Topic Review
Biomechanics of Table Tennis
Table tennis is a popular recreational and competitive sports at all levels. Recent research on table tennis maneuvers identified the differences between playing levels and between maneuvers using parameters which included ball and racket speed, joint kinematics and kinetics, electromyography, and plantar pressure distribution. Different maneuvers underlined changes on body posture and lines of movement which were accommodated particularly by the racket face angle, trunk rotation, knee and elbow joint movements, and thus different contributions of muscles. Higher-level players produced ball and strike at higher accuracy and repeatability but not necessarily lead to higher speed. In addition, higher-level players utilize superior whole-body coordination and footwork to compromise between agility and stability for a quality strike. Strengthening shoulder and wrist muscles could enhance the speed of the strike while personalized training shall be considered since motor coordination and adaptation vary among individuals.
  • 7.9K
  • 29 Oct 2020
Topic Review
Bodybuilding and Myostatin
MSTN is a gene that makes instructions for producing the protein myostatin, a protein that is part of the transforming growth factor beta family (TGFβ). The TGFβ family of proteins control the growth of tissues in the body, myostatin is found nearly exclusively in the skeletal muscles where it is active before and after birth. The protein actually controls skeletal growth by restraining it, preventing muscles becoming excessively large. Current research that surrounds myostatin is based around its potential treatment in muscle wasting disorders, animals that have mutations in the encoding gene MSTN show greater muscle mass, strength and in some circumstances reduced bodyfat, which can be known as myostatin-related muscle hypertrophy. This study aimed to see the prevalence of mutations in the male bodybuilder population (n = 92) and if having a mutation had any affect on their muscle size and/or muscle performance. The study which looked at mutation prevalence in rs1805086, arm circumference, pull-up max and push-up max. The results show that 17% (16) of the subject group had one mutation (AG), 83% (76) had the common outcome (AA) and 0% (0) had two mutations (GG). Those with the AG outcome had an average arm circumference of 46.37cmcompared with AA which had an average of 42.02cm. Those with the AG outcome had an average pull-up max score of 21 compared with AA with an average of 12. Those with the AG outcome had an average push-up max of 61 compared with AA with an average of 40. The study clearly shows that those with a mutation are rare, however the mutation does appear to give the subject a performance and size advantage over those with the common outcome.
  • 5.7K
  • 03 Nov 2020
Topic Review
Football Goalkeeper Injuries
Knowledge and research about football goalkeeper (GK) injuries are scarce, which prevents the development of evidence-based injury prevention programs. Fortunately, progress is evident in injury prevention strategies in outfield football players. However, a GK fulfills a unique role, and an injured GK can substantially impact a team. Thus, there is a need to clarify and summarize current knowledge concerning football goalkeeper pain and injuries.
  • 4.2K
  • 31 May 2021
Topic Review
Effects of Exercise on the Autonomic Nervous System
The autonomic nervous system (ANS) has an important impact on health in general. In response to environmental demands, homeostatic processes are often compromised, therefore determining an increase in the sympathetic nervous system (SNS)’s functions and a decrease in the parasympathetic nervous system (PNS)’s functions.
  • 3.2K
  • 21 Feb 2022
Topic Review
Nonparametric Limits of Agreement
The assessment of agreement in method comparison and observer variability analysis of quantitative measurements is usually done by the Bland-Altman Limits of Agreement, where the paired differences are implicitly assumed to follow a normal distribution. Whenever this assumption does not hold, the 2.5% and 97.5% percentiles are obtained by quantile estimation. In the literature, empirical quantiles have been used for this purpose. In this simulation study, we applied both sample, subsampling, and kernel quantile estimators as well as other methods for quantile estimation to sample sizes between 30 and 150 and different distributions of the paired differences. The performance of 15 estimators in generating prediction intervals was measured by their respective coverage probability for one newly generated observation. Our results indicated that sample quantile estimators based on one or two order statistics outperformed all the other estimators and can be used for deriving nonparametric Limits of Agreement. For sample sizes exceeding 80 observations, more advanced quantile estimators, such as the Harrell-Davis and estimators of Sfakianakis-Verginis type, which use all the observed differences, performed likewise well, but may be considered intuitively more appealing than simple sample quantile estimators that are based on only two observations per quantile.
  • 2.8K
  • 27 Oct 2020
Topic Review
Instability
Research in instability has focused on the analysis of muscle activation. This systematic entry was to analyze the effects of unstable devices on speed, strength and muscle power measurements administered in the form of controlled trials to healthy individuals in adulthood. 
