Human spinal cord organoids(hSCOs)offer a promising platform to study neurotrauma by addressing many limitations of traditional research models.These organoids provide access to human-specific physiological and geneti...Human spinal cord organoids(hSCOs)offer a promising platform to study neurotrauma by addressing many limitations of traditional research models.These organoids provide access to human-specific physiological and genetic mechanisms and can be derived from an individual's somatic cells(e.g.,blood or skin).This enables patient-specific paradigms for precision neurotrauma research,pa rticula rly relevant to the over 300,000 people in the United States living with chronic effects of spinal cord injury(SCI).展开更多
Background:The Science,PE,&Me!(SPEM)curriculum is a concept-based physical education curriculum that offers students coherent educational experiences for constructing health-related fitness knowledge through movem...Background:The Science,PE,&Me!(SPEM)curriculum is a concept-based physical education curriculum that offers students coherent educational experiences for constructing health-related fitness knowledge through movement experiences.The purpose of this study was to evaluate students’motivational response to the SPEM curriculum from the situational interest perspective.Methods:The study used a cluster randomized controlled design in which 30 elementary schools in one of the largest metropolitan areas in the eastern United States were randomly assigned to an experimental or comparison condition.Although all students in the 3rd,4th,and 5th grades in the targeted schools were eligible to participate in the study,a random sample of students from the experimental(n=1749;15 schools)and comparison groups(n=1985;15 schools)provided data.Students’motivational response to the SPEM curriculum or comparison curriculum was measured using the previously validated Situational Interest Scale-Elementary.Data were analyzed using structural mean modeling.Results:The results demonstrated that the experimental group(as reference group)showed significantly higher enjoyment(z=-2.01),challenge(z=-6.54),exploration(z=-12.195),novelty(z=-8.80),and attention demand(z=-7.90)than the comparison group.Conclusion:The findings indicate that the SPEM curriculum created a more situationally interesting context for learning than the comparison physical education curriculum.展开更多
BRICS is the acronym for an international association of 5 major emerging national economies： Brazil, Russia, India, China, and South Africa.According to the World Economic Forum, the BRICS economies are the most com...BRICS is the acronym for an international association of 5 major emerging national economies： Brazil, Russia, India, China, and South Africa.According to the World Economic Forum, the BRICS economies are the most competitive among all cotmtries and are distinguished by their significant regional and global influence. The health and wellness of the people within these countries is a primary agenda item of these governments for connecting their fast economic growth and the need to provide a better quality of life. As of 2015, BRICS countries represent 〉3.6 billion people or one-half of the world population. All 5 countries are members of the top 25 countries of the world by population and 4 of these cotmtries make the top 10 on this list.展开更多
Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets an...Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.展开更多
Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Hunting...Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Huntington’s disease)differ substantially between males and females.The higher prevalence of these brain disorders has been attributed to females having a greater longevity compared with males.Since one of the greatest risk factors of acquired brain injury(such as stroke,traumatic brain injury caused by fall)and neurodegenerative disease is age.展开更多
The maximal force a muscle can exert depends on its length,which has been explained by the sliding filament theory on the sarcomere level.1 A longer muscle can act over a greater range of motion and has more sarcomere...The maximal force a muscle can exert depends on its length,which has been explained by the sliding filament theory on the sarcomere level.1 A longer muscle can act over a greater range of motion and has more sarcomeres in series,which increases its capacity to produce force at a specific muscle contraction velocity because each sarcomere contracts at a lower velocity.展开更多
The first in vivo measurements of serial sarcomere number in human muscles before and after eccentric strength training have just been published and the results will interest anyone involved with sport or health:Train...The first in vivo measurements of serial sarcomere number in human muscles before and after eccentric strength training have just been published and the results will interest anyone involved with sport or health:Training the hamstrings 3 times per week for 9 weeks with the Nordic hamstring exercise was found to increase the number of sarcomeres in series in the biceps femoris long head(BFlh)by≥25%.1 In this commentary,we highlight an additional,paradoxical finding,which was not discussed by the authors;namely that the substantial serial sarcomere addition must have been accompanied by a subtraction of sarcomeres in parallel to match the relatively small increase in muscle volume after training.展开更多
Background:Integrating metabolomics in sports science provides valuable insights into the biochemistry of bodies during physical activity.However,due to their invasiveness,traditional blood sampling methods present ch...Background:Integrating metabolomics in sports science provides valuable insights into the biochemistry of bodies during physical activity.However,due to their invasiveness,traditional blood sampling methods present challenges in sports settings.The study investigated sex-specific metabolic responses,addressing a significant gap in exercise research,where female participation remains underrepresented.Methods:To address this,we explored volumetrically accurate microsampling as a dried blood spot(DBS)technique for assessing metabolomic changes in response to acute exercise in more than 130 participants.This study employed a targeted quantitative approach using isotopically labeled internal standards to measure over 100 metabolites with DBS,providing accurate and traceable results.An accuracy assessment using standard reference material and stability testing over 90 days further evaluated the suitability of DBS for sports metabolomics.Results:Our findings confirm that DBS offers a valid approach to capture metabolic changes during exercise,with 11 compounds within the confidence interval of the reference material and 59 compounds overlapping with database values.A wide panel of metabolites showed significant changes in differences of absolute concentrations upon bout exercise,with succinate and xanthine being the most significant compounds.Metabolites from the underexplored class of pyrimidines also showed significant changes.Conclusion:While metabolic regulations upon exercise are similar in both sexes,differences in the correlation with fitness-related metadata,such as peak volitional oxygen consumption and performance,indicate a higher complexity in women and a limitation of previous knowledge to men only.The quantification approach together with the simplicity of the sampling paves the way to expand this type of research toward other fields of personalized medical services.展开更多
