TECAR Therapy in Chronic Back Pain

Capacitive and resistive electric transfer (TECAR) therapy is a radiofrequency-based electrothermal modality designed to generate endogenous tissue heating. Preliminary evidence suggests that TECAR therapy may provide short-term improvements in pain and disability in individuals with low back pain. Some TECAR devices also incorporate a manufacturer-specific electrical stimulation function known as high-intensity electromyostimulation (Hi-EMS). However, the additional effects of combining Hi-EMS with TECAR therapy have not been established.

This randomized, assessor-blinded crossover trial will investigate whether adding Hi-EMS to TECAR therapy produces greater immediate improvements in pain and functional performance than TECAR therapy alone in individuals with chronic nonspecific low back pain. Each participant will receive both treatment conditions in a randomized order, allowing participants to serve as their own controls. The treatment sessions will be separated by a one-week washout period.

The study will evaluate immediate within-session responses and compare the magnitude of change between the two treatment conditions. The findings will help determine whether the concurrent use of Hi-EMS provides additional short-term benefits beyond those produced by TECAR therapy alone.

• TECAR Therapy plus Hi-EMS (Device): TECAR therapy will be delivered using the BACK4 system (Winback Europa SAS, Biarritz, France). The intervention will consist of 10 minutes of capacitive electrical transfer (CET) followed by 10 minutes of resistive electrical transfer (RET). A conductive cream will be applied to the treatment area, and a return plate will be positioned over the abdomen. The Hi-EMS Focal mode will be activated only during the 10-minute RET phase and adjusted to produce a strong but comfortable stimulation without pain or excessive discomfort.
• Tecar therapy alone (Device): TECAR therapy will be delivered using the BACK4 system (Winback Europa SAS, Biarritz, France). The intervention will consist of 10 minutes of capacitive electrical transfer (CET) followed by followed by 10 minutes of resistive electrical transfer (RET). A conductive cream will be applied to the treatment area, and a return plate will be positioned over the abdomen. Hi-EMS will not be activated during this condition.

Primary outcomes

• Pain intensity at rest [Immediately before and immediately after each treatment session]: Low back pain intensity at rest will be assessed using an 11-point Numerical Pain Rating Scale (NPRS), ranging from 0 ("no pain") to 10 ("worst pain imaginable"). Participants will rate their current low back pain while at rest before performing the functional test. Higher scores indicate greater pain intensity.
• Movement-Evoked Pain Intensity [Immediately before and immediately after each treatment session.]: Movement-evoked low back pain intensity will be assessed immediately after the Five-Times-Sit-to-Stand Test using an 11-point Numerical Pain Rating Scale (NPRS), ranging from 0 ("no pain") to 10 ("worst pain imaginable"). Participants will rate the greatest low back pain experienced while performing the test. Higher scores indicate greater pain intensity.

Secondary outcomes

• Pressure pain threshold [Immediately before and immediately after each treatment session.]: A computerized digital pressure algometer (AlgoMed, Medoc Ltd.) with a 1-cm² probe will assess lumbar pressure pain threshold (PPT). Pressure will be applied at 40 kPa/s, and participants will press a response button when the sensation first becomes painful. PPT will be measured three times bilaterally at sites 5 cm lateral to the L3 and L5 spinous processes, with 30-second intervals. The measurements will be averaged to obtain a single lumbar PPT value at each assessment.
• Five-Times-Sit-to-Stand Test [Immediately before and immediately after each treatment session.]: Functional performance will be assessed using the Five-Times-Sit-to-Stand Test. Participants will be instructed to complete five consecutive sit-to-stand repetitions as quickly and safely as possible. The time required to complete five repetitions will be measured using a stopwatch. The test will be performed twice, and the mean completion time of the two trials will be used for analysis.

Sex: All, ages: 21 Years to 60 Years

Inclusion criteria:

* 21 to 60 years old
* chronic nonspecific low back pain
* minimum pain intensity of 3 on a 0-10 scale
* be able to provide consent and comply with study procedures

Exclusion criteria:

* spinal fracture
* tumor
* radiculopathy
* neurological or vascular condition
* pregnancy
* cardiac pacemaker or other implanted device
* skin disorder or allergy
* altered sensation in the treatment area
* active or recent hemorrhage
* cognitive impairments
* liniments or heat rubs immediately before a study session
* treatment for low back within the previous 6 weeks
* currently receiving disability benefits because of low back pain
* current or pending litigation related to low back pain