827 research outputs found
LANDING PATTERN AND VERTICAL LOADING RATES DURING SHOD AND BAREFOOT RUNNING IN HABITUAL SHOD RUNNERS
There is evidence to support that habitual barefoot runners are able to disperse impact loading rates by landing pattern modification. However, case studies have been reported that barefoot running may cause stress fractures. It may be due to the immediate biomechanical response difference between habitual and novice barefoot runners. Therefore, purpose of this study was to examine the immediate effects of barefoot running in habitual shod runners. Thirty habitual shod runners were asked to run on an instrumented treadmill at 10km/hr in shod and barefoot. Vertical average (VALR) and instantaneous loading rates (VILR) were obtained by previously established methods. The landing pattern was presented as a ratio between number of footfall with heel-strike and the total step number. Twenty out of 30 participants demonstrated an automatic transition to a non-heel-strike landing. A mixed landing pattern was observed in 10 participants. Compared to shod running, both VALR and VILR significantly reduced during barefoot running (
Editorial: COVID-19 pandemic:A curve ball for athletes
More than 30 months since the discovery of the novel respiratory coronavirus in
2019, COVID-19 related public health orders and restrictions remain active in many
countries on the globe in late 2022. These measures, such as city lockdown, border
closure, travel restrictions, social distancing practice, and mandatory use of facemasks,
affect all segments of the population. During the pandemic, we have witnessed the
most significant disruption to the worldwide sports calendar since the World War
II. From a global perspective, many international sports events, such as The Olympic
Games Tokyo 2020, SummerWorld University Games, and theWorld Games have been
postponed; and more than 150 international sports events involving both professional
and recreational sportsmen have been canceled. In this series, we cover original articles
examining the effect of COVID-19 on the training routine and performance in five types
of athletes, including distance runners (Chan et al.), soccer/football players (Wagemans
et al.; Keemss et al.), bodybuilders (Imboden et al.; Iff et al.), volleyball players (Morath
et al.), and paralympic athletes (Busch et al.). We are aware that this field of research is
highly dynamic with new data available almost on a daily base. Hence, we aim to bemore
inclusive in this Research Topic and involve a wider scope of research questions and
different methodological approaches, which allow us a better coverage of this emerging
and evolving Research Topic.
These findings provide important information for athletes, coaches, physical trainers,
and healthcare team members to identify potential health issues that may be related to
the pandemic, plan specifically how we can minimize the negative influence, as well as
design contingency training plan for postponed tournaments.
Although COVID-19 attacks our respiratory system and potentially causes a decline
in physical condition, we observed adverse findings from the studies in this Research
Topic in terms of physical training. Iff et al. and Keemss et al. reported a pandemic
related negative impact on the physical performance in body builders and youth soccer players, respectively. In contrast, Chan et al. and Wagemans
et al. did not find any substantial differences in terms of physical
function or training intensity in professional soccer players
and recreational distance runners. Interestingly, it seems that
COVID-19 and its related public health restrictions result in a
greater influence on people’s mental than physical health. For
example, Imboden et al., Busch et al., and Iff et al. reported
that athletes exhibited poorer mood during the pandemic and
this psychological impact may indeed lead to a change in
living habits, such as increase alcoholic and cannabis intake.
From a global perspective, this Research Topic also includes an
investigation of COVID transmission within volleyball games.
Morath et al. conducted contact tracing in a professional
volleyball teamin Germany. They found that players who strictly
adhere to the recommended hygiene guidelines and regulations
during both training and matches are of lower risk contracting
the virus, but coaches and players are advised to avoid nonessential
interpersonal contacts outside the training hours to
prevent the spread of infection.
