Kinematic factors associated with start performance in World-class male sprinters

The aim was to investigate the kinematic factors associated with successful performance in the initial acceleration phase of a sprint in the best male athletes in the World at the 2018 World Indoor Athletics Championships. High speed video (150 Hz) was captured for eight sprinters in the men’s 60 m final. Spatio-temporal and joint kinematic variables were calculated from the set position to the end of the first ground contact post-block exit (GC1). Normalised average horizontal external power (NAHEP) defined performance and was the dependent variable for a series of regression analyses. Clear relationships were found between GC1 NAHEP and 10-m time, 60-m time, change in velocity, acceleration and contact time in the first ground contact (r = –0.74, –0.64, 0.96, 0.91 and –0.56, respectively). Stepwise multiple linear regression of joint kinematic variables in the first ground contact revealed that trunk angle at take-off and thigh separation angle at take-off explained nearly 90% of variation in GC1 NAHEP (R2 = 0.89). The athletes’ projection at take-off with a forward leaning trunk and large thigh separation is characteristic therefore of excellent initial acceleration performance and this will be a good visual guide for technical coaching instruction. This was the first study of its kind to adopt such a research design in a World-class sample in a representative environment. Future studies that combine detailed kinematic and kinetic data capture and analysis in such a setting will add further insight to the findings of this investigatio

"Hang the flesh off the bones": Cultivating an "ideal body" in Taijiquan and Neigong

In a globalized, media-driven society, people are being exposed to different cultural and philosophical ideas. In Europe, the School of Internal Arts (pseudonym) follows key principles of the ancient Chinese text The Yijinjing (The Muscle-Tendon Change Classic) “Skeleton up, flesh down”, in its online and offline pedagogy. This article draws on an ongoing ethnographic, netnographic and cross-cultural investigation of the transmission of knowledge in this atypical association that combines Taijiquan with a range of practices such as Qigong, body loosening exercises and meditation. Exploring the ideal body cultivated by the students, we describe and illustrate key (and often overlooked) body areas—namely the spine, scapula, Kua and feet, which are continually worked on in the School of Internal Arts’ exercise-based pedagogy. We argue that Neigong and Taijiquan, rather than being forms of physical education, are vehicles for adult physical re-education. This re-education offers space in which mind-body tension built over the life course are systematically released through specific forms of attentive, meditative exercise to lay the foundations for a strong, powerful body for martial artistry and health

Maternal cultural orientation and speech sound production in Spanish/English dual Language preschoolers

Empirical work has shown that maternal education is related to children’s language outcomes, especially in the societal language, among Spanish-English bilingual children growing up in the U.S. However, no study thus far has assessed the links between maternal cultural orientation and children’s speech sound production. This paper explores whether mothers’ orientation to American (acculturation) and Mexican culture (enculturation) and overall linear acculturation are related to children’s accuracy of production of consonants, of different sound classes, and of phonemes shared and unshared between languages in both English and Spanish at age 4;6 (4 years and 6 months). The results reveal a link between maternal acculturation and children’s segmental accuracy in English, but no relation was found between mothers’ enculturation and children’s speech sound production in Spanish. We interpreted the results in English as suggesting that more American-oriented mothers may have been using more English with their children, boosting their English production abilities and promoting English speech sound development. At the same time, we speculate that the results in Spanish were possibly due to the high and homogeneous levels of Mexican orientation among mothers, to language input differences attributable to distinct cultural practices, or to the status of Spanish as a minority language

Reliability, validity, and maturation-related differences of frontal and sagittal plane landing kinematic measures during drop jump and tuck jump screening tests in male youth soccer players

Objectives: To determine the inter-rater and intra-rater reliability of frontal and sagittal plane landing kinematic measures during drop jump (DVJ) and tuck jump (TJA) tasks in male youth soccer players, to assess the concurrent validity between DVJ and TJA tests, and to evaluate the ability of both tasks to detect differences between players’ stage of maturation. Design: Cross-sectional study. Participants: 223 male youth soccer players. Main outcome measures: Frontal plane knee projection angles (FPPA) , and hip (HF), knee (KF) and ankle (AF) flexion angles at initial contact (IC) and peak flexion (PF) (i.e., the deepest landing position) in the sagittal plane were assessed. Results: Good-to-excellent inter- and intra-rater reliability (ICC>0.75; TEMST 10; error0.6) were only identified for the TJA. Pre-PHV group reported higher FPPA, HF-IC, HF-PF, and KF-IC values, as well as lower AF-IC than post-PHV. Pre-PHV also displayed greater HF-IC and KF-IC than circa-PHV group. Conclusions: Although both tests are reliable, the TJA might be viewed as a more informative tool given it shows greater FPPA and can also detect differences by maturity status

