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Frontiers in Physiology 2023This study aims to systematically evaluate the effects of blood flow restriction (BFR) training on lower limb muscle activation and post-activation potentiation (PAP)...
This study aims to systematically evaluate the effects of blood flow restriction (BFR) training on lower limb muscle activation and post-activation potentiation (PAP) in athletes through a meta-analysis and discuss methods to improve instant muscle strength so as to provide a reference for training in this field. Randomized controlled trials (RCTs) that examined the impact of BFR training on muscle activation and PAP were gathered through database searches, such as CNKI, Wanfang, Web of Science, PubMed, and others. The Cochrane risk of bias tool was used to include and exclude literature. Quality evaluation and statistical analysis were conducted using ReviewManager 5.3 software, STATA 16.0, and other software programs. The sensitivity analysis and funnel plots were employed to assess result stability and publication bias. In total, 18 literature studies were included with a total of 267 subjects. The meta-analysis showed that BFR could significantly improve the RMS value of lower limb muscles [ = 0.98, 95% (0.71, 1.24), and < 0.00001]. BFR had a significant effect on the immediate explosive power of the lower limbs [ = 0.28, 95% (0.02, 0.53), and = 0.03], but the heterogeneity was obvious ( = 51%). The subgroup analysis showed that different training methods may be influencing factors that lead to the heterogeneity between studies. The measurement indexes were the counter movement jump (CMJ) [ = 0.45, 95% (0.20, 0.69), and = 0.0004], training mode to overcome body weight [ = 0.57, 95% (0.33, 0.82), and < 0.00001], and compressive strength of 40%-60% arterial occlusion pressure (AOP) [ = 0.57, 95% (0.31, 0.83), and < 0.0001], which reached the maximum effect and was statistically significant. BFR training can induce lower extremity muscle activation and PAP. Combining self-weight training with BFR exercises set at 40%-60% AOP appears to be particularly effective in inducing PAP, especially for enhancing CMJ. Furthermore, combining body-weight training with BFR is considered an effective warm-up method to improve CMJ. : http://inplasy.com, identifier INPLASY2023100087.
PubMed: 38028795
DOI: 10.3389/fphys.2023.1243302 -
The Journal of Nutrition Jun 2020The reward value of palatable foods is often cited as an important influence on eating behaviors, including intake of sugars. However, human neuroimaging studies have... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The reward value of palatable foods is often cited as an important influence on eating behaviors, including intake of sugars. However, human neuroimaging studies have generated conflicting evidence on the basic neural representation of taste and reward responses to caloric sweeteners (sucrose and glucose), and most relevant studies have used small subject numbers.
OBJECTIVE
We conducted a systematic review and a coordinate-based meta-analysis of studies reporting brain responses to oral sugar solutions.
METHODS
A systematic search of MEDLINE, Scopus, and PsycINFO through October 2019 identified fMRI studies (in healthy human adults, including those with overweight or obesity) assessing differences in responses to purified sweet and nonsweet taste stimuli. Data were extracted with the primary objective of quantifying evidence for the activation of brain regions associated with caloric sweet taste sensation. We used activation likelihood estimation meta-analysis methods. We also performed multiple sensitivity analyses to assess the generality of effects.
RESULTS
Of 455 unique articles, 15 met the criteria for inclusion. These contributed to 2 primary meta-analyses: 1) sucrose (13 experiments, 179 coordinates, n = 241) and 2) sucrose + glucose (16 experiments, 209 coordinates, n = 262). Consistent activation was apparent in primary taste areas: insula (69.2% of studies) and opercular cortex (76.9% of studies), precentral gyri (53.9% of studies), and globus pallidus and postcentral gyrus (30.8% of studies for each). Evidence of reward activity (caudate) was seen in the primary analyses (30.8% of studies) but not in sensitivity analysis.
CONCLUSIONS
We confirm the importance of primary taste areas for gustatory processing in human adults. We also provide tentative evidence for reward-related caudate activity in relation to the sweet taste of caloric sugars. A number of factors affect the observation and interpretation of brain responses, including reward-related activity. Firm conclusions require confirmation with large data set studies.