  • 2.2K
  • 27 Jan 2022
Topic Review
Physical Activity Patterns
Although “physical activity pattern” (PAP) is a widely used expression, its precise meaning remains vague. Indeed, PAP is sometimes used to describe physical activity (PA) levels/intensities, however the term is also applied to express how PA averages differ among group,  between different days (i.e., week and weekend days), across seasons (e.g., summer, winter), and between school and vacation time. A lack of a formal definition for PAP has not prevented researchers from using a vast array of instruments to measure PA (accelerometers, pedometers, questionnaires, direct observations, and heart rate monitors) in an attempt to capture PAP. Discrepancies also exist in how PAP has been expressed with researchers using daily mean PA, heart rate frequency, number of daily steps, time engaged in certain types of activity, and/or engagement in sports activities. Researchers have also used numerous statistical procedures in their attempts to capture PAP. Notwithstanding this diversity, we suggest that PAP should be used to jointly capture similarities/dissimilarities as well as stabilities/changes in children’s PA at an intra-personal level. PAP should be used to best describe individual streams of behaviours, and not exclusively PA levels/intensities. A formal and clear definition of PAP would support important, systematic, and coherent lines of empirical enquiry.
  • 2.1K
  • 24 Apr 2021
Topic Review
Electromyography in Sports
Muscular alterations as a consequence of hypoxic situations contribute not only to a decrease in life expectancy but also to a lower quality of life and health status. Our perspective, based on the results of this systematic review, is that Electromyography (EMG) is a suitable tool for monitoring the different skeletal muscle responses and has sufficient sensitivity to detect the muscle changes produced by hypoxic stimuli. Therefore, surface EMG (sEMG) maybe provide a practical point-of-care diagnostic test for medical diagnoses as well as a tool to improve sports performance. integrated EMG (iEMG) studies the physiology and pathology of denervation, re-innervation, and various myopathies. It also analyzes deep musculature such as muscular behavior, temporal activity patterns, fatigue, and muscular activation. sEMG is suitable for providing information about global muscle behavior, temporal activity patterns, muscle fatigue, and the activation level of the superficial musculature.
  • 2.0K
  • 15 Jan 2021
Topic Review
Born Equal: Can Genetics Make the Perfect Athlete?
Thanks to the dawn of accessible science to map the human genome and the research that is poured into it, genetics are playing a larger role in elite sports. Genetics have a large influence over many attributes necessary for athletic excellence such as strength, muscle size, muscle fibre composition, anaerobic threshold, lung capacity, and flexibility. The aim of the study was to analyse a large database of athletes, comparing their chosen sports and the level that they play. Analysis of the individuals will include genotypes in six heavily studied genes attributed to athlete potential: ACTN3, MSTN, NOS3, ACE, AMPD1 and TRHR. A combination of both nurture and nature will always be required to bring the most out of an individual, however it would be naïve to ignore natural gifts. Genotypes may give an advantage to certain individuals but the lines between which genotype bring the most benefits is blurred, certain genotypes such as those found in MSTN are very uncommon but have very high affinity for power sports and bodybuilding. Other genes such as the once hailed “sports gene” ACTN3 have far more varied distribution and no particular athlete appeared to be hampered from any genotype, however the C allele did have affinity towards strength and power. From the six analysed genes in the study both power/strength athletes and bodybuilders had completed genotype affinity, however these genes seem to have less impact on those that compete in endurance/stamina sports. The  ACTN3 C allele, MSTN G allele, NOS3 T allele, ACE II, AMPD1 C allele and TRHR C allele all show affinity towards power, strength and/or bodybuilding athletes, only the NOS3 C allele showed a true affinity towards endurance/stamina sports. 
  • 1.8K
  • 13 Aug 2022
Topic Review
N-Acetylcysteine
Exercise frequently alters the metabolic processes of oxidative metabolism in athletes, including exposure to extreme reactive oxygen species impairing exercise performance. Therefore, both researchers and athletes have been consistently investigating the possible strategies to improve metabolic adaptations to exercise-induced oxidative stress. N-acetylcysteine (NAC) has been applied as a therapeutic agent in treating many diseases in humans due to its precursory role in the production of hepatic glutathione, a natural antioxidant.
  • 1.8K
  • 03 Feb 2021
  • Page
  • of
  • 10