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With innovative portable force plate systems being widely implemented for lower-body neuromuscular performance assessment in an applied sports setting and the existing gap in the scientific literature regarding player performance during in-game competitive scenarios, the purpose of the present study was to compare changes in countermovement vertical jump (CVJ) performance pre-post a simulated 3×3 basketball tournament. Seven current or former members of a 3×3 national basketball team volunteered to participate in the present investigation. Upon completing standardized warm-up procedures, athletes stepped on a uni-axial force plate system sampling at 1,000 Hz and performed three maximal-effort CVJs with no arm swing. Then, the athletes proceeded to play a simulated 3×3 basketball tournament composed of two consecutive games, separated by a 15-min rest interval. Immediately following the completion of the second game, the identical CVJ testing procedures were repeated. Paired sample t-tests were used to examine prepost-tournament differences in nineteen CVJ performance metrics (p < 0.05). The results reveal that force-time metrics during both eccentric and concentric phases of the CVJ remain relatively unchanged pre-post simulated 3×3 basketball tournament. However, multiple force-time metrics within the eccentric phase of the CVJ changed by 12.1%-19.1% (e.g., eccentric peak power and peak velocity, eccentric duration), suggesting that the eccentric phase of CVJ might be responsive to performance stimulus to a greater extent than the concentric phase. Overall, these findings further support the importance of comprehensive CVJ analysis when intending to measure changes in neuromuscular performance. [ABSTRACT FROM AUTHOR]

Introduction: Advances in motion capture technology include markerless systems to facilitate valid data collection. Recently, the technological reliability of this technology has been reported for human movement assessments. To further understand sources of potential error, biological reliability must also be determined. The aim of this study was to determine the day-to-day reliability for a three-dimensional markerless motion capture (MMC) system to quantify 4 movement analysis composite scores, and 81 kinematic variables. Methods: Twenty-two healthy men (n = 11; ... + SD; age = 23.0 ± 2.6 years, height = 180.4.8 cm, weight = 80.4 ± 7.3 kg) and women (n = 11; age = 20.8 ± 1.1 years, height = 172.2 ± 7.4 cm, weight = 68.0 ± 7.3 kg) participated in this study. All subjects performed 4 standardized test batteries consisting of 14 different movements on four separate days. A three-dimensional MMC system (DARI Motion, Lenexa, KS) using 8 cameras surrounding the testing area was used to quantify movement characteristics. 1 x 4 RMANOVAs were used to determine significant differences across days for the composite movement analysis scores, and RM-MANOVAs were used to determine test day differences for the kinematic data (p < 0.05). Intraclass correlation coefficients (ICCs) were reported for all variables to determine test reliability. To determine biological variability, mean absolute differences from previously reported technological variability data were subtracted from the total variability data from the present study. Results: No differences were observed for any composite score (i.e., athleticism, explosiveness, quality, readiness; or any of the 81 kinematic variables. Furthermore, 84 of 85 measured variables exhibited good to excellent ICCs (0.61-0.99). When compared to previously reported technological variability data, 62.3% of item variability was due to biological variability, with 66 of 85 variables exhibiting biological variability as the primary source of error (i.e., >50% total variability). Discussion: Combined, these findings effectively add to the body of literature suggesting sufficient reliability for MMC solutions in capturing kinematic features of human movement. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the acute effects of lower limb wearable resistance on maximal horizontal deceleration biomechanics, across two different assessments. Twenty recreationally trained team sport athletes performed acceleration to deceleration assessments (ADA), and 5-0-5 change of direction (COD) tests across three load conditions (unloaded, 2% of BW, 4% of body weight (BW)), with load attached to the anterior and posterior thighs and shanks. Linear mixed effect models with participant ID as the random effect, and load condition as the fixed effect were used to study load-specific biomechanical differences in deceleration mechanics across both tests. Primary study findings indicate that for the ADA, in the 4% BW condition, participants exhibited significantly greater degrees of Avg Approach Momentum, as well as significant reductions in deceleration phase center of mass (COM) drop, and Avg Brake Step ground contact deceleration (GCD) in both the 2% BW, and 4% BW condition, compared to the unloaded condition. In the 5-0-5 tests, participants experienced significant reductions in Avg Approach Velocity, Avg deceleration (DEC), and Stopping Time in the 4% BW condition compared to the unloaded condition. Similar to the ADA test, participants also experienced significant reductions in Avg Brake Step GCD in both the 2% BW and 4% BW conditions, and significant increases in Avg Approach Momentum in the 4% BW condition, compared to the unloaded condition. Therefore, findings suggest that based on the test, and metric of interest, the addition of lower limb wearable resistance led to acute differences in maximal horizontal deceleration biomechanics. However, future investigations are warranted to further explore if the use of lower limb wearable resistance could present as an effective training tool in enhancing athlete's horizontal deceleration and change of direction performance. [ABSTRACT FROM AUTHOR]

