1. INTRODUCTION
Electrophysical devices based on diathermy are one of the modalities used by many professionals to treat pain. This form of heat is used to increase blood flow and improve tissue extensibility [1 - 4].
Tecartherapy technology is one of the diathermy resources that operate at low frequency (0.3 to 1.2 MHz) [2,3]. Lower frequencies heat deep tissues without overheating the surface. For this reason, the use of Tecartherapy is growing, as it provides more comfort and safety for the patient [5 - 9].
Tecartherapy is a non-invasive technology that uses electromagnetic waves to generate thermal energy and stimulate the body to self-regenerate [6,10 - 13]. Lower frequencies produce heat in deeper tissues, while higher frequencies heat more superficial tissues [10,12,14,15].
Energy is supplied to the tissues by an active electrode with a circular shape and diameters ranging from 25 mm to 70 mm and can be resistive (RES) or capacitive (CAP). And a metal plate as a passive electrode that is in contact with the patient’s skin, serving as a conductor. The energy passes between the electrodes and generates heat in the tissues [1,2,5,6,16 - 18].
The two modes of capacitive or resistive treatment induce different tissue responses depending on the resistance of the treated tissue [6,19]. The CAP electrode is coated with a polyamide material. Energy transmission generates heat in the superficial layers, with a selective action on low-impedance soft tissues (rich in water), such as adipose tissue, muscle, cartilage and lymphatic system [1,6,14,20,21]. The RES electrode does not have an insulating material, the radiofrequency energy passes directly through the body in the direction of the inactive electrode. This generates heat in the deeper and more resistant tissue layers (low water content), such as bone, muscle fascia, capsules and tendons [1,6,16,20,21].
The use of Tecartherapy in clinical practice has been carried out for more than 20 years, however studies to identify the effects and effectiveness are scarce [4,6]. The last three years have seen an increase in the number of studies, but the effects are still unclear. Therefore, the objective of this study was to identify the effects of Tecartherapy on different healthy or pathological osteomyoarticular tissues.
2. METHODOLOGY
This systematic review was written in accordance with PRISMA recommendations [22] and included articles between the years 2013 and 2023 referring to the effects of tecartherapy on osteoarticular tissues.
In this systematic review, experimental studies that met the following inclusion criteria were included: full text available, which used low-frequency equipment with two types of tips (capacitive and resistive) and articles that used the technology in human tissue. The results considered the effects after application and doses used in studies and regions in which the technology was applied.
To carry out this study, a search was carried out in the databases from December 6/2021 to May 20/2023 in the VHL, Cochrane, PeDro and PubMed. The search argument used was “Transfer electrical capacitive-resistive” OR “Tecar” OR “Therapy Tecar” OR “CRET”. With the same research argument in the IEEE Explore, Scielo and Web of Science databases, no articles related to the research topic were found. Furthermore, bibliographic references from other sources were explored to find studies that, perhaps, had not been retrieved from the databases.
Experimental studies that evaluated the effects of Tecartherapy on human tissues were selected in this review. Review, repeated studies, in vitro or cadaveric studies that used electrical transfer to carry out oncological exams or treatments were excluded. Titles and abstracts were selected by two authors independently. After that, the full texts that met the inclusion criteria were analyzed. Disagreements were resolved by the third author.
The data extracted from the studies were: effects on tissues, place of application, dose used, number of sessions, sample numbers, sex, age, device and results.
Methodological quality and risk of bias were assessed using the Cochrane ACROBAT-NRSI scale. The instrument assesses seven domains: 1) confusion, 2) study selection, participants, 3) intervention measurement, 4) non-receipt of assigned intervention, 5) losses, 6) outcome measurement, 7) selective reporting of results. The first three are pre-intervention domains and the other four are post-intervention domains. For each domain, “low”, “moderate”, “severe”, “critical” and “no information” ratings are assigned. The overall risk of bias in each study is the domain with the highest risk of bias as shown in Table 1 [23].
3. RESULTS
Figure 1 shows the flowchart of the articles included in the present study. A total of 2225 articles were found in the search carried out in the databases, two studies were retrieved in manual searches and duplicate studies were excluded.
1) confusion; 2) selection of study participants; 3) assessment of intervention; 4) non-receipt of assigned intervention; 5) losses; 6) assessment of outcomes; 7) selective report of outcomes.
Figure 1. Flowchart of studies included in the review.
The research involved the participation of 1240 individuals (466 men and 592 women) in a total of 38 studies selected for this review. Some studies do not mention the age or gender of the participants. Of those mentioned, the average age of the participants was 51 years old, with the youngest age being 18 years old and the oldest age being 84 years old.
The sample size of the studies varied greatly, however the study by Ganzit [16] was the study with the largest number of participants (327) and the study by Oh [13] had only one participant. The other studies had an average of 34 participants per study, with 66 being the largest number and 1 being the smallest number of participants among the selected studies. In relation to sex, 13 studies carried out their research with both sexes, with a female predominance with 361 participants and 328 men. In the studies that used one of the sexes, women (275) were also predominant in relation to men (85).
Studies demonstrate that the effects of Tecartherapy were obtained in symptomatic and asymptomatic patients. Table 2 presents the effects and protocols used to treat some osteoarticular pathologies and localized fat with tissue flaccidity. Increasing temperature to relieve pain and improve joint and/or muscle function was the most common effect among the studies. The temperature increased both on the surface and in the depth of the tissues.
