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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]

Sleep has been recognized as one of the most essential recovery methods necessary for achieving optimal performance. However, there is still a lack of scientific literature focused on examining its impact on one of the most prevalent skills in the game of basketball, the countermovement vertical jump (CVJ). Therefore, the purpose of the present study was to examine the relationship between sleep quality and quantity, and lower-body neuromuscular performance characteristics within a cohort of semiprofessional male basketball players. Twenty-eight athletes competing in a first-tier regional league in Serbia volunteered to participate in this investigation. Upon arrival at the gym, all athletes completed the Pittsburgh Sleep Quality Index (PSQI) self-rated questionnaire. Immediately after completion of the PSQI, each athlete stepped on a force plate system and performed three maximum-effort CVJs with no arm swing. The following force-time metrics were obtained for the analysis: eccentric and concentric absolute and relative mean and peak force and power, vertical jump height, and reactive strength index-modified. Pearson product-moment correlation coefficients were used to examine the strength of the linear relationships between sleep quality and quantity and lower-body neuromuscular performance characteristics (p < 0.05). The results indicated that sleep quality appears to have a greater impact on the concentric than the eccentric phase of the CVJ (e.g., concentric mean force [r = -0.830; p < 0.001], relative concentric peak force [r = -0.466; p = 0.013, eccentric mean power (r = -0.162; p = 0.409)], while no significant relationship was found between sleep quantity and lower-body neuromuscular performance (e.g., concentric peak force [r = -0.055; p = 0.782], relative eccentric mean power [r = -0.301; p = 0.107]). Overall, these findings offer valuable insights into the importance of good sleep hygiene (e.g., efficiency, duration) in an athletic population, and can help practitioners develop more effective training and recovery programs. [ABSTRACT FROM AUTHOR]

One of the reoccurring questions that arises during the countermovement vertical jump (CVJ) assessment is whether the learning effect has an impact on the accuracy of the results obtained. Thus, the purpose of the present investigation was to examine the impact of the short-term learning effect on the assessment of lower-body neuromuscular performance characteristics when performed on a portable one-dimensional force plate system. Sixteen recreationally active college-age males volunteered to participate in the present study. Each participant completed four sets of three non-consecutive CVJs with no arm swing throughout a single day. Besides strong verbal encouragement, participants were constantly instructed to focus on pushing the ground as explosively as possible. Fourteen force-time metrics were selected for CVJ performance analysis purposes: eccentric and concentric peak and mean force and power, eccentric and concentric duration, contraction time, jump height, reactive strength index-modified, and countermovement depth. Repeated measures multivariate analysis of variance was used to examine statistically significant differences across four testing time points (p < 0.05). The results indicate an absence of any meaningful differences across four testing time points in force-time metrics of interest during both eccentric and concentric phases of the CVJ. Moreover, no differences were observed in CVJ outcome metrics such as countermovement depth, suggesting that the movement strategy tends to remain consistent. Overall, these findings reveal that CVJ test repeatability is not affected by the short-term learning effect and that data are stable at least within the scope of this study and within this population. [ABSTRACT FROM AUTHOR]

Considering the importance of body composition and lower-body strength and power for basketball players' on-court performance, as well as a lack of sports science research focused on female athletes, the purpose of the present investigation was to record the anthropometric and countermovement vertical jump (CMJ) characteristics of top-tier U16 and U18 female basketball players and examine between-group differences in the aforementioned tests. Thirty-two athletes who were a part of the national basketball academy volunteered to participate in the present investigation. Following the body composition assessment conducted via a segmental multifrequency bioimpedance analyzer, athletes performed three CMJs while standing on a force plate system sampling at 1000 Hz. Independent t-test and Mann-Whitney U-test were used to examine between-group differences. The findings reveal significant differences in body composition and lower-body neuromuscular performance characteristics between female basketball players ages 16 and 18. Although no differences were observed in muscle and body fat percentages, the U18 group had significantly greater height, overall body mass (both muscle and fat mass), as well as greater segmental fat-free mass (trunk, both legs and arms), intracellular and extracellular water, and body mass index when compared to their U16 counterparts. On the other hand, the U18 group demonstrated longer eccentric, concentric, and braking phase duration, as well as overall contraction time when compared to the U16 players. In addition, the U18 athletes exhibited higher eccentric mean force and power, concentric impulse, peak power, and mean and peak force. [ABSTRACT FROM AUTHOR]

