Bioimpedance and Sensorimotor Effects of Percutaneous Electrolysis Protocols on the Patellar Tendon

Study Overview
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Brief Summary
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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
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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: 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. 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. 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. 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.

Official Title
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Characterization of the Effects on Bioimpedance and the Sensorimotor System After the Application of Percutaneous Electrolysis Protocols on the Patellar Tendon.

Conditions
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Healthy

Intervention / Treatment
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* Other: High-intensity and short-duration
* Other: Low-intensity and long-duration
* Other: High-intensity, short-duration and 20 Hz
* Other: Sham electrolysis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy. Between 18 and 45 years old. Exclusion Criteria: to suffer or to have suffered any pathology on the arm on the last 30 days. to suffer some disease discouraging current application or needling, as coagulation deficit, etc. to suffer some severe disease as diabetes mellitus, cancer, neurology disease, depression, fibromyalgia, etc. to suffer some cognitive disorders. to consume drugs as coagulants, anti-depressant, pregabalin, neuropeptide, opioids, etc during investigation or the first week before investigation. to consume NSAIDS the last 48 hours before investigation or during investigation. belonephobia. To consume caffeine 2 hours prior to the investigation or perform intense exercise on the same day as the measurement. To receive concomitant physical therapy treatments or have previously received percutaneous electrolysis treatment. professional athlete To be pregnant.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Randomized intervention of repeated measures, quadruple-blinded
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-intensity and short-duration<br>The technique consists of the percutaneous electrical stimulation of the tendon applying a galvanic current through a ultrasound-guided needle. | Other: High-intensity and short-duration<br>* 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.<br>|
| Experimental: Low-intensity and long-duration<br>The technique consists of the percutaneous electrical stimulation of the tendon applying a galvanic current through a ultrasound-guided needle. | Other: Low-intensity and long-duration<br>* 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.<br>|
| Experimental: High-intensity, short-duration and 20 Hz<br>The technique consists of the percutaneous electrical stimulation of the tendon applying a alternating current through a ultrasound-guided needle. | Other: High-intensity, short-duration and 20 Hz<br>* 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.<br>|
| Sham Comparator: Sham electrolysis<br>The technique consists of an introduction ultrasound-guided needle without electrical stimulation. | Other: Sham electrolysis<br>* The control ultrasound guided percutaneous electrolysis will be applied in the middle of the patellar tendon, without electrical stimulation during 366 seconds.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pain evoked with Von Frey Filaments. | We will use Von Frey Filaments to apply a 300g pressure in the evaluated areas (tibialis anterior muscle, inferior pole of the patella and patellar tendon). The subject will report the pain intensity verbally administered Numeric rate scale (NRS): 0 will be any pain and 10 will be the maximal perception of pain). The test will be performed with subject's eyes closed. | Pre-intervention and immediately after the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in transcutaneous electrical detection threshold. | We will use a transcutaneous active electrode to evaluate electrical detection threshold on the medial region of the tibia. We will apply an alternating current with a frequency of 2 Hz, a pulse duration of 150 msec and the intensity will be increased progressively. When the subjects perceives the electrical current, the evaluator will record the current intensity as the electrical detection threshold. | Pre-intervention and immediately after the intervention | 
| Change in percutaneous electrical detection threshold. | We will use the intervention needle as an active electrode to evaluate electrical detection threshold on the patellar tendon. The parameters of the electric current will be 2 Hz and 150 msec of pulse duration and the intensity will be increased progressively. When the subjects perceives the electrical current, the evaluator will record the current intensity as the electrical detection threshold. | Pre-intervention and immediately after the intervention | 
