hamstrings

The aim of this study was to investigate the acute effects of Romanian deadlift (RDL) and Nordic hamstring exercise (NHE) on the stiffness and flexibility of hamstring muscles. We hypothesized that a) the RDL would have a greater acute effect on increasing the flexibility, b) the NHE would have a greater acute effect on the increase in stiffness of the biceps femoris (BF) and semitendinosus (ST) in comparison to the semimembranosus (SM), and c) RDL would have a greater acute effect on the increase in stiffness of the SM in comparison to the ST. Twelve young, healthy participants (6 females; 22.8±3.0 years) performed RDL, and 12 participants (8 females; 22.8±3.1 years) performed NHE, with both interventions comprising 5 sets of 10 repetitions. Baseline and post-intervention stiffness was measured using shear– wave elastography, and flexibility using the passive straight leg raise test. There were no significant main effects of time (p=0.744), group (p=0.202), nor the interaction between time and group (p=0.131) for shear modulus. Similarly, no significant main effects of time (p=0.717) and group (p=0.856), nor an interaction between time and group (p=0.444), were observed for flexibility. These findings suggest that neither RDL nor NHE induce immediate measurable changes in hamstring muscle stiffness or flexibility. However, given the small group-specific sample size, the absence of significant effects should be interpreted cautiously and cannot be generalized beyond young, healthy recreationally active individuals.

matched text: “hamstring”

Ultimate Frisbee, a high intensity noncontact sport, poses significant injury risks due to the dynamic demands of sprinting, cutting, and jump landings. These injuries negatively impact athletic performance and carry potential long term consequences. Despite rapid global growth, current epidemiological data exhibit significant methodological variance, and the precise biomechanical mechanisms remain insufficiently classified. Consequently, this study systematically reviews the epidemiology and mechanisms of sports injuries in Ultimate Frisbee while narratively synthesizing sport specific prevention and rehabilitation strategies extrapolated from analogous high demand sports. Researchers systematically screened relevant literature from databases including PubMed, Web of Science, SPORTDiscus, the Cochrane Library, CNKI, Wanfang, VIP, and Google Scholar published between January 1990 and March 2025. The synthesized evidence indicates a profound predominance of lower extremity trauma including lateral ankle sprains, knee ligament tears, and hamstring strains. Conversely, upper extremity, trunk, and neurological traumas including concussions frequently result from aerial contests and high impact layouts. Because direct interventional evidence in Ultimate Frisbee remains scarce, mitigating these risks requires adopting targeted neuromuscular protocols, optimizing cleat surface mechanical interactions, and leveraging wearable technologies for workload prediction. Furthermore, post injury management necessitates the implementation of individualized rehabilitation protocols and objective functional metrics to effectively dictate safe return to play. This review establishes a comprehensive conceptual framework bridging epidemiological data with biomechanical mechanisms, ultimately guiding clinical practitioners and coaches in developing targeted risk management and performance optimization protocols.

matched text: “hamstring”