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1.
BACKGROUND: This study investigated whether the inspiratory muscles are susceptible to fatigue during acute airway narrowing because of increased airway resistance and hyperinflation. METHODS: Asthmatic subjects performed up to four series (on separate days) of 18 maximal static inspiratory efforts of 10 seconds' duration with 10 second rest intervals (50% duty cycle; total duration six minutes): at functional residual capacity (FRC) (control); after histamine induced bronchoconstriction, which decreased forced expiratory volume in one second (FEV1) to a mean of 55% (SD 11%) of the initial value; at a voluntarily increased lung volume (initial volume held at 140% control); and after inhalation of histamine at a voluntarily increased lung volume. RESULTS: For the group of subjects the mean (SD) maximal inspiratory pressure (MIP) in the control experiments was 114 (22) cmH2O and the initial volume was 3.5 (1.2) 1. After histamine inhalation the initial lung volume for contractions increased to 118% (5%) of the control volume. In the high lung volume experiments initial volumes were 140% (12%) of the control (volume without histamine) and 140% (15%) (with histamine). The relation between MIP and initial absolute lung volume was determined for each subject before fatigue developed. When the inspiratory pressures for each contraction in the endurance test were normalised to the pressure expected for that lung volume, no significant differences were found between the four experimental conditions for MIP, or between pressures sustained over the 18 contractions. CONCLUSIONS: Histamine induced bronchoconstriction and hyperinflation had no detectable effect on inspiratory muscle strength or endurance in these asthmatic subjects.  相似文献   

2.
BACKGROUND--Traditionally the radiological assessment of diaphragmatic movement has relied on fluoroscopy. Ultrasound scanning has recently been shown to be a sensitive and reproducible method of assessing hemidiaphragmatic movement in normal subjects. A study was undertaken to examine how movement of the diaphragm measured by ultrasound scanning relates to inspired lung volumes measured by spirometric testing. METHODS--Ultrasound examinations were performed on 14 normal volunteers using a 3.5 MHz sector transducer (Acuson 128). A fixed skin position on each lateral chest wall between the anterior clavicular and midaxillary line was selected symmetrically to obtain a longitudinal plane of each hemidiaphragm including the maximal renal bipolar length, allowing identification of the adjacent posterior aspect of the diaphragm. Craniocaudal excursions of the posterior part of each hemidiaphragm on successive respiratory cycles were recorded on videotape and compared with spirometric measurements recorded simultaneously on a water bath spirometer. Measurements were made in the sitting and supine position and were repeated on a separate occasion (at least two weeks apart) in 10 subjects by the same operator to assess reproducibility. RESULTS--The relation between inspired volume and hemidiaphragmatic movement was found to be linear. The gradient of these observed linear relations (hemidiaphragmatic excursion (mm)/inspired volume (1)) was calculated and their distribution for each hemidiaphragm followed a normal distribution irrespective of position. The 95% confidence limits of the right to left ratio of these gradients in the supine position were 0.53 and 1.7. Change of posture from the supine to the sitting position reduced the gradient. The technique had acceptable reproducibility with coefficients of variation for the supine position of 7.5% and 11.7% for right and left hemidiaphragm respectively. CONCLUSION--Ultrasound scanning is a simple, non-invasive and reproducible means of assessing hemidiaphragmatic movement, yielding quantitative information which relates to inspired lung volumes.  相似文献   

3.
Respiratory complications after laparotomy cholecystectomy may result from generalised muscle weakness and fatigue, or from reduced respiratory muscle function secondary to an upper abdominal incision. In a prospective study we compared maximal inspiratory effort (Pimax/mmHg) and dominant hand grip strength (kPa) (expressed as a percentage of zero hour value) in patients undergoing open cholecystectomy (OC) (n = 12), laparoscopic cholecystectomy (LC) (n = 25) and a control group of patients undergoing lower limb surgery (n = 12). Of the 12 OC patients, three suffered respiratory complications: two had atelectasis and one a chest infection, compared with no such complications in the other two groups (P < 0.05). Pimax decreased postoperatively in all groups (P < 0.05) and had returned to normal by 48 h in the LC and control groups. In contrast, in the OC group Pimax fell from 112.5 +/- 17.8 mmHg to as low as 81.3 +/- 16.5 mmHg at 72 h and only returned to preoperative levels at 120 h. The hand grip strength fell significantly in all groups at 24 h (P < 0.05) but normal levels were achieved again by 48 h in all groups, and there was no significant difference in the hand grip strength between the groups over the 5 days. These results suggest that generalised muscle fatigue after surgery is similar after open and laparoscopic cholecystectomy. Open cholecystectomy does, however, cause a more prolonged reduction in respiratory muscle function and this is likely to contribute to the higher incidence of respiratory complications in this group of patients.  相似文献   

