Hip adductor activations during run-to-cut manoeuvres in compression shorts: implications for return to sport after groin injury

Abstract

Athletes at high risk of groin strains in sports such as hockey and soccer often choose to wear shorts with directional compression to aid in prevention of or recovery from hip adductor strains. Large, eccentric contractions are known to result in or exacerbate strain injuries, but it is unknown if these shorts have a beneficial effect on hip adductor muscle activity. In this study, surface electromyography (EMG) of the adductor longus and ground reaction force (GRF) data were obtained simultaneously on 29 healthy individuals without previous history of serious injury while performing unanticipated 45° run-to-cut manoeuvres in a laboratory setting wearing shorts with non-directional compression (control, HeatGear, Under Armour, USA) or shorts with directional compression (directional, CoreShort PRO, Under Armour, USA), in random order. Average adductor activity in the stance leg was significantly lower in the directional condition than in the control condition during all parts of stance phase (all P < 0.042). From this preliminary analysis, wearing directional compression shorts appears to be associated with reduced stance limb hip adductor activity. Athletes seeking to reduce demand on the hip adductors as they approach full return to activities may benefit from the use of directional compression shorts.     

Exercise training increases the S-Klotho plasma levels in sedentary middle-aged adults: A randomised controlled trial. The FIT-AGEING study

ABSTRACT

This study aimed to investigate the effects of different training modalities on the soluble Klotho (S-Klotho) plasma levels in sedentary middle-aged adults. A total of 74 middle-aged adults (53.4 ± 5.0 years old; 52.7% women) were enrolled in the FIT-AGEING study. We conducted a 12-week randomised controlled trial. The participants were randomly assigned to 4 different groups: (i) a control group (no exercise), (ii) a physical activity recommendation from the World Health Organization group (PAR), (iii) a high intensity interval training group (HIIT), and (iv) a high intensity interval training group adding whole-body electromyostimulation training group (HIIT-EMS). S-Klotho plasma levels, anthropometric measurements, and body composition variables were measured before and after the intervention programme. All exercise training modalities induced an increase in the S-Klotho plasma levels (all P ≤ 0.019) without statistical differences between them (all P ≥ 0.696). We found a positive association between changes in lean mass index and changes in the S-Klotho plasma levels, whereas a negative association was reported between changes in fat mass outcomes and changes in the S-Klotho plasma levels after our intervention study. In conclusion, our results suggest that the link between exercise training and the increase in S-Klotho plasma levels could be mediated by a decrease of fat mass and an increase of lean mass.     

Nutritional strategies for promoting fat utilization and delaying the onset of fatigue during prolonged exercise

Carbohydrate ingestion before and during endurance exercise delays the onset of fatigue (reduced power output). Therefore, endurance athletes are recommended to ingest diets high in carbohydrate (70% of total energy) during competition and training. However, increasing the availability of plasma free fatty acids has been shown to slow the rate of muscle and liver glycogen depletion by promoting the utilization of fat. Ingested fat, in the form of long-chain (C 16-22 ) triacylglycerols, is largely unavailable during acute exercise, but medium-chain (C 8-10 ) triacylglycerols are rapidly absorbed and oxidized. We have shown that the ingestion of medium-chain triacylglycerols in combination with carbohydrate spares muscle carbohydrate stores during 2 h of submaximal (< 70% VO 2 peak) cycling exercise, and improves 40 km time-trial performance. These data suggest that by combining carbohydrate and medium-chain triacylglycerols as a pre-exercise supplement and as a nutritional supplement during exercise, fat oxidation will be enhanced, and endogenous carbohydrate will be spared. We have also examined the chronic metabolic adaptations and effects on substrate utilization and endurance performance when athletes ingest a diet that is high in fat (> 70% by energy). Dietary fat adaptation for a period of at least 2-4 weeks has resulted in a nearly two-fold increase in resistance to fatigue during prolonged, low- to moderate-intensity cycling (< 70% VO 2 peak). Moreover, preliminary studies suggest that mean cycling 20 km time-trial performance following prolonged submaximal exercise is enhanced by 80 s after dietary fat adaptation and 3 days of carbohydrate loading. Thus the relative contribution of fuel substrate to prolonged endurance activity may be modified by training, pre-exercise feeding, habitual diet, or by artificially altering the hormonal milieu or the availability of circulating fuels. The time course and dose-response of these effects on maximizing the oxidative contribution of fat for exercise metabolism and in exercise performance have not been systematically studied during moderate- to high-intensity exercise in humans.     