Recent literature has shown that the provision of feedback can enhance vertical jump performance acutely, as well as chronically when implemented during phases of training. The aim of our study was to investigate the influence of two types of visual feedback on performance and variability of countermovement jump-derived force-time characteristics in a cohort of male and female National Collegiate Athletic Association Division 1 basketball players. Specifically, individual visual feedback (IVF) was compared to a form of social comparison feedback (SCF), and authors hypothesized there to be performance increases and more stable measures in the SCF condition. In line with this hypothesis, findings suggested significantly enhanced performance in the SCF condition for seven out of eight force-time metrics (e.g. jump height and reactive strength index modified). However, given the small between-condition effect sizes, differences between conditions may lack practical significance. Furthermore, findings suggested less between-jump variability in the SCF condition, compared to the IVF condition, making for a more stable assessment. This in particular makes for more reliable measures, for which when studied over time, more subtle changes in performance may be observed. In summary, our findings highlight acutely enhanced vertical jump performance, and more stable measures, when athletes are exposed to an SCF condition, compared to a normal IVF condition. Practitioners are encouraged to consider these findings when planning vertical jump assessments and are discouraged from implementing different types of feedback at random, especially when measuring performance over time. [ABSTRACT FROM AUTHOR]

Introduction: With recent increases in the popularity of studying the physical construct of horizontal deceleration performance in team-sport athletes, the aim of the present study was to assess the inter-rater and intra-rater reliability of processing and quantifying horizontal deceleration ability using radar technology. Methods: Data from 92 NCAA Division 1 athletes from two different athletic teams (American football and Lacrosse) were used for the present investigation. All athletes performed two trials of the modified acceleration to deceleration assessment (ADA), which consisted of a maximal 10 m sprint acceleration, followed by a rapid deceleration. Four individual raters manually processed raw, radar-derived instantaneous velocity data for the ADA, and an automated script was used to calculate metrics of interest. Results: Primary study findings suggest moderate to excellent levels of agreement (ICC = 0.56-0.91) for maximal horizontal deceleration metrics between the four individual raters. The intra-rater analyses revealed poor to excellent consistency (ICC = 0.31-0.94) between ADA trials, with CV%'s ranging from 3.1% to 13.2%, depending on the respective metric and rater. Discussion: Our data suggests that if a foundational understanding and agreement of manual data processing procedures for radar-derived data is given between raters, metrics may be interpreted with moderate to excellent levels of confidence. However, when possible, and when using the Stalker ATS radar technology, authors recommend that practitioners use one trained individual to manually process raw data. Ideally, this process should become fully automated, based on selected filters or algorithms, rather than the subjectivity of the rater. [ABSTRACT FROM AUTHOR]

As technology within elite basketball advances and is more available to sporting organizations, novel approaches for assessing and addressing athletic performance during practice or competition are being continuously explored. The aim of this investigation was to examine changes in neuromuscular performance during live basketball play. Eight professional male basketball players volunteered to participate in this study. The testing procedures were conducted during a pre-tournament camp over a span of 2 days. During the first day, the athletes were familiarized with the testing procedures, and baseline measurements were obtained. Using a uniaxial force plate system sampling at 1,000 Hz, each athlete performed 3 countermovement vertical jumps (CVJ) without an arm swing before proceeding with their regular training activities. During the second day of the pre-tournament camp, the athletes repeated identical CVJ testing procedures before the start of the first quarter and post-first, second, third, and fourth quarter of a simulated 5- on-5 basketball game. Repeated-measures testing design was used to examine statistically significant differences in various forcetime metrics of interest in comparison to the baseline levels (p, 0.05). Besides a trivial decrease in eccentric mean force, the findings of this study revealed no statistically significant changes in any force-time metrics of interest within both eccentric and concentric phases of the CVJ (i.e., mean and peak force and power, jump height, impulse, velocity, and contraction time). Thus, we can conclude that these variables were not sensitive to acute fatigue, suggesting that the neuromuscular performances of professional male basketball players tend to remain unchanged throughout a 5-on-5 simulated game. [ABSTRACT FROM AUTHOR]

