Frequency-Dependent Effects of Percutaneous Femoral Nerve Stimulation on Quadriceps Strength in Athletes With Patellar Tendinopathy
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Electrical stimulation.
- Who it may be relevant to
- Registry conditions: Patellar Tendinopathy / Jumpers Knee. Basic parameters: 18 years — 40 years · Male.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Spain
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Frequency-Dependent Effects of Percutaneous Femoral Nerve Stimulation on Strength in Athletes With Patellar Tendinopathy: a Randomized Controlled Trial
Overview
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. In 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. The 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. By 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.
Interventions
- Device Electrical stimulation
All electrical stimulation procedures are performed under real-time ultrasound guidance to accurately locate the femoral nerve and ensure safe and consistent electrode placement. For the percutaneous interventions (PPNS), a sterile needle electrode is inserted adjacent to the femoral nerve and stimulation is delivered at either high frequency (100 Hz) or low frequency (2 Hz), depending on the study arm. For the transcutaneous intervention (TENS), surface electrodes are positioned over the femora
Primary outcome measures
- Change in Quadriceps Maximal Isometric Voluntary Contraction (MVC) [Time frame: Baseline (pre-intervention), and at 2 minutes, 10 minutes, 15 minutes, and 30 minutes post-intervention.]
Secondary outcome measures (3)
- Change in Quadriceps Rate of Force Development (RFD 0-250 ms) [Time frame: Baseline (pre-intervention), and at 2 minutes, 10 minutes, 15 minutes, and 30 minutes post-intervention.]
- Change in Quadriceps Impulse (0-250 ms) [Time frame: Baseline (pre-intervention), and at 2 minutes, 10 minutes, 15 minutes, and 30 minutes post-intervention.]
- Incidence of Adverse Events Assessed Through Post-Intervention Questionnaires [Time frame: Immediately after each intervention session.]
Eligibility criteria
Inclusion criteria
- Adults aged 18 to 40 years.
- Recreational or competitive athletes with clinically diagnosed patellar tendinopathy for at least 3 months.
- Ultrasound-confirmed patellar tendinopathy, including hypoechoic areas, tendon thickening, or neovascularization consistent with clinical diagnosis.
Presence of pain during tendon-loading activities (e.g., jumping, running, squatting).
- Ability to perform maximal voluntary isometric contractions of the quadriceps.
- Ability to comply with all study procedures and attend all experimental sessions.
- Written informed consent obtained prior to participation.
Exclusion criteria
- Previous knee surgery or traumatic knee injury within the past 12 months.
- Complete or partial patellar tendon rupture.
- Neurological disorders affecting lower limb strength or motor control.
- Contraindications to electrical stimulation, including implanted electrical devices (e.g., pacemaker).
- Current lower-limb radiculopathy or neuropathy.
- Skin infections, open wounds, or dermatological conditions at the stimulation site.
- Use of analgesics, anti-inflammatories, or corticosteroid injections within the past 48 hours.
- Participation in another interventional study in the previous 30 days.
- Pregnancy or suspected pregnancy.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Double blind
- Primary purpose
- Treatment
Study locations
Spain · 1 center
- Blanquerna University — Barcelona
Identifiers
NCT: NCT07237867 · 2025-04-05