Although the guest editors would love to see more
views, downloads, and citations of papers included in
this series, we sincerely hope that athletes, coaches, and
concerning healthcare professionals do not require the
information presented in this Research Topic due to another
wave of pandemic and disruption. May COVID-19 will be soon behind us and becomes a historical terminology in
near future
A validation study of a smartphone application for functional mobility assessment of the elderly
AbstractBackgroundTo minimize the reaction time and position judgment error using stopwatch-timed measures, we developed a smartphone application to measure performance in the five-time sit-to-stand (FTSTS) and timed up-and-go (TUG) tests.ObjectiveThis study aimed to validate this smartphone application by comparing its measurement with a laboratory-based reference condition.MethodsThirty-two healthy elderly people were asked to perform the FTSTS and TUG tests in a randomized sequence. During the tests, their performance was concurrently measured by the smartphone application and a force sensor installed in the backrest of a chair. The intraclass correlation coefficient [ICC(2,1)] and Bland–Altman analysis were used to calculate the measurement consistency and agreement, respectively, between these two methods.ResultsThe smartphone application demonstrated excellent measurement consistency with the lab-based reference condition for the FTSTS test [ICC(2,1) = 0.988] and TUG test [ICC(2,1) = 0.946]. We observed a positive bias of 0.27 seconds (95% limits of agreement, −1.22 to 1.76 seconds) for the FTSTS test and 0.48 seconds (95% limits of agreement, −1.66 to 2.63 seconds) for the TUG test.ConclusionWe cross-validated the newly developed smartphone application with the laboratory-based reference condition during the examination of FTSTS and TUG test performance in healthy elderly
Trajectory of functional outcome and health status after moderate-to-major trauma in Hong Kong: A prospective 5 year cohort study
Background
Trauma care systems in Asia have been developing in recent years, but there has been little long-term outcome data from injured survivors. This study aims to evaluate the trajectory of functional outcome and health status up to five years after moderate to major trauma in Hong Kong.
Methods
We report the five year follow up results of a multicentre, prospective cohort from the trauma registries of three regional trauma centres in Hong Kong. The original cohort recruited 400 adult trauma patients with ISS ≥ 9. Telephone follow up was conducted longitudinally at seven time points, and the extended Glasgow Outcome Scale (GOSE) and Short-Form 36 (SF36) were tracked.
Results
119 out of 309 surviving patients (39%) completed follow up after 5 years. The trajectory of GOSE, PCS and MCS showed gradual improvements over the seven time points. 56/119 (47.1%) patients reported a GOSE = 8 (upper good recovery), and the mean PCS and MCS was 47.8 (95% CI 45.8, 49.9) and 55.8 (95% CI 54.1, 57.5) respectively at five years. Univariate logistic regression showed change in PCS - baseline to 1 year and 1 year to 2 years, and change in MCS - baseline to 1 year were associated with GOSE = 8 at 5 years. Linear mixed effects model showed differences in PCS and MCS were greatest between 1-month and 6-month follow up.
Conclusions
After injury, the most rapid improvement in PCS and MCS occurred in the first six to 12 months, but further recovery was still evident for MCS in patients aged under 65 years for up to five years
Coupled Hartree-Fock-Bogoliubov kinetic equations for a trapped Bose gas
Using the Kadanoff-Baym non-equilibrium Green's function formalism, we derive
the self-consistent Hartree-Fock-Bogoliubov (HFB) collisionless kinetic
equations and the associated equation of motion for the condensate wavefunction
for a trapped Bose-condensed gas. Our work generalizes earlier work by Kane and
Kadanoff (KK) for a uniform Bose gas. We include the off-diagonal (anomalous)
pair correlations, and thus we have to introduce an off-diagonal distribution
function in addition to the normal (diagonal) distribution function. This
results in two coupled kinetic equations. If the off-diagonal distribution
function can be neglected as a higher-order contribution, we obtain the
semi-classical kinetic equation recently used by Zaremba, Griffin and Nikuni
(based on the simpler Popov approximation). We discuss the static local
equilibrium solution of our coupled HFB kinetic equations within the
semi-classical approximation. We also verify that a solution is the rigid
in-phase oscillation of the equilibrium condensate and non-condensate density
profiles, oscillating with the trap frequency.Comment: 25 page
Conserving and Gapless Approximations for an Inhomogeneous Bose Gas at Finite Temperatures
We derive and discuss the equations of motion for the condensate and its
fluctuations for a dilute, weakly interacting Bose gas in an external potential
within the self--consistent Hartree--Fock--Bogoliubov (HFB) approximation.