Introduction:Consumer wearables increasingly provide users with Composite Health Scores(CHS)–integrated biometric indices that claim to quantify readiness,recovery,stress,or overall well-being.Despite their growing a...Introduction:Consumer wearables increasingly provide users with Composite Health Scores(CHS)–integrated biometric indices that claim to quantify readiness,recovery,stress,or overall well-being.Despite their growing adoption,the validity,transparency,and physiological relevance of these scores remain unclear.This study systematically evaluates CHS fromleading wearablemanufacturers to assess their underlying methodologies,contributors,and scientific basis.Content:Information was synthesised from publicly available company documentation,including technical white papers,user manuals,app interfaces,and research literature where available.We identified 14 CHS across 10 major wearable manufacturers,including Fitbit(Daily Readiness),Garmin(Body Battery^(TM)and Training Readiness),Oura(Readiness and Resilience),WHOOP(Strain,Recovery,and Stress Monitor),Polar(Nightly Recharge^(TM)),Samsung(Energy Score),Suunto(Body Resources),Ultrahuman(Dynamic Recovery),Coros(Daily Stress),and Withings(Health Improvement Score).The most frequently incorporated biometric contributors in this catalogue of CHS were heart rate variability(86%),resting heart rate(79%),physical activity(71%),and sleep duration(71%).However,significant discrepancies were identified in data collection timeframes,metric weighting,and proprietary scoring methodologies.None of the manufacturers disclosed their exact algorithmic formulas,and few provided empirical validation or peer-reviewed evidence supporting the accuracy or clinical relevance of their scores.Summary and outlook:While the concept of CHS represent a promising innovation in digital health,their scientific validity,transparency,and clinical applicability remain uncertain.Future research should focus on establishing standardized sensor fusion frameworks,improving algorithmic transparency,and evaluating CHS across diverse populations.Greater collaboration between industry,researchers,and clinicians is essential to ensure these indices serve as meaningful health metrics rather than opaque consumer tools.展开更多
Background:The perception of effort is a key determinant of endurance performance and a barrier to physical activity in inactive populations.From a neurophysiological viewpoint,effort perception is thought to arise fr...Background:The perception of effort is a key determinant of endurance performance and a barrier to physical activity in inactive populations.From a neurophysiological viewpoint,effort perception is thought to arise from the brain processing of an efference copy of the motor command in sensory areas.However,recent research suggests that feedback from muscle spindles plays a significant role in this perception.In this study,tendon vibration protocols were employed to attenuate sensory feedback during subsequent cycling exercises.The aim was to assess whether vibration would increase cycling power output,muscle activation,and heart rate at fixed perceived effort intensities.Methods:Fifteen healthy young participants completed 2 experimental visits(vibration and sham).In each visit,participants performed two 3-min cycling bouts,1 at a moderate perceived effort intensity and 1 at a strong perceived effort intensity,before(pre)and after(post)an actual or a sham vibration protocol.Vibration was applied bilaterally on the patellar and Achilles tendons for 10 min.Power output,heart rate,and vastus lateralis electromyography(VL EMG)were recorded and averaged for each bout.Absolute values as well as relative change(%)between pre and post conditions were compared across sham and vibration conditions.Results:At moderate perceived effort,power output,heart rate,and VL EMG increased post-vibration compared to pre-vibration(p<0.05),while no difference was observed in the sham condition.At strong perceived effort,power output and VL EMG decreased post-sham(p<0.05)but remained unchanged post-vibration.Moreover,the relative change between pre and post conditions was significantly higher in the vibration conditions compared to the sham condition for all variables.Conclusion:This study shows that tendon vibration reduces effort perception during subsequent cycling bouts.This effect is likely a consequence of vibration-induced reduction in muscle spindle reafferent signaling to the brain,but this mechanism remains to be further elucidated.From an applied perspective,these findings highlight tendon vibration as a promising tool for enhancing physical activity engagement.展开更多
Musculoskeletal Symptoms(MSS)often arise from prolonged maintenance of bent postures in the neck and trunk during surgical procedures.To prevent MSS,a passive exoskeleton utilizing carbon fiber beams to offer support ...Musculoskeletal Symptoms(MSS)often arise from prolonged maintenance of bent postures in the neck and trunk during surgical procedures.To prevent MSS,a passive exoskeleton utilizing carbon fiber beams to offer support to the neck and trunk was proposed.The application of support force is intended to reduce muscle forces and joint compression forces.A nonlinear mathematical model for the neck and trunk support beam is presented to estimate the support force.A validation test is subsequently conducted to assess the accuracy of the mathematical model.Finally,a preliminary functional evaluation test is performed to evaluate movement capabilities and support provided by the exoskeleton.The mathematical model demonstrates an accuracy for beam support force within a range of 0.8–1.2 N Root Mean Square Error(RMSE).The exoskeleton was shown to allow sufficient Range of Motion(ROM)for neck and trunk during open surgery training.While the exoskeleton showed potential in reducing musculoskeletal load and task difficulty during simulated surgery tasks,the observed reduction in perceived task difficulty was deemed non-significant.This prompts the recommendation for further optimization in personalized adjustments of beams to facilitate improvements in task difficulty and enhance comfort.展开更多
