SIDE-TOSIDE ASYMMETRY OF LANDING KINETICS IN HEAVY AND LIGHT BASKETBALL PLAYERS DURING A DROP LANDING

This study examined (1) the effect of body mass on impact forces during drop landings in basketball players, and (2) side-to-side asymmetry in landing kinetics between legs. Thirty male basketball players were assigned into 'heavy" (n = 15, mass 82.7 i 4.3 kg) or "light" (n = 15, mass 63.1 * 2.8 kg) groups. Players performed five drop landings from a 0.42 m platform. Vertical ground reaction forces for both legs were sampled using two adjacent and embedded force plates. A mixed factorial analysis of variance (Body Mass x Side) was applied to normalised peak force and loading rate variables (a = -05). The left leg experienced higher forefoot peak force (1 5.946, p = .001), forefoot mean loading rate (10.9%, p = .007) and rearfoot mean loading rate (1 1.846, p = .014) than the right leg, suggesting that side-to-side asymmetry exists. No body mass effect was found

Segmented forefoot plate in basketball footwear: Does it influence performance and foot joint kinematics and kinetics?

This study examined the effects of shoes’ segmented forefoot stiffness on athletic performance and ankle and metatarsophalangeal joint kinematics and kinetics in basketball movements. Seventeen university basketball players performed running vertical jumps and 5-msprints atmaximumeffort with 3 basketball shoes of various forefoot plate conditions (medial plate, medial + lateral plates, and no-plate control). One-way repeated measures ANOVAs were used to examine the differences in athletic performance, joint kinematics, and joint kinetics among the 3 footwear conditions (α = .05). Results indicated that participants wearing medial + lateral plates shoes demonstrated 2.9% higher jump height than those wearing control shoes (P = .02), but there was no significant differences between medial plate and control shoes (P \u3e .05). Medial plate shoes produced greater maximum plantar flexion velocity than the medial + lateral plates shoes (P \u3c .05) during sprinting. There were no significant differences in sprint time. These findings implied that inserting plates spanning both the medial and lateral aspects of the forefoot could enhance jumping, but not sprinting performances. The use of a medial plate alone, although induced greater plantar flexion velocity at the metatarsophalangeal joint during sprinting, was not effective in improving jump heights or sprint times

Do rotational shear-cushioning shoes influence horizontal ground reaction forces and perceived comfort during basketball cutting maneuvers?

Background. Court shoe designs predominantly focus on reducing excessive vertical ground reaction force, but shear force cushioning has received little attention in the basketball population. We aimed to examine the effect of a novel shoe-cushioning design on both resultant horizontal ground reaction forces and comfort perception during two basketball-specific cutting movements. Methods. Fifteen university team basketball players performed lateral shuffling and 45-degree sidestep cutting at maximum effort in basketball shoes with and without the shear-cushioning system (SCS). Paired t-tests were used to examine the differences in kinetics and comfort perception between two shoes. Results. SCS shoe allowed for larger rotational material deformation compared with control shoes, but no significant shoe differences were found in braking phase kinetics during both cutting movements (P = 0.35). Interestingly, a greater horizontal propulsion impulse was found with the SCS during 45-degree cutting (P 0.05). Discussion. The application of a rotational shear-cushioning structure allowed for better forefoot comfort and enhanced propulsion performance in cutting, but did not influence the shear impact. Understanding horizontal ground reaction force information may be useful in designing footwear to prevent shear-related injuries in sport populations

EFFECT OF TOE WEDGES ON THE BIOMECHANICS OF THE FORWARD LUNGE IN BADMINTON

The badminton lunge movement accounts for 15% of all actions in a competitive single match. The purpose of this study was to assess the effects of different toe wedges during a forward badminton lunge. Eighteen healthy male subjects participated in the study where the biomechanics and performance of three different wedge conditions were evaluated (0 mm, 4 mm and 8 mm toe elevation). Ground reaction forces and kinematic data were in a laboratory. Results showed an increased peak ankle moment for the 8-mm wedge compared to 0-mm (P=0.003) and 4-mm (P=0.028) wedges along with a reduced hip flexion moment (P=0.049 and P=0.034, respectively), while the time to task completion remained unchanged. Results indicate that joint moments may be altered by badminton footwear with implications for fatigue

Inhibitory control, conscious processing of movement and anxiety

© 2019 Elsevier Ltd It has been suggested that a high propensity for reinvestment (i.e., conscious processing of movements) can disrupt performance, but the mechanisms responsible are not well understood. The purpose of this study was to examine whether people with superior inhibition function (i.e., ability to suppress unwanted thoughts and behaviours) were better able to suppress conscious processing of their movements (i.e., reinvestment). Inhibition function was assessed using a Go/NoGo button-press task, and individual propensity for reinvestment was assessed using the Movement Specific Reinvestment Scale (MSRS) and the Decision-Specific Reinvestment Scale (DSRS). The results revealed positive associations between inhibition function and reinvestment propensity, with better inhibition function evident in people who displayed a higher propensity to reinvest (MSRS and DSRS). Hierarchical regression analyses revealed that trait anxiety moderated the relationship between inhibition and movement specific reinvestment, with higher MSRS scores associated with better inhibition function in people with low trait anxiety. This association was not significant among people with high trait anxiety. Possible explanations for these results are discussed