Topics: Humans; Likelihood Functions; Magnetic Resonance Imaging; Sucrose; Sweetening Agents; Taste
PubMed: 32271923
DOI: 10.1093/jn/nxaa071 -
Experimental Gerontology Oct 2014Age-related muscle weakness is only partially related to muscle atrophy, due to neuromuscular changes including reduced voluntary muscle activation and antagonist muscle... (Meta-Analysis)
Meta-Analysis Review
Age-related muscle weakness is only partially related to muscle atrophy, due to neuromuscular changes including reduced voluntary muscle activation and antagonist muscle co-activation. The respective contribution of these mechanisms in exercise-induced strength gains at higher age is unclear. Here the literature was systematically reviewed for studies reporting exercise-induced effects on voluntary muscle activation and antagonist muscle co-activation in elderly persons. Seventeen relevant studies were identified, 4 investigated voluntary muscle activation, 8 antagonist muscle co-activation and 5 studies investigated both. Meta-analysis showed an exercise-induced improvement in voluntary activation in plantar flexors (weighted mean difference (WMD) +8.8%, p<0.001), and knee extensors (WMD +1.8%, p<0.001), with greater gains in activation capacity obtained in subjects with lower voluntary activation level prior to the onset of training. We found no significant overall effect of strength training on antagonist co-activation during ankle plantar flexion (WMD +0.6%, p=0.686) or knee extension (WMD -1.1%, p=0.699 for the RCT's and -1.8%, p=0.516 for the non-controlled trials). Based on our results we can conclude that there is evidence for exercise-induced increase in voluntary activation related to strength gains in the lower extremities in elderly persons. The results for exercise-induced effects on antagonist co-activation are inconsistent and more research is necessary to determine its contribution to strength gains following resistance training in elderly persons.
Topics: Age Factors; Aged; Aged, 80 and over; Aging; Female; Geriatric Assessment; Humans; Male; Middle Aged; Muscle Contraction; Muscle Strength; Muscle Weakness; Muscle, Skeletal; Resistance Training; Risk Factors; Sarcopenia; Treatment Outcome
PubMed: 25064039
DOI: 10.1016/j.exger.2014.07.012 -
The Cochrane Database of Systematic... Oct 2018Action observation (AO) is a physical rehabilitation approach that facilitates the occurrence of neural plasticity through the activation of the mirror-neural system,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Action observation (AO) is a physical rehabilitation approach that facilitates the occurrence of neural plasticity through the activation of the mirror-neural system, promoting motor recovery in people with stroke.
OBJECTIVES
To assess whether action observation enhances motor function and upper limb motor performance and cortical activation in people with stroke.
SEARCH METHODS
We searched the Cochrane Stroke Group Trials Register (last searched 4 September 2017), the Central Register of Controlled Trials (24 October 2017), MEDLINE (1946 to 24 October 2017), Embase (1974 to 24 October 2017) and five additional databases. We also searched trial registries and reference lists.
SELECTION CRITERIA
Randomized controlled trials (RCTs) of AO, alone or associated with physical practice in adults after stroke. The primary outcome was upper limb motor function. Secondary outcomes included dependence on activities of daily living (ADL), motor performance, cortical activation, quality of life, and adverse effects.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected trials according to the pre-defined inclusion criteria, extracted data, assessed risk of bias, and applied the GRADE approach to assess the quality of the evidence. The reviews authors contacted trial authors for clarification and missing information.
MAIN RESULTS
We included 12 trials involving 478 individuals. A number of trials showed a high risk of bias and others an unclear risk of bias due to poor reporting. The quality of the evidence was 'low' for most of the outcomes and 'moderate' for hand function, according to the GRADE system. In most of the studies, AO was followed by some form of physical activity.
PRIMARY OUTCOME
the impact of AO on arm function showed a small significant effect (standardized mean difference (SMD) 0.36, 95% CI 0.13 to 0.60; 8 studies; 314 participants; low-quality evidence); and a large significant effect (mean difference (MD) 2.90, 95% CI 1.13 to 4.66; 3 studies; 132 participants; moderate-quality evidence) on hand function.