Background:Due to its high relevance in sports and rehabilitation,the exploration of interventions to further optimize flexibility becomes paramount.While stretching might be the most common way to enhance range of mo...Background:Due to its high relevance in sports and rehabilitation,the exploration of interventions to further optimize flexibility becomes paramount.While stretching might be the most common way to enhance range of motion,these increases could be optimized by imposing an additional activation of the muscle,such as mechanical vibratory stimulation.While several original articles provide promising findings,contradictory results on flexibility and underlying mechanisms(e.g.,stiffness),reasonable effect size(ES)pooling remains scarce.With this work we systematically reviewed the available literature to explore the possibility of potentiating flexibility,stiffness,and passive torque adaptations by superimposing mechanical vibration stimulation.Methods:A systematic search of 4 databases(Web of Science,MEDLINE,Scopus,and Cochrane Public Library)was conducted until December2023 to identify studies comparing mechanical vibratory interventions with passive controls or the same intervention without vibration(sham)on range of motion and passive muscle stiffness in acute(immediate effects after single session)and chronic conditions(multiple sessions over a period of time).ES pooling was conducted using robust variance estimation via R to account for multiple study outcomes.Potential moderators of effects were analyzed using meta regression.Results:Overall,65 studies(acute:1162 participants,chronic:788 participants)were included.There was moderate certainty of evidence for acute flexibility(ES=0.71,p<0.001)and stiffness(ES=-0.89,p=0.006)effects of mechanical vibration treatments vs.passive controls without meaningful results against the sham condition(flexibility:ES=0.20,p<0.001;stiffness:ES=-0.19,p=0.076).Similarly,moderate certainty of evidence was found for chronic vibration effects on flexibility(control:ES=0.64,p=0.043;sham:ES=0.65,p<0.001).Lack of studies and large outcome heterogeneity prevented ES pooling for underlying mechanisms.Conclusion:Vibration improved flexibility in acute and chronic interventions compared to the stand-alone intervention,which can possibly be attributed to an accumulated mechanical stimulus through vibration.However,studies on biological mechanisms are needed to explain flexibility and stiffness effects in response to specific vibration modalities and timing.展开更多
Background:Stretching has wide appeal,but there seems to exist some mismatch between its purported applications and what the evidence shows.There is compelling evidence for some stretching applications,but for others,...Background:Stretching has wide appeal,but there seems to exist some mismatch between its purported applications and what the evidence shows.There is compelling evidence for some stretching applications,but for others,the evidence seems heterogeneous or unsupportive.The discrepancies even affect some systematic reviews,possibly due to heterogeneous eligibility criteria and search strategies.This consensus paper seeks to unify the divergent findings on stretching and its implications for both athletic performance and clinical practices by delivering evidence-based recommendations.Methods:A panel of 20 experts with a blend of practical experience and scholarly knowledge was assembled.The panel meticulously reviewed existing systematic reviews,defined key terminologies(e.g.,consensus definitions for different stretching modes),and crafted guidelines using a Delphi consensus approach(minimum required agreement:80%).The analysis focused on 8 topics,including stretching's acute and chronic(long-term)effects on range of motion,strength performance,muscle hypertrophy,stiffness,injury prevention,muscle recovery,posture correction,and cardiovascular health.Results:There was consensus that chronic and acute stretching(a)improves range of motion(although alternatives exist)and(b)reduces muscle stiffness(which may not always be desirable);the panel also agreed that chronic stretching(c)may promote vascular health,but more research is warranted.In contrast,consensus was found that stretch training does not(a)contribute substantively to muscle growth,(b)serve as an allencompassing injury prevention strategy,(c)improve posture,or(d)acutely enhance post-exercise recovery.Conclusion:These recommendations provide guidance for athletes and practitioners,highlighting research gaps that should be addressed to more comprehensively understand the full scope of stretching effects.展开更多
Purpose: This study presents the most recent estimates of prevalence of overweight, obesity, and screen-time viewing among Chinese school-aged children. Demographic differences in these estimates between sexes and res...Purpose: This study presents the most recent estimates of prevalence of overweight, obesity, and screen-time viewing among Chinese school-aged children. Demographic differences in these estimates between sexes and resident locales were also examined.Methods: Cross-sectional analyses of 116,615 Chinese school children 9 to 17 years of age who participated in the 2016 Physical Activity and Fitness in China—The Youth Study project. Outcomes were the prevalence of children's overweight(85 th ≤ body mass index(BMI) < 95 th percentile) and obesity(BMI ≥95 th percentile)(defined by the Working Group on Obesity in China) and not meeting screen-time viewing recommendations("not meeting" was defined as more than 2 h per day of viewing activities after school). Analyses were conducted on the whole sample and by school grade cohorts(primary, junior middle, and junior high schools), sex, and residence locales(urban, rural).Results: Overall, 14.4%(95% confidence interval(CI): 13.8%–15.0%) of children and adolescents were overweight, 11.9%(95%CI: 11.0%–13.0%) were obese, and 36.8%(95%CI: 34.7%–38.9%) did not meet screen-time viewing recommendations. Across the 3-grade cohorts, boys were more likely to be obese than girls, and primary and junior middle school children living in urban areas were more likely to be obese than those living in rural areas. Primary and junior middle school boys were less likely to meet screen-time recommendations than girls, and junior high school children living in urban areas were less likely to meet screen-time recommendations than school children of the same grades living in rural areas.Conclusion: In 2016, the prevalence of obesity among Chinese school children was about 12%, and about 37% of them did not meet screen-time viewing recommendations. The prevalence of obesity and sedentary behavior was generally higher among boys than among girls, and it was higher for children living in urban areas than for those living in rural areas.展开更多
Gestational diabetes mellitus(GDM)is the most prevalent metabolic disorder during pregnancy.Women diagnosed with GDM have a substantially greater risk of developing type 2 diabetes within 5-10 years after delivery,and...Gestational diabetes mellitus(GDM)is the most prevalent metabolic disorder during pregnancy.Women diagnosed with GDM have a substantially greater risk of developing type 2 diabetes within 5-10 years after delivery,and the risk is increased by excess body weight.Uncontrolled hyperglycemia during pregnancy is potentially harmful to both mother and fetus,resulting in a greater need for Caesarian-section deliveries,delivery of larger infants with more excess body fat,a greater risk of infant death and stillbirth,and an elevated risk of infant hypoglycemia immediately after birth.Fortunately,engaging in physical activity prior to and during pregnancy may lower the risk of developing GDM.Pregnant women should also be advised how to safely increase their physical activity during pregnancy and the postpartum period.An initial approach to becoming more physically active can simply be to encourage women to incorporate more unstructured physical activity into daily living,both before and during pregnancy.Giving women an appropriate exercise prescription can encourage them to participate in physical activity safely and effectively throughout pregnancy to prevent and/or manage GDM.Engaging in 30 min of moderate intensity physical activity on most,if not all,days of the week has been adopted as a recommendation for all pregnant women.展开更多
