Translational sports medicine最新文献

The increase in combat sports practice and the creation of weight divisions for fairer competitions led to dehydration practice as a strategy of inclusion in inferior divisions. However, this technique can damage kidney and heart functions due to alterations in blood volume. This study evaluated the acute effects of weight loss through dehydration on the kidney function of Mixed Martial Arts and Muay Thai fighters. The sample was composed of 30 athletes of both Mixed Martial Arts (n = 15) and Muay Thai (n = 15) fighters. Both groups went through two protocols for collecting data about the athlete's profile, vital signs, and urinary and blood samples in three different moments: before weigh-in, official weigh-in day, and fight day. The athletes' profiles and the dehydration methods employed were found to be consistent with those reported in the literature. The participants lost weight 1 month before the fight and had alterations that developed into glycosuria, leukocyturia, and proteinuria noted on both official weigh-in and combat days. Proteinuria and high creatinine depuration suggest acute kidney damage with an increase in filtration rate due to dehydration. As shown, there is a necessity for proper athlete orientation regarding dehydration and possible damage to the body's physiological integrity and sport performance, and developing a guide on more appropriate weight control protocols that do not put athletes' health at risk should be established and publicized.

Background: Various protein-based dietary supplements are widely used by individuals engaged in strength training to optimize gains in muscle strength and fat-free mass. However, gaps remain in the scientific literature regarding a comprehensive comparison-particularly the effectiveness of different types of supplemented proteins in healthy adults. This systematic review and network meta-analysis aimed to compare the effectiveness of protein-based dietary supplements, combined with strength training, on increasing muscle strength and fat-free mass in healthy adults.

Methods: A network meta-analysis was conducted using randomized controlled trials evaluating different protein supplements combined with strength training. The outcomes assessed were muscle strength (primary) and fat-free mass (secondary). The search was performed in PubMed, Scopus, and Embase up to May 2024, with no restrictions on language or publication date.

Results: A total of 78 studies were included, comprising 4755 participants across two outcomes and involving 13 types of protein supplements, plus placebo and control groups. Compared to placebo, for strength, collagen was the most effective supplement (SMD = 0.41; 95% CI: 0.09 to 0.73; p = 0.0125; SUCRA 88.05%), followed by whey protein (SMD = 0.15; 95% CI: 0.03 to 0.27; p = 0.0145; SUCRA 64.34%). The other supplements showed no statistically significant differences compared to placebo (p > 0.05). For fat-free mass, results were similar. Collagen showed a statistically superior effect (SMD = 0.94; 95% CI: 0.48 to 1.40; p < 0.0001; SUCRA 98.92%), followed by whey protein (SMD = 0.16; 95% CI: 0.05 to 0.28; p = 0.0051; SUCRA 60.23%). Other supplements showed no statistically significant differences (p > 0.05).

Conclusion: Collagen and whey protein are the only protein supplements effective in enhancing strength training effects. Moreover, collagen shows a superior effect compared to whey protein for both outcomes.

Background: Current return-to-sport screening paradigms after anterior cruciate ligament (ACL) injury are inadequate as they fail to reflect cognitive-motor sports demands. This pilot study aimed to evaluate dual-task ability in individuals with ACL reconstruction (ACLR) using a novel dual-task test paradigm. Specifically, we compared (1) cognitive and motor performance between individuals with ACLR and controls, (2) hop test performance between the injured and non-injured legs within the ACLR group, and (3) performance across test-retest sessions.

Materials and methods: Twenty sports active individuals (10 ACLR, 10 controls) performed the dual-task paradigm twice within a week, comprising a cognitive test, a dual-task drop-vertical hop test, and an upper-body hand-tapping test. All tests incorporated a visuospatial working-memory task (cognitive performance), with the latter two additionally engaging attention, decision-making, and inhibitory control (motor performance). Between-group, between-leg, and test-retest differences were analyzed using independent and paired t-tests with Cohen's d effect sizes (ESs). Test-retest reliability was examined using intraclass correlation coefficient (ICC), along with the within-person standard deviation and minimal detectable change.

