Temporal trends in 6-minute walking distance for older Japanese adults between 1998 and 2017

BackgroundThe 6-minute walking distance (6MWD) is an excellent measure of both functional endurance and health. The primary aim of this study was to estimate temporal trends in 6MWD for older Japanese adults between 1998 and 2017; the secondary aim was to estimate concurrent trends in body size (i.e., height and mass) and self-reported participation in exercise/sport.MethodsAdults aged 65–79 years were included. Annual nationally representative 6MWD data (n = 103,505) for the entire period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in means (and relative frequencies) were estimated at the gender–age level by best-fitting sample-weighted linear/polynomial regression models, with national trends estimated by a post-stratified population-weighting procedure. Temporal trends in distributional variability were estimated as the ratio of coefficients of variation.ResultsBetween 1998 and 2017 there was a steady, moderate improvement in mean 6MWD (absolute = 45 m (95% confidence interval (95%CI): 43–47); percent = 8.0% (95%CI: 7.6%–8.4%); effect size = 0.51 (95%CI: 0.48–0.54)). Gender- and age-related temporal differences in means were negligible. Variability in 6MWD declined substantially (ratio of coefficients of variation = 0.89, 95%CI: 0.87–0.92), with declines larger for women compared to men, and for 75–79-year-olds compared to 65–74-year-olds. Correspondingly, there were moderate and negligible increases in mean height and mass, respectively, and negligible increases in the percentage who participated in exercise/sport at least 3 days per week and at least 30 min per session.ConclusionThere has been a steady, moderate improvement in mean 6MWD for older Japanese adults since 1998, which is suggestive of corresponding improvements in both functional endurance and health. The substantial decline in variability indicates that the temporal improvement in mean 6MWD was not uniform across the distribution. Trends in 6MWD are probably influenced by corresponding trends in body size and/or participation in exercise/sport.     

Validation of self-report measures of physical activity: a case study using the New Zealand Physical Activity Questionnaire

Accurate measurement of physical activity is fundamentally important in epidemiological research of physical activity behavior A widely used telephone-based physical activity questionnaire was compared with other methods of administration and objective measures (pedometers and accelerometers) among 80 adults (43 women). The telephone questionnaire was comparable to both the self-administered form and international telephone-administered equivalent. Although moderate correlation coefficients with objective measures supported the use of the questionnaire, wide prediction intervals generated using Bland Altman methods highlighted large discrepancies between the measures, particularly in the moderate intensity category. These findings illustrate the limitations of correlation coefficients in validation studies and the inaccuracy of self-report questionnaires in measuring physical activity.     

Differential contribution of personality to the explanation of variance in achievement in the first language and mathematics at high school level

This study assessed the differential contribution of personality to the explanation of variance in achievement in the mother tongue and mathematics at the high school level. The results indicated that personality, as measured by the HSPQ, aided the explication of variance in achievement in the mother tongue significantly, but had little influence on mathematics. Personality contributed as much to the explanation of variance in the mother tongue as did the composite cognitive variable. The influence of personality on achievement in mathematics was shown to be negligible. Some practical implications for the teaching of the first language are drawn.     

Lost and Found: Making Sense of Foreign Spaces and the Self with Public Transport

How does public transport both enable and restrict one’s negotiation and interaction with cultural, social and material landscapes? The understanding of social space and self is guided by one’s journey through those spaces, by witnessing events and public conduct. This article presents autoethnographic accounts of two communication studies researchers placed in Cape Town, South Africa, and Helsinki, Finland, for more than three months. In both situations, researchers relied on public transport with which they were unfamiliar. This study considers how those experiences were perceived, and how the researchers encountered and experienced the new social environments, local population and themselves.     

Specific tackling situations affect the biomechanical demands experienced by rugby union players

Tackling in Rugby Union is an open skill which can involve high-speed collisions and is the match event associated with the greatest proportion of injuries. This study aimed to analyse the biomechanics of rugby tackling under three conditions: from a stationary position, with dominant and non-dominant shoulder, and moving forward, with dominant shoulder. A specially devised contact simulator, a 50-kg punch bag instrumented with pressure sensors, was translated towards the tackler (n = 15) to evaluate the effect of laterality and tackling approach on the external loads absorbed by the tackler, on head and trunk motion, and on trunk muscle activities. Peak impact force was substantially higher in the stationary dominant (2.84 ± 0.74 kN) than in the stationary non-dominant condition (2.44 ± 0.64 kN), but lower than in the moving condition (3.40 ± 0.86 kN). Muscle activation started on average 300 ms before impact, with higher activation for impact-side trapezius and non-impact-side erector spinae and gluteus maximus muscles. Players’ technique for non-dominant-side tackles was less compliant with current coaching recommendations in terms of cervical motion (more neck flexion and lateral bending in the stationary non-dominant condition) and players could benefit from specific coaching focus on non-dominant-side tackles.     

Tribute to Dr Jacques Rogge: muscle activity and fatigue during hiking in Olympic dinghy sailing

‘A tribute to Dr J. Rogge’ aims to systematically review muscle activity and muscle fatigue during sustained submaximal quasi-isometric knee extension exercise (hiking) related to Olympic dinghy sailing as a tribute to Dr Rogge’s merits in the world of sports. Dr Jacques Rogge is not only the former President of the International Olympic Committee, he was also an orthopaedic surgeon and a keen sailor, competing at three Olympic Games. In 1972, in fulfilment of the requirements for the degree of Master in Sports Medicine, he was the first who studied a sailors’ muscle activity by means of invasive needle electromyography (EMG) during a specific sailing technique (hiking) on a self-constructed sailing ergometer. Hiking is a bilateral and multi-joint submaximal quasi-isometric movement which dinghy sailors use to optimize boat speed and to prevent the boat from capsizing. Large stresses are generated in the anterior muscles that cross the knee and hip joint, mainly employing the quadriceps at an intensity of 30–40% maximal voluntary contraction (MVC), sometimes exceeding 100% MVC. Better sailing level is partially determined by a lower rate of neuromuscular fatigue during hiking and for ≈60% predicted by a higher maximal isometric quadriceps strength. Although useful in exercise testing, prediction of hiking endurance capacity based on the changes in surface EMG in thigh and trunk muscles during a hiking maintenance task is not reliable. This could probably be explained by the varying exercise intensity and joint angles, and the great number of muscles and joints involved in hiking.

Highlights

• Dr Jacques Rogge, former president of the International Olympic Committee and Olympic Finn sailor, was the first to study muscle activity during sailing using invasive needle EMG to obtain his Master degree in Sports Medicine at the Ghent University.

• Hiking is a critical bilateral and multi-joint movement during dinghy racing, accounting for >60% of the total upwind leg time. Hiking generates large stresses in the anterior muscles that cross the knee and hip joint.

• Hiking is considered as a quasi-isometric bilateral knee extension exercise. Muscle activity measurements during sailing, recorded by means of EMG, show a mean contraction intensity of 30-40% maximal voluntary contraction with peaks exceeding 100%.

• Hiking performance is strongly related to the development of neuromuscular fatigue in the quadriceps muscle. Since maximal strength is an important determinant of neuromuscular fatigue during hiking, combined strength and endurance training should be incorporated in the training program of dinghy sailors.

     

Together for a Better Multicultural Society

I propose that educators construct pedagogical responses to youth in schools in ways that consider classrooms to be the result of and the boardroom for complex global flows. Youth's production of individual and collective identities wherein flows are apprehended, discarded, combined, and recombined, rages against purifying processes of neocolonial classrooms.