Eco-guided Neuromodulation of the Femoral Nerve on the Performance of Amateur Athletes.

The intervention consists of the bilateral, ultrasound-guided insertion of a needle for percutaneous electrical nerve stimulation (PENS), following a theta-burst pattern designed to produce long-term potentiation-like effects. An asymmetric biphasic compensated current with a rectangular positive phase and a triangular negative phase is applied at a frequency of 100 Hz for 5 seconds, followed by 55 seconds of rest, repeated five times. The pulse width is 240 µs, and the intensity is maintained above the motor threshold and below the pain threshold.

Percutaneous electrical nerve stimulation (PENS) applied under ultrasound guidance at 10 Hz, consisting of 10 seconds of stimulation followed by 10 seconds of rest, repeated ten times. The current intensity is adjusted to produce visible muscle contraction without pain.

Percutaneous electrical nerve stimulation (PENS) applied under ultrasound guidance at 100 Hz for 5 seconds, followed by 55 seconds of rest, repeated five times. The current intensity is adjusted to elicit a mild tingling sensation while remaining below the pain threshold.

A sham PENS procedure involving ultrasound-guided needle insertion at the same anatomical site without electrical stimulation. The device is manipulated to simulate treatment, but no current is delivered. Participants are informed they might not feel any sensation during the session.

Percutaneous electrical nerve stimulation (PENS) applied under ultrasound guidance using high-intensity bursts delivered bilaterally at a current intensity close to 1000 mA, repeated three times. The stimulation intensity is individually adjusted to approach but not exceed the participant's tolerance threshold.