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Maffiuletti N.A.,Neuromuscular Research Laboratory | Roig M.,McGill University | Roig M.,Copenhagen University | Karatzanos E.,National and Kapodistrian University of Athens | Nanas S.,National and Kapodistrian University of Athens
BMC Medicine | Year: 2013

Background: Neuromuscular electrical stimulation (NMES) therapy may be useful in early musculoskeletal rehabilitation during acute critical illness. The objective of this systematic review was to evaluate the effectiveness of NMES for preventing skeletal-muscle weakness and wasting in critically ill patients, in comparison with usual care.Methods: We searched PubMed, CENTRAL, CINAHL, Web of Science, and PEDro to identify randomized controlled trials exploring the effect of NMES in critically ill patients, which had a well-defined NMES protocol, provided outcomes related to skeletal-muscle strength and/or mass, and for which full text was available. Two independent reviewers extracted data on muscle-related outcomes (strength and mass), and participant and intervention characteristics, and assessed the methodological quality of the studies. Owing to the lack of means and standard deviations (SDs) in some studies, as well as the lack of baseline measurements in two studies, it was impossible to conduct a full meta-analysis. When means and SDs were provided, the effect sizes of individual outcomes were calculated, and otherwise, a qualitative analysis was performed.Results: The search yielded 8 eligible studies involving 172 patients. The methodological quality of the studies was moderate to high. Five studies reported an increase in strength or better preservation of strength with NMES, with one study having a large effect size. Two studies found better preservation of muscle mass with NMES, with small to moderate effect sizes, while no significant benefits were found in two other studies.Conclusions: NMES added to usual care proved to be more effective than usual care alone for preventing skeletal-muscle weakness in critically ill patients. However, there is inconclusive evidence for its benefit in prevention of muscle wasting. © 2013 Maffiuletti et al.; licensee BioMed Central Ltd.

Maffiuletti N.A.,Neuromuscular Research Laboratory
European Journal of Applied Physiology | Year: 2010

The main aim of this review is to discuss some evidence-based physiological and methodological considerations for optimal use of neuromuscular electrical stimulation (NMES) in healthy and impaired skeletal muscles. After a quick overview of the main applications, interests and limits of NMES use, the first section concentrates on two crucial aspects of NMES physiology: the differences in motor unit recruitment pattern between NMES and voluntary contractions, and the involvement of the nervous system during peripheral NMES. The second section of the article focuses on the most common NMES parameters, which entail the characteristics of both the electrical current (the input) and the evoked contraction (the output). © 2010 Springer-Verlag.

Crivelli G.,University of Lausanne | Maffiuletti N.A.,Neuromuscular Research Laboratory
Medicine and Science in Sports and Exercise | Year: 2014

Purpose: The effects of β2-agonists on human skeletal muscle contractile function are unclear, more particularly in the presence of fatigue. Moreover, it remains to be ascertained whether central motor drive during voluntary contractions could counter for eventual contractile alterations induced by β2-agonists. This study explored central and peripheral neuromuscular adjustments of the quadriceps induced by β2-agonist terbutaline after fatiguing exercise. Methods: On 2 d, nine men performed 120 intermittent (5-s contraction/5-s relaxation) submaximal (50% maximal voluntary contraction [MVC]) voluntary contractions, 2 h after having ingested a terbutaline (8 mg) or placebo capsule, in a double-blind randomized order. The isometric knee extension peak torque of single twitch and tetanic (10 and 100 Hz) contractions and of MVC was recorded before (PRE) and after (POST) the fatiguing exercise. Twitch maximal rate of torque relaxation (-dT/dt) was also calculated. Central motor drive was estimated via quadriceps electromyogram recorded during the submaximal voluntary contractions. Results: In PRE and POST conditions, MVC and twitch peak torque were not modified by terbutaline. PRE twitch -dT/dt was 22% higher in terbutaline compared with placebo (P < 0.005), but it did not differ significantly between treatments at POST. The evoked torque of 10- and 100-Hz tetanus were significantly lower in terbutaline compared with placebo, regardless of time (-16% and -17% respectively, P < 0.05). Central motor drive during voluntary exercise did not differ between treatments. Conclusions: These results demonstrate that terbutaline affected the contractile function of the quadriceps muscle during electrically evoked contractions both before and after fatiguing exercise. However, this did not impair the maximal voluntary force-generating capacity of the knee extensors and did not result in any compensatory adjustments of the central nervous system. Copyright © 2013 by the American College of Sports Medicine.

Hortobagyi T.,University of Groningen | Maffiuletti N.A.,Neuromuscular Research Laboratory
European Journal of Applied Physiology | Year: 2011

This review provides evidence for the hypothesis that electrostimulation strength training (EST) increases the force of a maximal voluntary contraction (MVC) through neural adaptations in healthy skeletal muscle. Although electrical stimulation and voluntary effort activate muscle differently, there is substantial evidence to suggest that EST modifies the excitability of specific neural paths and such adaptations contribute to the increases in MVC force. Similar to strength training with voluntary contractions, EST increases MVC force after only a few sessions with some changes in muscle biochemistry but without overt muscle hypertrophy. There is some mixed evidence for spinal neural adaptations in the form of an increase in the amplitude of the interpolated twitch and in the amplitude of the volitional wave, with less evidence for changes in spinal excitability. Cross-sectional and exercise studies also suggest that the barrage of sensory and nociceptive inputs acts at the cortical level and can modify the motor cortical output and interhemispheric paths. The data suggest that neural adaptations mediate initial increases in MVC force after short-term EST. © 2011 The Author(s).

Veldman M.P.,University of Groningen | Maffiuletti N.A.,Neuromuscular Research Laboratory | Hallett M.,U.S. National Institutes of Health | Zijdewind I.,University of Groningen | And 2 more authors.
Neuroscience and Biobehavioral Reviews | Year: 2014

This analytic review reports how prolonged periods of somatosensory electric stimulation (SES) with repetitive transcutaneous nerve stimulation can have 'direct' and 'crossed' effects on brain activation, corticospinal excitability, and motor performance. A review of 26 studies involving 315 healthy and 78 stroke and dystonia patients showed that the direct effects of SES increased corticospinal excitability up to 40% (effect size: 0.2 to 6.1) and motor performance up to 14% (effect size: 0.3 to 3.1) but these two features did not correlate. SES did not affect measures of intracortical excitability. Most likely, a long-term potentiation-like mechanism in the excitatory glutamatergic connections between the primary sensory and motor cortices mediates the direct effects of SES on corticospinal excitability and motor performance. We propose two models for the untested hypothesis that adding SES to unilateral motor practice could magnify the magnitude of inter-limb transfer. If tenable, the hypothesis would expand the evolving repertoire of sensory augmentation of cross-education using mirrors and add SES as an alternative to conventional rehabilitation strategies such as constraint-induced movement therapy. © 2014 Elsevier Ltd.

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