Browsing by Subject "Quadriceps"

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    Isokinetic strength of the quadriceps and hamstrings in professional handball players
    (Servicio de Publicaciones. Universidad de Murcia, 2025) Karalić, Tamara; Balać, Igor; Pavlović, Ratko; Nikolić, Siniša; Ljubojević, Adriana; Vukić, Željko; Radulović, Nikola; Gerdijan, Nikolina; Sin departamento asociado
    The aim of this study was to evaluate the strength of the left and right hamstring and the quadriceps muscle group in professional handball players. It also aimed to assess the statistical significance of the relationship between these two muscle groups. The study included eight professional handball players from the "Borac" team, Banja Luka. Standard anthropometric measurements were taken. The following variables were assessed: maximum quadriceps torque (MQT), maximum hamstring torque (MHT), and hamstring–quadriceps ratio (HQR), to determine the presence of muscle imbalances bilaterally and unilaterally. Isokinetic testing of knee strength was performed on both knees at the Institute for Sports, Faculty of Physical Education and Sports, University of Banja Luka, using the CON-TREX CYK device, which allows comprehensive assessment of muscle and joint function. Based on the findings, there was no significant muscle imbalance in handball players, i.e., no significant difference in quadriceps or hamstring strength between the left and right legs, either bilaterally or unilaterally (p > 0.05). The strength of the left and right quadriceps and hamstrings showed minimal variation, with no evidence of muscle imbalance. In professional and elite sports, information from isokinetic diagnostics is essential for designing training programs and preventing injuries. This study provides normative data for the handball player population.
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    Open Access
    Muscle atrophy following anterior cruciate ligament reconstruction: A narrative review
    (Universidad de Murcia, Departamento de Histología e Histopatología, 2026) Kaneguchi, Akinori; Ozawa, Junya; Biología Celular e Histología
    Muscle weakness is a common issue following anterior cruciate ligament (ACL) reconstruction and is closely linked to muscle atrophy. Preventing or reducing this atrophy is a key goal of rehabilitation. This review summarizes current knowledge on muscle atrophy after ACL reconstruction, including its spatial distribution, time course, underlying mechanisms, and potential interventions. Atrophy affects multiple lower limb muscles and may be influenced by the type of graft used. Tendon harvesting appears to negatively impact the muscle belly of the donor muscle, while atrophy may also occur in the contralateral limb independently of graft harvesting. Muscle atrophy is often already present before surgery and tends to worsen postoperatively. Although partial recovery may occur, long-term deficits are frequently observed. At the muscle fiber level, evidence is inconsistent regarding which fiber types are more vulnerable to atrophy. A transient shift toward faster fiber types has been reported after surgery. On the cellular and molecular level, satellite cell depletion via apoptosis may hinder muscle regrowth and thereby contribute to persistent muscle atrophy. Concurrently, increased expression of myostatin, atrogin-1, and muscle RING-finger-1, along with postoperative inflammation, may promote protein degradation, further exacerbating muscle atrophy. Rehabilitation strategies that involve early immobilization or non-weight bearing may exacerbate atrophy. Interventions such as eccentric training, neuromuscular electrical stimulation, blood flow restriction training, pharmacological agents, and nutritional support demonstrate potential, but no definitive treatment has been established. Future studies using appropriate animal models to clarify the molecular mechanisms of muscle atrophy will be crucial for developing effective therapies.