Background: Maximal force plays a pivotal role in enhancing performance across various dynamic sports, particularly in sprinting biomechanics. However, muscle strength asymmetry among major muscle groups like the hamstrings and quadriceps may hinder sprint performance and raise injury risks. This study examines how intra- and inter-limb strength asymmetry relates to sprint kinematics and the power-force-velocity profile in youth athletes.
Methods: Seventy-four youth athletes from football, volleyball, and handball completed two testing sessions, 48 h apart. Assessments included anthropometric measurements, sprint tests, and isokinetic dynamometer strength evaluations at 60°.s1 and 180°.s1. Sprint kinematics were analyzed using the Optojump Next system, and force-velocity profile variables were determined via Samozino's method. Asymmetry analysis used a standard percentage difference equation.
Results: Weak to moderate correlations (r = -0.46 to 0.45) were found between strength asymmetry and sprint parameters, suggesting limited impact of asymmetry on sprint kinematics and kinetics. Although most participants showed asymmetry levels below the 15% threshold deemed functionally significant, outliers had asymmetry values up to 42%, indicating considerable variability.
Conclusions: Lower extremity strength asymmetry moderately affects sprint kinematics and force-velocity profiles in young team athletes, challenging traditional views. Further research is needed to explore the mechanisms between strength asymmetry and sprint performance, aiming to inform targeted training interventions that optimize performance and reduce injury risks in youth athletes.
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http://dx.doi.org/10.1016/j.knee.2024.10.020 | DOI Listing |
Alzheimers Dement
December 2024
University of Washington Alzheimer's Disease Research Center, University of Washington School of Medicine, Seattle, WA, USA.
Background: The relationship between Alzheimer's disease (AD) pathology and the associated clinical syndrome a patient presents with remains indeterminate. Cognitively-defined subgroups of AD have revealed distinctions based on relative cognitive impairments, including AD-Language, where challenges in language are substantial, and AD-No Domain, where no relative asymmetries across cognitive domains occur. Pathological features of AD have been associated as the primary neuropathology of the logopenic variant of primary progressive aphasia (lvPPA).
View Article and Find Full Text PDFClin Biomech (Bristol)
December 2024
UGA Biomechanics Laboratory, Department of Kinesiology, University of Georgia, Athens, GA, USA.
Background: Female soccer athletes with a history of anterior cruciate ligament injury are more susceptible to secondary injuries and potentially worse sport performance. The purpose of this study was to determine if female soccer athletes post anterior cruciate ligament reconstruction demonstrate worse jump height and reactive strength index performance and lower involved limb hip, knee, and ankle joint power and absorption, and larger joint power and absorption asymmetries compared to matched uninjured athletes.
Methods: Eleven Division I female soccer athletes post anterior cruciate ligament reconstruction (18.
Sports (Basel)
December 2024
Research Center for Sport and Health Sciences, University of Iceland, 102 Reykjavik, Iceland.
Given the increasing use of innovative force plate systems in applied sports settings and the impact that anterior cruciate ligament (ACL) injuries have on team success, the purpose of the present study was to compare the lower-body neuromuscular performance characteristics of athletes who underwent ACL reconstruction (ACLR) and their non-injured counterparts (i.e., healthy controls).
View Article and Find Full Text PDFJ Funct Morphol Kinesiol
December 2024
Escuela de Ciencias de la Actividad Física, El Deporte y la Salud, Facultad de Ciencias Médicas, Universidad de Santiago de Chile, Santiago 8370003, Chile.
Assessing the reliability of measurement instruments and equipment is essential to ensure the accurate tracking of athletes over extended periods, minimizing the measurement errors caused by chance or other factors. However, a less common but equally important analysis is the verification of inter-measurement agreement, which complements the reliability results. To evaluate the intra- and inter-test reliability of an isometric hip adduction strength and asymmetries test in professional soccer players.
View Article and Find Full Text PDFJ Funct Morphol Kinesiol
December 2024
Institut Supérieur de Sport et de l'Éducation Physique du Kef, Université de Jendouba, Le Kef 7100, Tunisia.
In karate, the ability to execute high-velocity movements, particularly kicks and punches, is heavily dependent on the strength and power of the lower limb muscles, especially the knee extensors. As such, this study aimed to evaluate the effects of an 8-week eccentric training program utilizing the reverse Nordic exercise (RNE) integrated into karate training compared with regular karate training only on measures of physical fitness in youth karate athletes. Twenty-seven youth karatekas were recruited and allocated to either RNE group (n = 13; age = 15.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!