SECONDARY OUTCOMES
there was a large significant effect for ADL outcome (SMD 0.86, 95% CI 0.11 to 1.61; 4 studies, 226 participants; low-quality evidence). We were unable to pool other secondary outcomes to extract the evidence. Only two studies reported adverse effects without significant adverse AO events.
AUTHORS' CONCLUSIONS
We found evidence that AO is beneficial in improving upper limb motor function and dependence in activities of daily living (ADL) in people with stroke, when compared with any control group; however, we considered the quality of the evidence to be low. We considered the effect of AO on hand function to be large, but it does not appear to be clinically relevant, although we considered the quality of the evidence as moderate. As such, our confidence in the effect estimate is limited because it will likely change with future research.
Topics: Activities of Daily Living; Hand; Humans; Motor Skills; Neuronal Plasticity; Quality of Life; Randomized Controlled Trials as Topic; Recovery of Function; Stroke Rehabilitation; Upper Extremity
PubMed: 30380586
DOI: 10.1002/14651858.CD011887.pub2 -
Neuropsychology Review Sep 2022Fatigue is one of the most debilitating symptoms for people with multiple sclerosis (PwMS). By consolidating a diverse and conflicting evidence-base, this systematic... (Meta-Analysis)
Meta-Analysis Review
Fatigue is one of the most debilitating symptoms for people with multiple sclerosis (PwMS). By consolidating a diverse and conflicting evidence-base, this systematic review and meta-analysis aimed to gain new insights into the neurobiology of MS fatigue. MEDLINE, ProQuest, CINAHL, Web of Science databases and grey literature were searched using Medical Subject Headings. Eligible studies compared neuroimaging and neurophysiological data between people experiencing high (MS-HF) versus low (MS-LF) levels of perceived MS fatigue, as defined by validated fatigue questionnaire cut-points. Data were available from 66 studies, with 46 used for meta-analyses. Neuroimaging studies revealed lower volumetric measures in MS-HF versus MS-LF for whole brain (-22.74 ml; 95% CI: -37.72 to -7.76 ml; p = 0.003), grey matter (-18.81 ml; 95% CI: -29.60 to -8.03 ml; p < 0.001), putamen (-0.40 ml; 95% CI: -0.69 to -0.10 ml; p = 0.008) and acumbens (-0.09 ml; 95% CI: -0.15 to -0.03 ml; p = 0.003) and a higher volume of T1-weighted hypointense lesions (1.10 ml; 95% CI: 0.47 to 1.73 ml; p < 0.001). Neurophysiological data showed reduced lower-limb maximum voluntary force production (-19.23 N; 95% CI: -35.93 to -2.53 N; p = 0.02) and an attenuation of upper-limb (-5.77%; 95% CI:-8.61 to -2.93%; p < 0.0001) and lower-limb (-2.16%; 95% CI:-4.24 to -0.07%; p = 0.04) skeletal muscle voluntary activation, accompanied by more pronounced upper-limb fatigability (-5.61%; 95% CI: -9.57 to -1.65%; p = 0.006) in MS-HF versus MS-LF. Results suggest that MS fatigue is characterised by greater cortico-subcortical grey matter atrophy and neural lesions, accompanied by neurophysiological decrements, which include reduced strength and voluntary activation. Prospero registration Prospero registration number: CRD42016017934.
Topics: Brain; Cross-Sectional Studies; Fatigue; Humans; Multiple Sclerosis; Organ Size
PubMed: 33961198
DOI: 10.1007/s11065-021-09508-1 -
Sports Medicine (Auckland, N.Z.) Jun 2022The 5' adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that is activated by increases in the cellular AMP/adenosine... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The 5' adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that is activated by increases in the cellular AMP/adenosine diphosphate:adenosine triphosphate (ADP:ATP) ratios and plays a key role in metabolic adaptations to endurance training. The degree of AMPK activation during exercise can be influenced by many factors that impact on cellular energetics, including exercise intensity, exercise duration, muscle glycogen, fitness level, and nutrient availability. However, the relative importance of these factors for inducing AMPK activation remains unclear, and robust relationships between exercise-related variables and indices of AMPK activation have not been established.
