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Background: Injury to the anterior cruciate ligament is one of the most common knee injuries. Following anterior cruciate ligament reconstruction, strength deficits and reduced quadriceps and hamstring muscle mass are common. Traditional strengthening protocols recommend the use of heavy loads. However, following surgery, heavy-load exercises are contraindicated to protect the joint and graft. Blood flow restriction resistance training is an alternative that optimizes muscle recovery. The aim of this study was to evaluate the effects of blood flow restriction resistance training on muscle mass and strength after ACLR. Methods: The Pubmed, Cochrane Library, and PEDro databases were used to constitute the corpus of this systematic review. The methodological quality of the studies was assessed with the Cochrane Collaboration's analysis grid. Results: Thirty-four articles were identified in the initial search, and five randomized controlled trials were included in this review. Not all studies reported significant results regarding strength and muscle mass. Two of these studies observed a significant improvement in strength associated with blood flow restriction resistance training compared with the control group. A significant increase in muscle mass was observed in one study. Conclusions: The blood flow restriction resistance training method shows superior efficacy to training without occlusion, yet this device has not been shown to be more effective than heavy-load resistance training in terms of muscular strength and muscle mass. Blood flow restriction resistance training shows superior efficacy in both these variables when used with low loads. However, there are still few random controlled trials on this subject, and this review presents their limitations and biases. Future research is needed on guidelines for the application of blood flow restriction resistance training in clinical populations. [ABSTRACT FROM AUTHOR]

Despite the high incidence of knee injuries reported in non-professional sports, the implementation of specific training programmes aimed at mitigating the kinematic and kinetic factors associated with these injuries remains limited. To determine the effects of a tailored exercise programme on kinematic and kinetic variables during side-cutting activities. Fifty-seven physically active participants were randomised into control group (CG; n: 28) that received no intervention, and an experimental group (EG; n: 29), that performed an individualised exercise programme that included a combination of strength, neuromuscular, proprioceptive, eccentric training and whole-body vibration (WBV) exercises. Knee, hip and trunk angles, vertical ground reaction force (VGRF), force in the antero-posterior (AP) and medio-lateral (ML) axes, acceleration, contact time and impulse were assessed during three types of side-cutting, two open manoeuvres (30º and 45º – SC30 and SC45 –respectively) and one closed manoeuvre (45º – SC45cl-). After the 12-week intervention, EG participants had lower knee extension during all side-cuttings, shorter contact time and lower acceleration, VGRF and impulse compared to CG during side-cutting manoeuvres. A tailored exercise programme could be an effective neuromuscular and biomechanical strategy to reduce risk factors for knee injury in healthy, physically active young people. [ABSTRACT FROM AUTHOR]

Background: The demands of professional tennis, including physical and psychological aspects, contribute to the frequency of retirements at elite levels of the sport. Purpose: The aim of this study was to explore the frequency of injuries and the factors that influence the retirements of professional tennis players competing in the Davis Cup over the last two decades. Study Design: Retrospective cohort study. Methods: The data set includes data from 6,060 men's singles matches that included 1,814,141 games from Davis Cup ties played between 2000 to 2019. Factors that might influence the retirements were studied by means of generalized linear models using Poisson distribution. Incidence rates by 1000 games and incidence rate ratios of retirements are provided as association measures. Results: The retirement incidence was 1.05 per 1000 games [95% CI: 0.90, 1.21]. The main risk factors associated with retirements were matches played on hard courts (IRR: 2.52 [95% CI: 1.32, 4.83]) and matches played in the final two matches of the tie and in a best-of-5-set format (IRR: 2.63 [95% CI: 1.69, 4.09] and IRR: 5.52 [95% CI: 3.50, 8.69], respectively). The most common injuries that led to retirements were those affecting the lower extremities, specifically involving muscular or tendinous tissues. Conclusion: This study provides valuable insights for coaches, players, support teams, and epidemiologists regarding retirements and their associated risk factors in Davis Cup tournaments. These findings may guide future research and inform strategies aimed at managing player health and performance in professional tennis. Level of evidence: Level 2b. [ABSTRACT FROM AUTHOR]

Purpose: Among female athletes, dynamic knee valgus (DKV) is one of the most common injuries, especially anterior cruciate ligament (ACL) injuries. This study aims to compare lower limb coordination in athletes with and without DKV during walking. Methods: In this case-control study, 32 recreational female athletes were recruited in two... [ABSTRACT FROM AUTHOR]

BackgroundEarly sport specialization is not a requirement for success at the highest levels of competition and is believed to be unhealthy physically and mentally for young athletes. It also discourages unstructured free play, which has many benefits.PurposeTo review the available evidence on early sports specialization and identify areas where scientific data are lacking.Study designThink tank, roundtable discussion.ResultsThe primary outcome of this think tank was that there is no evidence that young children will benefit from early sport specialization in the majority of sports. They are subject to overuse injury and burnout from concentrated activity. Early multisport participation will not deter young athletes from long-term competitive athletic success.ConclusionYouth advocates, parents, clinicians, and coaches need to work together with the sport governing bodies to ensure healthy environments for play and competition that do not create long-term health issues yet support athletic competition at the highest level desired.

SignificanceMechanosignaling is vital for maintaining the structural integrity of bone under physiologic conditions. These signals activate and suppress multiple signaling cascades regulating bone formation and resorption. Understanding these pathways is of prime importance to exploit their therapeutic potential in disorders associated with bone loss due to disuse, trauma, or disruption of homeostatic mechanisms.Recent advancesIn the case of cells of the bone, an impressive amount of data has been generated that provides evidence of a complex mechanism by which mechanical signals can maintain or disrupt cellular homeostasis by driving transcriptional regulation of growth factors, matrix proteins and inflammatory mediators in health and inflammation. Mechanical signals act on cells in a magnitude dependent manner to induce bone deposition or resorption. During health, physiological levels of these signals are essential for maintaining bone strength and architecture, whereas during inflammation, similar signals can curb inflammation by suppressing the nuclear factor kappa B (NF-κB) signaling cascade, while upregulating matrix synthesis via mothers against decapentaplegic homolog and/or Wnt signaling cascades. Contrarily, excessive mechanical forces can induce inflammation via activation of the NF-κB signaling cascade.Critical issuesGiven the osteogenic potential of mechanical signals, it is imperative to exploit their therapeutic efficacy for the treatment of bone disorders. Here we review select signaling pathways and mediators stimulated by mechanical signals to modulate the strength and integrity of the bone.Future directionsUnderstanding the mechanisms of mechanotransduction and its effects on bone lay the groundwork for development of nonpharmacologic mechanostimulatory approaches for osteodegenerative diseases and optimal bone health.