Background: Explosive power, sprint speed, and change-of-direction (COD) speed are key determinants of basketball performance, yet evidence on how plyometric training affects all three concurrently in adolescent basketball players, particularly COD speed, is limited. This exploratory study compared changes in these qualities over 10 weeks between two teams, one of which added a plyometric program. Methods: Thirty-three male players from two clubs, one club per group (experimental, E, n = 16; control, C, n = 17), participated. The E group performed plyometric training twice weekly in addition to regular technical-tactical training; the C group performed technical-tactical training only, so the E group had a larger total training volume. Jump (squat, countermovement, drop, and arm-swing countermovement jumps), sprint (5, 10, and 20 m), and COD tests (Reactive Shuttle Test, Lane Arrow Closeout, Lane Agility Drill, Modified 505 Test) were performed before and after the program. Groups were compared at follow-up using one-way ANCOVA with initial scores as covariate and Holm adjustment within three outcome domains. Results: The E group showed greater baseline-adjusted follow-up performance on eight of eleven outcomes (partial η2 = 0.141–0.622); all remained significant after adjustment except the 5 m sprint. No significant differences were found for the arm-swing countermovement jump, 10 m sprint, or Modified 505 Test. Conclusions: These preliminary findings suggest that adding a plyometric program may be associated with greater improvements in explosive power, short sprint speed, and COD speed in adolescent basketball players. Club-based allocation and the E group’s larger training volume preclude causal inference; randomized, volume-matched, multi-club trials are needed.
Background and Objectives: Anterior cruciate ligament (ACL) injury prevention research in pediatric and adolescent athletes frequently relies on biomechanical assessments of landing and cutting tasks. However, interpretation of developmental biomechanics is complicated by changes in body size, neuromuscular control, and biological maturation during growth. This systematic methodological review evaluated whether youth ACL biomechanics studies adequately account for growth and maturation in study design, task prescription, biomechanical normalization, modeling assumptions, and statistical analysis. Methods: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE, Embase, CINAHL, SPORTDiscus, Scopus, Google Scholar, and Web of Science were searched through July 2026. Eligible studies included participants ≤19 years performing ACL-relevant landing, cutting, change-of-direction, pivoting, or deceleration tasks with quantitative biomechanical or neuromuscular outcomes. Data were extracted regarding maturity assessment, task scaling, normalization, modeling assumptions, and statistical treatment of developmental variables. Results: Fifty-four reports met eligibility criteria. Forty-three reports (79.6%) evaluated landing tasks exclusively, seven (13%) evaluated cutting and change of direction tasks exclusively, and four (7.4%) evaluated both landing and cutting tasks. Cross-sectional/observational designs were most common (28/54; 51.9%), followed by intervention/repeated-measures (16/54; 29.6%) and longitudinal/cohort studies (10/54; 18.5%). Formal biological-maturity assessment with a specified method was documented in 25 reports (46.3%). Two additional reports (3.7%) described a formal or group maturity classification but did not identify the method. Nine reports (16.7%) used age/development groupings only, and 18 (33.3%) reported no formal maturity assessment. Variability was observed in task prescription, normalization, and reporting of growth-related statistical methods. Conclusions: Youth ACL biomechanics research is not consistently growth-aware. Future studies should integrate maturity assessment, task scaling, biomechanical normalization, and developmentally appropriate statistical approaches to improve interpretation and reproducibility.
Background and Objectives: This cross-sectional study examined associations between kinanthropometric indicators and lower-body force-time performance in 34 professional male boxers. Athletes were recruited by convenience sampling; no a priori sample-size calculation was performed. Methods: CMJ, countermovement rebound jump, and isometric-squat outcomes were assessed using a force platform. Three missing derived anthropometric estimates were recalculated from recorded measurements, and site-specific corrected-girth calculations, the Rocha bone-mass equation, and the Kerr adipose-mass input were corrected following confirmation by the study anthropometry investigator. A matrix of 117 Spearman correlations was evaluated with Benjamini–Hochberg false-discovery-rate adjustment. Results: CMJ peak force was correlated with BMI (rho = 0.697), body mass (rho = 0.663), corrected girths (rho = 0.622), estimated muscle mass (rho = 0.573), and adipose mass (rho = 0.508). Isometric-squat peak force was correlated with corrected girths (rho = 0.651), estimated muscle mass (rho = 0.638), sitting height (rho = 0.547), and estimated bone mass (rho = 0.521). Thirteen of 117 exploratory associations survived FDR correction. Conclusions: In this exploratory sample, observed relationships with absolute force tended to be larger than those with relative, ballistic, or time-dependent outputs, but formal differences between dependent correlations were not tested. The observed associations, including those based on anthropometric tissue-mass estimates, do not establish causal or body-mass-independent effects.
