Muscle Functional Exercise Research Articles

Skeletal Muscle Force and Functional Exercise Tolerance Before and After Lung Transplantation: A Cohort Study

We investigated the impact of lung transplantation and outpatient pulmonary rehabilitation after lung transplantation on skeletal muscle function and exercise tolerance. Skeletal muscle force (Quadriceps force, QF), exercise tolerance (six minute walking distance, 6MWD) and lung function were assessed in 36 patients before and after lung transplantation. Seventeen male and 19 female patients (age 57 +/- 4) showed skeletal muscle weakness before the transplantation. A further 32 +/- 21% reduction was seen 1.2 (interquartile range 0.9 to 2.0) months after LTX. The number of days on the intensive care unit was significantly related to the observed deterioration in muscle force after LTX. At this time point 6MWD was comparable to pre-LTX. Rehabilitation started 37 (IQR 29 to 61) days after LTX. 6MWD and QF improved significantly (140 +/- 91 m, and 35 +/- 48%, respectively; p < 0.05) with rehabilitation. QF remained below pre-LTX values. The evolution of the 6MWD with the transplantation and the subsequent rehabilitation was less in female compared to male subjects. We conclude that muscle strength deteriorates after lung transplantation, particularly in patients with long ICU stay. Outpatient pulmonary rehabilitation is feasible after lung transplantation and leads to recovery of skeletal muscle function. In female patients this recovery is significantly less compared to male recipients.

Rising from a chair A simple screening test for physical function in predialysis patients

Patients with chronic end-stage renal diseases have decreased physical fitness. This physical deconditioning is relative but the consequences in daily life are related to functional thresholds. The main purpose of this study was to gather information about physical performance, physical fitness and activity in predialysis patients. A second aim was to investigate the possibility of identifying patients at risk of physical deconditioning using clinical tests. Fifty-five predialysis patients with a glomerular filtration rate (GFR) of <or=20 ml/min/1.73 m(2) were investigated. They filled out questionnaires about their physical activity. Muscle performance was measured by using an electronic force transducer for grip strength and knee extension. Clinical tests, such as 'Timed up and go', walking, standing heel-rise and 'Climbing up a 45-cm high step', were performed. There were no associations between GFR and the assessments of the above-mentioned tests. However, odds ratios calculated for 'Rising from a 45-cm chair without using the arms' and GFR and diabetes showed that, for every 1 ml/min/1.73 m(2) drop in GFR, the odds were 1.5 times higher that the patient would not be able to rise from a chair and, when the diagnosis was diabetes, the odds ranged from 1.7 to 21 times higher. Patients, especially diabetics, with chronic renal failure with a GFR of <or=20 ml/min/1.73 m(2) have decreased physical fitness. 'Rising from a 45-cm chair without using the arms' is an uncomplicated test to use in the clinical setting for identifying patients who need help with muscle training and functional exercise in order to improve their everyday functioning.

Short-term recombinant human growth hormone administration improves respiratory function in abstinent anabolic–androgenic steroid users

Objectives To determine whether 6 days recombinant human growth hormone (rhGH) administration, in an abstinent anabolic–androgenic steroid (AAS) using group had any respiratory, endurance exercise and biochemical effects compared with an abstinent AAS control group. Methods Male subjects ( n = 48) were randomly divided, using a single blind procedure into two groups: (1) control group (C) n = 24, means ± SD, age 32 ± 11 years; height 1.8 ± 0.06 m; (2) rhGH using group (0.019 mg kg −1 day −1) (GH) n = 24, means ± SD, age 32 ± 9 years; height 1.8 ± 0.07 m. Anthropometry, respiratory muscle function and endurance exercise were investigated. Respiratory measurements examined, were forced expiratory volume in one second, forced vital capacity, maximum inspiratory pressure and maximum expiratory pressure. Endurance exercise was assessed by measuring peak oxygen uptake (VO 2peak). Biochemical analysis included; haemoglobin, packed cell volume, glucose, sodium, urea, creatinine, total protein, albumin, testosterone and insulin like growth factor-I (IGF-I). Results Forced expiratory volume in one second/forced vital capacity, maximum inspiratory pressure, maximum expiratory pressure, and IGF-I significantly increased compared with the control group (all P < 0.05). Body mass index, fat free mass index, peak oxygen uptake, maximum inspiratory pressure, maximum expiratory pressure, IGF-I and serum sodium significantly increased, whilst body fat, total protein and albumin, significantly decreased within the GH group (all P < 0.017). Conclusion The findings of this study indicated that short-term high dose rhGH increased aerobic performance and respiratory muscle strength in former AAS users.