Aberrant Transferrin and Ferritin Upregulation Elicits Iron Accumulation and Oxidative Inflammaging Causing Ferroptosis and Undermines Estradiol Biosynthesis in Aging Rat Ovaries by Upregulating NF-Κb-Activated Inducible Nitric Oxide Synthase: First Demonstration of an Intricate Mechanism

We report herein a novel mechanism, unraveled by proteomics and validated by in vitro and in vivo studies, of the aberrant aging-associated upregulation of ovarian transferrin and ferritin in rat ovaries. The ovarian mass and serum estradiol titer plummeted while the ovarian labile ferrous iron and total iron levels escalated with age in rats. Oxidative stress markers, such as nitrite/nitrate, 3-nitrotyrosine, and 4-hydroxy-2-nonenal, accumulated in the aging ovaries due to an aberrant upregulation of the ovarian transferrin, ferritin light/heavy chains, and iron regulatory protein 2(IRP2)-mediated transferrin receptor 1 (TfR1). Ferritin inhibited estradiol biosynthesis in ovarian granulosa cells in vitro via the upregulation of a nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and p65/p50-induced oxidative and inflammatory factor inducible nitric oxide synthase (iNOS). An in vivo study demonstrated how the age-associated activation of NF-κB induced the upregulation of iNOS and the tumor necrosis factor α (TNFα). The downregulation of the keap1-mediated nuclear factor erythroid 2-related factor 2 (Nrf2), that induced a decrease in glutathione peroxidase 4 (GPX4), was observed. The aberrant transferrin and ferritin upregulation triggered an iron accumulation via the upregulation of an IRP2-induced TfR1. This culminates in NF-κB-iNOS-mediated ovarian oxi-inflamm-aging and serum estradiol decrement in naturally aging rats. The iron accumulation and the effect on ferroptosis-related proteins including the GPX4, TfR1, Nrf2, Keap1, and ferritin heavy chain, as in testicular ferroptosis, indicated the triggering of ferroptosis. In young rats, an intraovarian injection of an adenovirus, which expressed iron regulatory proteins, upregulated the ovarian NF-κB/iNOS and downregulated the GPX4. These novel findings have contributed to a prompt translational research on the ovarian aging-associated iron metabolism and aging-associated ovarian diseases

The colour we wear: Impact on self-predicted and actual motor performance

The effect of colouron different aspects of performance has been the subject of substantial research interest, and red had been shown to have varying effects on not only performance, but perceptions as well. This study examined the effect of apparel colour on self-predicted and actual motor performance. Thirty-six young adults (18 females, 18 males; 20.4 SD 1.32 years old), who had no experience in football, performed a task consisting of an agility ladder drill and football shooting, in each of three bib colours (red, blue, black). Self-predicted and actual performances were measured on the dimensions of shooting accuracy and kicking power. A significant effect of colour on self-predicted shooting accuracy was found. Participants expected themselves to shoot less accurately when they were wearing a red bib, compared to when wearing blue and black bibs. No effect of colour on actual performance was found and no significant interaction was found between colour and sex. The findings suggest that wearing red could reduce users’ expectations of their performance in a novel motor task; there is no effect on actual performance

Gender and leg-dominance differences in shoe properties and foot injuries in badminton:a cross-sectional survey

BACKGROUND: While the roles of injury prevention and performance enhancement have increasingly been investigated for badminton footwear, there is a lack of research on gender-specific badminton footwear. The purpose of this study was to examine the gender differences in footwear demands and foot injuries in badminton. METHODS: The study was a cross-sectional survey, in which 326 recreational badminton players were recruited. The questionnaire was divided into four sections enquiring about the characteristics of (1) participant profiles, (2) importance of shoe properties (3) shoe complaints (4) and pain or discomfort in different foot regions. The Mann-Whitney U test and Wilcoxon Signed Ranks test were performed to determine the differences between genders and the differences between leg dominance, respectively. The significance level was set at 0.05. RESULTS: Both males and females rated shoe fit as the most important features, followed by the overall comfort and injury protection. Females considered the shoe forefoot cushioning, comfort, breathability and colour as more important compared with the other properties, which showed distinct pattern differences from males. The shoe problem results indicated that plantar pain of the non-dominant foot was considered the most commonly reported footwear problem by both males and females. The problem of excessive arch-support on the dominant and non-dominant sides of male participants was significantly higher than females (p < 0.05). Occasional pain or frequent pain were mainly distributed in the forefoot, followed by the rearfoot and midfoot regions. CONCLUSION: There were small differences in footwear demand between the dominant and non-dominant sides, but several differences existed between females and males. The results from gender differences suggested that female shoes prefer a specific shoe last for better fit, rather than a modified version of male shoes. In the future, the design of badminton shoes should consider footwear demands and foot discomfort profiles in respective male and female badminton players