[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-studies-list:{\"conditionNormalized\":\"patellar-tendinopathy--jumpers-knee\",\"overallStatus\":[\"RECRUITING\",\"AVAILABLE\",\"NOT_YET_RECRUITING\"],\"orderBy\":\"LastUpdateSubmitDate:desc\",\"size\":25,\"offset\":0}":3,"health-study-condition:patellar-tendinopathy--jumpers-knee":28},{"pageToken":4,"total":5,"offset":6,"count":5,"results":7},null,2,0,[8,66],{"id":9,"slug":10,"hasResults":11,"nctId":12,"briefTitle":13,"officialTitle":14,"acronym":15,"eligibilityCriteria":16,"healthyVolunteers":11,"sex":17,"minAge":18,"maxAge":19,"enrollmentInfo":20,"targetDuration":4,"studyType":23,"phases":24,"briefSummary":26,"conditions":27,"keywords":29,"overallStatus":53,"whyStopped":4,"lastUpdateSubmitDate":54,"lastUpdatePostDateStruct":55,"startDateStruct":58,"completionDateStruct":60,"leadSponsor":62,"locationsCount":65},"100620763","long-hold-yielding-isometric-exercise-for-patellar-tendinopathy-in-weightlifting-athletes-100620763",false,"NCT07361848","Long-Hold Yielding Isometric Exercise for Patellar Tendinopathy in Weightlifting Athletes","Randomized Controlled Trial Evaluating the Effects of Long-Hold Yielding Isometric Exercise on Pain, Function, Vascularity, and Mechanical Properties of the Patellar Tendon in Competitive Weightlifting Athletes","QuantFlow","Inclusion Criteria:\n\n1. Competitive weightlifting athletes (Olympic weightlifting or CrossFit) training ≥3 times per week.\n2. Age 18-45 years.\n3. Symptom duration of at least 6 weeks.\n4. Presence of vascularized patellar tendinopathy, defined as Doppler-detectable intratendinous neovascularization using standardized settings.\n5. VISA-P score \\\u003C 80 at baseline.\n6. Ability to perform loaded lower-limb exercises safely.\n7. Willingness to refrain from other structured isometric interventions focused on the patellar tendon during the study period.\n8. Ability to provide informed consent.\n9. Sex\u002FGender requirement: both men and women eligible; the study includes sex-stratified analysis to examine potential sex-based differences in tendon response.\n\nExclusion Criteria:\n\n1. Previous knee surgery within the past 12 months.\n2. Partial or complete patellar tendon rupture (confirmed clinically or by ultrasound).\n3. Coexisting knee conditions (e.g., meniscal tear, ACL\u002FPCL injury, patellofemoral joint instability) that significantly affect load tolerance.\n4. Systemic diseases affecting tendon health (e.g., diabetes, rheumatoid arthritis, connective tissue disorders).\n5. Corticosteroid injection in the patellar tendon within the last 6 months.\n6. Participation in other clinical trials involving exercise or tendon-loading interventions.\n7. Neuromuscular or medical conditions limiting safe performance of isometric or plyometric exercise.\n8. Pregnancy.\n9. Inability to commit to follow-up assessments at 8, 12, and 24 weeks.","ALL","18 Years","45 Years",{"count":21,"type":22},24,"ESTIMATED","INTERVENTIONAL",[25],"NA","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.\n\nResearchers will compare the long-hold isometric intervention with routine training recommendations to determine its effects on symptoms and tendon function.\n\nParticipants will perform the supervised isometric protocol and complete pain ratings, functional tests, and ultrasound evaluations of the patellar tendon.",[28],"Patellar Tendinopathy \u002F Jumpers Knee",[30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52],"patellar tendinopathy","long hold yielding isometrics","weightlifting athletes","tendon vascularity","shear-wave elastography","quantitative ultrasound","echotexture","echostructure","ehointensity","echovariation","doppler imaging","tendon stifness","stress-strain curve","young's modulus","biomechanics","jumper's knee","iPulley isokinetic","countermovement jump","force platform biomechanics","tissue mechanical properties","musculoskeletal imaging","clincal trial","randomized controlled trial","NOT_YET_RECRUITING","2026-01-14",{"date":56,"type":57},"2026-01-23","ACTUAL",{"date":59,"type":22},"2027-02-01",{"date":61,"type":22},"2028-04-01",{"name":63,"class":64},"Universidad