Hamstring strains are one of most common sports injuries.The purpose of this literature review is to summarize studies on hamstring strain injury rate,mechanism,and risk factors in the last several decades with a focu...Hamstring strains are one of most common sports injuries.The purpose of this literature review is to summarize studies on hamstring strain injury rate,mechanism,and risk factors in the last several decades with a focus on the prevention and rehabilitation of this injury.Hamstring injury commonly occurs in sporting events in which high speed sprinting and kicking are frequently performed,such as Australian football. English rugby,American football,and soccer.Basic science studies have demonstrated that a muscle strain injury occurs due to excessive strain in eccentric contraction instead of force,and that elongation speed and duration of activation before eccentric contraction affect the severity of the injury.Hamstring strain injury is likely to occur during the late swing phase and late stance phase of sprint running.Shortened optimum muscle length,lack of muscle flexibility,strength imbalance,insufficient warm-up,fatigue,lower back injury,poor lumbar posture,and increased muscle neural tension have been identified as modifiable risk factors while muscle compositions,age,race,and previous injuries are non-modifiable risk factors.The theoretical basis of some of these risk factors,however,is lacking,and the results of clinical studies on these risk factors are inconsistent.Future studies are needed to establish the cause-and-effect relationships between those proposed risk factors and the injury.展开更多
Background: The activities carried out by soldiers in the army involve great physical demands and require intense trainings to perform combat-specific tasks. Musculoskeletal injury is a potential threat to the health ...Background: The activities carried out by soldiers in the army involve great physical demands and require intense trainings to perform combat-specific tasks. Musculoskeletal injury is a potential threat to the health and physical integrity of the soldier. This study aimed to evaluate the prevalence of lower limb musculoskeletal injuries among soldiers and to propose a training protocol to prevent the most frequent injuries.Methods: This observational(cross-sectional) study recruited a sample of 103 soldiers who required medical attention,from a total 202 new battalion soldiers. The medical records(paper and online) had a form of running text. All data collected were recorded by the registered physicians of the battalion medical post. The records were analyzed by the following variables: medical diagnosis, injury site, mechanism, type of treatment, time loss, existence of previous injury,and recurring injury.Results: A total of 112 musculoskeletal injuries were diagnosed in 71 soldiers, and other types of diseases/injuries were diagnosed in the other soldiers. Joint pain accounted for 55.4% of the diagnoses. The knee was the most affected site, while trauma and overload were the most common mechanisms of injury. Drug treatment was used most frequently, accounting for 58% of the cases. The majority of the sample obtained a temporary leave of absence for1 to 6 days or not at all. Previous injuries and recurrence were not presented as risk factors for injury. With the data received, a protocol for the prevention of injuries to the lower limbs was proposed.Conclusions: This study indicated that the most frequent site of injury is the knee, and joint pain is the most common diagnosis. These results may support the necessity to develop a neuromuscular training protocol to prevent lower limb injuries, which we suggest to be applied in future studies.展开更多
Hamstring muscle strain injury is one of the most common injuries in sports involving sprinting and kicking.Hamstring muscle strain injuries occur at a high rate and have a high re-injury rate,which results in loss of...Hamstring muscle strain injury is one of the most common injuries in sports involving sprinting and kicking.Hamstring muscle strain injuries occur at a high rate and have a high re-injury rate,which results in loss of training and competition time,which has a significant impact on the quality of life of the injured athletes.~1Preventing and rehabilitating hamstring muscle strain injury is an important task for clinicians and scientists in sports medicine.Understanding the mechanisms underlying hamstring injury is critical for developing appropriate strategies to prevent and rehabilitate hamstring injuries.Understanding the展开更多
Background:Hamstring muscle strain injury(hamstring injury) due to excessive muscle strain is one of the most common injuries in sports.The relationships among hamstring muscle optimal lengths and hamstring flexibilit...Background:Hamstring muscle strain injury(hamstring injury) due to excessive muscle strain is one of the most common injuries in sports.The relationships among hamstring muscle optimal lengths and hamstring flexibility and strength were unknown,which limited our understanding of risk factors for hamstring injury.This study was aimed at examining the relationships among hamstring muscle optimal length and flexibility and strength.Methods:Hamstring flexibility and isokinetic strength data and three-dimensional kinematic data for hamstring isokinetic tests were collected for11 male and 10 female recreational athletes.The maximal hamstring muscle forces,optimal lengths,and muscle lengths in standing were determined for each participant.Results:Hamstring muscle optimal lengths were significantly correlated to hamstring flexibility score and gender,but not to hamstring strength.The greater the flexibility score,the longer the hamstring muscle optimal length.With the same flexibility score,females tend to have shorter hamstring optimal muscle lengths compared to males.Hamstring flexibility score and hamstring strength were not correlated.Hamstring muscle optimal lengths were longer than but not significantly correlated to corresponding hamstring muscle lengths in standing.Conclusion:Hamstring flexibility may affect hamstring muscle maximum strain in movements.With similar hamstring flexibility,hamstring muscle maximal strain in a given movement may be different between genders.Hamstring muscle lengths in standing should not be used as an approximation of their optimal lengths in calculation of hamstring muscle strain in musculoskeletal system modeling.展开更多
基金supported by the Belle Carnell Regenerative Neurorehabilitation Fundthe National Institutes of Health(R01NS113935 to CKF)。
文摘Human spinal cord organoids(hSCOs)offer a promising platform to study neurotrauma by addressing many limitations of traditional research models.These organoids provide access to human-specific physiological and genetic mechanisms and can be derived from an individual's somatic cells(e.g.,blood or skin).This enables patient-specific paradigms for precision neurotrauma research,pa rticula rly relevant to the over 300,000 people in the United States living with chronic effects of spinal cord injury(SCI).