Results: No significant differences were observed between ACLR and controls at the first test session (p = 0.09 - 0.34; ESs = 0.19-0.62 [very small-medium]), although ACLR mean performances were 3.8%-14.1% lower. At retest, ACLR performed significantly worse than CTRL for most outcomes (p = 0.01 - 0.03; ESs = 0.91-1.17 [large]) and showed smaller improvements for a hop test outcome (p = 0.04; ES = 0.97 [large]). No differences were found between ACLR legs, both groups improved across test sessions, and test-retest reliability was excellent for ACLR (ICCs = 0.74-0.97) and ranged from poor to excellent in CTRL (ICCs = 0.19-0.86).

Conclusions: This pilot study demonstrates the feasibility and preliminary reliability of the dual-task paradigm, particularly within the ACLR group. Poorer cognitive, hop, and upper-body test performances and smaller test-retest improvements for the ACLR group suggest persistent dual-task deficits following injury, supporting the paradigm's utility for ecologically valid ACL rehabilitation and return-to-sport assessment.

The Lisfranc ligamentous complex is the principal stabilizer of the tarsometatarsal joint and functions as the midfoot keystone. Injuries often follow an axial or rotational load applied to a plantarflexed foot, producing ligamentous disruption or, in severe cases, fracture-dislocation of the tarsometatarsal complex. Up to one-third of Lisfranc injuries are initially missed, particularly in low-energy mechanisms or polytrauma settings. Weight-bearing radiographs are essential for detecting subtle injuries and uncovering diastasis between the medial cuneiform and the second metatarsal. The Myerson classification categorizes injuries based on joint congruity, the direction of displacement, and extent of involvement. The decision to pursue conservative or surgical treatment depends on the Lisfranc ligament stability and displacement. Nonoperative management is appropriate only in nondisplaced injuries; delayed treatment can result in persistent midfoot pain, arch collapse, post-traumatic arthritis, and diminished function. Surgical techniques include open reduction and internal fixation, primary arthrodesis, bridge plating, suture button fixation, and percutaneous approaches. Lateral column injuries involving the fourth and fifth tarsometatarsal joints are advised to be treated with K-wire fixation. Anatomic alignment is the strongest predictor of successful recovery and return to activity. Residual displacement > 2 mm is associated with inferior outcomes and significantly reduced return-to-play rates, particularly in athletes who can have lasting effects even with successful fixation and may not reach preinjury performance levels. Optimal management is yet to be determined, and inadequate fixation increases poor outcomes, underscoring the importance of early recognition, precise reduction, and appropriate fixation strategy. This study is novel and integrates recent evidence including diagnostic and prognostic utility of weight-bearing, the clinical outcomes and biomechanics of treatment approaches including flexible fixation constructs such as suture button systems, and postoperative outcomes including gait analysis, return-to-play, and athletic performance outcomes.

Background: Research on the association between changes in handgrip strength (HGS) and risk factors for lifestyle-related diseases in children and adolescents may help clarify the inverse association between HGS and morbidity/mortality.

Objective: This systematic review with meta-analysis aimed to investigate the cross-sectional and longitudinal associations between HGS and markers of insulin resistance and inflammation in children and adolescents.

Methods: Observational studies that investigated the cross-sectional and/or longitudinal associations between HGS and markers of insulin resistance and inflammation in children and adolescents were searched. Summary effect size measures were calculated using a random-effects model estimation and reported as Fisher's r-to-z transformed correlation coefficients and 95% confidence intervals.

Results: Fifteen studies (12 cross-sectional, two cross-sectional and longitudinal, and one longitudinal) were included in the systematic review, of which 11 studies were also included in the meta-analyses for cross-sectional correlation. Relative (per body mass) but not absolute HGS was significantly associated (very low evidence) with markers of insulin resistance. Relative HGS was also significantly associated (very low evidence) with most of the inflammatory markers investigated. The three longitudinal studies included had insufficient information to perform a meta-analysis.

Conclusions: The results from cross-sectional studies indicated the association (very low evidence) between HGS and several markers of insulin resistance and inflammation existed when studies utilized the relative HGS per body mass. However, no significant relationship was found when studies used absolute HGS. Furthermore, as longitudinal studies were limited, future longitudinal follow-up studies are an important means of resolving these issues.