Within‐High‐School Versus Across‐High‐School Scaling of Admissions Assessments: Implications for Validity and Diversity Effects

Previous research has established that SAT scores and high school grade point average (HSGPA) differ in their predictive power and in the size of mean differences across racial/ethnic groups. However, the SAT is scaled nationally across all test takers while HSGPA is scaled locally within a school. In this study, the researchers propose that this difference in how SAT scores and HSGPA are scaled partially explains differences in validity and subgroup differences. Using a large data set consisting of 170,390 students each of whom matriculated at one of 114 separate colleges, the researchers find that awarding SAT scores by ranking SAT within a high school generally results in substantial reduction in the size of subgroup mean differences for this predictor. However, validity for predicting first‐year GPA is also reduced by a small amount. Conversely, placing HSGPA onto a nationally normed metric through the use of multiple regression procedures results in a moderate increase in the size of subgroup mean differences, while also producing a small increase in validity. Taken together, these findings suggest that differences in predictor scaling can partially explain differences in the size of subgroup mean differences between HSGPA and SAT scores and have implications for predictive power.     

Bullying and the Unique Socioemotional Needs of Gifted and Talented Early Adolescents: Veteran Teacher Perspectives and Practices

Much is written at the elementary school level concerning bullying and the socioemotional needs of gifted and talented (GT) students; however, in the last 10 years, little qualitative research exists concerning the early adolescent GT age group. In the social environment of classroom life, early and current research indicates that many of these students experience neurotic perfectionism, overexciteabilities (OEs), developmental asynchrony, and bullying. The formation of autonomous classes (GT-only classes) has afforded some hope concerning the amelioration of such problems; nevertheless, in this study, detailed evidence of classroom bullying in the form of social ostracism and teasing has been found with this GT age group. If left unchecked, psychological autopsies have shown these students suffering emotional difficulties and even committing suicide as a result of school and classroom torment. With such potential for classroom bullying problems, few studies address what veteran teachers of early adolescent GT students do to keep students psychologically safe. Within the social milieu of classroom life, and in comparison to research standards, this study explores three efficacious teacher perspectives and practices.     

Snippets of physics

The fact that an accelerated charge radiates energy is considered an elementary textbook result in electromagnetism. Nevertheless, this process of radiation (and its reaction on the charged particle) raises several conundrums about which technical papers are written even today. In this installment, we will try to understand why an accelerated charge radiates in a simple, yet rigorous, manner.     

Young deafblind adults in action: becoming self-determined change agents through advocacy

Six young deafblind adults took a 1-week course on civic engagement and advocacy, which provided the focus for a participatory action research study with a collective case study design. They selected advocacy topics, were briefed on these policy issues, and were paired with experienced mentors for meetings with legislators in Washington, DC. Eight themes were identified from constant comparative and in vivo analysis of classroom discussion notes, interviews, and journals: (a) defining advocacy and advocate, (b) rights and equality, (c) expectations, (d) role of education in change, (e) deafblind expertise, (f) characteristics of effective change agents, (g) advocacy is teamwork, (h) future advocacy. In the classroom, the participants learned about policy issues, communication considerations, and leadership, then applied this knowledge in the legislative arena. Through the advocacy process, they learned to apply their personal strengths as advocates and experienced the importance of teamwork in advocacy.     

Self-efficacy, job satisfaction, motivation and commitment: exploring the relationships between indicators of teachers’ professional identity

This study investigates how relevant indicators of teachers’ sense of their professional identity (job satisfaction, occupational commitment, self-efficacy and change in level of motivation) are related. A model is proposed, tested with structural equation modelling (SEM) and refined using data from 1,214 Dutch teachers working in secondary education. Classroom self-efficacy and relationship satisfaction play a key influencing role in the relationships between the indicators. Using multiple-group SEM, the parameters of the overall model are similar for the novice, experienced and senior teachers in a constrained model. This aspect of similarity across experience groups is in line with findings of previous research on teachers’ professional identity. The present study contributes to the further development of a solid theory on teachers’ professional identity, which has been lacking.     

Adaptation of the Students' Motivation Towards Science Learning (SMTSL) questionnaire in the Greek language

The present study aimed at adapting in the Greek language the Students' Motivation Towards Science Learning (SMTSL) questionnaire developed by Tuan, Chin, and Shieh (INT J SCI EDUC 27(6): 639-654, 2005a) into a different cultural context, a different age group, that is, in university students and with a focus on physics learning. Three hundred and fifty Greek student teachers participated in the study. The original instrument consisted of 35 items allocated in six scales: self-efficacy, use of active learning strategies, science learning value, performance goals, achievement goals, and learning environment stimulation. The instrument's internal consistency was acceptable and comparable to previous studies' reports. Confirmatory factor analysis (CFA) was applied on the data in order to test an a priori hypothesis regarding the SMTSL's factorial structure based on previous studies' findings. The results of the study showed that the six-factor conceptual model of students' motivation proposed by the SMTSL applies in this different cultural setting and in this group of university students with reference to physics learning. Along with the six distinct motivational constructs confirmed, students' motivational beliefs were also explained by a general motivational construct assumed to be at their basis. Suggestions for further improvement of the Greek version of the SMTSL are also discussed.