基金the Office of the Director,U.S.National Institutes of Health,under Award Number R25RR015674-1.
文摘Background:The Science,PE,&Me!(SPEM)curriculum is a concept-based physical education curriculum that offers students coherent educational experiences for constructing health-related fitness knowledge through movement experiences.The purpose of this study was to evaluate students’motivational response to the SPEM curriculum from the situational interest perspective.Methods:The study used a cluster randomized controlled design in which 30 elementary schools in one of the largest metropolitan areas in the eastern United States were randomly assigned to an experimental or comparison condition.Although all students in the 3rd,4th,and 5th grades in the targeted schools were eligible to participate in the study,a random sample of students from the experimental(n=1749;15 schools)and comparison groups(n=1985;15 schools)provided data.Students’motivational response to the SPEM curriculum or comparison curriculum was measured using the previously validated Situational Interest Scale-Elementary.Data were analyzed using structural mean modeling.Results:The results demonstrated that the experimental group(as reference group)showed significantly higher enjoyment(z=-2.01),challenge(z=-6.54),exploration(z=-12.195),novelty(z=-8.80),and attention demand(z=-7.90)than the comparison group.Conclusion:The findings indicate that the SPEM curriculum created a more situationally interesting context for learning than the comparison physical education curriculum.
文摘BRICS is the acronym for an international association of 5 major emerging national economies： Brazil, Russia, India, China, and South Africa.According to the World Economic Forum, the BRICS economies are the most competitive among all cotmtries and are distinguished by their significant regional and global influence. The health and wellness of the people within these countries is a primary agenda item of these governments for connecting their fast economic growth and the need to provide a better quality of life. As of 2015, BRICS countries represent 〉3.6 billion people or one-half of the world population. All 5 countries are members of the top 25 countries of the world by population and 4 of these cotmtries make the top 10 on this list.
基金funded by Eurostars project,grant number E!12764。
文摘Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.
基金supported by NIH/NICHD RO1HD109157supported by his American Heart AssociationAward Career Development Award (932980)National Science Foundation CAREER award (NSF2401215)
文摘Background:The prevalence,age of onset,and symptomatology of traumatic brain injury,stroke,and neurodegenerative diseases(such as Alzheimer’s disease(AD),Parkinson’s disease,amyotrophic lateral sclerosis,and Huntington’s disease)differ substantially between males and females.The higher prevalence of these brain disorders has been attributed to females having a greater longevity compared with males.Since one of the greatest risk factors of acquired brain injury(such as stroke,traumatic brain injury caused by fall)and neurodegenerative disease is age.
文摘The maximal force a muscle can exert depends on its length,which has been explained by the sliding filament theory on the sarcomere level.1 A longer muscle can act over a greater range of motion and has more sarcomeres in series,which increases its capacity to produce force at a specific muscle contraction velocity because each sarcomere contracts at a lower velocity.
文摘The first in vivo measurements of serial sarcomere number in human muscles before and after eccentric strength training have just been published and the results will interest anyone involved with sport or health:Training the hamstrings 3 times per week for 9 weeks with the Nordic hamstring exercise was found to increase the number of sarcomeres in series in the biceps femoris long head(BFlh)by≥25%.1 In this commentary,we highlight an additional,paradoxical finding,which was not discussed by the authors;namely that the substantial serial sarcomere addition must have been accompanied by a subtraction of sarcomeres in parallel to match the relatively small increase in muscle volume after training.
基金This work is supported by the University of Vienna,the Faculty of Chemistry and Centre for Sport Science and University Sports.The Vienna Business Agency,Austria funded FR.
文摘Background:Integrating metabolomics in sports science provides valuable insights into the biochemistry of bodies during physical activity.However,due to their invasiveness,traditional blood sampling methods present challenges in sports settings.The study investigated sex-specific metabolic responses,addressing a significant gap in exercise research,where female participation remains underrepresented.Methods:To address this,we explored volumetrically accurate microsampling as a dried blood spot(DBS)technique for assessing metabolomic changes in response to acute exercise in more than 130 participants.This study employed a targeted quantitative approach using isotopically labeled internal standards to measure over 100 metabolites with DBS,providing accurate and traceable results.An accuracy assessment using standard reference material and stability testing over 90 days further evaluated the suitability of DBS for sports metabolomics.Results:Our findings confirm that DBS offers a valid approach to capture metabolic changes during exercise,with 11 compounds within the confidence interval of the reference material and 59 compounds overlapping with database values.A wide panel of metabolites showed significant changes in differences of absolute concentrations upon bout exercise,with succinate and xanthine being the most significant compounds.Metabolites from the underexplored class of pyrimidines also showed significant changes.Conclusion:While metabolic regulations upon exercise are similar in both sexes,differences in the correlation with fitness-related metadata,such as peak volitional oxygen consumption and performance,indicate a higher complexity in women and a limitation of previous knowledge to men only.The quantification approach together with the simplicity of the sampling paves the way to expand this type of research toward other fields of personalized medical services.
