Metabolic and structural changes in lower-limb skeletal muscle following neuromuscular electrical stimulation: a systematic review

BACKGROUND: Transcutaneous neuromuscular electrical stimulation (NMES) can be applied as a complementary intervention to regular exercise training programs. A distinction can be made between high-frequency (HF) NMES and low-frequency (LF) NMES. In order to increase understanding of the mechanisms of functional improvements following NMES, the purpose of this study was to systematically review changes in enzyme activity, muscle fiber type composition and muscle fiber size in human lower-limb skeletal muscles following only NMES. METHODS: Trials were collected up to march 2012 and were identified by searching the Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL and The Physical Therapy Evidence Database (PEDro) databases and reference lists. 18 trials were reviewed in detail: 8 trials studied changes in enzyme activities, 7 trials studied changes in muscle fiber type composition and 14 trials studied changes in muscle fiber size following NMES. RESULTS: The methodological quality generally was poor, and the heterogeneity in study design, study population, NMES features and outcome parameters prohibited the use of meta-analysis. Most of the LF-NMES studies reported significant increases in oxidative enzyme activity, while the results concerning changes in muscle fiber composition and muscle size were conflicting. HF-NMES significantly increased muscle size in 50% of the studies. CONCLUSION: NMES seems to be a training modality resulting in changes in oxidative enzyme activity, skeletal muscle fiber type and skeletal muscle fiber size. However, considering the small sample sizes, the variance in study populations, the non-randomized controlled study designs, the variance in primary outcomes, and the large heterogeneity in NMES protocols, it is difficult to draw definitive conclusions about the effects of stimulation frequencies on muscular changes

New Normative Values for Handgrip Strength: Results From the UK Biobank

OBJECTIVES: To develop normative values for right and left handgrip after stratification for confounders like gender, age, and height. Cross-sectional, descriptive. SETTING: General population. PARTICIPANTS: of 502,713 people living in the United Kingdom. INTERVENTION: None. Handgrip strength was measured using a Jamar hydraulic hand dynamometer, considered to be an accurate instrument to measure handgrip strength. In addition, self-reported chronic conditions and ethnic background were and lung function was assessed using spirometry. RESULTS: After individuals with missing data, a nonwhite ethnic background, the more self-reported conditions, and/or an obstructive lung function FEV1/FVC <0.7), new normative values for right and left handgrip derived from 224,830 and 224,852 individuals (54.2% women; age: 55.0 height: 169.0 [9.2] cm; body mass index: 26.9 [4.4] kg/m2) with a spirometry (FEV1: 3.0 [0.8] L). Men were stronger than women. Moreover, significant associations were found between handgrip strength and between handgrip strength and age. Finally, percentiles 5, 10, 25, 50, and 95 were calculated for right and left handgrip strength, after for gender, age, and height. CONCLUSION: The UK Biobank dataset provided opportunity to determine new normative values for handgrip strength in women aged 39 to 73 years. These normative values take into height, and measurement side. Therefore, these new normative handgrip values are of broad clinical interest

The metabolic response during resistance training and neuromuscular electrical stimulation (NMES) in patients with COPD, a pilot study

SummaryResistance training and transcutaneous neuromuscular electrical stimulation (NMES) are new modalities in rehabilitation of severely disabled patients with chronic obstructive pulmonary disease (COPD). The purpose of this study was to compare the metabolic response during resistance training and during NMES of the quadriceps femoris muscles in patients with COPD entering pulmonary rehabilitation.Pulmonary function, body composition, peak aerobic capacity, the Medical Research Council dyspnoea grade, the one-repetition maximum strength assessment were evaluated in 13 COPD patients. Additionally, peak oxygen uptake, peak minute ventilation and Borg symptom scores were assessed during a resistance training session and a NMES session.The median peak oxygen uptake and median peak minute ventilation during the resistance training session were significantly higher compared to the NMES session. Additionally, these higher metabolic responses were accompanied by higher symptom Borg scores for dyspnoea and leg fatigue.To conclude, the metabolic response was significantly lower during a NMES session compared to a resistance exercise training session in patients with COPD. Nevertheless, both modalities seem to result in an acceptable metabolic response accompanied by a clinically acceptable sensation of dyspnoea and leg fatigue

Heterogeneity in clinical characteristics and co-morbidities in dyspneic individuals with COPD GOLD D: Findings of the DICES trial