Background: Several risk factors have been identified for knee anterior cruciate ligament (ACL) injuries. Yet, their contributions still raise questions when attempting to identify at-risk populations with whom they are associated. Objectives: The purpose of this study was to identify combinations of characteristics in athlete populations at risk of non-contact ACL injuries using principal component analysis. Methods: From a cohort of 161 sports practitioners aged 28.6 ± 8 years who had presented a non-contact ACL injury, five risk factors were assessed on the healthy contralateral knee: passive knee alignment (valgus and recurvatum), knee laxity (KT-1000 test), and isokinetic hamstring strength at 60°/s and at 180°/s. Female sex, age and BMI were considered as individual risk factors. The profile of the population at risk of non-contact ACL injury was determined using a principal component analysis. Results: A total of 31% of the patients were females, 34% were under 24 years old, and 63% had a BMI > 22.5 Kg/m2. The knee axis was valgus in 37% and recurvatum in 80%. An anterior–posterior laxity ≥ 4 mm was present in 38% of the cases. Weakness of the hamstring was present at 60°/s (<1.3 Nm/kg) and 180°/s (<1.0 Nm/kg) in 49% and 54% of the cases, respectively. The principal component analysis explained only 61% of the variance in non-contact ACL injury. Three profiles of the population could be identified: “female with dynamical factors” (knee valgus and weakness of the hamstring strength), “male with physiological factors” (old age and high BMI), and “knee morphology” (valgus, recurvatum and laxity). Conclusions: In the absence of a comparison with a non-injured population, combinations of the potential factors associated with non-contact ACL injuries have been identified, and three independent populations could be at risk.
Background and Objectives: Comparisons between individual and multiplayer gaming can reflect social context, but in a fixed-order design condition cannot be separated from order-related effects. This exploratory study therefore focused on group-level Group Cohesiveness Scale (GCS) ratings across a sequential paradigm in which individual play always preceded multiplayer play. A study-specific OpenPose posture-consistency metric and a device/software-derived beta-band output from a small EEG subsample were retained only as ancillary exploratory observations. Methods: Sixty healthy young adults (mean age, 21.21 ± 3.07 years) completed the individual condition first and the multiplayer condition second in 10 assigned groups of six, separated by a one-hour break. GCS scores were averaged within each group, yielding 10 paired group-level means. OpenPose recordings from all 60 participants were summarized descriptively because participant-level paired values required for inferential reanalysis were unavailable. One randomly selected participant per group wore a NeuroSky MindWave Mobile 2 device (n = 10); because the exact eegID processing pipeline and artifact-control procedures were not retained, this output was treated only as a device/software-specific ancillary metric. Results: Mean group-level GCS ratings were 18.13 ± 0.55 after the first, individual condition and 23.55 ± 4.17 after the second, multiplayer condition (mean difference, +5.42). The retained statistical summary reported p < 0.0043; because the original SPSS output is unavailable, 0.0043 is treated as an upper bound rather than an exact recoverable p-value. Using the arithmetic mean of the two condition SDs as the standardizer, Cohen’s d_av was 2.30. Mean OpenPose posture-consistency scores were 97.13 ± 2.90 and 93.25 ± 6.24, respectively; this comparison is descriptive only. In the ancillary EEG subsample, the retained software-derived beta-band values were 34.55 ± 12.92 and 47.56 ± 15.33 a.u. (p = 0.022; Cohen’s d_av = 0.92), but the physiological source of this difference cannot be determined from the available methodology. Conclusions: Within this fixed sequential paradigm, the second, multiplayer condition was accompanied by higher group-level GCS ratings, but the difference cannot be attributed specifically to multiplayer interaction because condition was completely confounded with order, time, familiarization, anticipation, fatigue, and repeated-task effects. The OpenPose and EEG observations remain ancillary and hypothesis-generating and do not support causal, attentional, engagement, or cortical interpretations.