Adolescent female handball players are at elevated risk of anterior cruciate ligament (ACL) injury. Early interventions during preadolescence seem crucial for improving motor strategies and potentially preventing injuries. This randomised controlled trial on preadolescent female handball players investigated the effects of an 8-week ACL injury prevention program (ACL-IPP) targeting modifiable neuromuscular and biomechanical risk factors and assessed retention effects 8 weeks post-intervention. Thirty-five elite preadolescent female handball players (11-13 years old) were randomised to the ACL-IPP group (n = 18) or a control group that performed shoulder injury prevention exercises (n = 17), with supervised training conducted for 15 min twice weekly. Biomechanical and neuromuscular assessments of participants' side-cutting manoeuvres were performed at baseline, immediately after the 8-week intervention (post-intervention) and at an 8-week follow-up (16 weeks from baseline). The primary outcome was the between-group change in m. semitendinosus EMG preactivity, measured during the 50 ms preceding initial contact of the side-cutting manoeuvre at 8 weeks. There were no significant between-group differences in changes in semitendinosus preactivity (p = 0.950), isometric hip external rotation strength, hip flexion, knee internal rotation at initial contact or peak knee abduction moments of the handball-specific side-cut manoeuvre. Similarly, no retention effects were observed after 16 weeks. These findings suggest that the implemented 8-week ACL-IPP was insufficient to elicit meaningful improvements in ACL injury risk factors in this population. Greater training volume, different exercise selection and/or extended intervention duration may be required to induce neuromuscular and biomechanical adaptations in preadolescent female handball players. Trial Registration: ClinicalTrials.gov identifier: NCT05955599.

Introduction: This study aimed to compare the influence of the knee and hip joint angles on the quadriceps muscles and tendon shear wave velocity (SWV) between men and prepubertal boys.

Methods: Ten prepubertal boys and ten men participated in one experimental session, which included SWV measurements at rest for the vastus lateralis (VL), the rectus femoris (RF), and the patellar tendon (PT). Each volunteer was tested in ten randomized positions, including five knee joint angles (30, 50, 70, 90, and 110°, 0° = full extension) and two hip joint angles (0° and 80°, 0° = full extension). The SWV values were analyzed independently with a three-way ANOVA, while considering the knee angle, hip angle, and the age group.

Results: Significant knee angle × age interactions were observed for VL (p = 0.008), RF (p = 0.008), and PT (p < 0.001). Boys and men did not present a difference in VL and RF SWV. However, boys exhibited significantly lower PT SWV values than men from a 30° to 90° knee flexion angle (p < 0.001). Additionally, a hip angle × knee angle interaction (p < 0.001) has been observed for RF SWV and highlighted greater values with a 0° hip joint angle, whatever the knee joint angles.

Conclusion: These results suggested that boys and men present similar muscle elastic properties in VL and RF. However, lower SWV was observed for PT in boys up to 90° knee joint flexion.

Introduction: Limited knowledge exists regarding how retirement from a professional soccer career may influence players' future quality of life and overall health status. This study aimed to explore the reasons for ending professional soccer careers and to examine the postretirement health and quality of life among former soccer players in Kosovo.

Materials and methods: Seventy-three retired male professional soccer players from Kosovo participated in this cross-sectional study with a retrospective design. The participants completed a questionnaire covering demographics, career details, reasons for retiring, history of soccer-related injuries, current health and activity status, and psychological aspects associated with their professional careers and retirement. Players were divided into two groups: medical retirees (MRs) and nonmedical retirees (NMRs). The Mann-Whitney U test was used to compare continuous data between the two groups, and cross-tabulation methods were employed for categorical data.

Results: Nonmedical reasons were the main cause of retirement among Kosovar soccer players (p < 0.001), with job-related issues (58.8%) as the main retirement reason. The NMR group retired later and had longer careers than the MR group, though this was not statistically significant. Lower extremity injuries, particularly ankle and knee injuries, were the most prevalent among all players. After retirement, the NMR group engaged more in physical activity and continued playing soccer significantly more than the MR group (p < 0.001 and p = 0.021). The MR group reported significantly more pain (p < 0.001), analgesic use (p = 0.001), fear of career-ending injuries (p < 0.001), and depression symptoms during their careers (p < 0.001). Overall, NMR had significantly better quality of life and health status than MR (p < 0.001 and p < 0.001, respectively).

