1,521 research outputs found
BMI-for-age graphs with severe obesity percentile curves: Tools for plotting cross-sectional and longitudinal youth BMI data
Abstract Background Severe obesity is an important and distinct weight status classification that is associated with disease risk and is increasing in prevalence among youth. The ability to graphically present population weight status data, ranging from underweight through severe obesity class 3, is novel and applicable to epidemiologic research, intervention studies, case reports, and clinical care. Methods The aim was to create body mass index (BMI) graphing tools to generate sex-specific BMI-for-age graphs that include severe obesity percentile curves. We used the Centers for Disease Control and Prevention youth reference data sets and weight status criteria to generate the percentile curves. The statistical software environments SAS and R were used to create two different graphing options. Results This article provides graphing tools for creating sex-specific BMI-for-age graphs for males and females ages 2 to <20 years. The novel aspects of these graphing tools are an expanded BMI range to accommodate BMI values ˃35 kg/m2, inclusion of percentile curves for severe obesity classes 2 and 3, the ability to plot individual data for thousands of children and adolescents on a single graph, and the ability to generate cross-sectional and longitudinal graphs. Conclusions These new BMI graphing tools will enable investigators, public health professionals, and clinicians to view and present youth weight status data in novel and meaningful ways
Predictors of Knee Functional Joint Stability in Uninjured Physically Active Adults
Noncontact knee injuries are a major problem for male and female agility sports athletes. These injuries commonly manifest with a valgus collapse that implicates failure of mechanical and/or sensorimotor mechanisms in maintaining knee functional joint stability (FJS). Previous studies have elucidated the role of some mechanical and sensorimotor characteristics in knee FJS. The contributions of active joint position sense (AJPS) and time-to-peak torque (TTPT) have not been investigated. Therefore, the current evidence-base is incomplete and noncontact knee injury control programs may not be as effective as could be. Identifying the role of AJPS and TTPT in knee FJS will deliver new data that potentially assists design of more effective noncontact knee injury control programs. The purpose of this study was to determine how gender, mechanical joint stability, and selected sensorimotor characteristics predict knee FJS. Two analyses were performed, each with a specific operational definition of knee FJS: 1. adapted crossover hop for distance (ACHD); 2. single-leg stop-jump (SLSJ) total knee valgus displacement.
Thirty-four subjects participated (male (M) 18; female (F) 16; age 24.1 ± 3.5 years; height 171.8 ± 9.6cm; mass 70.6 ± 12.2kg). The dominant leg was tested. The ACHD analysis included: ACHD (cm), gender (M/F), prone knee extension AJPS (motion analysis system; °), anterior tibial displacement (ATD; mm), and isokinetic hamstrings TTPT (240°•sec–1; msec). The SLSJ analysis included: SLSJ valgus/varus displacement (motion analysis system; °), gender, AJPS, ATD, SLSJ medial hamstrings feedforward and feedback muscle activation (surface electromyography; % maximum voluntary isometric contraction × sec), and TTPT. Multiple linear regression was performed.
For the ACHD analysis, gender and TTPT contributed to a model that predicted ACHD performance (R2 = 0.60, P = 0.00). For the SLSJ analysis, 56% of subjects demonstrated varus displacement and valgus/varus raw data and final equation residuals demonstrated a non-normal distribution.
