Effects of different frequencies of conventional transcutaneous electrical nerve stimulation on pressure pain threshold and tolerance

Investigation of grip strength, pain threshold, pain tolerance and function in smartphone users

PURPOSE/AIM OF THE STUDY

Few studies have demonstrated the effects of smartphone use on grip strength and upper extremity function. The present study was purposed to compare smartphone users' grip/lateral pinch strength, pain threshold/tolerance and upper limb function.

MATERIALS AND METHODS

A prospective cross-sectional study was conducted with 241 individuals. Participants were divided into three groups with the cut-off values of the Smartphone Addiction Scale (SAS). The Edinburgh Handedness Inventory (EHI) was used to determine the dominant side. Thumb pain threshold and tolerance were evaluated with the algometer. A hand dynamometer measured the grip and lateral pinch strength. Upper extremity functions were evaluated with the Shortened Disabilities of the Arm, Shoulder and Hand Questionnaire (Quick-DASH).

RESULTS

Handgrip strength of the dominant/non-dominant extremities and Quick-DASH scores were higher in low-level smartphone users (p < 0.05). There was no significant difference between the groups on lateral pinch strength and pain threshold/tolerance (p > 0.05). Smartphone usage significantly affected dominant and non-dominant hand grip strength (Standardized β1 = -0.15, β2 = -0.15, p < 0.05). In addition, the smartphone use level negatively affected dominant lateral pinch strength (Standardized β = -0.12, p = 0.05). On the other hand, smartphone use positively affected upper extremity function (Standardized β = 0.17, p < 0.05).

CONCLUSIONS

As smartphone addiction increases, standard handgrip strength and functionality decrease. Pain threshold/tolerance is not affected by smartphone use. Future studies should focus on fine motor skills to present a more comprehensive upper limb function evaluation.

Efficacy of the Parasympathetic Tone Activity monitor to assess nociception in healthy dogs anaesthetized with propofol and sevoflurane

OBJECTIVE

To compare a Parasympathetic Tone Activity (PTA) monitor with cardiovascular changes in invasive mean arterial pressure (IMAP) and heart rate (HR) when evaluating the response to nociceptive stimuli in anaesthetized dogs.

STUDY DESIGN

Prospective experimental study.

ANIMALS

A group of nine (seven male and two female) adult Beagle dogs weighing 13.4 ± 1.5 kg (mean ± standard deviation).

METHODS

Anaesthesia was induced with propofol and maintained with sevoflurane in oxygen. Electrical stimuli of different nociceptive intensities were applied for 30 seconds. Stimuli were classified in each patient according to the response obtained (relevant change ≥ 20%) as low (no response), medium (PTA only) or high (PTA and IMAP/HR). Immediate and averaged values of PTA, IMAP and HR were recorded every second from 60 seconds before to 120 seconds after application of the nociceptive stimulus. Time to nociceptive response and peak response were evaluated with analysis of variance and t test.

RESULTS

Immediate PTA baseline values did not differ significantly before application of the low, medium and high stimuli (73 ± 15, p = 0.966). Immediate PTA response was observed with the medium stimulus at 33 ± 7 seconds with a maximum decrease of 57 ± 13% at 69 ± 5 seconds. With the high stimulus, the immediate PTA response was of a similar magnitude to the medium stimulus with a response at 28 ± 7 seconds (p = 0.221) and a maximum decrease of 68 ± 15% (p = 0.115) at 72 ± 7 seconds (p = 0.436). The cardiovascular change occurred (22 ± 8 seconds) prior to the immediate PTA response (p = 0.032).

CONCLUSIONS AND CLINICAL RELEVANCE

The PTA monitor detected nociceptive stimuli at lower intensities than those eliciting cardiovascular changes. However, nociceptive stimuli of higher intensities provoked cardiovascular changes that occurred before a PTA response was observed.