Selective Low-level Leg Muscle Training Alleviates Dyspnea in Patients with Heart Failure.

Abstract Objectives The purpose of this study was to demonstrate in patients with moderate to severe heart failure that exertional dyspnea can be alleviated by improving muscle function. Background Dyspnea is a frequent limiting symptom in patients with chronic heart failure (CHF). This sensation may originate from activation of receptors in the musculature rather than the lung. Methods To investigate whether dyspnea could be alleviated by selective changes in leg muscle function, we performed isolated lower-limb training in 17 patients with severe CHF. Eight patients learned guided imagery relaxation techniques and served as an active control group. Exercise training consisted of three months of low-level bicycle and treadmill exercise such that minute ventilation was Results In the active control group, no changes in leg muscle function, pulmonary function, maximal and submaximal exercise performance or quality-of-life questionnaires were observed. In the training group, peak torque of leg flexors (pre: 39 ± 15 ft-lb; post: 50 ± 13 ft-lb; p Conclusions We concluded that improvement of limb muscle function alleviates dyspnea and improves exercise performance in patients with CHF.

Selective low-level leg muscle training alleviates dyspnea in patients with heart failure

ObjectivesThe purpose of this study was to demonstrate in patients with moderate to severe heart failure that exertional dyspnea can be alleviated by improving muscle function. BackgroundDyspnea is a frequent limiting symptom in patients with chronic heart failure (CHF). This sensation may originate from activation of receptors in the musculature rather than the lung. MethodsTo investigate whether dyspnea could be alleviated by selective changes in leg muscle function, we performed isolated lower-limb training in 17 patients with severe CHF. Eight patients learned guided imagery relaxation techniques and served as an active control group. Exercise training consisted of three months of low-level bicycle and treadmill exercise such that minute ventilation was <25 l/min. Leg calisthenics were also performed. Maximal and submaximal exercise performance, respiratory and quadriceps muscle strength and endurance and quality-of-life and dyspnea scales were measured before and after each intervention. Metabolic stress testing (VO2), pulmonary function tests and isokinetic strength testing were also performed. ResultsIn the active control group, no changes in leg muscle function, pulmonary function, maximal and submaximal exercise performance or quality-of-life questionnaires were observed. In the training group, peak torque of leg flexors (pre: 39 ± 15 ft-lb; post: 50 ± 13 ft-lb; p < 0.002) increased and the fatigue ratio decreased, indicating improved strength and endurance of the leg muscles. Maximal inspiratory and expiratory mouth pressures and maximum voluntary ventilation were unchanged. Peak VO2was increased (pre:12 ± 2.2 ml/kg/min; post: 14 ± 2.6 ml/kg/min) as well as the duration of exercise at 70% peak VO2increased (pre: 11.5 ± 3.1 min; post: 21.5 ± 5.4 min; p < 0.003). Perceived dyspnea during the submaximal testing was decreased. Minnesota Living with Heart Failure Score, Guyatt Dyspnea Scale, and the Transitional Dyspnea Index were all improved with training (all p < 0.05). ConclusionsWe concluded that improvement of limb muscle function alleviates dyspnea and improves exercise performance in patients with CHF.

