Efeitos do ΔF sobre a acomodação da corrente interferencial em sujeitos saudáveis

Abstract

Aims: To evaluate in how much time the interferential current (IFC) accommodation occurs, and how many times this accommodation happens in 10 minutes using different patterns of variations in the frequency of stimulation: ∆F null = 0; ∆F low = 30% and ∆F high = 70%. Materials and methods: crossover trial, with 15 volunteers, with mean age of 22.53 ± 0.91 years, of both genders. The patients were submitted to IFC for 10 minutes as bipolar with the electrodes longitudinally arranged on the vertebrae L1 and S1. The equipment parameters were: base frequency of 4000Hz, AMF 100 Hz, delivery ramp of ΔF 1:1, ΔF depending on the day and the subgroup, for 10 minutes. The accommodation threshold as well as how many times the current accommodated in the total time of stimulation were evaluated. Results: The time of the first accommodation and the number of accommodation evidenced no significant difference (p > 0.05). Conclusion: It was observed that there was no effect with the variation of the different ∆F analyzed.

Comparison of the effects of interferential current between male and female healthy adults

“…However, although there are technical ways of limiting the accommodation threshold, its effectiveness is questionable. As a consequence, a periodic manual rise of the current amplitude is needed [10,11]. Therefore, studies addressing the accommodation variables regarding differences between genders are relevant in order to look for special procedures while stimulating male or female populations.…”

“…In order to test the accommodation phenomena, all participants were positioned lying down to receive the IC applied in a tetrapolar arrangement, 4000Hz (100 Hz AMF) [10,11] for 20 minutes. The equipment used was the Neurovector Sapphire Line (Ibramed ® , Brazil), which has the IC both in the bi-or tetra-polar form; carrier frequency of 2, 4 or 8 kHz; amplitude modulated frequency and slope between 1-100 Hz, and ramp delivery slope of 1:1, 1:5:1 or 6:6 seconds.…”

“…Due to the larger coverage area and effects, the tetrapolar arrangement has been reported to have advantages when compared to the bipolar. In the bipolar arrangement the current interference will occur inside the electrical equipment, while in the tetrapolar, two currents with slight different frequencies promote the interferential resultant effect directly in the patient [7][8][9][10][11][12][13][14].…”

Effect of interferential current of different amplitude-modulated frequencies, on threshold and number of accommodations on healthy painless individuals

“…For chronic low back pain, intensity considered as "high", however "comfortable", is able to decrease pain 2 . IC has tools looking at preventing sensitivity to current accommodation, such as Δf and slope, however they have not shown to be effective to change accommodation threshold 9,10 . Previous studies investigating such parameters have shown frequencies similar to those investigated herein.…”

“…There are still controversies about ideal modulation ranges as well as about the role of AMF 7,8 and other parameters. Among them, there is Δf (frequency amplitude) and slope (Δf slope patterns, usually with variations in 1:1, 1:5:1 or 6:6 seconds, indicated for chronic, sub-acute and acute cases, respectively) 9,10 . Accommodation is a phenomenon induced by decreased number of nervous depolarizations due to repetitive and prolonged stimulation.…”