With innovative force plate technology being available to many sports organizations worldwide that allow for time-efficient in-depth neuromuscular performance assessment, the purpose of the present study was to examine the relationship between some of the most commonly analyzed countermovement vertical jump (CVJ) force-time metrics and basketball playing time and efficiency. Twenty-four professional male basketball players volunteered to participate in the present study. The CVJ testing procedures were conducted within the first quarter of the competitive season span. Following a standardized warm-up protocol, each athlete stepped on a dual uni-axial force plate system sampling at 1,000 Hz and performed three maximum-effort CVJs with no arm swing. To minimize the possible influence of fatigue, each jump trial was separated by a 10–15 s rest interval and the average value across three jumps was used for performance analysis purposes. Basketball playing efficiency and average playing time were obtained at the end of the regular season competitive period from the coaching staff records and the official team records. Pearson product-moment correlation coefficients (r) were used to examine the strength of the relationships between force-time metrics and basketball playing time and efficiency, separately for each dependent variable (p < 0.05). A significant positive association was observed between playing efficiency and eccentric mean force and eccentric mean and peak power (r = 0.406–0.552). Similarly, an increase in eccentric mean power was positively correlated with the number of minutes played during the competitive season (r = 0.464). Moreover, the aforementioned relationship remained present even when eccentric mean power was expressed relative to the player’s body mass (r = 0.406). Thus, the findings of the present study indicate that, at the professional level of men’s basketball competition, CVJ eccentric strength and power have a positive impact on both playing time and efficiency. [ABSTRACT FROM AUTHOR]

Given its fast-growing popularity and unique on-court competitive demands, 3 × 3 basketball has captured a considerable amount of attention over recent years. However, unlike research focused on studying 5 × 5 basketball players, there is a lack of scientific literature focused on examining countermovement vertical jump (CMJ) and sprint performance characteristics of 3 × 3 athletes. Thus, the purpose of the present study was to compare force-time metrics during both eccentric and concentric phases of the CMJ and acceleration and deceleration capabilities between 3 × 3 and 5 × 5 top-tier professional male basketball athletes. Ten 3 × 3 and eleven 5 × 5 professional basketball players volunteered to participate in the present study. Upon completion of a standardized warm-up, each athlete performed three maximum-effort CMJs, followed by two 10 m sprints. A uni-axial force plate system sampling at 1,000 Hz was used to analyze CMJ force-time metrics and a radar gun sampling at 47 Hz was used to derive sprint acceleration-deceleration measures. Independent t-tests and Hedge's g were used to examine between-group statistically significant differences (p<0.05) and effect size magnitudes. The findings of the present study reveal that 3 × 3 and 5 × 5 professional male basketball players tend to display similar neuromuscular performance characteristics as no significant differences were observed in any force-time metric during both eccentric and concentric phases of the CMJ (g=0.061-0.468). Yet, prominent differences were found in multiple measures of sprint performance, with large effect size magnitudes (g = 1.221-1.881). Specifically, 5 × 5 basketball players displayed greater average and maximal deceleration and faster time-to-stop than their 3 × 3 counterparts. Overall, these findings provide reference values that sports practitioners can use when assessing athletes' CMJ and sprint performance capabilities as well as when developing sport-specific training regimens to mimic on-court competitive demands. [ABSTRACT FROM AUTHOR]

Given the complex nature of the handball as a game, players are required to possess a distinct set of physical and physiological attributes to attain peak performance. With the countermovement vertical jump (CVJ) being widely implemented as a non-invasive and time-efficient testing modality in sports settings, the purpose of the present study was twofold: (a) to establish a CVJ profile of professional female handball players and (b) to examine differences in force-time metrics between starters and non-starters. Forty-two professional female handball players (e.g., SuperLeague) volunteered to participate in this study. Each athlete performed three maximum-effort CVJs with no arm swing while standing on a uni-axial force plate system sampling at 1,000 Hz. Independent t-tests were used to examine differences in each variable between starters and non-starters. The results revealed that starters attained superior performance within the eccentric phase of the CVJ when compared to non-starters, particularly in terms of eccentric peak velocity (-0.957 ± 0.242 vs. -0.794 ± 0.177 m·s-1), eccentric mean power (320.0 ± 77.7 vs. 267.1 ± 75.2 W), and eccentric peak power (929.0 ± 388.1 vs. 684.4 ± 214.2 W). While not reaching the level of statistical significance, moderate-tolarge effect sizes were observed for concentric impulse, peak velocity, and mean and peak force and power, all in favor of players included in the starting lineup (g = 0.439-0.655). Overall, these findings suggest that at the top-tier level of handball competition, the ability to secure a spot in a starting lineup may be possibly influenced by the athlete's eccentric performance capabilities. Thus, the development of lower-body eccentric strength and power may positively impact on-court athlete performance and ultimately help the team secure the desired game outcome. [ABSTRACT FROM AUTHOR]

