Attempting an effective treatment is essential to the physiotherapist to understand how his conducts affect body tissues and the whole system, besides understand properly how and when therapeutic modalities could be use in the rehabilitation process. There are several research articles pointing the use of heat as an efficient agent to accelerate tissue healing. Clarifying the remaining doubts related to therapeutic modalities use can be beneficial for functional rehabilitation.

In physiotherapy, shortwave diathermy is one of the standards treatments for heat inducement. The capacitance shortwave technique consists in the use of two pad electrodes that can be positioned in three different arrangements: coplanar (placed side by side on the same aspect of the part to be treated), contraplanar (placed over opposite aspects of the body part to be treated) and longitudinal (one electrode is placed at each end of the limb in opposite aspects of the body par to be treated). There is no evidence of which arrangement is the most efficient.

Besides shortwave diathermy being a very established therapeutic modality, the use of this recourse in the most effective way rely on the properly answer of the remaining questions related to its application. Therefore, the purpose of this study is to analyze which one of the capacitance shortwave technique is the most efficient in inducing and maintaining heat.

Given the high-frequency waves field orientation could be suggested that the coplanar arrangement will lead to bigger heat inducement, and will maintain it for longer time.

The data for the sample size calculation was taken from a pilot study of 8 subjects. The software used to calculate the sample was GPower 3.1.9.2. A 18 subjects sample were obtained to reach a power of 90%, needed to detect a difference on the average of the groups in repeated measures with an alpha of 5%. The sample size was raised to 20 subjects for eventually lost. The subjects will be chosen through social media and informal invitations.

The subjects will attend to the laboratory four times, the first day for orientation and measurements (body mass and skinfold), the data collection will start on the second day.

The room temperature will be set between 23 °C and 25 °C, and the humidity around 70%. The subject will be placed in supine position on the stretcher, instructed to relax and not touch the right thigh region for 20 minutes before the intervention (for body temperature stabilization).

The thigh size will be measured form the base of the patella to the anterior superior iliac spine and the center marked to determine the place where the temperature will be collected. The minimum space between electrodes position will be at least of the size of one electrode. The temperature of the right thigh will be measured by infrared thermography before the intervention, right after the removal and every minute until the total time of the intervention.

To summarize the data, it will be used descriptive statistics, the values of average, standard deviation and the collected measurements will be identified. Through Shapiro-Wilk test the distribution of data regarding normality will be verified. To compare the initial and the final test values the ANOVA and the post-hoc of Bonferroni will be used. In the case of data being out of the normal standards, a transformation will be used to reach the normality. If the data still don't reach the normality after the transformation, the non-parametric tests will be used (Mann-Whitney e Kruskal Walis). The confidence level adopted for all tests will be 95% (p <0.05).

Inclusion Criteria:

• No orthopedic injury in three months prior to the study;
• A minimum of 19 years of age, and a maximum of 40 years;
• Male;
• Must agree not to practice exercise the day before the study and not ingest caffeine, alcohol, or food one hour before intervention.

Exclusion Criteria:

• Skinfold minor than 2cm;
• Circulatory system disease;
• Ischemic tissue or malignant tumors;
• External fixation, metal or pacemaker;
• Any thigh open wound;
• Muscular or neurological disease;
• Diabetes diagnosed;
• Cigarette smoker.

Means and standard deviations of temperature change.

Immediately following publication. No end date.

Anyone who wishes to access the data.

The participants were monitored for adverse events over the duration of treatment (at least 5 days, considering the washout period minimum of 1 day).

Other adverse events refers to burns.