| Change in pain evoked with a transcutaneous electrical stimulus. | We will use a transcutaneous active electrode to evaluate pain evoked with electrical stimulus on the medial side of the tibia. The parameters of electric current will be 2 hz and 150 msec of pulse duration and the intensity will be x3-4 respect to the electrical detection threshold determined using an electrical transcutaneous stimulus. The subject will report the pain intensity with a verbally administered numeric rate scale (NRS): 0 will be no pain and 10 will be the maximal perception of pain. | Pre-intervention and immediately after the intervention | 
| Change in pain evoked with a percutaneous electrical stimulus. | We will use the intervention needle as an active electrode to evaluate electrical detection threshold on the patellar tendon. The parameters of electric current will be 2 Hz and 150 msec of pulse duration and the intensity will be x4-6 respect to the electrical detection threshold determined using an electrical percutaneous simulus. The subject will report the pain intensity with a verbally administered numeric rate scale (NRS): 0 will be no pain and 10 will be the maximal perception of pain. | Pre-intervention and immediately after the intervention | 
| Change in maximum strength during knee extension with dynamometer | The subject will be sitting with 90 degrees knee flexion and the dynamometer located at the ankle. He/she will must extend the knee executing maximal isometric force during 5 seconds, 2 times with 1 minute to rest between them. | Pre-intervention and immediately after the intervention | 
| Change in surface electromyography signal during knee extension | The subject will be sitting with 90 degrees knee flexion and the dynamometer located at the ankle and a surface electromyography located at the muscles vastus medialis and lateralis, from the muscle quadriceps femoris. He/she will must extend the knee executing maximal isometric force during 5 seconds, 2 times with 1 minute to rest between them. | Pre-intervention and immediately after the intervention | 
| Questionnaire Victorian Institute of Sport Assessment - Patella (VISA-P) | The subject will fulfil the visa-p questionnaire, that assess symptoms, simple test of function, and the ability to play sports, to control that the sample recruited are healthy subjects. | One week before intervention | 
| Change in patellar tendon bioimpedance | We will use four needles in the patellar tendon as electrodes to measure bioimpedance with a specific device (ImpediMed´s SFB7). We will measure using 256 frequences ranging from 3 Kilohertz (KHz) to 1 Megahertz (MHz) in different time frames. Firstly, we will measure three times prior to the introduction of the intervention needle. Then we will measure once more after the introduction of the intervention needle. Finally, we will performed four repeated measures after the intervention (immediately, 5, 10 and 15 minutes after of the intervention). | pre-intervention / baseline, immediately after the introduction the intervention needle and immediately after the intervention | 
| Pain induced during bioimpedance measurement. | We will continuously measure pain intensity produced by the bioimpedance recording using a digital visual analogue scale (VAS) integrated in a potentiometer: 0 will be no pain and 10 will be the maximal perception of pain. | Immediately after the intervention, immediately after the introduction the intervention needle and immediately after of the intervention. | 
| Conditioned pain modulation | First, we will measure pressure pain threshold with an algometer on the patellar tendon. Then, we will repeat the assesment of the pressure pain threshold on the patellar tendon meanwhile we apply a moderate painful pressure on the contralateral arm (5/10 on a numeric rate scale NRS: 0 will be no pain and 10 will be the maximal perception of pain) with a pressure cuff. The change between both pressure pain threshold will assess the conditioned pain modulation. After, we will repeat the same procedure but using cutaneous electrical threshold instead of pressure. | One week before the intervention | 
| International Physical Activity Questionnaire (IPAQ) | The subjects will answer International Physical Activity Questionnaire to assess the level of physical activity. | One week before the intervention | 
| Questionnaire about intervention effects past 24 hours. | The subjects will answer a questionnaire about the intervention effects and the possible side effects. | 24 hours after the intervention | 
| Pain induced during intervention | We will continuously measure pain intensity produced by the intervention using a digital visual analogue scale (VAS) integrated in a potentiometer: 0 will be no pain and 10 will be the maximal perception of pain. | During the 16 minutes of intervention | 
| Change in threshold to elicit mechanical perception with Von Frey Filaments | We will use Von Frey Filaments of increasing caliber to apply different pressure forces in the evaluated areas (tibialis anterior muscle, inferior pole of the patella and patellar tendon). The evaluator will score the caliber of the filament that produce a mechanical perception in the subject as the mechanical pressure threshold. The test will be performed with subject's eyes closed. | Pre-intervention and immediately after the intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Percutaneous electrolysis, Patellar tendon, Bioimpedance, Sensorimotor system, Percutaneous electrical stimulation