SummaryIntroductionChronic obstructive pulmonary disease (COPD) is a complex and heterogeneous respiratory disease with important extra-pulmonary features and comorbidities. The aim of this study was to assess clinical heterogeneity in a well-defined subgroup of individuals with COPD GOLD D, including possible gender differences.MethodsPulmonary function, arterial blood gases, exercise performance, quadriceps muscle function, problematic activities of daily life, dyspnea, health status and comorbidities have been assessed in 117 individuals with a MRC dyspnea grade 4/5 and COPD GOLD D entering pulmonary rehabilitation.ResultsA broad range of values were found for diffusion capacity, exercise capacity, quadriceps muscle function and health status. Indeed, the high coefficients of variation were found for these outcomes. Problematic activities of daily life as well as objectified comorbidities also varied to a great extent. Moreover, significant gender differences were found for exercise performance, lower-limb muscle function and various comorbidities.ConclusionThe current findings emphasize that COPD is a heterogeneous disease whose clinical presentation varies significantly, even in individuals with very severe COPD with the same degree of dyspnea and all classified as GOLD D.Trial registration: NTR2322

Effects of neuromuscular electrical stimulation of muscles of ambulation in patients with chronic heart failure or COPD: a systematic review of the English-language literature.

Despite optimal drug treatment, many patients with CHF or COPD still suffer from disabling dyspnea, fatigue and exercise intolerance. They also exhibit significant changes in body composition. Attempts to rehabilitate these patients are often futile because conventional exercise training modalities are limited by the severity of exertional dyspnea. Therefore, there is substantial interest in new training modalities that do not evoke dyspnea, such as transcutaneous neuromuscular electrical stimulation (NMES). Herein, we systematically review the literature that addresses the effects of NMES applied to the muscles of ambulation. We focused on the effects of NMES on strength, exercise capacity, and disease-specific health status in patients with CHF or COPD. We also address the methodological quality of the reported studies as well as the safety of NMES. Manuscripts published prior to December 2007 were identified by searching the Medline /PubMed, Embase, Cochrane Controlled Trials Register, CINAHL and The Physical Therapy Evidence Database (PEDro) databases. Fourteen trials were identified: nine trials that examined NMES in CHF and five in COPD. PEDro scores for methodological quality of the trials were generally moderate tot good. Many of the studies reported significant improvements in muscle strength, exercise capacity and/or health status. Nonetheless the limited number of studies, the disparity in patient populations and variability in NMES methodology prohibit the use of meta-analysis. Yet, from the viewpoint of a systematic review NMES looks promising as a means of rehabilitating patients with COPD and CHF. At least, there is sufficient evidence to warrant more large prospective RCTs

Short Physical Performance Battery: Response to Pulmonary Rehabilitation and Minimal Important Difference Estimates in Patients With Chronic Obstructive Pulmonary Disease

Objective: To determine the response to a pulmonary rehabilitation (PR) program and minimal important differences (MIDs) for the Short Physical Performance Battery (SPPB) subtests and SPPB summary score in patients with chronic obstructive pulmonary disease (COPD). Design: Retrospective analysis using distribution- and anchor-based methods. Setting: PR center in the Netherlands including a comprehensive 40-session 8-week inpatient or 14-week outpatient program. Participants: A total of 632 patients with COPD (age, 65±8y; 50% male; forced expiratory volume in the first second=43% [interquartile range, 30%-60%] predicted). Interventions: Not applicable. Main Outcome Measure: Baseline and post-PR results of the SPPB, consisting of 3 balance standing tests, 4-meter gait speed (4MGS), and 5-repetition sit-to-stand (5STS). The chosen anchors were the 6-Minute Walk Test and COPD Assessment Test. Patients were stratified according to their SPPB summary scores into low-performance, moderate-performance, and high-performance groups. Results: 5STS (∆=−1.14 [−4.20 to −0.93]s) and SPPB summary score (∆=1 [0-2] points) improved after PR in patients with COPD. In patients with a low performance at baseline, balance tandem and 4MGS significantly increased as well. Based on distribution-based calculations, the MID estimates ranged between 2.19 and 6.33 seconds for 5STS and 0.83 to 0.96 points for SPPB summary score. Conclusions: The 5STS and SPPB summary score are both responsive to PR in patients with COPD. The balance tandem test and 4MGS are only responsive to PR in patients with COPD with a low performance at baseline. Based on distribution-based calculations, an MID estimate of 1 point for the SPPB summary score is recommended in patients with COPD. Future research is needed to confirm MID estimates for SPPB in different centers