Lower-body strength and power are commonly measured performance qualities across a number of sports. In recent years, more attention has been given to relationships, primarily between lower-body strength and linear speed performance. While still limited, evidence is in agreement that lower-body strength positively contributes to linear speed performance. However, what is less well understood is if there comes a point in an athlete's development, at which, further working on increasing maximal strength may not fully compliment additional gains in speed performance. Within this study, authors aimed to provide practitioners with lower-body strength and power thresholds that can discriminate between slow and fast performers, within a group of collegiate American football players. The sample was further divided into a high-body and low-body weight group, and authors hypothesized that by using logistic regression, supplemented with receiver operator curve analyses, optimal cut-off points (i.e., relative lower-body strength thresholds) that are able to significantly discriminate between slow and fast linear speed performers may be identified. Findings indicate that optimal cut-off scores differed between the groups of athletes, as well as the lower body strength and power tests. All models were able to significantly distinguish between slower and faster performers, and area under the curve values ranged from 0.695 to 0.903. Although thresholds will likely vary based on factors such as sex, training age, and sport, findings from this investigation may be used to benchmark athletes and to further individualize training aimed at improving linear speed performance. [ABSTRACT FROM AUTHOR]

Although different strategies have been implemented to manage recovery-fatigue status in athletes, there is still a lack of consensus on which recovery protocols have the greatest impact and effectiveness when implemented with basketball players, including both physiological and psychological recovery methods. Thus, the purpose of this systematic review is to: (a) determine which recovery methods attain the greatest benefit in restoring the process of attenuating fatigue and (b) provide sports practitioners with guidelines on how some of the most effective recovery strategies can be used to optimize athletes' recovery and ultimately enhance their performance. Using the PRISMA guidelines, a total of 3931 research reports were obtained through four database searches (i.e., PubMed, Scopus, Cochrane, and Web of Science), from which only 25 met the inclusion and exclusion criteria. The recovery protocols analyzed in this systematic review were: sleep, nutrition, hydration, ergogenic aids, cold-water immersion, compression garments, massage, acupuncture, tapering, mindfulness, and red-light irradiation. The results revealed that all recovery strategies are capable of attenuating fatigue and enhancing recovery in basketball players to a certain degree. However, an individualized approach should be promoted, where a combination of proactive recovery modalities appears to result in the most rapid rates of recovery and athletes' ability to maintain high-level performance. Recovery should be programmed as an integral component of training regimens. Also, cooperation and communication between coaches, players, and the rest of the team staff members are essential in minimizing the risk of non-functional overreaching or injury and optimizing basketball players' on-court performance. [ABSTRACT FROM AUTHOR]

The isometric mid-thigh pull test permits the collection of multiple metrics related to athletic performance, such as peak force (PF), time to peak force (TTPF), and force at specific time points (e.g., 100, 150, 200 ms). However, practitioners are often constrained to a weight room setting due to the stationary nature of squat racks, making field-based athlete testing difficult. The purpose of this study was to compare force-time variables collected during a maximal effort isometric mid-thigh pull performed within a custom-built squat rack and barbell-based system (IMTP) to an isometric pull performed on a dual-handle portable device (DHP). A commercially available force platform (Sparta Science, Menlo Park, CA, USA) which samples at a rate of 1,000Hz was utilized in both conditions. Twenty recreationally active individuals with ≥2 years (Mean±SD; 7.1±2.3 yrs) of resistance training experience participated in the present study. Following a standardized warm-up participants performed three maximal effort isometric tests on both the IMTP and DHP, in a randomized counterbalanced manner. A large correlation was observed for PF (r=0.844, p<0.001), with no significant difference between systems (IMTP = 2107.9 ± 509.8, DHP = 2005.2 ± 543.7 N). However, PF values showed 5% systematic error for DHP. In addition, Force at 250 ms significantly differed (IMTP = 1474.8 ± 418.8, DHP = 1220.2 ± 380.6 N, p=0.003). Lastly, TTPF varied between systems (IMTP = 2.2 ± 1.2, DHP = 2.9 ± 0.9 s, p=0.012) and was not significantly correlated (r=0.343). Isometric strength testing using DHP appears to be a near valid method for the assessment of maximal effort isometric strength. Kinetic measures from portable rigs should be interpreted with caution when compared to IMTP. [ABSTRACT FROM AUTHOR]

