Electrical Stimulation

Neuromuscular electrical stimulation (NMES) is widely used to improve muscle strength and mitigate atrophy. However, its clinical efficacy is often limited by early neuromuscular fatigue, muscle damage, and discomfort, which reduce patient tolerance and contraction time. Photobiomodulation (PBM) has emerged as a potential therapy to enhance muscle performance and accelerate recovery by minimizing fatigue and damage. Despite its potential, few studies have investigated the effects of PBM applied specifically before an NMES-evoked fatigue protocol. This randomized, double-blind, placebo-controlled trial aims to evaluate the acute effects of PBM on neuromuscular fatigue, muscle damage, and functional outcomes in healthy young subjects. Participants will receive either active PBM (cluster probe: 5 lasers 810nm/200mW; 4 LEDs 660nm/10mW; Total Energy: 249.6 J per limb) or sham treatment 5 minutes before a fatiguing NMES protocol (80 contractions at 20% MVIC, 80 Hz, 1ms pulse width) applied to the quadriceps muscle. Assessments will be performed at baseline, immediately post-intervention, and at 24h, 48h, and 72h post-intervention. Primary outcomes include maximum and evoked isometric strength, mechanical work, and electrical muscle activity. Secondary outcomes include muscle damage (ultrasound echo-intensity), delayed onset muscle soreness (DOMS), functional performance (unilateral vertical jump), and clinical discomfort. The study seeks to determine if PBM can effectively modulate NMES-induced fatigue and muscle damage, potentially optimizing its clinical application.

Background: Shoulder instability is commonly observed in adolescents and young females, ranging from asymptomatic multidirectional instability (MDI) to symptomatic conditions. Patients with MDI often experience shoulder pain, muscle tension, and episodes of subluxation. This condition is associated with hypermobility spectrum disorder (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS), both characterized by generalized joint laxity and recurrent joint dislocations, significantly affecting daily activities and athletic performance. Current literature lacks clarity on the actual humeral head displacement, shoulder joint kinetics, and muscle activity characteristics during movement in patients with MDI accompanied by HSD or hEDS. Additionally, the effects of electrical stimulation on different shoulder muscles and its impact on humeral head displacement in MDI patients remain to be validated. Objective: The purposes of this study are to (1) examine whether patients with hEDS/HSD and MDI have increased humeral head translation compared to healthy controls during three isometric contraction ; (2) investigate the relationship between humeral head translation and associated muscle activity during three isometric exercises ; (3) examine the effect of NMES and NMCT to humerus/scapula muscles on humeral head translations in MDI patients with hEDS/HSD Outcome measurements: The primary outcomes include changes in acromiohumeral distance (AHD) or humeroglenoid distance (HGD) under four conditions (no stimulation, NMCT, BLH/Infraspinatus/MD stimulation, and SA stimulation) during three isometric contractions (shoulder flexion, horizontal adduction, and fully extended elbow holding weight). The secondary outcomes assess muscle activation differences in BLH, infraspinatus, MD, UT, LT, and SA before and after NMCT.

Cubital tunnel syndrome is the second most common compression neuropathy. In severe cases, functional recovery, even with surgery, is often poor. Therefore, alternative adjunct treatments capable of increasing the speed of nerve regeneration are much needed.