OBJECTIVES
The purpose of this analysis was to (1) investigate correlations between factors influencing AMPK activation and the magnitude of change in AMPK activity during cycling exercise, (2) investigate correlations between commonly reported measures of AMPK activation (AMPK-α2 activity, phosphorylated (p)-AMPK, and p-acetyl coenzyme A carboxylase (p-ACC), and (3) formulate linear regression models to determine the most important factors for AMPK activation during exercise.
METHODS
Data were pooled from 89 studies, including 982 participants (93.8% male, maximal oxygen consumption [[Formula: see text]] 51.9 ± 7.8 mL kg min). Pearson's correlation analysis was performed to determine relationships between effect sizes for each of the primary outcome markers (AMPK-α2 activity, p-AMPK, p-ACC) and factors purported to influence AMPK signaling (muscle glycogen, carbohydrate ingestion, exercise duration and intensity, fitness level, and muscle metabolites). General linear mixed-effect models were used to examine which factors influenced AMPK activation.
RESULTS
Significant correlations (r = 0.19-0.55, p < .05) with AMPK activity were found between end-exercise muscle glycogen, exercise intensity, and muscle metabolites phosphocreatine, creatine, and free ADP. All markers of AMPK activation were significantly correlated, with the strongest relationship between AMPK-α2 activity and p-AMPK (r = 0.56, p < 0.001). The most important predictors of AMPK activation were the muscle metabolites and exercise intensity.
CONCLUSION
Muscle glycogen, fitness level, exercise intensity, and exercise duration each influence AMPK activity during exercise when all other factors are held constant. However, disrupting cellular energy charge is the most influential factor for AMPK activation during endurance exercise.
Topics: AMP-Activated Protein Kinases; Acetyl-CoA Carboxylase; Adenosine Diphosphate; Adenosine Monophosphate; Female; Glycogen; Humans; Male; Muscle, Skeletal
PubMed: 34878641
DOI: 10.1007/s40279-021-01610-x -
Journal of Clinical Nursing Jul 2015The aims of this systematic review and meta-analysis were to summarise current knowledge regarding gum chewing intervention for activation of the gastrointestinal (GI)... (Meta-Analysis)
Meta-Analysis Review
AIMS AND OBJECTIVES
The aims of this systematic review and meta-analysis were to summarise current knowledge regarding gum chewing intervention for activation of the gastrointestinal (GI) system following caesarean delivery.
BACKGROUND
GI symptoms such as nausea, vomiting and defecatory difficulties are bothersome for women following a caesarean delivery. There is category A recommendation to not withhold oral intake postoperatively. However, current practice guidelines vary widely on time to initiate oral feeding post caesarean delivery, and additional research is needed. Gum chewing has been shown to stimulate the GI system in other postoperative patient populations.
DESIGN
A systematic review and meta-analysis.
METHODS
An electronic review was undertaken using the following resources: PubMed (Medline), CINAHL, EMBASE and ClinicalTrials.gov databases. Key words used in various combinations included cesarean section; cesarean delivery; postoperative chewing gum; bowel movement; bowel function and complications.
RESULTS
A total of 171 articles were found of which 166 were excluded: 157 were duplicates and the remainder did not meet the inclusion criteria. Five randomised control trials were included in the meta-analysis, focusing on gum chewing as an intervention as compared with a nongum chewing intervention, with a total of 846 participants. Compared with the nongum chewing group, gum chewing showed a beneficial impact on the major outcomes of digestive system activation, including bowel sound, gas passage and defecation.
CONCLUSIONS
This meta-analysis supports the effectiveness of gum chewing post caesarean delivery as a noninvasive/nonpharmacological intervention for reactivation of bowel movement.
RELEVANCE TO CLINICAL PRACTICE
Gum chewing in the immediate postoperative period following caesarean delivery may provide a socially acceptable, low-cost and safe intervention to reduce postcaesarean delivery GI complications and restore GI function.