Problem Statement: In the United States, collegiate diving coaches look at two main types of competitions to recruit divers: state high school leagues and club leagues such as USA Diving or the Amateur Athletic Union. It is generally perceived that the judging between these two types of competition is not consistent, but few studies have been conducted to quantify these potential inconsistencies and analyze whether these are individual or systemic biases. Purpose: By comparing equivalent dives from the same diver in both a high school and club diving meet, this study sought to identify judging differences and develop a method for correcting scores between high school and club competitions. Approach: Using all applicable scores across a five-year timespan (2016-2021), including factors such as gender and type of dive, investigators analyzed one-meter springboard diving scores to ascertain if scoring discrepancies exist between club and high school diving competitions. Results: The results revealed statistically significant differences between club and high school net scores for each dive type (all p<0.001), and medium-to-large effect sizes were found for all sub-groups, ranging from 0.577-0.753, except for female reverse dives, which displayed large ES of 0.808. Subsequently, researchers identified correction values to more accurately compare scores between high school and club competitions. Conclusions: Statistical analysis demonstrates significant differences in scoring between club and high school diving scores for all dives and sub-groupings of dives and divers, thus warranting a method for remediating these differences. The corrections developed may provide an initial step towards objectifying scoring within a subjectively scored sport, as well as improving collegiate diving recruitment. [ABSTRACT FROM AUTHOR]

Over the last few years, researchers and sport scientists have expressed an increased interest in the effects of interlimb asymmetry on aspects of sport performance such as jumping, sprinting, and changing direction. This study aimed to evaluate the diagnostic utility of three different means of classifying asymmetry to highlight if a 6-week resistance training intervention can meaningfully reduce levels of asymmetry, and to determine the relation between asymmetry reduction and improvements in change of direction (CoD) performance, if any. Eighteen, division-two collegiate American football skill position players completed all pre- and post-intervention procedures. These procedures involved the completion of the Bulgarian Split Squat (BSS) exercise from which asymmetries in relative average power (Rel.AP), and relative peak power (Rel.PP) were derived. Additionally, participants completed three repetitions within the 505 and L-drill tests to quantify CoD performance. Results from our study show that participants classified as asymmetrical, exhibiting observed asymmetry in Rel.PP scores larger than the sample mean plus one standard deviation, had the greatest likelihood of reducing asymmetry (OR = 6.99, 95% CI: 1.4, 12.5) and improving L-drill performance (OR = 1.33, 95% CI: -2.1, 4.8). Further, our training intervention meaningfully reduced Rel.AP asymmetry (p = 0.027, Cohen's d = 0.73). At the group level, these reductions in asymmetry were accompanied by improvements in L-drill performance that were larger than the sample smallest worthwhile change (SWC). At the individual level, however, change scores in asymmetry and change scores in CoD performance only showed small, non-significant correlations. [ABSTRACT FROM AUTHOR]

Endothelial dysfunction and arterial stiffness indicate vessel damage and are detectable before overt cardiovascular disease. Chronic cardiorespiratory endurance activity improves arterial endothelial function and stiffness. The influence of chronic resistance activity on these variables is less definitive and thus deserves attention. The primary aim of this investigation was to determine if endothelial dysfunction and arterial stiffness were present in apparently healthy young adults who chronically engage in resistance activity with minimal cardiorespiratory endurance activity. Investigators measured endothelial function as LnRHI and arterial stiffness as AI@75 using the EndoPAT-2000. Investigators measured upper-body muscular strength using a standardized one-repetition maximum (1-RM) bench press. The LnRHI and AI@75 between males and females were compared via an independent-samples t-test and Mann-Whitney U test, respectively. Correlations between 1-RM, bench press to body weight ratio, LnRHI, and AI@75 were evaluated via Pearson's correlation. Males' LnRHI was abnormal according to manufacturer standards and lower than females' (p = .005), but AI@75 was normal and similar for both sexes (p = .22). The 1-RM and bench press to body weight ratio correlated negatively with LnRHI (p = .03 and p = .01, respectively). The bench press to body weight ratio correlated negatively with AI@75 (p = .03), and percentage body fat correlated positively with the AI@75 (p = .003). Young adult males with considerable upper-body muscular strength due to chronic resistance activity, who complete minimal cardiorespiratory endurance activity, appear to have detectable signs of early endothelial dysfunction. [ABSTRACT FROM AUTHOR]

