Immediate effect of foot reflexology in patients with diabetic neuropathy: Randomized Clinical Trial

Introduction. Diabetic neuropathy (DN) is one of the most frequent chronic complications of type 2 diabetes mellitus (DM2). One technique capable of influencing the central and peripheral nervous system is foot reflexology (FR). Therefore, the objective of this study was to analyze the immediate effect of FR in DN type 2 patients. Method. This was a randomized controlled clinical trial, with 12 participants selected from a list of diabetic patients from the Basic Health Units of the city of Alfenas-MG. The sample consisted of two groups: Control Group (n=5) and Intervention Group (n=7). The instruments used were: surface electromyography for analysis of the lateral and medial gastrocnemius muscles, baropodometry to evaluate the balance from the variables of mean pressure and mass division, and the cardiofrequency meter to analyze the relationship between the sympathetic and parasympathetic nervous system and cardiovascular stress. Statistical analysis was used the Shapiro-Wilk test and later the independent t test and Mann Whitney for intergroup comparison. Results. There was only a difference in the EMG of the right lateral gastrocnemius muscle (p=0.04). Conclusion. It was

FR is a popular and non-invasive TCM technique based on reflex zones that has as its principle the general balance of the body and adequate energy circulation of the organs and viscera 13 . This technique is based on the application of pressure on the tissular surface of specific points of the feet, which when stimulated, trigger functional responses in the organism 14 . Currently FP is well known for its physiological and neurophysiological effects such as activation of blood and lymphatic circulation, decreased pain, and stress; reduction of fatigue, improvement of balance and functionality and restoration of quality of life [15][16][17][18] . The literature does not describe the effect of this technique on the autonomic nervous system (ANS), plantar area and electrical activity of the lateral gastrocnemius (GL) and medial (GM) muscle affected by DN. Therefore, the first hypothesis is that the ANS be influenced after 30 minutes of FP. The second hypothesis is that FR has an effect on the plantar area due to the possible change in balance. Finally, the last hypothesis is that after the immediate stimulation of reflex zones of the feet a modification of the electromyographic signal of the GL and GM muscles occurs.
The present study aimed to analyze the immediate effect of FR in patients with type 2 diabetic neuropathy.

Study design
It is a randomized controlled clinical trial that was approved by the Research Ethics Committee of the Foundation of Higher Education do Sapucaí (#659.819). All participants were informed in accordance with the objectives and procedures and signed an Informed Consent Term.

Sample
Participants were recruited from February to August 2018. 116 individuals with DM were contacted from a list of Basic Health Units (BHU) in the city of Alfenas-MG. Of these, 45 participants were selected who answered the call, and 17 were excluded because they did not meet the inclusion criteria: age between 55 and 75 years, 10 years or more onset of 2DM, Body Mass Index (BMI) less than 29 , 9 kg/m2 and present a score above three by the scale of neuropathic impairment and symptoms 19 . Thirty-eight subjects were then left with two groups: Control Group (CG, n=14) and Intervention Group (IG, n=14). There was a sample loss of both groups due to non-attendance on the day of care. Thus, five subjects remained for the CG and seven for the IG.
Exclusion criteria were superior motor neuron injury, constant use of muscle relaxant, need for gait aid, and orthopedic, circulatory and / or dermatological problems of the lower extremities ( Figure 1).

Evaluation and revaluation instruments
Initially the individuals were evaluated by an evaluation form standardized by the researchers with the following clinical and anthropometric data: age, gender, weight, height, BMI and time of diagnosis of 2DM.
1.Heart rate variability (HRV) The HRV evaluation was performed using the Polar® V800 HR GPS heart rate monitor that allows the calculation of HRV using the Poincaré plot, in which each RR interval is plotted on Cartesian graph as a function of the previous RR interval, by adjusting the points in an ellipse , in which longitudinal axis is the standard deviation "a" (SD2), which expresses the tendency of the set of RR intervals analyzed in the long term; and the transverse axis represents the standard deviation "b" (SD1), which expresses the instantaneous variability of the R-R intervals without trend influence 20 .
In order to collect the HRV data, the subjects were  The skin was cleaned with 70% alcohol and tricotomy to reduce the impedance and consequently to obtain a better EMG signal, and then the electrodes were placed in the GL and GM according to the electromyographic procedures 22 The EMG collection of the GL and GM muscles was    The entire procedure was performed on the same day, evaluation, and reassessment. First, the data of the HRV, EMG, baropodometry, FP application and reevaluation were collected following the same sequence of the evaluation ( Figure 6).

Statistical analysis
Descriptive statistics were used to characterize the sample in relation to clinical and demographic data. The Shapiro-Wilk test was used to determine the normality of the data. The independent t-test was applied for variables: mass, height, age, body mass index (BMI), baropodometry and EMG; and Mann Whitney test for the HRV variable.

RESULTS
The demographic data of the CG and GI regarding the variables age, height, mass, BMI, and gender were described in Table 1. The groups did not differ in relation to height, mass, and BMI, but they differed in relation to age.        The GL and GM muscle architecture of sedentary youngsters at rest showed that there was no difference between the length of muscle fibers 28 . However, that massage associated with static stretching besides helping to gain flexibility 29 may also contribute to the decrease in spinal reflex excitability coming from the present study.
As a result, it is noted that the execution of FP for 30 minutes was not sufficient to influence the ANS. After 25 minutes of RP, a significant decrease in relation to the heart rate (HR) of young and asymptomatic individuals occurred due to the parasympathetic action, which is not consistent with the present study 30 .
Another hypothesis is that both the age and the position of analysis of the test are contributing factors for the influence of the data of the present study since healthy individuals aged 51 to 60 years obtained lower HRV in the time and frequency domain after ten minutes of analysis in the supine position, observing that the sympathetic action overlaps with the parasympathetic activity 31 .
Cardiovascular stress is a factor that is closely related to ANS. FR had no effect on HR and stress coming from the present study, and this may be related to both the time and the manner of application of the technique 32 .
Regarding the MP and MD findings, it was noted that there was no statistically significant difference. These results could be justified because of having been carried out immediately. A study conducted with individuals with DN demonstrated that ten sessions were able to generate improvement in the dynamic balance 33 . Contradicting the study, it is observed that eight weeks of reflex massage in the elderly was not enough to modify the balance 34 since