The effect on handgrip strength of low-frequency percutaneous electric stimulation applied to the median and cubital nerves: A randomized, double-blind controlled trial

Effects of Adding Four Sessions of Ultrasound-Guided Percutaneous Electrical Nerve Stimulation to an Exercise Program in Patients with Shoulder Pain: A Randomized Controlled Trial

Objective: Percutaneous electrical nerve stimulation (PENS) appears to be effective for the treatment of musculoskeletal pain. The aim of this trial was to investigate the effects on disability and pain, as well as on the psychological aspects of adding PENS into an exercise program in patients with subacromial pain syndrome. Methods: A randomized, parallel-group clinical trial was conducted. Sixty patients with subacromial pain were allocated into exercise alone (n = 20), exercise plus PENS (n = 20), or exercise plus placebo PENS (n = 20) groups. Patients in all groups performed an exercise program twice daily for 3 weeks. Patients allocated to the PENS group also received four sessions of ultrasound-guided PENS targeting the axillar and suprascapular nerves. Patients allocated to the exercise plus placebo PENS received a sham PENS application. The primary outcome was related disability (Disabilities of the Arm, Shoulder, and Hand, DASH). Secondary outcomes included mean pain, anxiety levels, depressive symptoms, and sleep quality. They were assessed at baseline, one week after, and one and three months after. An analysis was performed using intention-to-treat with mixed-models ANCOVAs. Results: The results revealed no between-group differences for most outcomes (related disability: F = 0.292, p = 0.748, n2p = 0.011; anxiety: F = 0.780, p = 0.463, n2p = 0.027; depressive symptoms: F = 0.559, p = 0.575, n2p = 0.02; or sleep quality: F = 0.294, p = 0.747, n2p = 0.01); both groups experienced similar changes throughout the course of this study. Patients receiving exercise plus PENS exhibited greater improvement in shoulder pain at one month than those in the exercise (Δ -1.2, 95%CI -2.3 to -0.1) or the placebo (Δ -1.3, 95%CI -2.5 to -0.1) groups. Conclusions: The inclusion of four sessions of ultrasound-guided PENS targeting the axillar and suprascapular nerves into an exercise program did not result in better outcomes in our sample of patients with subacromial pain syndrome at one and three months after treatment.

Immediate effects of percutaneous electrical nerve stimulation in patients with lateral elbow pain

INTRODUCTION

Ultrasound guided-percutaneous electrical nerve stimulation appears to be effective in the treatment of chronic musculoskeletal pain.

OBJECTIVE

To investigate the immediate effects of one session of percutaneous electrical nerve stimulation on the radial nerve in patients with lateral elbow pain.

METHODS

A randomized clinical trial was conducted. Sixty patients with chronic lateral elbow pain were allocated into real-percutaneous electrical nerve stimulation (n = 30) or sham-percutaneous electrical nerve stimulation (n = 30) where the patients received one-single session of the real or sham percutaneous stimulation on the radial nerve, respectively. Pressure pain thresholds, pain intensity, pain-free grip strength, and the self-perceived improvement were evaluated after the intervention.

RESULTS

Significant differences between groups for pain intensity (-11.55, 95% CI -21.79 to -1.30, p < .028), but not for pressure pain threshold or pain-free grip strength, were found. Patients receiving real-percutaneous stimulation had significant improvement in pain-free grip strength on the treated side. The proportion of individuals reporting moderate to large self-perceived improvement (≥4) was significantly higher (p = .026) after real-percutaneous stimulation than after sham-percutaneous stimulation.

CONCLUSION

A single session of real-percutaneous electrical nerve stimulation targeting the radial nerve in subjects with lateral elbow pain decreased pain intensity between groups and increased pain-free grip strength on the treated side but not between groups.

Neurorobotics and neuroprostheses: Towards a new anatomy

The idea of this Special Issue arose from the technological advances in bionic, robotic, and neural rehabilitation systems and the common need to comprehend in detail how human anatomical structures can be replicated or controlled. Motor control theories, among others, include the generalized control program theory, the equilibrium point hypothesis, or the optimal control approach in which neural commands to the muscles are a result of the central nervous system solving an optimization problem for a specific cost function. No matter the alternative interpretation selected to replicate biological control of human movements, artificial "anatomies" should consider not only motor capabilities from the central nervous system but integrate bioinspired mechanical features (such as compliance) in artificial limbs. The development of wearable robotics and neuroprosthetic systems for human movement compensation and control is naturally inspired by human anatomy and biology. Cutting-edge technological advances in the field of biomedical and neural engineering are bringing us more and more close to a new artificial anatomy with which humans could augment their motor capabilities or replace them after they are compromised. Either augmentative/assistive or rehabilitation technologies in the near future will require engineering solutions based on novel approaches to create usable neurorobotic and neuroprosthetic systems for the most relevant societal needs.