The goal of this clinical trial is to evaluate whether a long-hold yielding isometric exercise program improves pain, tendon vascularity, mechanical properties, and functional performance in weightlifting athletes with patellar tendinopathy. The study will also explore the safety and feasibility of this exercise strategy.
Researchers will compare the long-hold isometric intervention with routine training recommendations to determine its effects on symptoms and tendon function.
Participants will perform the supervised isometric protocol and complete pain ratings, functional tests, and ultrasound evaluations of the patellar tendon.
Competitive weightlifting athletes (Olympic weightlifting or CrossFit) training ≥3 times per week.
Age 18-45 years.
Symptom duration of at least 6 weeks.
Presence of vascularized patellar tendinopathy, defined as Doppler-detectable intratendinous neovascularization using standardized settings.
Previous knee surgery within the past 12 months.
Partial or complete patellar tendon rupture (confirmed clinically or by ultrasound).
Coexisting knee conditions (e.g., meniscal tear, ACL/PCL injury, patellofemoral joint instability) that significantly affect load tolerance.
Systemic diseases affecting tendon health (e.g., diabetes, rheumatoid arthritis, connective tissue disorders).