Identification of Kinematic Variables Specific of Patellar Tendinopathy in Athletes at Risk

* Subject aged between 18 and 45 years * Male subject * Regularly participating in physical activity involving jumping (a predisposing factor for patellar tendinopathy) twice a week for at least one year. * Participants affiliated with or covered by a social security scheme SPECIFIC INCLUSION CRITERIA FOR THE PATELLAR TENDINOPATHY GROUP Patients with at least 2 of the following 3 criteria: * Modified Öhberg score ≥2 according to L Öhberg, H Alfredson (2002) * VISA-PF \< 80/100 according to Kaux et al. (2016) and/or OSTRC P ≥ 6/100 according to Owoeye et al. (2018) * Single Leg Decline Squat (SLDS): VAS ≥ 1/10 with pain mapping at the patellar tendon; according to Coombes et al. (2020) SPECIFIC INCLUSION CRITERIA FOR THE HEALTHY GROUP Patients with 0 or 1 of the following 3 criteria: * Modified Öhberg score ≥2 according to L Öhberg, H Alfredson (2002) * VISA-PF \< 80/100 according to Kaux et al. (2016) and/or OSTRC P ≥ 6/100 according to Owoeye et al. (2018) * Single Leg Decline Squat (SLDS): VAS ≥ 1/10 with pain mapping at the patellar tendon; according to Coombes et al. (2020) Non inclusion Criteria: * Significant medical and surgical history involving the lower limbs (e.g., ACL ligament reconstruction, meniscectomy, etc.) * Contraindications to participating in sports activities * Other pathologies involving the lower limbs (\< 6 months), e.g., torn knee ligaments, ankle sprain, knee sprain, etc. * Participants who have not given their informed consent * Participants subject to legal protection measures (legal guardianship, conservatorship, curatorship) * Participants deprived of their liberty by judicial or administrative decision