Table 3 shows the effects of Tecartherapy on asymptomatic tissues. Heat increased blood flow improving flexibility and extensibility in some tissues.
Table 2. Effects of Tecartherapy on symptomatic tissues.
1Resistive Tip, 2Capacitive Tip, 3Transfer Eletrical Capacitive and Resistive, 4Range of motion.
Table 3. Effects of Tecartherapy on asymptomatic tissues.
1Resistive Tip, 2Capacitive Tip, 3Transfer Eletrical Capacitive and Resistive, 4Hemoglobin.
4. DISCUSSION
This study aimed to identify the effects of Tecartherapy on different healthy or pathological osteomyoarticular tissues. In symptomatic tissues, pain relief and improvement in joint and/or muscle function were the most cited effects. In asymptomatic tissues, improvement in tissue mobility and flexibility were the most cited findings. These effects were promoted by the heat stimulated with the application of Tecartherapy.
The increase in temperature was found both at the surface and deep within the tissues. Heat stimulates circulation, promotes tissue relaxation (mainly muscle tissue), improves the drainage of edema and hematoma [3,7,21,23 - 25]. Increased blood flow improves oxygenation, increases hemoglobin saturation, microcirculation, nutrition and removal of metabolic waste [1 - 3,6,10,13,15,17]. All of these effects significantly reduce muscle and/or joint pain, improving the function of these tissues [9,13,16,20,25 - 29]. However, the Yeste-Fabregat [30] study showed that there was hypersensitivity in trigger points immediately after the application of Tecar. When compared to other physiotherapy techniques, there was a 10% reduction in pain after 30 minutes of application. Increasing intramuscular blood flow has been shown to recover muscle after exhaustive training and improve muscle fatigue more quickly than rest and manual massage [1,10,19].
The use of kinesiotherapy or another technique associated with Tecartherapy optimized the results for muscle recovery, pain reduction and increased joint and/or muscle mobility [5,13,15,31 - 36]. In the study by Yokota [1] they observed that the flexibility and relaxation of the quadriceps muscle returned to baseline more quickly in the group that used Tecartherapy compared to the control that rested after exhaustive training. In the study by Duñabeitia [37] found that biomechanical parameters (step length, step frequency, step height and step angle) improved more quickly with Tecartherapy than with passive rest after an exhaustive training session. On the other hand, in the study by De Sousa-De Sousa [38] the use of Tecartherapy before pre-competition did not result in an improvement in the athletes’ performance. Suggesting that increased blood flow improves muscle recovery and not muscle performance.
In addition to muscle relaxation, the increase in temperature increased fluid reabsorption from persistent edema. In the study by Cau [39] they compared Tecartherapy with other techniques (manual drainage, pressotherapy) for the treatment of lymphedema. The result with Tecartherapy was more effective and with a smaller number of sessions. In another study, Vincent reported significant improvement in the fourt/h and seventh session with the use of Tecartherapy to treat edema after femoral fracture.
The thermal effects of Tecartherapy are promoted with moderate to high intensities. Non-thermal effects, with low intensity, are also found with the application of Tecartherapy. The use of low intensities is sufficient to accelerate and/or increase cellular metabolic activity [11,28,40]. The passage of electrical current flow can produce an electromagnetic interaction in tissues with little or no thermal effect. Unlike thermal effects, the non-thermal effects of radiofrequency are believed to occur predominantly at the cellular level. Allowing the treatment of diseases in the acute and subacute phases, without causing an increase in the inflammatory process that occurs due to the increase in tissue temperature [14,41]. The study by Monaretti [12] demonstrated in the histology of human tissue treated with radiofrequency at a temperature of 40˚C that the reticular dermis appears thicker and more organized. Suggesting a remodeling of the collagen present and without inflammatory signs. In Maia’s [42] study, Tecartherapy with a hyperthermic dose was used associated with manual therapy for tissue flaccidity in the gluteal region and presented satisfactory results in tissue flaccidity.
In addition to these effects, high intensity reduced the perimetry of abdominal circumference, thickness of subcutaneous fat and skin folds, noticing an improvement in the cellulite aspect of the lower limbs. Some studies associated physical activity and obtained satisfactory results [4,43,44].
Regarding tips, Tecarterapia uses two types of tips: capacitive and resistive. The combination of tips was the most used, as the heat is transmitted to all tissues, both superficial and deep. In the comparative study between the tips Meyer [4] concluded that the combination of capacitive and resistive tips presented better results when compared to the isolated use of each tip.
The use of Tecartherapy in clinical practice has been used for almost 20 years, but only a few recent studies have investigated its clinical effectiveness. Many of the effects require further study as well as comparison of results with other diathermy devices.
One limitation of this study is the adversity of protocols and the types of tissues used in the studies. Not allowing a consensus on which tip should be applied to a given type of tissue. It was also not possible to identify the dose that should be prescribed for each type of pathology studied.
5. CONCLUSION
Tecartherapy has shown beneficial effects on both healthy and symptomatic tissues. The increase in temperature was predominant in all tissues, with greater warming at depth than at the surface. In the treatment of symptomatic tissues, Tecartherapy showed a reduction in pain and improved function in different tissues such as muscles, tendons and joints. And in healthy tissues, increased blood flow and tissue mobility improved muscle and tendon function. In addition to these effects, cell proliferation and reduction of lipids within adipocytes have been cited in some studies. Effects that require future studies.
ACKNOWLEDGEMENTS
This study was financed in part by the Coordination for the Improvement of Higher Education Personnel, Brazil.