基金funded by the Health Research Board in Ireland(Grant ID:HRB ILP-PHR-2024-005)Research Ireland(Grant ID:12/RC/2289_P2).
文摘Introduction:Consumer wearables increasingly provide users with Composite Health Scores(CHS)–integrated biometric indices that claim to quantify readiness,recovery,stress,or overall well-being.Despite their growing adoption,the validity,transparency,and physiological relevance of these scores remain unclear.This study systematically evaluates CHS fromleading wearablemanufacturers to assess their underlying methodologies,contributors,and scientific basis.Content:Information was synthesised from publicly available company documentation,including technical white papers,user manuals,app interfaces,and research literature where available.We identified 14 CHS across 10 major wearable manufacturers,including Fitbit(Daily Readiness),Garmin(Body Battery^(TM)and Training Readiness),Oura(Readiness and Resilience),WHOOP(Strain,Recovery,and Stress Monitor),Polar(Nightly Recharge^(TM)),Samsung(Energy Score),Suunto(Body Resources),Ultrahuman(Dynamic Recovery),Coros(Daily Stress),and Withings(Health Improvement Score).The most frequently incorporated biometric contributors in this catalogue of CHS were heart rate variability(86%),resting heart rate(79%),physical activity(71%),and sleep duration(71%).However,significant discrepancies were identified in data collection timeframes,metric weighting,and proprietary scoring methodologies.None of the manufacturers disclosed their exact algorithmic formulas,and few provided empirical validation or peer-reviewed evidence supporting the accuracy or clinical relevance of their scores.Summary and outlook:While the concept of CHS represent a promising innovation in digital health,their scientific validity,transparency,and clinical applicability remain uncertain.Future research should focus on establishing standardized sensor fusion frameworks,improving algorithmic transparency,and evaluating CHS across diverse populations.Greater collaboration between industry,researchers,and clinicians is essential to ensure these indices serve as meaningful health metrics rather than opaque consumer tools.
基金supported by the French National Research Agency(Agence Nationale de la Recherche,ANR,Grant No.ANR-23-CE37-0014)for the Effort_(LESS)Project.
文摘Background:The perception of effort is a key determinant of endurance performance and a barrier to physical activity in inactive populations.From a neurophysiological viewpoint,effort perception is thought to arise from the brain processing of an efference copy of the motor command in sensory areas.However,recent research suggests that feedback from muscle spindles plays a significant role in this perception.In this study,tendon vibration protocols were employed to attenuate sensory feedback during subsequent cycling exercises.The aim was to assess whether vibration would increase cycling power output,muscle activation,and heart rate at fixed perceived effort intensities.Methods:Fifteen healthy young participants completed 2 experimental visits(vibration and sham).In each visit,participants performed two 3-min cycling bouts,1 at a moderate perceived effort intensity and 1 at a strong perceived effort intensity,before(pre)and after(post)an actual or a sham vibration protocol.Vibration was applied bilaterally on the patellar and Achilles tendons for 10 min.Power output,heart rate,and vastus lateralis electromyography(VL EMG)were recorded and averaged for each bout.Absolute values as well as relative change(%)between pre and post conditions were compared across sham and vibration conditions.Results:At moderate perceived effort,power output,heart rate,and VL EMG increased post-vibration compared to pre-vibration(p<0.05),while no difference was observed in the sham condition.At strong perceived effort,power output and VL EMG decreased post-sham(p<0.05)but remained unchanged post-vibration.Moreover,the relative change between pre and post conditions was significantly higher in the vibration conditions compared to the sham condition for all variables.Conclusion:This study shows that tendon vibration reduces effort perception during subsequent cycling bouts.This effect is likely a consequence of vibration-induced reduction in muscle spindle reafferent signaling to the brain,but this mechanism remains to be further elucidated.From an applied perspective,these findings highlight tendon vibration as a promising tool for enhancing physical activity engagement.
基金funded by China Scholarship Council,Grant Number 201906840121department of rehabilitation medicine,University Medical Center Groningen,University of Groningen,grant number:O/085350.
文摘Musculoskeletal Symptoms(MSS)often arise from prolonged maintenance of bent postures in the neck and trunk during surgical procedures.To prevent MSS,a passive exoskeleton utilizing carbon fiber beams to offer support to the neck and trunk was proposed.The application of support force is intended to reduce muscle forces and joint compression forces.A nonlinear mathematical model for the neck and trunk support beam is presented to estimate the support force.A validation test is subsequently conducted to assess the accuracy of the mathematical model.Finally,a preliminary functional evaluation test is performed to evaluate movement capabilities and support provided by the exoskeleton.The mathematical model demonstrates an accuracy for beam support force within a range of 0.8–1.2 N Root Mean Square Error(RMSE).The exoskeleton was shown to allow sufficient Range of Motion(ROM)for neck and trunk during open surgery training.While the exoskeleton showed potential in reducing musculoskeletal load and task difficulty during simulated surgery tasks,the observed reduction in perceived task difficulty was deemed non-significant.This prompts the recommendation for further optimization in personalized adjustments of beams to facilitate improvements in task difficulty and enhance comfort.