Conclusions: This study highlights the impact of retirement reasons on the long-term health and quality of life of soccer players in Kosovo. It calls for enhanced support systems to prepare athletes for life after soccer, mitigating negative health outcomes associated with forced retirement due to injuries.

Objectives: We examined how shoe recommendation based on gait analysis influences subjective perceptions of comfort, performance and injury reduction in runners while monitoring spatiotemporal and kinematic parameters.

Design: Single-blind crossover randomised controlled trial with repeated measures.

Method: Twenty-one women runners completed a clinical gait analysis and four 5-min treadmill trials at a self-selected comfortable speed sequentially in their own shoes (OS), the first experimental shoes (randomised), their OS, and the second experimental shoes (randomised). The two experimental shoes were identical except for their colour (randomised) and were presented to runners as either a 'basic' shoe or, deceptively, a 'gait-matched' shoe selected for them based on the clinical gait analysis conducted.

Results: Running Comfort Assessment Tool (RUN-CAT) scores and 100 mm visual analogue scale ratings of subjective comfort, performance and injury reduction differed significantly between own and experimental shoes (p  <  0.001). Post-hoc comparisons revealed that runners' OS were the most comfortable (83.3 ± 3.8 mm) followed by gait-matched (66.1 ± 21.5 mm) and then basic (49.0 ± 24.1 mm) shoes. RUN-CAT, performance and injury reduction ratings were similar between own and gait-matched shoes, but gait-matched shoes had better mean difference (95% confidence intervals), RUN-CAT (15.6 mm [5.7, 25.5]), performance (17.1 mm [5.6, 28.6]) and injury reduction (30.1 mm [8.9, 51.2]) scores than the basic shoes. Discrete spatiotemporal, foot strike angle and resultant tibial acceleration parameters were not significantly different between shoes (p ≥ 0.157). Most runners overall preferred their OS (71.4%), followed by gait-matched (23.8%) and basic (4.8%) shoes.

Conclusions: Shoe recommendation and description can significantly affect subjective shoe comfort and overall preferences without significantly altering spatiotemporal and kinematic parameters. Runners should be cautious while choosing shoes based on recommendations and descriptors derived from gait analysis or based solely on perceived comfort as runners' subjective perceptions can be artificially manipulated. Trial Registration: Australian New Zealand Clinical Trials Registry: ACTRN12623000516684.

Background: Rugby involves frequent, high-intensity collisions. While cumulative fatigue is known to impair performance, recent evidence suggests a dissociation between subjective fatigue and objective performance. Understanding this gap is critical for optimizing training and reducing injury risk in collision sports.

Methods: Twenty-nine amateur male rugby players each performed 30 maximal-effort tackles against a stationary tackle dummy. The kinetics and kinematics tackle motion was captured using a 3D motion analysis system (Vicon Motion Systems Ltd, UK) including 10 motion capture cameras. The subjective fatigue, encompassing physical, mental, and motivation aspects, was assessed using visual analog scales at four distinct time points (Pre, Post1, Post2, and Post3). The objective performance was evaluated through countermovement jump (CMJ) height and tackle variables (velocity, momentum, and kinetic energy) extracted from the tackle motion. The analyses included repeated-measures ANOVA, Friedman tests, linear mixed models, and Spearman's correlations.

Results: Physical and mental fatigue increased significantly over time (p < 0.05), particularly after the 20th tackle. However, despite a slight improvement in CMJ performance, no statistically significant changes were detected in kinetics and kinematics parameters. A moderate positive association was revealed between CMJ height and tackle velocity, as determined by correlational analysis. However, no significant relationship was found between subjective fatigue and CMJ height.

Conclusion: Repeated tackling led to substantial subjective fatigue without corresponding declines in objective performance. This dissociation suggests that athletes may experience fatigue without associated actual performance impairment. Perceived fatigue increased markedly after around 20 tackles. However, performance decline may occur only beyond this threshold, which was not reached in the present protocol. These results highlight the need to integrate subjective and objective assessments when monitoring athletes to optimize training and reduce injury risk.