participants were included. Statistical and narrative synthesis revealed specific local abdominal exercises, programs from four weeks duration, three sessions per week and sessions of ≥30 min were associated with greatest improvements to LAM thickness. Only the variables exercise type, program duration and session frequency showed a significant between groups difference for the subgroup analysis. The main limitation was inability to perform subgroup analyses for all variables across all muscles measured at rest and during contraction, due to non-reporting of data.
CONCLUSION
This review provides preliminary guidance to practitioners on how the LAM respond to different exercise dosages. Future research should trial these findings.
Topics: Humans; Abdominal Muscles; Exercise Therapy; Low Back Pain; Ultrasonography
PubMed: 38763566
DOI: 10.1016/j.jbmt.2024.01.016 -
Journal of Bodywork and Movement... Apr 2024Hypopressive exercises have been mainly used in the treatment of pelvic floor dysfunctions. Recently it has started to spread among healthy women. However, no... (Review)
Review
BACKGROUND
Hypopressive exercises have been mainly used in the treatment of pelvic floor dysfunctions. Recently it has started to spread among healthy women. However, no comprehensive review is available in this population.
PURPOSE
Assess the current evidence of the effects of hypopressive exercises on healthy women.
METHODS
This study was registered on PROSPERO (CRD42020203103). The search was performed in Scielo, Pubmed, Lilacs, Embase, Scopus, Pedro, Trip Database, Web of Science, and Google Scholar. The last search was performed on November 1st, 2021. Inclusion criteria were randomized controlled trials and single-arm trials, healthy women, acute or late effects of hypopressive exercises, and pre and post-training analysis. Exclusion criteria included non-original research, conference proceedings, dissertations and theses. Downs and Black checklist were used to assess the methodological quality. Study design, participants characteristics, description of the intervention, follow-up period, variables, instruments, and outcomes were extracted and recorded.
RESULTS
From the 410 studies, five were selected. The variable of major interest was waist circumference, which showed a decrease with exercise. It also seemed to have plausible positive effects on height, lower back mobility, abdominal and pelvic floor muscle contraction, respiratory flow and apnea, and hemodynamic responses.
CONCLUSION
This study suggests that the current literature on the effects of hypopressive exercise on healthy women is very limited. Despite the plausible positive effects identified, we cannot recommend its practice due to the serious methodological problems. Therefore, more studies are needed to elucidate the benefits and adverse effects of hypopressive exercises.
Topics: Humans; Female; Exercise Therapy; Pelvic Floor; Waist Circumference; Muscle Contraction; Muscle Strength
PubMed: 38763553
DOI: 10.1016/j.jbmt.2024.01.012 -
Medicine May 2024Heart failure is a common and severe condition, often complicated by diastolic dysfunction. Current standard therapies such as ACEIs and ARBs have limited efficacy in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Heart failure is a common and severe condition, often complicated by diastolic dysfunction. Current standard therapies such as ACEIs and ARBs have limited efficacy in managing diastolic function. Sacubitril/Valsartan, an emerging therapy, warrants rigorous investigation to elucidate its impact on diastolic function in heart failure patients.
METHODS
This systematic review and meta-analysis were conducted adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and utilized the PICO schema. Searches were performed on 4 databases-PubMed, Embase, Web of Science, and Cochrane Library-without temporal restrictions. Inclusion and exclusion criteria were strictly defined, and quality assessments were conducted using the Cochrane Collaboration Risk of Bias tool. Both fixed-effects and random-effects models were used for statistical analysis, depending on inter-study heterogeneity assessed by I2 statistics and Chi-square tests.
RESULTS
Out of 1129 identified publications, 8 studies met the criteria and were included in the meta-analysis. These studies consisted of both randomized controlled trials and cohort studies and featured diverse global populations. Significant reductions were found in the echocardiographic parameter E/e' ratio and LAVi upon treatment with Sacubitril/Valsartan compared to standard therapies, with mean differences of -1.38 and -4.62, respectively, both with P values < .01.
CONCLUSIONS
This meta-analysis demonstrates that Sacubitril/Valsartan significantly improves diastolic function parameters in heart failure patients compared to standard treatments. These findings underscore the potential benefits of Sacubitril/Valsartan in the management of heart failure, particularly for patients with diastolic dysfunction.
Topics: Humans; Valsartan; Aminobutyrates; Drug Combinations; Biphenyl Compounds; Heart Failure; Angiotensin Receptor Antagonists; Tetrazoles; Diastole
PubMed: 38728489
DOI: 10.1097/MD.0000000000037965 -
Translational Sports Medicine 2024Five electronic databases (PubMed (Medline), Web of Science, Embase, Sport Discus, and Cochrane Library) were searched for controlled trials that assessed the MPS... (Review)
Review
METHODS
Five electronic databases (PubMed (Medline), Web of Science, Embase, Sport Discus, and Cochrane Library) were searched for controlled trials that assessed the MPS response to RE in healthy, adult humans, postabsorptive state. Individual study and random-effects meta-analysis arewere used to inform the effects of RE and covariates on MPS. Results from 79 controlled trials with 237 participants were analysed.
RESULTS
Analysis of the pooled effects revealed robust increases in MPS following RE (weighted mean difference (WMD): 0.032% h, 95% CI: [0.024, 0.041] % h, = 92%, = 37, < 0.001). However, the magnitude of the increase in MPS was lower in older adults (>50 y: WMD: 0.015% h, 95% CI: [0.007, 0.022] % h, = 76%, = 12, = 0.002) compared to younger adults (<35 y: WMD: 0.041% h, 95% CI: [0.030, 0.052] % h, = 88%, = 25, < 0.001). Individual studies have reported that the temporal proximity of the RE, muscle group, muscle protein fraction, RE training experience, and the loading parameters of the RE (i.e., intensity, workload, and effort) appeared to affect the MPS response to RE, whereas sex or type of muscle contraction does not.
CONCLUSION
A single bout of RE can sustain measurable increases in postabsorptive MPS soon after RE cessation and up to 48 h post-RE. However, there is substantial heterogeneity in the magnitude and time course of the MPS response between trials, which appears to be influenced by participants' age and/or the loading parameters of the RE itself.
PubMed: 38716482
DOI: 10.1155/2024/3184356 -
American Journal of Physical Medicine &... May 2024Unloader braces are a treatment modality for medial compartment knee osteoarthritis (MC-KOA). The functional mechanisms involved are not yet fully understood. Therefore,...
Unloader braces are a treatment modality for medial compartment knee osteoarthritis (MC-KOA). The functional mechanisms involved are not yet fully understood. Therefore, this two-part systematic review (SR) examines the following research questions: How is muscle activation altered by MC-KOA, and do MC unloader braces alter muscle activation? If so, could this alteration be part of the unloading mechanism by affecting the altered muscle activity in MC-KOA?A systematic literature search was conducted using PubMed, LIVIVO, Web of Science, Google Scholar, and CENTRAL for articles published until August 2023. The first SR, examining neuromuscular alterations, identified 703 articles, with a final inclusion of 20. The second SR, which evaluated the neuromuscular effects of unloader braces, identified 123 articles with the final inclusion of 3. Individuals with MC-KOA demonstrated increased activity and co-contraction of the periarticular knee muscles, whereas MC unloader braces seemed to reduce activity and co-contraction. In contrast to the belief that unloader braces result in muscle weakness as they decrease muscle activity and co-contraction, our limited insights indicate that they rather might reduce the pathological increase. This may result in joint load reduction owing to lower compressive forces. However, further investigation is required.
PubMed: 38709674
DOI: 10.1097/PHM.0000000000002521