The Effect of Muscular Fatigue on Lower Limb Kinematics During Single-Leg Drop Landing in Female Athletes

The Effect of Muscular Fatigue on Lower Limb Kinematics During Single-Leg Drop Landing in Female Athletes

this study will be conducted to investigate the effect of muscular fatigue on lower limb kinematics during single-leg drop landing in female professional volleyball players using a mobile-based motion analysis application.

Muscular fatigue impairs neuromuscular control and alters lower limb kinematics during dynamic tasks such as landing, increasing the risk of injury. For example, repetitive jump-landing tasks, as frequently performed in volleyball, have been shown to induce progressive changes in lower limb biomechanics, including reduced ankle plantarflexion and altered knee alignment, which may compromise energy absorption and joint stability.Female athletes face a higher incidence of knee and ligament injuries than males, including ACL tears and ankle sprains, due to sex-specific biomechanical and neuromuscular characteristics such as reduced hamstring activation, increased joint laxity, and altered landing mechanics .Markerless, smartphone-based systems such as OpenCap provide a validated, cost-effective, and field-based solution for 3D kinematic analysis.By applying OpenCap to evaluate the effects of muscular fatigue on single-leg drop landing in professional female volleyball players, this study aims to detect early deviations in movement patterns that may predispose athletes to injury. These findings can inform preseason screening and guide the development of tailored neuromuscular training programs, contributing to context-specific, sex-informed injury prevention strategies in female sport

Inclusion Criteria:

• Female volleyball players aged 20-25 years
• Practice professional volleyball training or competition experience of at least 2 years
• typically engage in a high volume of training, with regular participation in at least five training sessions per week
• Willingness to adhere to fatigue protocol and provide informed consent

Exclusion Criteria:

• Current or recent (within the past 6 months) lower limb injury or medical condition
• History of lower limb surgeries
• Neurological disorders or balance impairments .
• Experiencing pain or discomfort during jumping or landing tasks
• Body mass index (BMI) greater than 30 kg/m²
• Inability to comply with the fatigue protocol or follow instructions for the landing tasks