Short sprints are predominantly assessed using timing gates and analyzed through parameters of the mono-exponential equation, including estimated maximal sprinting speed ( M S S ) and relative acceleration ( T A U ), derived maximum acceleration (MAC), and relative propulsive maximal power ( P M A X ), further referred to as the No Correction model. However, the frequently recommended flying start technique introduces a bias during parameter estimation. To correct this, two additional models (Estimated TC and Estimated FD) were proposed. To estimate model precision and sensitivity to detect the change, 31 basketball players executed multiple 30 m sprints. Athlete performance was simultaneously measured by a laser gun and timing gates positioned at 5, 10, 20, and 30 m. Short sprint parameters were estimated using a laser gun, representing the criterion measure, and five different timing gate models, representing the practical measures. Only the MSS parameter demonstrated a high agreement between the laser gun and timing gate models, using the percent mean absolute difference ( % M A D ) estimator ( % M A D < 10%). The MSS parameter also showed the highest sensitivity, using the minimum detectable change estimator ( % M D C 95 ), with an estimated % M D C 95 < 17%. Interestingly, sensitivity was the highest for the No Correction model ( % M D C 95 < 7%). All other parameters and models demonstrated an unsatisfying level of sensitivity. Thus, sports practitioners should be cautious when using timing gates to estimate maximum acceleration indices and changes in their respective levels. [ABSTRACT FROM AUTHOR]

While various quantifiable physical attributes have been found to contribute to athletes' performance, there is a lack of scientific literature focused on examining how they relate to success during competition performance. The aim of this study was to investigate different countermovement jump (CMJ)-derived force–time characteristics and their utility in distinguishing high from low performers within a measure of on-court contribution (i.e., minutes per game played). Twenty-nine collegiate athletes (n = 15 males and n = 14 females) volunteered to participate in this investigation and performed CMJs on dual force plates sampling at 1000 Hz, weekly over the course of their basketball season. The athletes' average of their three best test-days across the season was used for further analysis. To identify their on-court contribution, athletes were divided into groups with high and low minutes per game, based on a median-split analysis. The findings suggest that at the overall group level (i.e., both genders), the modified reactive strength index (mRSI) and braking rate of force development (RFD) revealed the greatest between-group magnitudes of difference, with athletes playing more minutes per game showing greater performance. At the team-specific level, the braking RFD, average braking velocity, and mRSI were shown to be the greatest differentiators between groups for the men's team. The women's high-minutes group displayed greater magnitudes of mRSI and jump height. By identifying the neuromuscular qualities seen in top performers within their respective populations, the attributed physical performance underpinning these qualities may be identified, providing practitioners with insights into physical performance qualities and training methodologies that have the potential to influence basketball performance. [ABSTRACT FROM AUTHOR]

Cabarkapa, D, Cabarkapa, DV, Philipp, NM, Knezevic, OM, Mirkov, DM, and Fry, AC. Pre-post practice changes in countermovement vertical jump force-time metrics in professional male basketball players. J Strength Cond Res 37(11): e609-e612, 2023--Despite the countermovement vertical jump (CVJ) being one of the most popular noninvasive and time-efficient methods for monitoring neuromuscular status, there is a lack of scientific literature focused on examining fatigue-induced alterations in performance in elite athletes. Thus, the purpose of this study was to examine changes in force-time metrics pre-post practice in professional male basketball players. Seventeen athletes competing in first-tier and second-tier national basketball leagues in Europe participated in this study. While standing on a uniaxial force plate sampling at 1,000 Hz, each athlete completed 3 CVJs pre-practice and post-practice. The practice consisted of individual and team shooting drills, position-specific player development drills, 5-on-0 offensive actions, and 5-on-5 play, including full-court transition (;2 hours). The findings reveal that pre-post practice changes in force-time metrics seemto be phase specific. Despite a trivial increase in eccentric mean force (920.4 6 100.2, 929.4 6 100.0 N), most changes were observed within the concentric phase of the CVJ. The concentric phase duration increased pre-post practice (0.233 6 0.027, 0.242 6 0.033 seconds), whereas concentric impulse (262.9618.8, 258.6621.6 N·s), peak velocity (2.9360.22, 2.8660.22m·s21), mean force (2052.46179.2, 2002.76188.2 N), mean power (3,165.56269.5, 3,030.96326.8W), and peak power (5,523.46607.3, 5,246.6 6663.7W) experienced a significant decrease. Moreover, alongside longer contraction time(0.66360.065, 0.68660.074 seconds), lower vertical jump height (41.0 6 6.8, 38.9 6 6.6 cm) and reactive strength index-modified (0.634 6 0.113, 0.579 6 0.111 m·s21) values were observed post-practice. Overall, these findings may allow practitioners to detect fatigue-induced changes in CVJ forcetime metrics in professional male basketball players that can ultimately improve the acute and longitudinal training-adaptation monitoring process. [ABSTRACT FROM AUTHOR]