Segmental and extrasegmental hypoalgesic effects of low-frequency pulsed current and modulated kilohertz-frequency currents in healthy subjects: randomized clinical trial

Objective: To compare the segmental and extrasegmental hypoalgesic effects of TENS, IFC and Aussie current on pressure pain threshold (PPT) during and after stimulation in healthy subjects. The second objective was to compare the sensory comfort related to electrical stimulation.Material and Methods: 120 healthy subjects were randomized in TENS, IFC, Aussie current or placebo groups. The electrical stimulation was administered on the forearm. The PPT was measured on the forearm (segmental measure) and on the lower leg (extrasegmental measure) by an algometer at baseline, during and after stimulation of the forearm, and the sensory comfort in relation to electrical stimulation was measured with a visual analogue scale. Statistical analysis was performed using linear mixed models for PPT analysis and one-way ANOVA for sensory comfort analysis.Results: The TENS, IFC and Aussie current increased the segmental and extrasegmental PPTs during application of current compared to the placebo. The PPTs measures and sensory comfort were not significantly different between the TENS, IFC and Aussie current groups.Conclusions: Segmental and extrasegmental hypoalgesic effects may be produced using TENS, IFC or Aussie currents in healthy subjects. Furthermore, all of them presented a similar sensory comfort.

Transcutaneous electrical nerve stimulation and cervical joint manipulation on pressure pain threshold

Aim: Transcutaneous electrical nerve stimulation (TENS) and cervical joint manipulation (CJM) are often used for pain treatment. Methods: A total of 144 healthy subjects will be randomly allocated into four groups: active TENS and CJM, placebos TENS and CJM, placebo TENS and active CJM, active TENS and placebo CJM. TENS will be applied for 20 min followed by CJM. All subjects will be assessed before, during and after interventions, using a digital pressure algometer. Discussion: This is the first study to assess the combined effects of TENS and CJM on pressure pain threshold in healthy individuals. It is possible that both methods combined can enhance the hypoalgesic effect because they activate different analgesic pathways.

Study registration: NCT03531541 (ClinicalTrials.gov).

Study protocol of hypoalgesic effects of low frequency and burst-modulated alternating currents on healthy individuals

The aim of the study will be to compare different types of analgesic electrical currents in relation to the pressure pain threshold and sensory comfort in healthy individuals. A total of 100 individuals will be randomly assigned to four groups: transcutaneous electrical nerve stimulation, interferential current, Aussie current or placebo. The electrical stimulation will be administered with a strong level for 30 min and to the placebo group, the electrodes will be positioned while the equipment will remain switched off. The pressure pain threshold and sensory comfort will be measured with an algometer and the visual analogue scale, respectively. The level of significance will be p < 0.05. Study registration: NCT01950728 (clinical trials).

Effects of Transcutaneous Electrical Nerve Stimulation at Two Frequencies on Urinary Incontinence in Poststroke Patients: A Randomized Controlled Trial

OBJECTIVE

The objective of this study was to compare the effects of two frequencies of transcutaneous electrical nerve stimulation (TENS) on urinary incontinence caused by stroke.

METHODS

Eighty-one patients with poststroke urinary incontinence were recruited and randomized into the following three groups with a 1:1 ratio: a 20-Hz TENS group, a 75-Hz TENS group, and a no-treatment control group (n = 27 per group). TENS currents were biphasic square waves with pulse durations of 150 μsecs and pulse frequencies of 20 Hz or 75 Hz and were applied for 30 mins once per day for 90 days. The positive electrodes were placed in the region of the second sacral level on opposite sides of the vertebral column; the negative electrodes were placed on the inside of the middle and lower third of the junction between the posterior superior iliac spine and the ischial node. Overactive Bladder Symptom Scores, Barthel Index, urodynamic values, and voiding diary parameters were assessed before and after 90 days.

RESULTS

The patients treated with 20 Hz had superior Overactive Bladder Symptom Scores, Barthel Index totals, urodynamic values, and voiding diary parameters (P < 0.05). In the 75-Hz group, values were statistically improved compared with the no-treatment group (P < 0.05), but the results were significantly inferior to those of the 20-Hz group (P < 0.05).

CONCLUSIONS

Twenty-hertz TENS improved incontinence symptoms and promoted activities of daily living better than 75-Hz TENS. These results will aid future research regarding TENS parameters.