Topics: Adult; Cesarean Section; Chewing Gum; Constipation; Female; Humans; Postoperative Nausea and Vomiting; Pregnancy
PubMed: 25850885
DOI: 10.1111/jocn.12836 -
Frontiers in Human Neuroscience 2017This review examined 83 articles using neuroimaging modalities to investigate the neural correlates underlying static and dynamic human balance control, with aims to... (Review)
Review
This review examined 83 articles using neuroimaging modalities to investigate the neural correlates underlying static and dynamic human balance control, with aims to support future mobile neuroimaging research in the balance control domain. Furthermore, this review analyzed the mobility of the neuroimaging hardware and research paradigms as well as the analytical methodology to identify and remove movement artifact in the acquired brain signal. We found that the majority of static balance control tasks utilized mechanical perturbations to invoke feet-in-place responses (27 out of 38 studies), while cognitive dual-task conditions were commonly used to challenge balance in dynamic balance control tasks (20 out of 32 studies). While frequency analysis and event related potential characteristics supported enhanced brain activation during static balance control, that in dynamic balance control studies was supported by spatial and frequency analysis. Twenty-three of the 50 studies utilizing EEG utilized independent component analysis to remove movement artifacts from the acquired brain signals. Lastly, only eight studies used truly mobile neuroimaging hardware systems. This review provides evidence to support an increase in brain activation in balance control tasks, regardless of mechanical, cognitive, or sensory challenges. Furthermore, the current body of literature demonstrates the use of advanced signal processing methodologies to analyze brain activity during movement. However, the static nature of neuroimaging hardware and conventional balance control paradigms prevent full mobility and limit our knowledge of neural mechanisms underlying balance control.
PubMed: 28443007
DOI: 10.3389/fnhum.2017.00170 -
Effects of joint stabilizers on proprioception and stability: A systematic review and meta-analysis.Physical Therapy in Sport : Official... May 2017The current review and meta-analysis systematically investigated the effect of joint stabilizers on proprioception, postural stability, and neurological activity. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The current review and meta-analysis systematically investigated the effect of joint stabilizers on proprioception, postural stability, and neurological activity.
METHODS
Systematic identification of published literature was performed on online databases; Scopus, PEDro, SportDiscus, and EMBASE, followed by a critical PEDro methodological quality appraisal. Data from the studies were extracted and summarized in a tabular format.
RESULTS
Of 2954 records, 50 studies, involving 1443 participants met our inclusion criteria. In the included studies, 60% of studies reported significant enhancements (p < 0.05), 19% of studies reported enhancements (p > 0.05) and 21% of studies reported no effects of joint stabilizers on proprioception and/or postural stability. Meta-analysis of pooled studies demonstrated beneficial effects of joint stabilizers on the knee (95% CI: 0.35°-0.61°) and ankle (at 10: 0.1°-0.65°) joint proprioception, and negligible effects on postural stability (-0.28°-0.19°).
CONCLUSION
The pooled evidence suggests that application of joint stabilizers enhances joint proprioception and stability by not merely altering the mechanical stability of the underlying musculoskeletal structures but by also causing subtle changes in cerebral haemodynamics and musculoskeletal activation. These findings support clinical implications of joint stabilizers as a prophylactic and rehabilitation measure in modern sports and rehabilitation settings.
Topics: Ankle Joint; Athletic Tape; Braces; Humans; Knee Joint; Postural Balance; Proprioception
PubMed: 28262354
DOI: 10.1016/j.ptsp.2016.05.006 -
Journal of Clinical Medicine Feb 2022Subjective tinnitus is the perception of sound without the presence of an external source. Increasing evidence suggests that tinnitus is associated with inflammation. In... (Review)
Review
Subjective tinnitus is the perception of sound without the presence of an external source. Increasing evidence suggests that tinnitus is associated with inflammation. In this systematic review, the role of inflammation in subjective tinnitus was studied. Nine animal and twenty human studies reporting inflammatory markers in both humans and animals with tinnitus were included. It was established that TNF-α and IL-1β are increased in tinnitus, and that microglia and astrocytes are activated as well. Moreover, platelet activation may also play a role in tinnitus. In addition, we elaborate on mechanisms of inflammation in tinnitus, and discuss potential treatment options targeting inflammatory pathways.
PubMed: 35207270
DOI: 10.3390/jcm11041000