A robust machine learning framework to identify signatures for frailty: a nested case-control study in four aging European cohorts

Phenotype-specific omic expression patterns in people with frailty could provide invaluable insight into the underlying multi-systemic pathological processes and targets for intervention. Classical approaches to frailty have not considered the potential for different frailty phenotypes. We characterized associations between frailty (with/without disability) and sets of omic factors (genomic, proteomic, and metabolomic) plus markers measured in routine geriatric care. This study was a prevalent case control using stored biospecimens (urine, whole blood, cells, plasma, and serum) from 1522 individuals (identified as robust (R), pre-frail (P), or frail (F)] from the Toledo Study of Healthy Aging (R=178/P=184/F=109), 3 City Bordeaux (111/269/100), Aging Multidisciplinary Investigation (157/79/54) and InCHIANTI (106/98/77) cohorts. The analysis included over 35,000 omic and routine laboratory variables from robust and frail or pre-frail (with/without disability) individuals using a machine learning framework. We identified three protective biomarkers, vitamin D3 (OR: 0.81 [95% CI: 0.68–0.98]), lutein zeaxanthin (OR: 0.82 [95% CI: 0.70–0.97]), and miRNA125b-5p (OR: 0.73, [95% CI: 0.56–0.97]) and one risk biomarker, cardiac troponin T (OR: 1.25 [95% CI: 1.23–1.27]). Excluding individuals with a disability, one protective biomarker was identified, miR125b-5p (OR: 0.85, [95% CI: 0.81–0.88]). Three risks of frailty biomarkers were detected: pro-BNP (OR: 1.47 [95% CI: 1.27–1.7]), cardiac troponin T (OR: 1.29 [95% CI: 1.21–1.38]), and sRAGE (OR: 1.26 [95% CI: 1.01–1.57]). Three key frailty biomarkers demonstrated a statistical association with frailty (oxidative stress, vitamin D, and cardiovascular system) with relationship patterns differing depending on the presence or absence of a disability

Maturity alters drop vertical jump landing force-time profiles but not performance outcomes in adolescent females

The stretch-shortening cycle (SSC) assists in effective force attenuation upon landing and augments force generation at take-off during a drop vertical jump (DVJ). General performance outcomes such as jump height or peak measures have been used to assess SSC function in youth populations; however, these discrete metrics fail to provide insight into temporal jump-landing characteristics. This study assessed DVJ force-time profiles in 1013 middle and high-school female athletes (n = 279 prepubertal, n = 401 pubertal, n = 333 postpubertal). Maturity status was determined using the Pubertal Maturation Observation Scale. Ground reaction force data were analysed to extract a range of variables to characterize force-time profiles. SSC function was categorized as poor, moderate or good dependent on the presence of an impact peak and spring-like behaviour. No differences in jump height or ground contact time were observed between maturity groups (p > 0.05). Significant differences in absolute peak landing and take-off force were evident between all maturational statuses (p < 0.05). Relative to bodyweight normalized forces, only peak take-off force was significantly different between prepubertal and postpubertal groups (p < 0.05; d = 0.22). Spring-like behaviour showed small improvements from pubertal to postpubertal (p < 0.05; d = 0.25). Most females displayed poor SSC function at prepubertal (79.6%), pubertal (77.3%) and postpubertal (65.5%) stages of maturity. Large increases in absolute forces occur throughout maturation in female athletes, however, only small maturational differences were found in relative force or spring-like behaviour. Consequently, most girls display poor SSC function irrespective of maturity

Sugar-sweetened beverage consumption from 1998–2017: Findings from the health behaviour in school-aged children/school health research network in Wales

To date no study has examined time trends in adolescent consumption of sugar-sweetened beverages and energy drinks, or modelled change in inequalities over time. The present study aimed to fill this gap by identifying historical trends among secondary school students in Wales, United Kingdom. The present study includes 11–16 year olds who completed the Health Behaviour in School-aged Children (HBSC) survey and the Welsh School Health Research Network (SHRN) survey between 1998 to 2017. Multinomial regression models were employed alongside tests for interaction effects. A total of 176,094 student responses were assessed. From 1998 to 2017, the prevalence of daily sugar-sweetened beverage consumption decreased (57% to 18%) while weekly consumption has remained constant since 2006 (49% to 52%). From 2013 to 2017, daily consumption of energy drinks remained stable (6%) while weekly consumption reports steadily decreased (23% to 15%). Boys, older children and those from a low socioeconomic group reported higher consumption rates of sugar-sweetened beverages and energy drinks. Consumption according to socioeconomic group was the only characteristic to show a statistically significant change over time, revealing a widening disparity between sugar-sweetened beverage consumption rates of those from low and high socioeconomic groups. Findings indicate a positive shift in overall consumption rates of both sugar-sweetened beverages and energy drinks. Adolescents from a low socioeconomic group however were consistently shown to report unfavourable sugar-sweetened beverages consumption when compared to peers from high socioeconomic group. Given the established longer term impacts of sugar-sweetened beverage and energy drink consumption on adolescent health outcomes, urgent policy action is required to reduce overall consumption rates, with close attention to equity of impact throughout policy design and evaluation plans