Researchers and strength and conditioning practitioners have had an increased interest in the effects of interlimb asymmetries on different aspects of sport performance over the past couple of years. Interlimb asymmetries have been found to negatively affect performance in key performance indicators (KPI) such as jumping, sprinting, and changing directions, within various sports populations. However, there is no consensus about a meaningful threshold at which asymmetries start to negatively affect KPIs or performance. The aim of this study was to investigate a potentially meaningful threshold for three asymmetry metrics (mean peak velocity [mPV], mean peak power [mPP], mean average power [mAP]) that were extracted from the Bulgarian split squat and found to be significantly related to change of direction performance (via L-drill test) within a sample of collegiate American football players. Receiver operating characteristic (ROC) curves were used to identify asymmetry thresholds for all metrics that discriminated between faster and slower performers in the L-drill. Players with asymmetries over 10.65% (mAP), 14.59% (MPP), and 14.96% (mPV) were identified by ROC curves as more likely to be classified as low performers. These findings may be helpful for practitioners interested in screening athletes for interlimb asymmetries that may negatively affect their change of direction performance. [ABSTRACT FROM AUTHOR]

People may exercise at the ends of their day to fit activity into their schedule; the purpose of this investigation was to determine if metabolic or perceived exertion outcomes differed between maximal runs early in the morning and late at night. After consuming a standardized, glucose drink, thirteen recreationally active individuals completed an early-morning and a latenight run on the treadmill while researchers measured metabolic (aerobic capacity and substrate usage) and perceived exertion outcomes. Point of application #1: Aerobic capacity (maximal consumption of oxygen) and the usage of fat as a fuel to support energy production during exercise were similar between runs. Point of application #2: Maximal perceived exertion (Borg's 6-20) was similar during early-morning and late-night runs. Point of application #3: While research indicates that people may prefer activity in the morning or evening, and this might impact metabolic responses to the exercise bout, most of our participants (n=8) identified with no preference for exercising in the early-morning or late-night. [ABSTRACT FROM AUTHOR]

Introduction: While using force-plate derived measures of vertical jump performance, reflective of stretch-shortening-cycle (SSC) efficiency is common practice in sport science, there is limited evidence as to which tests and measures may be most sensitive toward neuromuscular fatigue. The aim of this study was to explore the SSC fatigue response to a one-week high-intensity fatiguing phase of training in National Collegiate Athletic Association (NCAA) Division-I basketball players., Methods: The study timeline consisted of three weeks of baseline measures, one week of high-intensity training, and two weeks of follow-up testing. Countermovement jumps (CMJ) and 10-5 hop tests were performed at baseline, as well as at two time-points during, and three time-points following the fatiguing training period, allowing for performance-comparisons with baseline., Results: Compared to the weekly training sum at baseline, during the high intensity training phase, athletes were exposed to very large increases in selected external load metrics (ES = 1.44-3.16), suggesting that athletes experienced fatigue acutely, as well as potential longer lasting reductions in performance. Vertical jump data suggested that in the CMJ, traditional metrics such as jump height, as well as metrics reflecting kinetic outputs and movement strategies, were sensitive to the stark increase in high-intensity training exposure. The 10-5 hop test suggested a fatigue-induced loss of tolerance to ground impact reflected by performance reductions in metrics related to jump height and reactive strength qualities., Discussion: These findings emphasize that when monitoring neuromuscular fatigue, variables and assessments may not be looked at individually, but rather as part of a more global monitoring approach., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Philipp, Nijem, Cabarkapa, Hollwedel and Fry.)

With force plates being widely implemented for neuromuscular performance assessment in sport-specific settings and various force-time metrics being able to differentiate athletes based on their performance capabilities, the purpose of the present study was to examine the differences in countermovement vertical jump (CVJ) characteristics between starting and non-starting professional male basketball players (e.g., ABA League). Twenty-three athletes (height = 199.2 ± 7.7 kg, body mass = 94.2 ± 8.2 kg, age = 23.8 ± 4.9 years) volunteered to participate in the present investigation. Upon completion of a standardized warm-up protocol, each athlete performed three maximal-effort CVJs without an arm swing while standing on a uni-axial force plate system sampling at 1,000 Hz. Independent t -tests were used to examine statistically significant differences ( p  < 0.05) in each force-time metric between starters ( n  = 10) and non-starters ( n  = 13). No significant differences in any of the CVJ force-time metrics of interest were observed between the two groups, during both the eccentric and concentric phases of the movement (i.e., impulse, duration, peak velocity, and mean and peak force and power). Moreover, starters and non-starters demonstrated similar performance on CVJ outcome (e.g., jump height) and strategy metrics (e.g., countermovement depth). Overall, these findings suggest that at the professional level of play, the ability to secure a spot in the starting lineup is not primarily determined by the players' CVJ performance characteristics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Cabarkapa, Cabarkapa, Aleksic, Philipp, Scott, Johnson and Fry.)