文摘Background:Due to its high relevance in sports and rehabilitation,the exploration of interventions to further optimize flexibility becomes paramount.While stretching might be the most common way to enhance range of motion,these increases could be optimized by imposing an additional activation of the muscle,such as mechanical vibratory stimulation.While several original articles provide promising findings,contradictory results on flexibility and underlying mechanisms(e.g.,stiffness),reasonable effect size(ES)pooling remains scarce.With this work we systematically reviewed the available literature to explore the possibility of potentiating flexibility,stiffness,and passive torque adaptations by superimposing mechanical vibration stimulation.Methods:A systematic search of 4 databases(Web of Science,MEDLINE,Scopus,and Cochrane Public Library)was conducted until December2023 to identify studies comparing mechanical vibratory interventions with passive controls or the same intervention without vibration(sham)on range of motion and passive muscle stiffness in acute(immediate effects after single session)and chronic conditions(multiple sessions over a period of time).ES pooling was conducted using robust variance estimation via R to account for multiple study outcomes.Potential moderators of effects were analyzed using meta regression.Results:Overall,65 studies(acute:1162 participants,chronic:788 participants)were included.There was moderate certainty of evidence for acute flexibility(ES=0.71,p<0.001)and stiffness(ES=-0.89,p=0.006)effects of mechanical vibration treatments vs.passive controls without meaningful results against the sham condition(flexibility:ES=0.20,p<0.001;stiffness:ES=-0.19,p=0.076).Similarly,moderate certainty of evidence was found for chronic vibration effects on flexibility(control:ES=0.64,p=0.043;sham:ES=0.65,p<0.001).Lack of studies and large outcome heterogeneity prevented ES pooling for underlying mechanisms.Conclusion:Vibration improved flexibility in acute and chronic interventions compared to the stand-alone intervention,which can possibly be attributed to an accumulated mechanical stimulus through vibration.However,studies on biological mechanisms are needed to explain flexibility and stiffness effects in response to specific vibration modalities and timing.
文摘Background:Stretching has wide appeal,but there seems to exist some mismatch between its purported applications and what the evidence shows.There is compelling evidence for some stretching applications,but for others,the evidence seems heterogeneous or unsupportive.The discrepancies even affect some systematic reviews,possibly due to heterogeneous eligibility criteria and search strategies.This consensus paper seeks to unify the divergent findings on stretching and its implications for both athletic performance and clinical practices by delivering evidence-based recommendations.Methods:A panel of 20 experts with a blend of practical experience and scholarly knowledge was assembled.The panel meticulously reviewed existing systematic reviews,defined key terminologies(e.g.,consensus definitions for different stretching modes),and crafted guidelines using a Delphi consensus approach(minimum required agreement:80%).The analysis focused on 8 topics,including stretching's acute and chronic(long-term)effects on range of motion,strength performance,muscle hypertrophy,stiffness,injury prevention,muscle recovery,posture correction,and cardiovascular health.Results:There was consensus that chronic and acute stretching(a)improves range of motion(although alternatives exist)and(b)reduces muscle stiffness(which may not always be desirable);the panel also agreed that chronic stretching(c)may promote vascular health,but more research is warranted.In contrast,consensus was found that stretch training does not(a)contribute substantively to muscle growth,(b)serve as an allencompassing injury prevention strategy,(c)improve posture,or(d)acutely enhance post-exercise recovery.Conclusion:These recommendations provide guidance for athletes and practitioners,highlighting research gaps that should be addressed to more comprehensively understand the full scope of stretching effects.
基金supported by the Key Project of the National Social Science Foundation of China (No. 16ZDA227)
文摘Purpose: This study presents the most recent estimates of prevalence of overweight, obesity, and screen-time viewing among Chinese school-aged children. Demographic differences in these estimates between sexes and resident locales were also examined.Methods: Cross-sectional analyses of 116,615 Chinese school children 9 to 17 years of age who participated in the 2016 Physical Activity and Fitness in China—The Youth Study project. Outcomes were the prevalence of children's overweight(85 th ≤ body mass index(BMI) < 95 th percentile) and obesity(BMI ≥95 th percentile)(defined by the Working Group on Obesity in China) and not meeting screen-time viewing recommendations("not meeting" was defined as more than 2 h per day of viewing activities after school). Analyses were conducted on the whole sample and by school grade cohorts(primary, junior middle, and junior high schools), sex, and residence locales(urban, rural).Results: Overall, 14.4%(95% confidence interval(CI): 13.8%–15.0%) of children and adolescents were overweight, 11.9%(95%CI: 11.0%–13.0%) were obese, and 36.8%(95%CI: 34.7%–38.9%) did not meet screen-time viewing recommendations. Across the 3-grade cohorts, boys were more likely to be obese than girls, and primary and junior middle school children living in urban areas were more likely to be obese than those living in rural areas. Primary and junior middle school boys were less likely to meet screen-time recommendations than girls, and junior high school children living in urban areas were less likely to meet screen-time recommendations than school children of the same grades living in rural areas.Conclusion: In 2016, the prevalence of obesity among Chinese school children was about 12%, and about 37% of them did not meet screen-time viewing recommendations. The prevalence of obesity and sedentary behavior was generally higher among boys than among girls, and it was higher for children living in urban areas than for those living in rural areas.
