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

NCT07237867 | Recruiting

• 1 other identifier: 2025-04-05
• Study Type: interventional
• Target: 19
• Locations: 1 country
• Sites: 1

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

Keywords

Peripheral Percutaneous Nerve Stimulation; Transcutaneous Electrical Nerve Stimulation

Outcome Measures

Primary Outcomes (1)

• Change in Quadriceps Maximal Isometric Voluntary Contraction (MVC)

  Quadriceps maximal isometric voluntary contraction (MVC) is measured using a calibrated isometric force sensor with the participant seated and the knee positioned at 60° of flexion. MVC is recorded as the peak force output during a standardized 5-second maximal contraction. The primary endpoint is the change in MVC from pre-intervention to immediately post-intervention across the three stimulation conditions (high-frequency PPNS, low-frequency PPNS, and TENS). Higher values indicate greater quadriceps force production.

  Baseline (pre-intervention), and at 2 minutes, 10 minutes, 15 minutes, and 30 minutes post-intervention.

Secondary Outcomes (3)

• Change in Quadriceps Rate of Force Development (RFD 0-250 ms)

  Baseline (pre-intervention), and at 2 minutes, 10 minutes, 15 minutes, and 30 minutes post-intervention.

• Change in Quadriceps Impulse (0-250 ms)

  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

  Immediately after each intervention session.

Study Arms (3)

High-Frequency PPNS (100 Hz)

EXPERIMENTAL

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

Device: Electrical stimulation

Low-Frequency PPNS (2 Hz)

EXPERIMENTAL

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

Device: Electrical stimulation

Transcutaneous Electrical Nerve Stimulation (TENS)

ACTIVE COMPARATOR

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.

Device: Electrical stimulation

Interventions

Electrical stimulation 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.

Also known as: Ultrasound-guided electrical stimulation

High-Frequency PPNS (100 Hz); Low-Frequency PPNS (2 Hz); Transcutaneous Electrical Nerve Stimulation (TENS)

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Hospital Clinic of Barcelona: lead

Study Sites (1)

Blanquerna University

Barcelona, Barcelona, 08020, Spain

RECRUITING

MeSH Terms

Interventions

Electric Stimulation

Intervention Hierarchy (Ancestors)

Physical Stimulation; Investigative Techniques

Central Study Contacts

Javier Picañol Parraga Picañol, Phd

CONTACT

+34655394127; xpicanol@ub.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Phd in Neuroscience

Study Record Dates

• First Submitted: November 15, 2025
• First Posted: November 20, 2025
• Study Start: September 20, 2025
• Primary Completion: November 30, 2025
• Study Completion: December 15, 2025
• Last Updated: December 5, 2025

Record last verified: 2025-11

Locations

ES (1)