Effect of intensity of electric current and evidence of blinding method

• Register: REBEC
• Last refreshed on: 29 May 2023
• Main ID: RBR-8h32gy
• Date of registration: 17/08/2015
• Prospective Registration: No
• Primary sponsor: Universidade Federal de Sergipe
• Public title: Effect of intensity of electric current and evidence of blinding method
• Scientific title: Effect of intensity of interferential current and validation of the placebo method
• Date of first enrolment: 15/08/2012
• Recruitment status: Data analysis completed
• URL: http://ensaiosclinicos.gov.br/rg/RBR-8h32gy
• Study type: Intervention
• Study design: Randomized clinical trial, parallel, double blind, five arm.
• Phase: N/A

Countries of recruitment

Brazil

Contacts

• Name: Josimari Melo de Santana
• Affiliation: Universidade Federal de Sergipe

• Name: Fernanda Mendonça Araújo
• Affiliation: Universidade Federal de Sergipe

Key inclusion & exclusion criteria

Inclusion criteria: Healthy subjects; 18 to 60 years of age.
Exclusion criteria: Participants with peripheral nerve injury in the upper limbs; presence of pain in the upper limbs; pregnancy; chronic diseases; use of cardiac pacemaker; epilepsy; allergy to the material of the electrodes; current use of analgesic medication or in the last seven days; altered skin conditions or loss of sensation in the established areas of electrode placement.

Age minimum: 18Y
Age maximum: 60Y
Gender: -

Health Condition(s) or Problem(s) studied

R52.9

Unspecified pain

Intervention(s)

Other

D26.660

The subjects were randomly divided into five groups, described as follows:
Adjusted motor group: 25 participants of both sexes were recruited, the interferential current (IFC) was applied for 30 minutes and a frequency of 100Hz was used, the intensity was gradually increased until a strong contraction but comfortable reported by the subject; at intervals of 5 minutes, the intensity was increased again until a strong sensation.
Fixed motor group: 25 participants of both sexes were recruited, the IFC was applied for 30 minutes at a frequency of 100Hz, the intensity was gradually increased until a strong contraction, but comfortable; this intensity was maintained at this level throughout the procedure.
Sensory group: 25 participants of both sexes were recruited, the IFC was applied for 30 minutes at a frequency of 100Hz, the intensity was increased until a motor contraction was produced, and then the pulse amplitude was decreased to 10% below motor contraction.
Inactive placebo group: 25 participants of both sexes were recruited, the subjects were connected to an IFC device that was turned on to appear that the device was functioning, but no stimulation was delivered; the subjects were connected to the device for 30 minutes.
New placebo group: 25 participants of both sexes were recruited, an external device, manufactured exclusively for this study, was connected to the IFC device in order to modify the release of electrical current, enabling the current to be released only during the first 40 seconds of stimulation (at frenquency of 100Hz), and then cease the passage of current; the subjects were connected to the device for 30 minutes.
In all groups, the electrodes were placed on the subject's forearm.

E02.342

Primary Outcome(s)

At the end of the study, it was observed a percentage of 60% of subjects, included in the new placebo group, who believed they received active treatment.

Over 50% of subjects, included in the new placebo group, respond receiving an active treatment, when questioned by the investigator immediately after the intervention.

Secondary Outcome(s)

At the end of study, none of the placebo groups significantly altered the pressure pain threshold, cutaneous sensitive threshold and pain intensity after treatment, presenting a difference greater than 5% of pretreatment value. Only in the adjusted motor group there was significant change less than 5% in all variables.

Let there be no significant changes in the pressure pain threshold, measured by digital algometry, in the cutaneous sensitive threshold, measured by esthesiometry, and in the pain intensity, measured by 11-point numerical rating scale, after intervention in the placebo groups, from the observation of a greater variation than 5% in pre and post treatment.

Source(s) of Monetary Support

Universidade Federal de Sergipe

Secondary Sponsor(s)

Universidade Federal de Sergipe