Account is taken of the depletion of the condensate and the anomalous Bose
correlations, which are important at finite temperatures. We give a critical
analysis of the self-consistent HFB approximation in terms of the
Hohenberg--Martin classification of approximations (conserving vs gapless) and
point out that the Popov approximation to the full HFB gives a gapless
single-particle spectrum at all temperatures. The Beliaev second-order
approximation is discussed as the spectrum generated by functional
differentiation of the HFB single--particle Green's function. We emphasize that
the problem of determining the excitation spectrum of a Bose-condensed gas
(homogeneous or inhomogeneous) is difficult because of the need to satisfy
several different constraints.Comment: plain tex, 19 page
Pentaquark as Kaon-Nucleon Resonance
Several recent experiments have reported evidence for a narrow feature in the
K(+)-neutron system, an apparent resonant state ~ 100 MeV above threshold and
with a width < 25 MeV. This state has been labelled as Theta(+) (previously as
Z(*)), and because of the implied inclusion of a anti-strange quark, is
referred to as a pentaquark, that is, five quarks within a single bag. We
present an alternative explanation for such a structure, as a higher angular
momentum resonance in the isospin zero K(+) -N system. One might call this an
exit channel or a molecular resonance. In a non-relativistic potential model we
find a possible candidate for the kaon-nucleon system with relative angular
momentum L=3, while L=1 and 2 states possess centrifugal barriers too low to
confine the kaon and nucleon in a narrow state at an energy so high above
threshold. A rather strong state-dependence in the potential is essential,
however, for eliminating an observable L=2 resonance at lower energies.Comment: 4 page
Recreational specialization and the marine-based conservation behaviour intention of recreational divers in Hong Kong
This study examined divers' recreational specialization, pro-environmental attitudes, and marine-based conservation behaviour intentions. A questionnaire-based data collection approach was used to survey 398 divers who visited popular diving sites in Hong Kong by employing structural equation modelling to determine the potential relationships among the proposed variables. The results showed a statistically positive relationship between divers' recreational specialization and their pro-environmental attitudes, along with a statistically valid relationship between divers' recreational specialization and their marine-based conservation behaviour intentions. However, divers' pro-environmental attitudes were not statistically significant with their marine-based conservation behaviour intentions; thus, the discrepancy regarding different research findings between the current and previous studies was further discussed. In particular, our findings confirmed that recreational specialization could be a reliable predictor of divers' pro-environmental attitudes and marine-based conservation behaviour intentions to fill the research gaps regarding scuba diving-based nature tourism in Hong Kong. Consequently, management implications and recommendations were presented in accordance with the development of marine environmental conservation and sustainable scuba diving tourism in Hong Kong
Visiting urban green space as a climate-change adaptation strategy: Exploring push factors in a push–pull framework
Urban green space (UGS) offers users multiple ecosystem services and amenities. This study investigated whether residents used UGS visitation in summer as a sustainable measure to tackle hot weather and associated climate-change impacts in humid-subtropical Hong Kong. Attributes of the indoor residential environment, seldom examined in park-visitation studies, were evaluated as push factors to visit UGS through a push–pull theoretical framework. A questionnaire survey of 483 respondents targeted urban park users. The results indicated that UGS visit frequency and stay duration were relatively low in hot summer. Ordinal multiple regression showed that indoor living conditions, residence location, living routine, and habit and personal health impacts were significantly correlated with UGS visits. Interdependence between push and pull factors was detected, demonstrating that intrinsic UGS environmental conditions could constrain UGS visits despite the motivations of push factors. The results indicated the need to improve the microclimate-regulating function in UGS. It could be achieved mainly by optimizing the nature-based design to promote UGS as an adaptive measure to combat the thermal stress brought by climate change. The findings yielded hints to shape visiting habits and suggestions to improve UGS management
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