4.
Reliability of an isokinetic test of muscle strength and endurance   总被引:3,自引:0,他引:3  
Funding for this study was provided by the U.S. Army Medical Research and Development Command, Project No. 85PP5866, under the Joint Working Group on Drug Dependent Degradation in Military Performance Program. The opinions or assertions contained herein are private ones of the authors and are not to be construed as official or reflecting the views of the Department of Defense or the Uniformed Services University of the Health Sciences. The reliability of an isokinetic test of muscle strength and endurance was evaluated. Eleven males and 9 females underwent testing on three separate occasions, 2-4 days apart. The protocol included a velocity spectrum test (VST-5 repetitions at velocities ranging from 90-330 degrees /sec) and a muscle endurance test (number of contractions performed in 45 sec at 180 degrees /sec). In the VST, no significant within-subject test day differences were noted at any velocity. Reliability was generally higher at slower velocities and higher for knee extension than flexion. Mean intraclass correlation coefficients (ICCs) for peak torque across velocities were 0.88 for extension and 0.79 for flexion. For the endurance test, two reliable measures were total work performed and average power (ICCs = 0.92); relative endurance measures had ICCs of less than 0.80. Thresholds for demonstrating experimental effects and the number of subjects to test at different detection levels are-recommended.J Orthop Sports Phys Ther 1989;10(8):315-322.  相似文献   

5.
The effects of intermittent negative pressure ventilation have been studied in 20 patients with chronic obstructive pulmonary disease during an exacerbation of their disease. Measurements of arterial blood gas tensions and maximal inspiratory pressure (MIP) were performed before and after six hours of negative pressure ventilation or standard treatment (control day) given in random order on two consecutive days. After negative pressure ventilation the mean (SD) value of MIP increased from 68.1 (21.5) to 74.8 (20) cm H2O;* arterial oxygen tension (PaCO2) fell from 60.6 (12.2) to 50.9 (8.9) mm Hg* but PaO2 changed little (from 48.4 (7.4) to 47.6 (8.2) mm Hg). There were no significant changes on the control day in arterial blood gas tensions (PaO2 47.8 (8.1) and 48.9 (9.4) and Paco2 59.8 (10.9) and 57.5 (8.06) mm Hg) or in MIP (69.4 (22.4) and 70.9 (22.9) cm H2O). Six patients tolerated negative pressure ventilation poorly and these patients showed less improvement after negative pressure ventilation. Our results suggest that intermittent negative pressure ventilation can increase alveolar ventilation in patients with an exacerbation of chronic obstructive lung disease, particularly in those who tolerate the procedure well. Most subjects showed a fall in PaCO2 and an increase in MIP. The fact that PaO2 was unchanged despite the fall in PaCO2 suggests that gas exchange may deteriorate with negative pressure ventilation in these patients.  相似文献   

6.
Several studies have shown positive correlations between muscle strength, flexibility, and the frequency of low-back pain. Weak trunk musculature and decreased endurance have thereby come to be identified as significant risk factors in the development of occupational back problems. Because it is widely accepted that exercise plays an important role in the conservative treatment and prevention of low-back pain, the goals of most rehabilitative programs involves improving the strength and endurance of the low-back pain patient. Whereas electrical stimulation has been shown to increase the muscle strength of the lower extremities, this effect has not been demonstrated for the trunk muscles. Part 2 is a prospective controlled study designed to document and to compare objectively the effects of electrical stimulation and exercise on trunk muscle strength. A total of 117 healthy women were divided randomly into four groups. Two groups received electrical stimulation with different electrical parameters, one group received exercises, and one group acted as a control group. The results showed that low-frequency electrical stimulation and exercises significantly (P less than .05) increased isokinetic back-muscle strength compared to the control and medium-high-frequency electrical stimulation groups. Both types of electrical stimulation, however, significantly increased (P less than .05) the endurance in the back muscles compared with the control and the exercise groups. This study showed that electrical stimulation may be a valuable treatment in the early care of low-back pain patients in maintaining and increasing strength and endurance of back muscles when a more active exercise program is too painful to perform.  相似文献   

7.