文摘Gestational diabetes mellitus(GDM)is the most prevalent metabolic disorder during pregnancy.Women diagnosed with GDM have a substantially greater risk of developing type 2 diabetes within 5-10 years after delivery,and the risk is increased by excess body weight.Uncontrolled hyperglycemia during pregnancy is potentially harmful to both mother and fetus,resulting in a greater need for Caesarian-section deliveries,delivery of larger infants with more excess body fat,a greater risk of infant death and stillbirth,and an elevated risk of infant hypoglycemia immediately after birth.Fortunately,engaging in physical activity prior to and during pregnancy may lower the risk of developing GDM.Pregnant women should also be advised how to safely increase their physical activity during pregnancy and the postpartum period.An initial approach to becoming more physically active can simply be to encourage women to incorporate more unstructured physical activity into daily living,both before and during pregnancy.Giving women an appropriate exercise prescription can encourage them to participate in physical activity safely and effectively throughout pregnancy to prevent and/or manage GDM.Engaging in 30 min of moderate intensity physical activity on most,if not all,days of the week has been adopted as a recommendation for all pregnant women.
文摘Hamstring strains are one of most common sports injuries.The purpose of this literature review is to summarize studies on hamstring strain injury rate,mechanism,and risk factors in the last several decades with a focus on the prevention and rehabilitation of this injury.Hamstring injury commonly occurs in sporting events in which high speed sprinting and kicking are frequently performed,such as Australian football. English rugby,American football,and soccer.Basic science studies have demonstrated that a muscle strain injury occurs due to excessive strain in eccentric contraction instead of force,and that elongation speed and duration of activation before eccentric contraction affect the severity of the injury.Hamstring strain injury is likely to occur during the late swing phase and late stance phase of sprint running.Shortened optimum muscle length,lack of muscle flexibility,strength imbalance,insufficient warm-up,fatigue,lower back injury,poor lumbar posture,and increased muscle neural tension have been identified as modifiable risk factors while muscle compositions,age,race,and previous injuries are non-modifiable risk factors.The theoretical basis of some of these risk factors,however,is lacking,and the results of clinical studies on these risk factors are inconsistent.Future studies are needed to establish the cause-and-effect relationships between those proposed risk factors and the injury.
基金funded by the Coordination for the Improvement of Higher Level(CAPES)scholarship
文摘Background: The activities carried out by soldiers in the army involve great physical demands and require intense trainings to perform combat-specific tasks. Musculoskeletal injury is a potential threat to the health and physical integrity of the soldier. This study aimed to evaluate the prevalence of lower limb musculoskeletal injuries among soldiers and to propose a training protocol to prevent the most frequent injuries.Methods: This observational(cross-sectional) study recruited a sample of 103 soldiers who required medical attention,from a total 202 new battalion soldiers. The medical records(paper and online) had a form of running text. All data collected were recorded by the registered physicians of the battalion medical post. The records were analyzed by the following variables: medical diagnosis, injury site, mechanism, type of treatment, time loss, existence of previous injury,and recurring injury.Results: A total of 112 musculoskeletal injuries were diagnosed in 71 soldiers, and other types of diseases/injuries were diagnosed in the other soldiers. Joint pain accounted for 55.4% of the diagnoses. The knee was the most affected site, while trauma and overload were the most common mechanisms of injury. Drug treatment was used most frequently, accounting for 58% of the cases. The majority of the sample obtained a temporary leave of absence for1 to 6 days or not at all. Previous injuries and recurrence were not presented as risk factors for injury. With the data received, a protocol for the prevention of injuries to the lower limbs was proposed.Conclusions: This study indicated that the most frequent site of injury is the knee, and joint pain is the most common diagnosis. These results may support the necessity to develop a neuromuscular training protocol to prevent lower limb injuries, which we suggest to be applied in future studies.
文摘Hamstring muscle strain injury is one of the most common injuries in sports involving sprinting and kicking.Hamstring muscle strain injuries occur at a high rate and have a high re-injury rate,which results in loss of training and competition time,which has a significant impact on the quality of life of the injured athletes.~1Preventing and rehabilitating hamstring muscle strain injury is an important task for clinicians and scientists in sports medicine.Understanding the mechanisms underlying hamstring injury is critical for developing appropriate strategies to prevent and rehabilitate hamstring injuries.Understanding the
基金supported by the National Natural Science Foundation of China(No.81572212)the Fundamental Research Funds for the Central Universities of China(No.2016BS013)
文摘Background:Hamstring muscle strain injury(hamstring injury) due to excessive muscle strain is one of the most common injuries in sports.The relationships among hamstring muscle optimal lengths and hamstring flexibility and strength were unknown,which limited our understanding of risk factors for hamstring injury.This study was aimed at examining the relationships among hamstring muscle optimal length and flexibility and strength.Methods:Hamstring flexibility and isokinetic strength data and three-dimensional kinematic data for hamstring isokinetic tests were collected for11 male and 10 female recreational athletes.The maximal hamstring muscle forces,optimal lengths,and muscle lengths in standing were determined for each participant.Results:Hamstring muscle optimal lengths were significantly correlated to hamstring flexibility score and gender,but not to hamstring strength.The greater the flexibility score,the longer the hamstring muscle optimal length.With the same flexibility score,females tend to have shorter hamstring optimal muscle lengths compared to males.Hamstring flexibility score and hamstring strength were not correlated.Hamstring muscle optimal lengths were longer than but not significantly correlated to corresponding hamstring muscle lengths in standing.Conclusion:Hamstring flexibility may affect hamstring muscle maximum strain in movements.With similar hamstring flexibility,hamstring muscle maximal strain in a given movement may be different between genders.Hamstring muscle lengths in standing should not be used as an approximation of their optimal lengths in calculation of hamstring muscle strain in musculoskeletal system modeling.