Home based neuromuscular electrical stimulation as a new rehabilitative strategy for severely disabled patients with chronic obstructive pulmonary disease (COPD)

Background: Passive training of specific locomotor muscle groups by means of neuromuscular electrical stimulation (NMES) might be better tolerated than whole body exercise in patients with severe chronic obstructive pulmonary...

Nutritional supplementation in stable chronic obstructive pulmonary disease.

Low body weight in patients with chronic obstructive pulmonary disease (COPD) is associated with an impaired pulmonary status, reduced diaphragmatic mass, lower exercise capacity and higher mortality rate when compared to adequately nourished individuals with this disease. Nutritional support may therefore be a useful part of their comprehensive care. To conduct a systematic review of randomized controlled trials (RCTs) to clarify whether nutritional supplementation (caloric supplementation for at least 2 weeks) improved anthropometric measures, pulmonary function, respiratory muscle strength and functional exercise capacity in patients with stable COPD. Randomized controlled trials (RCTs) were identified from the Cochrane Airways Group register of RCTs, a hand-search of abstracts presented at international meetings and consultation with experts. Two reviewers independently selected trials for inclusion, assessed quality and extracted the data. Within each trial and for each outcome, we calculated an effect size. The effect sizes were then pooled by a random-effects model. Homogeneity among the effect sizes was also tested. From 272 references, nine RCTs were ultimately included. Six papers were considered as high quality and only two studies were double-blinded. For each of the outcomes studied, the effect of nutritional support was small: the 95% confidence intervals around the pooled effect sizes all included zero. The effect of nutritional support was homogeneous across studies. Nutritional support had no significant effect on anthropometric measures, lung function or exercise capacity in patients with stable COPD.

A Study of the Trunk Muscle Function and Therapeutic Exercise in Patients with Chronic Low Back Pain

A Study of the Trunk Muscle Function and Therapeutic Exercise in Patients with Chronic Low Back Pain

Skeletal Muscle Function and Its Relation to Exercise Tolerance in Chronic Heart Failure

Objectives. This study sought to define the relation between muscle function and bulk in chronic heart failure (HF) and to explore the association between muscle function and bulk and exercise capacity.Background. Skeletal muscle abnormalities have been postulated as determinants of exercise capacity in chronic HF. Previously, muscle function in chronic HF has been evaluated in relatively small numbers of patients and with variable results, with little account being taken of the effects of muscle wasting.Methods. One hundred male patients with chronic HF and 31 healthy male control subjects were studied. They were matched for age (59.0 ± 1.0 vs. 58.7 ± 1.7 years [mean ± SEM]) and body mass index (26.6 ± 0.4 vs. 26.3 ± 0.7 kg/m2). We assessed maximal treadmill oxygen consumption (V̇o2), quadriceps maximal isometric strength, fatigue (20-min protocol, expressed in baseline maximal strength) and computed tomographic cross-sectional area (CSA) at midthigh.Results. Peak V̇o2was lower in patients (18.0 ± 0.6 vs. 33.3 ± 1.4 ml/min per kg, p < 0.0001), although both groups achieved a similar respiratory exchange ratio at peak exercise (1.15 ± 0.01 vs. 1.19 ± 0.03, p = 0.13). Quadriceps (582 vs. 652 cm2, p < 0.05) and total leg muscle CSA (1,153 vs. 1,304 cm2, p < 0.005) were lower in patients with chronic HF. Patients were weaker than control subjects (357 ± 12 vs. 434 ± 18 N, p < 0.005) and also exhibited greater fatigue at 20 min (79.1% vs. 92.1% of baseline value, p < 0.0001). After correcting strength for quadriceps CSA, significant differences persisted (5.9 ± 0.2 vs. 7.0 ± 0.3 N/cm2, p < 0.005), indicating reduced strength per unit muscle. In patients, but not control subjects, muscle CSA significantly correlated with peak absolute V̇o2(R = 0.66, p < 0.0001) and is an independent predictor of peak absolute V̇o2.Conclusions. Patients with chronic HF have reduced quadriceps maximal isometric strength. This weakness occurs as a result of both quantitative and qualitative abnormalities of the muscle. With increasing exercise limitation there is increasing muscle weakness. This progressive weakness occurs predominantly as a result of loss of quadriceps bulk. In patients, this muscular atrophy becomes a major determinant of exercise capacity.