Introduction and hypothesis

Limited knowledge exists about pelvic floor muscle (PFM) function in ethnic groups. The aim of this study was to compare PFM strength and endurance in a group of black, white and mixed-race women.

Methods

This was a cross-sectional study. Maximum voluntary contraction (MVC) and endurance were measured with a perineometer and vaginal balloon sensor. Two sets of three MVC of the PFM were recorded; resting phase was 5 min. Demographic variables and factors associated with PFM strength were assessed.

Results

A total of 122 nulliparous black (n?=?44), white (n?=?44) and mixed-race (n?=?34) students participated. PFM of black women were stronger than that of white (p?=?0.02) or mixed-race (p?<?0.01) women. The MVC of PFM in black women decreased (p?=?0.02) between the first and second set of contractions.

Conclusions

Ethnic differences were found. Further clinical studies are needed to confirm an association between PFM function and pelvic floor disorders.  相似文献   

8.
Kang SW  Shin JC  Park CI  Moon JH  Rha DW  Cho DH 《Spinal cord》2006,44(4):242-248
STUDY DESIGN: Prospective single centre study. OBJECTIVES: Pulmonary rehabilitation focuses on improving the expiratory muscle function in order to increase the reduced cough capacity in patients with cervical spinal cord injuries (SCI). However, an improvement in the inspiratory function is also important for coughing effectively. Therefore, this study was to examine the significance of the inspiratory muscle strength on the cough capacity in the patients with a cervical SCI. SETTING: SCI unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: The vital capacity (VC), maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP) were measured. Moreover, the unassisted peak cough flow (PCF) and assisted PCF under three conditions were evaluated. RESULTS: All three assisted cough methods showed a significantly higher value than the unassisted method (P < 0.001). The VC correlated with the voluntary cough capacity and the MIP (R = 0.749) correlated more significantly with the VC than the MEP (R = 0.438) (P < 0.01). The MIP showed a higher correlation with both the unassisted PCF and all three assisted PCFs than the MEP (P < 0.001). CONCLUSIONS: The management of the inspiratory muscle strength should be considered in the pulmonary rehabilitation at cervical SCI patients.  相似文献   

9.
S Z Newell  D K McKenzie    S C Gandevia 《Thorax》1989,44(11):903-912
To determine whether patients with chronic airflow limitation have a specific alteration in skeletal muscle performance, the strength and endurance of inspiratory and limb muscles were compared in 11 patients with chronic airflow limitation and 11 control subjects during maximal voluntary contractions. Peak inspiratory pressure at observed functional residual capacity (FRC) was significantly less in the patients than in the control subjects (mean 72 (SD 25) v 93 (21) cm H2O), though only two patients had low maximal pressures across a wide volume range. Maximal voluntary torque of the elbow flexor muscles was also reduced in the patients but the difference was not significant (60 (17) v 72 (18) Nm). During the endurance sequence of 18 maximal voluntary contractions (10 s duration, 5 s rest interval) the decline in peak and average force was less for the inspiratory muscles than for the elbow flexors in both groups. Inspiratory muscle endurance was slightly greater in the patients with chronic airflow limitation than in the control subjects, whereas limb muscle endurance was slightly impaired in the patients. In three patients with chronic airflow limitation, two of whom had low maximal inspiratory pressures at FRC, the ability to drive the diaphragm voluntarily was examined by stimulating the phrenic nerves during maximal inspiratory efforts. Each patient was capable of full activation of the diaphragm during the maximal inspiratory efforts. These results suggest that the relative preservation of inspiratory muscle performance in patients with chronic airflow limitation may be an adaptive response to respiratory "loading."  相似文献   