Gender and hamstrings TTPT should be considered in noncontact knee injury control programs evaluated by single-leg hop tests. Future multivariate studies should consider new knee proprioception tests and employ additional functional tasks to identify clinically important knee valgus displacement
Copper-catalysed C-H functionalisation gives access to 2-aminobenzimidazoles
This paper describes the development, optimisation and exemplification of a copper-catalysed C–H functionalisation to form pharmaceutically relevant 2-aminobenzimidazoles from aryl-guanidines. High throughput screening was used as a tool to identify a catalytically active copper source, DoE was used for reaction optimisation and a range of aryl-guanidines were prepared and exposed to the optimum conditions to afford a range of 2-aminobenzimidazoles in moderate to good yields. The methodology has been applied to the synthesis of Emedastine, a marketed anti-histamine pharmaceutical compound, with the key cyclisation step performed on a gram-scale
Novel Glass Material with Low Loss and Permittivity for 5G/6G Integrated Circuits
A new borosilicate glass with lower loss and permittivity than any commercial glass has been proposed in this contribution as a substrate or interposer for mm-wave and THz integrated electronics. The glass is composed of a microstructure enclosing high-purity boron rich areas and silicon rich areas. This phase-separated areas are several orders of magnitude smaller than the wavelength at 1 THz
Variability and complexity of knee neuromuscular control during an isometric task in uninjured physically active adults: a secondary analysis exploring right/left and dominant/nondominant asymmetry
Work is needed to better understand the control of knee movement and knee health. Specifically, work is needed to further understand knee muscle force control variability and complexity and how it is organized on both sides of the body. The purpose of this study was to explore side-to-side comparisons of magnitude- and complexity-based measures of knee muscle force control to support future interpretations of complexity-based analyses and clinical reasoning in knee injury control. Participants (male/female n = 11/5) performed constant-force isometric efforts at 50% maximal effort. Force variability was quantified during the constant-force efforts using a coefficient of variation (CV%) and force complexity using approximate entropy (ApEn) and detrended fluctuation analysis (DFA) α. Outcomes were right/left and dominant/nondominant group-level and individual-level comparisons. A limb-symmetry index was calculated for each variable and clinically significant absolute asymmetry was defined (>15%). The only significant side-to-side difference was for right/left DFA α (p = 0.00; d = 1.12). Maximum absolute asymmetries were (right/left, dominant/nondominant): CV 18.2%, 18.0%; ApEn 34.5%, 32.3%; DFA α 4.9%, 5.0%. Different side-to-side comparisons yield different findings. Consideration for how side-to-side comparisons are performed (right/left, dominant/nondominant) is required. Because a significant difference existed for complexity but not variability, this indicates that both complexity-based and magnitude-based measures should be used when studying knee muscle force control
Prevalence and magnitude of preseason clinically-significant single-leg balance and hop test asymmetries in an English adult netball club
Objectives Side-to-side asymmetry of lower-limb motor-performance is associated with increased noncontact injury risk in agility-sports. Side-to-side symmetry-analyses using single-leg balance and hop tests has not been reported for community-level adult netball players. The purpose of this study was to perform preseason side-to-side symmetry-analyses using eyes-closed-balance (ECB), triple-hop-for-distance (THD), single-hop-for-distance (SHD), and vertical-hop (VH) tests.
Design Cross-sectional;
Setting Community-level adult netball club.
Participants Twenty-three female players (age 28.7 ± 6.2yr; height 171.6 ± 7.0 cm; mass 68.2 ± 9.8 kg).
Main outcome measures Right-left group-level comparisons (paired t-test) and individual-level comparisons (absolute-asymmetry (%)). A limb symmetry index was calculated for each test and a clinically-significant absolute-asymmetry defined as >10%. Clinically-significant absolute-asymmetry prevalence (%) was computed for each test.
Results There were no right-left significant differences for any test. Maximum absolute-asymmetries for the ECB, THD, SHD, and VH were 93.3%, 15.2%, 16.7%, and 60.3%, respectively. The prevalence of clinically-significant absolute-asymmetries for the ECB, THD, SHD, and VH was 91.3%, 8.7%, 8.7%, and 52.2%, respectively.
Conclusions Group-level comparisons with statistical tests fail to expose the extent of clinically-significant absolute-asymmetries. Most players demonstrated preseason clinically-significant absolute-asymmetries for the ECB and VH tests. Preseason clinically-significant absolute-asymmetries that may predispose increased lower-limb noncontact injury risk are widespread in a community-level adult netball club
Lower-limb motor-performance asymmetries in English community-level female field hockey players: Implications for knee and ankle injury prevention
Objectives: Side-to-side asymmetry of lower-limb motor-performance is associated with increased agility-sport noncontact injury-risk. Left leg preferential use (unilaterality) in hockey may influence lower-limb motor-performance asymmetry. Symmetry-analyses have not been reported for female hockey players. This study performed symmetry-analyses using the eyes-closed-balance test (ECB), anterior reach test (ART), triple-hop-for-distance (THD), and six-metre hop-for-time (6MHT). Design: Cross-sectional. Setting: Community-level club. Participants: Thirty players (age 25.6 ± 4.5yr; height 165.6 ± 5.9 cm; mass 64.8 ± 5.5 kg). Main outcome measures: Right-left group-level (t-test with Bonferroni adjustment) and individual-level (absolute-asymmetry (%)) comparisons. A limb symmetry index (LSI) was computed for each player and a clinically-significant absolute-asymmetry defined >10% as per previous literature. Clinically-significant absolute-asymmetry prevalence (%) was calculated across tests. For unilaterality, prevalence of superior left-side performance was calculated. Results: There were no right-left significant differences across tests. Findings for ECB, ART, THD, and 6MHT were: absolute-asymmetry, 28.7 ± 26.9%, 3.5 ± 2.8%, 3.5 ± 3.4%, 6.1 ± 4.7%; prevalence of clinically-significant absolute-asymmetries, 70.0%, 3.3%, 6.7%, 26.7%; prevalence of superior left-side performance, 46.7%, 53.0%, 50.0%, 47.0%. Conclusions: Statistical tests fail to expose clinically-significant absolute-asymmetries. Many players demonstrated clinically-significant absolute-asymmetries for ECB and 6MHT tests. Clinical interpretation of LSIs and absolute-asymmetries need not consider unilaterality. Clinically-significant absolute-asymmetries previously linked to injury-risk are common in a community-level, adult female hockey players
Alterations in peripheral joint muscle force control in adults with musculoskeletal disease, injury, surgery, or arthroplasty: A systematic review and meta-analysis
Purpose To systematically review and analyse whether musculoskeletal conditions affect peripheral joint muscle force control (i.e. magnitude and/or complexity of force fluctuations).
