Influence of different frequencies of transcutaneous electrical nerve stimulation on the threshold and pain intensity in young subjects

Immediate analgesic effect of two modes of transcutaneous electrical nerve stimulation on patients with chronic low back pain: a randomized controlled trial

Objective

To compare and assess the immediate analgesic effects of conventional and burst transcutaneous electrical nerve stimulation in patients with chronic low back pain.

Methods

We conducted a three-arm single-blinded randomized controlled trial. A total of 105 patients with non-specific chronic low back pain aged between 18 and 85 years were randomly assigned into the following groups: Placebo Group (sham electrical stimulation), Conventional TENS Group (continuous stimulation at 100Hz for 100µs with sensory intensity), and Burst TENS Group (stimulation at 100Hz modulated at 2Hz for 100µs with motor-level intensity). All groups received a single application of transcutaneous electrical nerve stimulation for 30 minutes. The outcomes, namely, pain intensity, quality of pain, and pressure pain threshold were measured by the visual analog scale, McGill pain questionnaire, and algometry, respectively. The patients were evaluated before and immediately after the transcutaneous electrical nerve stimulation application.

Results

Pain intensity (visual analog scale score) and quality of pain (McGill pain questionnaire score) significantly decreased (p<0.05) in Intervention Groups (Conventional TENS Group and Burst TENS Group). A positive effect was observed in the interventions compared to the Placebo Group in all domains of the McGill pain questionnaire (p<0.05), excepting for the pain intensity. Pressure pain threshold significantly increased (p<0.05) immediately after the transcutaneous electrical nerve stimulation application in both Intervention Groups, but not in the Placebo Group. For significant difference was found during assessment when comparing both Intervetion Group.

Conclusion

Both transcutaneous electrical nerve stimulation modes were effective for pain modulation. Moreover, there was an increase in the pressure pain threshold. No significant results were found to indicate the best mode for the treatment of chronic low back pain.

Clinical Trial Registration: RBR-59YGRB.

Efficacy of different-frequency TEAS on acute pain after the total knee arthroplasty: a study protocol for a parallel group randomized trial

BACKGROUND

Total knee arthroplasty (TKA) is an optimal option for patients with middle-to-end-stage knee osteoarthritis. However, the management of postoperative acute pain remains inefficient. Transcutaneous electrical acupoint stimulation (TEAS) is a nonpharmacological method to manage postoperative acute pain. Different frequencies of TEAS have been tested using varying parameters, but the optimal analgesic frequency remains controversial. The aim of this study was to explore the optimal analgesic frequency of TEAS for treating acute pain after the primary unilateral TKA.

METHODS/DESIGN

This is a double-blind, randomized controlled trial. A total of 156 patients are randomly assigned to: G1, 5 Hz TEAS; G2, 100 Hz TEAS; G3, mixed TEAS (alternative use of daily 5 Hz and 100 Hz TEAS) and G4, placebo TEAS. In the G1, G2 and G3 groups, TEAS is conducted at acupoints SP9 and GB34 of the leg that was operated on (at a wave of continuous, balanced and asymmetrical biphasic square, with a pulse width of 200 μs, and a strong but comfortable current) for 30 min prior to a 30-min rehabilitation session per day for 2 weeks. In G4 group, TEAS is delivered at a strong but comfortable current for 30 s, then the current is gradually decreased to none over the next 15 s. The primary outcomes are measured before surgery, at baseline (POD 3, before TEAS intervention), week 1 and 2 after TEAS intervention with the Numeric Pain Rating Scale and The American Knee Society Score. The secondary outcomes include: (1) Active range of motion of the knee that was operated on; (2) Surface electromyography of both quadriceps; (3) Modified 30-s sit to stand test; (4) Additional usage of analgesia; and (5) SF-36. The additional outcomes include: (1) Patients' satisfaction rate; (2) Patient's expectation rate; and (3) Incidence of analgesia-related side effects. To test the blinding of participants and assessors, they are asked to guess whether the subjects received active or placebo TEAS within 5 min after the latest intervention. The safety and financial cost of TEAS are assessed.

DISCUSSION

Mixed TEAS has more favorable effect on acute pain control than the placebo or 5 Hz or 100 Hz TEAS.

TRIAL REGISTRATION

ChiCTR1800016347 . Date of registration was 26 May 2018. Retrospectively registered.

Transcutaneous electrical nerve stimulation reduces exercise-induced perceived pain and improves endurance exercise performance

Purpose

Muscle pain is a natural consequence of intense and prolonged exercise and has been suggested to be a limiter of performance. Transcutaneous electrical nerve stimulation (TENS) and interferential current (IFC) have been shown to reduce both chronic and acute pain in a variety of conditions. This study sought to ascertain whether TENS and IFC could reduce exercise-induced pain (EIP) and whether this would affect exercise performance. It was hypothesised that TENS and IFC would reduce EIP and result in an improved exercise performance.

Methods

In two parts, 18 (Part I) and 22 (Part II) healthy male and female participants completed an isometric contraction of the dominant bicep until exhaustion (Part I) and a 16.1 km cycling time trial as quickly as they could (Part II) whilst receiving TENS, IFC, and a SHAM placebo in a repeated measures, randomised cross-over, and placebo-controlled design. Perceived EIP was recorded in both tasks using a validated subjective scale.

Results

In Part I, TENS significantly reduced perceived EIP (mean reduction of 12%) during the isometric contraction (P = 0.006) and significantly improved participants’ time to exhaustion by a mean of 38% (P = 0.02). In Part II, TENS significantly improved (P = 0.003) participants’ time trial completion time (~2% improvement) through an increased mean power output.

Conclusion

These findings demonstrate that TENS can attenuate perceived EIP in a healthy population and that doing so significantly improves endurance performance in both submaximal isometric single limb exercise and whole-body dynamic exercise.