Complutense de Madrid","OTHER",1,{"id":67,"slug":68,"hasResults":11,"nctId":69,"briefTitle":70,"officialTitle":71,"acronym":72,"eligibilityCriteria":73,"healthyVolunteers":11,"sex":74,"minAge":18,"maxAge":75,"enrollmentInfo":76,"targetDuration":4,"studyType":23,"phases":78,"briefSummary":79,"conditions":80,"keywords":81,"overallStatus":84,"whyStopped":4,"lastUpdateSubmitDate":85,"lastUpdatePostDateStruct":86,"startDateStruct":88,"completionDateStruct":90,"leadSponsor":92,"locationsCount":65},"100611229","frequency-dependent-effects-of-percutaneous-femoral-nerve-stimulation-on-quadriceps-strength-in-athletes-with-patellar-tendinopathy-100611229","NCT07237867","Frequency-Dependent Effects of Percutaneous Femoral Nerve Stimulation on Quadriceps Strength in Athletes With Patellar Tendinopathy","Frequency-Dependent Effects of Percutaneous Femoral Nerve Stimulation on Strength in Athletes With Patellar Tendinopathy: a Randomized Controlled Trial","ppns","Inclusion Criteria:\n\n* Adults aged 18 to 40 years.\n* Recreational or competitive athletes with clinically diagnosed patellar tendinopathy for at least 3 months.\n* Ultrasound-confirmed patellar tendinopathy, including hypoechoic areas, tendon thickening, or neovascularization consistent with clinical diagnosis.\n\nPresence of pain during tendon-loading activities (e.g., jumping, running, squatting).\n\n* Ability to perform maximal voluntary isometric contractions of the quadriceps.\n* Ability to comply with all study procedures and attend all experimental sessions.\n* Written informed consent obtained prior to participation.\n\nExclusion Criteria:\n\n* Previous knee surgery or traumatic knee injury within the past 12 months.\n* Complete or partial patellar tendon rupture.\n* Neurological disorders affecting lower limb strength or motor control.\n* Contraindications to electrical stimulation, including implanted electrical devices (e.g., pacemaker).\n* Current lower-limb radiculopathy or neuropathy.\n* Skin infections, open wounds, or dermatological conditions at the stimulation site.\n* Use of analgesics, anti-inflammatories, or corticosteroid injections within the past 48 hours.\n* Participation in another interventional study in the previous 30 days.\n* Pregnancy or suspected pregnancy.","MALE","40 Years",{"count":77,"type":22},19,[25],"This study investigates the immediate effects of different peripheral electrical nerve stimulation protocols applied to the femoral nerve on quadriceps strength in athletes with patellar tendinopathy. Patellar tendinopathy is a common overuse injury that often reduces quadriceps activation and limits sports performance. Peripheral percutaneous nerve stimulation (PPNS) and transcutaneous electrical nerve stimulation (TENS) are frequently used in rehabilitation, but their frequency-dependent effects on muscle strength are not well established.\n\nIn this randomized crossover trial, each participant receives three stimulation protocols in separate sessions: high-frequency PPNS (100 Hz), low-frequency PPNS (2 Hz), and conventional TENS. All stimulation is delivered at the maximal tolerated motor threshold and, for PPNS conditions, under ultrasound guidance. Quadriceps maximal isometric strength is evaluated using an isometric force sensor before and after each intervention.\n\nThe primary objective is to compare the acute changes in maximal voluntary contraction (MVC) following each stimulation protocol. The study aims to clarify whether different stimulation frequencies can enhance, reduce, or have no effect on quadriceps strength in this athletic population.\n\nBy identifying frequency-specific neuromodulatory responses, this study may help clinicians and sports practitioners select the most appropriate stimulation parameters to optimize rehabilitation and performance in individuals with patellar tendinopathy.",[28],[82,83],"Peripheral Percutaneous Nerve Stimulation","Transcutaneous Electrical Nerve Stimulation","RECRUITING","2025-11-29",{"date":87,"type":57},"2025-12-05",{"date":89,"type":57},"2025-09-20",{"date":91,"type":22},"2025-12-15",{"name":93,"class":64},"Hospital Clinic of Barcelona"]