Postactivation performance enhancement has been reported for multijoint resistance exercise, with both neural and intrinsic muscle mechanisms suggested as contributing factors. The purpose of this investigation was to examine whether regulatory light-chain (RLC) phosphorylation in a primary mover is associated with enhanced weightlifting performance. Nine male athletes performed 15 sets of 3 repetitions of a multijoint weightlifting activity (clean pull) at 85% 1 repetition maximum. Measures of performance, peak barbell velocity (PV), and average barbell power (AP) were determined by video analysis. Muscle biopsies were taken within 30-60 seconds of completion of the previous lifting set from the vastus lateralis before (PRE), during (MID), and after (POST) a training session. AP was significantly greater for sets 3, 4, and 5 compared with set 1, with large effect sizes (0.8-1.0). Increases in PV did not reach significance; however, the effect size increase for sets 3 and 4 versus set 1 was moderate (0.4). Relative change scores for AP and RLC phosphorylation were positively and negatively correlated at MID (r = 0.60; p = 0.05) and POST (r = -0.74; p = -0.01) exercise, respectively. These data suggest that RLC phosphorylation initially may be associated with postactivation performance enhancement during repeated multijoint exercise. [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]

The vertical jump has been widely used in a sport setting for the assessment of lower-body power. Recently, accelerometry has gained popularity as an inexpensive testing modality for assessment of vertical jump performance characteristics. However, accelerometer anatomical placement could affect the accuracy of the data collected. The purpose of this study was to examine the impact of accelerometer placement on assessment of vertical jump performance parameters. Seventeen healthy recreationally active subjects performed three nonconsecutive maximal vertical jumps with no arm swing. Subjects were instructed to keep the hands on the hips and reach 90-degrees internal knee flexion during the eccentric phase of the jumping motion. Two identical accelerometers sampling at 100 Hz were positioned on the abdomen (AB; 5 cm inferior to umbilicus) and on the hip (HP; 5 cm above greater trochanter). Both devices were secured with elastic bands and collected data simultaneously. Ground reaction force curves were computed from the raw accelerometry data from which the following variables were derived: peak concentric force (PCF), peak landing force (PLF), vertical jump height (VJH) based on flight time, and impulse (IMP) excluding subject's body weight. No significant differences were found between AB and HP accelerometer placement for PCF, PLF, and IMP. However, despite a small effect size, HP accelerometer placement resulted in a significantly lower VJH by 1.2 cm. Additionally, strong agreement and consistency of the measurements were observed across all dependent variables examined in the present investigation, suggesting that both AB and HP accelerometer placements may seem appropriate for analysis of vertical jump performance. [ABSTRACT FROM AUTHOR]

The testosterone-to-cortisol ratio (T/C) has been shown to be positively correlated with strength and power. However, few studies have examined the relationship between a standardized power performance measurement and T/C throughout a season of intercollegiate competition. The purpose of this study was to examine the relationships between salivary T/C and vertical jump (VJ) performance of female National Collegiate Athletic Association Division II basketball players across a season. Saliva samples were taken before practice, weekly, for a total of 29 weeks. Samples were assayed for testosterone (T) and cortisol (C). After saliva collection, players completed two countermovement VJs, with the best jump used for data analysis. A positive correlation between T/C and VJ was seen only during the preseason phase. Statistically significant differences were observed across the season for T/C and VJ. T/C in the nonconference phase was significantly lower than the preseason phase and the late-conference phase, p =.013 and p =.047, respectively. VJ was significantly lower in the late-conference phase when compared to the preseason and nonconference phases, p <.001 and p =.026, respectively. VJ in the early-conference phase was also significantly lower than the preseason phase, p <.001. These data support the literature that has indicated a positive relationship between the T/C and lower-body power but only in the preseason phase. This relationship reverses and trends toward a negative relationship, before disappearing in the second half of the season. Monitoring T/C may provide value in assessing female athletes' performance potential in the preseason phase. T/C should be interpreted with more caution once the competitive season begins. [ABSTRACT FROM AUTHOR]