Methods A literature search was conducted using MEDLINE, CINAHL and SPORTDiscus databases (from inception-8th April 2021) for studies involving: 1) participants with musculoskeletal disease, injury, surgery, or arthroplasty in the peripheral joints of the upper/lower limb; 2) comparison with an unaffected control group or unaffected contralateral limb; and 3) measures of the magnitude and/or complexity of force fluctuations during targeted isometric contractions. The methodological quality of studies was evaluated using a modified Downs and Black Quality Index. Studies were combined using the standardized mean difference (SMD) in a random-effects model.
Results 14 studies (investigating 694 participants) were included in the meta-analysis. There was a significant effect of musculoskeletal conditions on peripheral joint muscle force coefficient of variation (CV; SMD = 0.19 [95 % CI 0.06, 0.32]), whereby individuals with musculoskeletal conditions exhibited greater CV than controls. Subgroup analyses revealed that CV was only greater: 1) when comparison was made between symptomatic and asymptomatic individuals (rather than between affected and contralateral limbs; SMD = 0.22 [95 % CI 0.07, 0.38]); 2) for conditions of the knee (SMD = 0.29 [95 % CI 0.14, 0.44]); and 3) for ACL injury post-surgery (SMD = 0.56 [95 % CI 0.36, 0.75]).
Conclusion Musculoskeletal conditions result in an increase in peripheral joint muscle force CV, with this effect dependent on study design, peripheral joint, and surgical status. The greater force CV is indicative of decreased force steadiness and could have implications for long-term tissue health/day-to-day function
Eyetracking metrics reveal impaired spatial anticipation in behavioural variant frontotemporal dementia.
Eyetracking technology has had limited application in the dementia field to date, with most studies attempting to discriminate syndrome subgroups on the basis of basic oculomotor functions rather than higher-order cognitive abilities. Eyetracking-based tasks may also offer opportunities to reduce or ameliorate problems associated with standard paper-and-pencil cognitive tests such as the complexity and linguistic demands of verbal test instructions, and the problems of tiredness and attention associated with lengthy tasks that generate few data points at a slow rate. In the present paper we adapted the Brixton spatial anticipation test to a computerized instruction-less version where oculomotor metrics, rather than overt verbal responses, were taken into account as indicators of high level cognitive functions. Twelve bvFTD (in whom spatial anticipation deficits were expected), six SD patients (in whom deficits were predicted to be less frequent) and 38 healthy controls were presented with a 10 × 7 matrix of white circles. During each trial (N = 24) a black dot moved across seven positions on the screen, following 12 different patterns. Participants' eye movements were recorded. Frequentist statistical analysis of standard eye movement metrics were complemented by a Bayesian machine learning (ML) approach in which raw eyetracking time series datasets were examined to explore the ability to discriminate diagnostic group performance not only on the overall performance but also on individual trials. The original pen and paper Brixton test identified a spatial anticipation deficit in 7/12 (58%) of bvFTD and in 2/6 (33%) of SD patients. The eyetracking frequentist approach reported the deficit in 11/12 (92%) of bvFTD and in none (0%) of the SD patients. The machine learning approach had the main advantage of identifying significant differences from controls in 24/24 individual trials for bvFTD patients and in only 12/24 for SD patients. Results indicate that the fine grained rich datasets obtained from eyetracking metrics can inform us about high level cognitive functions in dementia, such as spatial anticipation. The ML approach can help identify conditions where subtle deficits are present and, potentially, contribute to test optimisation and the reduction of testing times. The absence of instructions also favoured a better distinction between different clinical groups of patients and can help provide valuable disease-specific markers
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