Exercise intolerance in chronic heart failure is not associated with impaired recovery of muscle function or submaximal exercise performance

This study investigated whether recovery of skeletal muscle function is impaired in patients with heart failure and whether impaired recovery is associated with abnormal submaximal systemic exercise tolerance during repeated testing. Patients with heart failure experience fatigue during daily activities. Because abnormalities of skeletal muscle play a role in their exercise intolerance, these symptoms may reflect a delay in muscle recovery and a resulting limitation in submaximal exercise tolerance. Two protocols were used. In protocol 1, knee extensor strength and endurance, and their recovery after fatiguing exercise, were evaluated in 11 patients (mean [+/- SEM] age 62 +/- 5 years, New York Heart Association functional class 2.3 +/- 0.2, ejection fraction 24 +/- 5%) and in 10 age-matched sedentary control subjects. Protocol 2 examined the recovery of knee extensor endurance and submaximal exercise tolerance, as quantified on a self-powered treadmill, over 24 h in 18 patients (mean age 65 +/- 3 years, functional class 2.4 +/- 0.2, ejection fraction 23 +/- 3%) and in 10 control subjects. Peak oxygen consumption was reduced in both heart failure groups (15.4 +/- 1.4 and 15.6 +/- 1.0 ml/kg per min) compared with that in the respective control groups (23.1 +/- 2.9 and 25.6 +/- 1.0 ml/kg per min, both p < 0.05), as was muscle endurance but not muscle strength. In protocol 1, knee extensor endurance recovered more slowly in the patients than in control subjects (to 62 +/- 4% and 87 +/- 7% of the baseline value after 5 min, respectively, p < 0.05). In protocol 2, submaximal exercise tolerance was lower in the patients with heart failure than in control subjects (1,075 +/- 116 vs. 1,390 +/- 110 m), but knee extensor endurance and walking distance recovered fully by 10 and 30 min, respectively. Although these findings confirm earlier studies that demonstrated impaired muscle endurance in patients with heart failure, the results provide no evidence that recovery of either muscle function or submaximal exercise tolerance is delayed beyond the initial 5 to 10 min after exercise.

Exploration of Mechanical and Electromyographic Responses of Trunk Muscles to High-Intensity Resistive Exercise

The purposes of this study were to determine the effects of high intensity exercise on fatigue of the trunk muscles within a test session, and on multiple kinetic and electromyographic (EMG) variables over a 6-week training period. Fourty-five normal men and women (20-40 years of age) completed the study. The KIN/COM trunk testing unit (Chattecx Corporation, Chattanooga, Tennessee) was used for both testing and training. The results of the study follow: 1) The KIN/COM trunk testing system was very accurate, and the method used was highly reproducible for the kinetic variables. Reproducibility for the endurance variables was mixed, and isolated EMG variables were poor. 2) Kinetic and EMG decrements associated with fatigue did occur in the trunk muscles with ten continuous cycles of maximal concentric and eccentric contractions. 3) Trunk muscle strength gains were highest for the same mode of exercise used in training (specificity), but significant strength gains also were seen in different modes of muscle contraction (transfer of training). For the trunk extensors, the eccentric form of exercise was superior. 4) The rate of isometric torque development and decay was increased by exercise in men. 5) Trunk muscle endurance was retained when gains in strength occurred. 6) The majority of variables reflecting strength and endurance were retained. The methods and results can serve as guidelines for the evaluation of trunk muscle function and resistive exercise in the clinic.