Frequency-Dependent Effects of Percutaneous Femoral Nerve Stimulation on Quadriceps Strength in Athletes With Patellar Tendinopathy

NCT ID: NCT07237867

Last Updated: 2025-12-05

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 19 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-20
• Study Completion Date: 2025-12-15

Brief Summary

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.

Conditions

Patellar Tendinopathy / Jumpers Knee

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

High-Frequency PPNS (100 Hz)

Participants receive peripheral percutaneous nerve stimulation (PPNS) applied to the femoral nerve at 100 Hz.

Group Type: EXPERIMENTAL

Electrical stimulation

Intervention Type: DEVICE

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 femoral nerve region using ultrasound guidance to confirm anatomical landmarks and optimize current delivery. In all conditions, stimulation is applied at the maximal tolerated motor threshold to elicit visible quadriceps activation.

Low-Frequency PPNS (2 Hz)

Participants receive peripheral percutaneous nerve stimulation (PPNS) applied to the femoral nerve at 2 Hz.

Group Type: EXPERIMENTAL

Electrical stimulation

Intervention Type: DEVICE

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 femoral nerve region using ultrasound guidance to confirm anatomical landmarks and optimize current delivery. In all conditions, stimulation is applied at the maximal tolerated motor threshold to elicit visible quadriceps activation.

Transcutaneous Electrical Nerve Stimulation (TENS)

Participants receive conventional transcutaneous electrical nerve stimulation (TENS) applied over the femoral nerve region using surface electrodes. Intensity is set at the maximal tolerated motor threshold to elicit visible quadriceps activation. The stimulation frequency and parameters are consistent with standard clinical practice for motor-level TENS.

Group Type: ACTIVE_COMPARATOR

Electrical stimulation

Intervention Type: DEVICE

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 femoral nerve region using ultrasound guidance to confirm anatomical landmarks and optimize current delivery. In all conditions, stimulation is applied at the maximal tolerated motor threshold to elicit visible quadriceps activation.

Interventions

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 femoral nerve region using ultrasound guidance to confirm anatomical landmarks and optimize current delivery. In all conditions, stimulation is applied at the maximal tolerated motor threshold to elicit visible quadriceps activation.

Intervention Type: DEVICE

Other Intervention Names

Ultrasound-guided electrical stimulation

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.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 40 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: No

Sponsors

Hospital Clinic of Barcelona

OTHER

Sponsor Role: lead

Responsible Party

Xavier Picañol Parraga

Phd in Neuroscience

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Blanquerna University

Barcelona, Barcelona, Spain

Site Status: RECRUITING

Countries

Spain

Central Contacts

Javier Picañol Parraga Picañol, Phd

Role: CONTACT

xpicanol@ub.edu

+34655394127

Facility Contacts

Francesco Sartori, Phd

Role: primary

sartorifrancesco99@gmail.com

663583945

Other Identifiers

2025-04-05

Identifier Type: -

Identifier Source: org_study_id