Right ventricular function and region-specific adaptation in athletes engaged in high-dynamic sports: A meta-analysis

Background Structural remodeling of the right ventricle (RV) is widely documented in athletes. However, functional adaptation, including RV pressure generation and systolic free-wall longitudinal mechanics, remains equivocal. This meta-analysis compared RV pressure and function in athletes and controls. Methods A systematic review of online databases was conducted up to June 4, 2020. Meta-analyses were performed on RV systolic pressures (RVSP), at rest and during exercise, tricuspid annular plane systolic displacement (TAPSE), myocardial velocity (S’), and global and regional longitudinal strain. Bias was assessed using Egger’s regression for asymmetry. Data were analyzed using random-effects models with weighted mean difference (WMD) and 95% confidence interval (95%CI). Results Fifty-three studies were eligible for inclusion. RVSP was obtained from 21 studies at rest (n=1043:1651; controls:athletes) and 8 studies during exercise (n=240:495) and was significantly greater in athletes at rest (WMD: 2.9mmHg, CI: 1.3-to-4.5mmHg; P=0.0005) and during exercise (11.0, 6.5-to-15.6 mmHg; P<0.0001) vs. controls. Resting TAPSE (P<0.0001) and S’ (P=0.001) were greater in athletes. In contrast, athletes had similar RV free-wall longitudinal strain (17 studies; n=450:605), compared to controls, but showed greater longitudinal apical strain (16 studies; n=455:669; 0.9%, 0.1- to-1.8%;P=0.03) and lower basal strain (-2.5%, -1.4-to -3.5%;P<0.0001). Conclusions Functional RV adaptation, characterized by increased tricuspid annular displacement and velocity and a greater base-to-apex strain gradient, is a normal feature of the athlete’s heart, together with a slightly elevated RVSP. These findings contribute to our understanding of RV in athletes and highlight the importance of considering RV function in combination with structure in the clinical interpretation of the athlete’s heart

Contributions and limitations of using machine learning to predict noise-induced hearing loss

Purpose Noise-induced hearing loss (NIHL) is a global issue that impacts people’s life and health. The current review aims to clarify the contributions and limitations of applying machine learning (ML) to predict NIHL by analyzing the performance of different ML techniques and the procedure of model construction. Methods The authors searched PubMed, EMBASE and Scopus on November 26, 2020. Results Eight studies were recruited in the current review following defined inclusion and exclusion criteria. Sample size in the selected studies ranged between 150 and 10,567. The most popular models were artificial neural networks (n = 4), random forests (n = 3) and support vector machines (n = 3). Features mostly correlated with NIHL and used in the models were: age (n = 6), duration of noise exposure (n = 5) and noise exposure level (n = 4). Five included studies used either split-sample validation (n = 3) or ten-fold cross-validation (n = 2). Assessment of accuracy ranged in value from 75.3% to 99% with a low prediction error/root-mean-square error in 3 studies. Only 2 studies measured discrimination risk using the receiver operating characteristic (ROC) curve and/or the area under ROC curve. Conclusion In spite of high accuracy and low prediction error of machine learning models, some improvement can be expected from larger sample sizes, multiple algorithm use, completed reports of model construction and the sufficient evaluation of calibration and discrimination risk

Cultivating health in martial arts and combat sports pedagogies: A theoretical framework on the care of the self

“Martial arts and combat sports” (MACS) are a myriad of systems of embodied movements and underlying philosophy and pedagogies. Due to the intrinsic complexity of MACS, they have the potential to both reshape practitioners’ selves and improve their wellbeing, as well as to hamper the pursuit of sustainable, healthy lifestyles. This article provides an interdisciplinary theoretical framework to critically approach both the “light” and the “dark” sides of martial pedagogies. The model we propose develops the Foucauldian notion of “the care of the self,” which has been considerably overlooked in martial arts scholarship. Furthermore, by viewing health as a goal for cultivation, this proposal places the situated practices linked to materiality and discourses at the centre of the theoretical and empirical analyses. The article thus takes into account the internal diversity and cross-institutional variance of martial pedagogies by allowing scholars to explore four forms of cultivation (self, shared, social, ecological) prompted on a day-to-day basis. To conclude, we discuss the main methodological implications for multimodal research arising from the framework in order to foster future inquiries