Basketball is one of the most popular sports worldwide. The basketball dunk uses a very powerful jumping motion to forcefully push a basketball through a goal positioned at a height of 10 feet (3.05m). In the modern game of basketball, the dunk is very popular due to its very high field goal percentage. Due to lack of research on this event, the purpose of this study was to examine the kinetic variables of peak force, peak power, rate of force development, impulse and time during the concentric phase of the five most commonly used variations of a basketball dunk: one-leg left (1LL), one-leg right (1LR), two-leg left-right (2LLR), two-leg right-left (2LRL) and two leg stationary (2LS). Ten healthy recreationally active men (X±SD, age=22.4±2.5, weight=89±6.3kg, height=192.8±4.9cm, vertical jump=73.7±12.4cm) who were capable of dunking a basketball volunteered to participate in this research study. Kinetic variables measured in this study were obtained from a force plate and data acquisition system sampling at 1000Hz. Based on our data we conclude that the basketball dunk is a very powerful activity that requires high levels of strength and power. Our data suggest that the most time consuming dunk approach was a 2LS (0.820±0.116sec) while the fastest dunk approach was 1LL (0.311±0.039sec), which can serve as a guideline for which dunk should be utilized at certain times during an on-court game performance. The highest peak power output was observed for 2LS (6261.9±1104.1W) which also had the lowest rate of force development (5851.3±3069.5N/sec) and impulse (408.2±41.1N/sec). The highest peak forces were observed for 2LLR (3158.4±376.3N) and 2LRL (3206.8±518.2N) dunk approaches. Knowing the specific biomechanical characteristics of a motion can help target optimal training for each individual and lead to enhanced basketball performance, specifically the basketball dunk in this case. In conclusion, this study serves as a foundation and guideline for further research by presenting the previously unexplored kinetic and kinematic variables of a basketball dunk. [ABSTRACT FROM AUTHOR]

Basketball is one of the most popular sports worldwide. The basketball dunk uses a very powerful jumping motion to forcefully push a basketball through a goal positioned at a height of 10 feet (3.05m). In the modern game of basketball, the dunk is very popular due to its very high field goal percentage. Due to lack of research on this event, the purpose of this study was to examine the kinetic variables of peak force, peak power, rate of force development, impulse and time during the concentric phase of the five most commonly used variations of a basketball dunk: one-leg left (1LL), one-leg right (1LR), two-leg left-right (2LLR), two-leg right-left (2LRL) and two leg stationary (2LS). Ten healthy recreationally active men (X±SD, age=22.4±2.5, weight=89±6.3kg, height=192.8±4.9cm, vertical jump=73.7±12.4cm) who were capable of dunking a basketball volunteered to participate in this research study. Kinetic variables measured in this study were obtained from a force plate and data acquisition system sampling at 1000Hz. Based on our data we conclude that the basketball dunk is a very powerful activity that requires high levels of strength and power. Our data suggest that the most time consuming dunk approach was a 2LS (0.820±0.116sec) while the fastest dunk approach was 1LL (0.311±0.039sec), which can serve as a guideline for which dunk should be utilized at certain times during an on-court game performance. The highest peak power output was observed for 2LS (6261.9±1104.1W) which also had the lowest rate of force development (5851.3±3069.5N/sec) and impulse (408.2±41.1N/sec). The highest peak forces were observed for 2LLR (3158.4±376.3N) and 2LRL (3206.8±518.2N) dunk approaches. Knowing the specific biomechanical characteristics of a motion can help target optimal training for each individual and lead to enhanced basketball performance, specifically the basketball dunk in this case. In conclusion, this study serves as a foundation and guideline for further research by presenting the previously unexplored kinetic and kinematic variables of a basketball dunk. [ABSTRACT FROM AUTHOR]