Bioimpedance and Sensorimotor Effects of Percutaneous Electrolysis Protocols on the Patellar Tendon
Condition: Healthy
Study type: Interventional

Summary: 
      Percutaneous electrolysis is a physical therapy technique, whose main objective is the
      treatment of the signs and symptoms associated with tendinopathies by applying a galvanic
      current through a blunt dry needle. Despite its clinical use being already stablished, the
      physiological mechanisms underlying this therapy are still unknown and thus, the optimal
      parameterization. The present study proposes to perform different stimulation protocols of
      percutaneous electrolysis on healthy subjects patellar tendon to answer those questions.
    

Detailed description: 
      Intervention will be performed in the middle of the patellar tendon, using ultrasonography to
      guide the needle insertion, without risk of affecting any adjacent structure. The theoretical
      basis of the technique is to produce specific controlled changes in the intervened tissue,
      and the pathological symptoms, through the accumulation of an electric charge. For this
      reason, the protocols will be the following:

        1. High-intensity and short-duration: 3 squared pulses of a high intensity galvanic current
           (3 mA) for 3 seconds with 3 seconds rests between pulses and 1 second of pulses ramp.
           The current will be off during the first 348 seconds of the intervention and the last 18
           seconds it will be on. The total intervention time will be 366 seconds.

        2. Low-intensity and long-duration: 3 squared pulses of a low intensity galvanic current
           (0.1 mA) during 90 seconds, with 3 seconds rests between pulses and 30 seconds of pulses
           ramp. The total intervention time will be 366 seconds.

        3. High-intensity, short-duration and 20 Hertz (Hz): 3 squared pulses of a high intensity
           compensated biphasic squared current (3 mA), during 3 seconds with 3 seconds rests
           between pulses and 1 second of pulses ramp. The alternative frequency of 20 Hz and the
           pulse width of 50 ms. The current will be off during the first 348 seconds of the
           intervention and the last 18 seconds it will be on. The total intervention time will be
           366 seconds.

        4. Sham electrolysis group will got the same intervention, but without applying electrical
           current.

      The study design will be an crossover clinical trial, with randomized order of intervention
      with repeated measurements. Therefore, each subject will be have the four protocols at
      randomized order, with a gap of at least one week between them. The study will be full
      blinded.

      The capacity to recruit the inhibitory system will be evaluated by means of conditioned pain
      modulation. Moreover, somatosensory thresholds will be evaluated in the knee, as well as knee
      extension strength. In addition, we will undertake continuous measures of the electrical
      bioimpedance of the patellar tendon, to study the changes produced by the intervention in the
      different intra and extracellular tissue components.

      The conditioned modulation of pain assesment will take place one week before to the
      intervention, and the remaining measurements will be measured pre-intervention and
      post-intervention for each protocol.
    

Intervention name(s): High-intensity and short-duration; Low-intensity and long-duration; High-intensity, short-duration and 20 Hz; Sham electrolysis
Intervention type(s): Other; Other; Other; Other
Intervention description(s): The ultrasound guided percutaneous electrolysis will be applied in the middle of the patellar tendon.
The parameters will be 3 squared pulses of a high intensity current (3 mA), that will be applied for 3 seconds with 3 seconds rests between pulses and 1 second of pulses ramp.
The current will be off on the first 348 seconds of the intervention approximately and the last 18 seconds it will be on. The total treatment time will be 366 seconds.; The ultrasound guided percutaneous electrolysis will be applied in the middle of the patellar tendon.
The parameters will be 3 squared pulses of a low intensity direct current (0.1 mA) during 90 seconds, with 3 seconds rests between pulses and 1 second of pulses ramp.
The total treatment time will be 366 seconds.; The ultrasound guided percutaneous electrolysis will be applied in the middle of the patellar tendon.
The parameters will be 3 pulses of a high intensity compensated biphasic current (3 mA), during 3 seconds with 3 seconds rests between pulses and 1 second of pulses ramp. The alternating frequency will be of 20 Hz and the pulse width of 50 microseconds.
The current will be off on the first 348 seconds of the intervention approximately and the last 18 seconds it will be on. The total treatment time will be 366 seconds.; The control ultrasound guided percutaneous electrolysis will be applied in the middle of the patellar tendon, without electrical stimulation during 366 seconds.
Intervention MeSH terms: Oxymetazoline
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomized intervention of repeated measures, quadruple-blinded
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Percutaneous electrolysis; Patellar tendon; Bioimpedance; Sensorimotor system; Percutaneous electrical stimulation