10.
Radiologic imaging is vital to determining whether lung volume reduction surgery (LVRS) is a potential therapeutic option for patients with severe chronic obstructive pulmonary disease. The importance of imaging in patient selection for LVRS has been emphasized by numerous studies relating preoperative imaging features to postoperative outcomes. This article reviews the radiologic features assessed in the LVRS evaluation, summarizes the relationships between preoperative radiologic features and postoperative outcomes, and addresses the limitations of imaging in guiding patient selection.  相似文献   

11.
Measurements of relaxed expiratory volume in one second (REV1·0) and forced inspiratory volume in one second (FIV1·0) were made on 50 subjects on two occasions to know the variability of these procedures in the individual subject. The mean coefficients of variation for REV1·0 and FIV1·0 were 6·74% and 8·92%, respectively. The 95% confidence limit of difference between highest readings obtained on two occasions for REV1·0 and FIV1·0 was 0·38 litre and 0·214 litre, respectively. These results compare favourably with similar data reported for other ventilatory tests. We feel that if a little time is spent teaching subjects to produce REVs, then reproducible results may be obtained.  相似文献   

12.
A De Troyer  S Borenstein    R Cordier 《Thorax》1980,35(8):603-610
We investigated pulmonary mechanics in 25 patients, 9 to 55 years of age, with a variety of generalised neuromuscular diseases and variable degrees of respiratory muscle weakness. The average degree of inspiratory muscle force was 39.2% (range 8-83%) of predicted. The lung volume restriction far exceeded that expected for the degree of muscle weakness: the observed decrement in respiratory muscle force should, theoretically, decrease vital capacity to 78% of its control value, while the mean VC in our patients was only 50% of predicted. Analysis of lung pressure-volume curves indicated that the two principal causes of the disproportionate loss of lung volume were a reduction in lung distensibility probably caused by widespread microatelectasis, and a decrease in the outward pull of the chest wall. Because it reflects both direct (loss of distending pressure) and secondary (alterations in the elastic properties of the lungs and chest wall) effects of respiratory muscle weakness on lung function, we conclude that, in these patients, the vital capacity remains the most useful measurement to follow evolution of the disease process or response to treatment.  相似文献   

13.
目的研究呼吸功能训练对肺癌肺叶切除术患者术后呼吸功能及排痰的影响。方法选取我院2015年5月~2016年11月收治的80例接受肺叶切除术治疗的肺癌患者作为研究对象。将2015年5月至2016年2月期间接受常规护理的40例患者纳入对照组,手术前后接受健康宣教、吸氧、雾化吸入等常规护理;将2016年3月至2016年11月期间在常规护理基础上接受术前呼吸功能训练的40例患者纳入研究组。比较两组患者术前、术后7 d的呼吸功能包括每分钟最大通气量(MVV)、用力肺活量(FVC)、1秒用力呼气容积(FEV_1)、动脉血氧分压(PaO_2)、动脉二氧化碳分压(PaCO_2)、排痰量、术后住院时间、并发症发生率。结果术后两组患者MVV%、FVC%、FEV_1%、PaO_2水平均低术前,PaCO_2水平均高于术前,差异有统计学意义(P0.05);术后对照组MVV%、FVC%、FEV_1%、PaO_2水平低于研究组,差异有统计学意义(P0.05);两组患者术后PaCO_2水平比较,差异无统计学意义(P0.05);对照组患者术后排痰量低于研究组,术后住院时间高于研究组,差异有统计学意义(P0.05);术后对照组患者并发症总发生率高于研究组,差异有统计学意义(P0.05)。结论呼吸功能训练能降低肺叶切除术对肺癌患者术后呼吸功能的影响,改善呼吸功能,促进排痰,缩短术后住院时间,降低并发症发生风险,促进患者康复。  相似文献   

14.
The effects on maximal isometric trunk muscle strength and endurance after wearing a soft heat-retaining lumbar belt or a weightlifter's belt were studied. The soft belt (SB) study group comprised 12 construction workers with healthy backs, and the weightlifter's belt (WB) group comprised 24 construction workers with current or previous low back pain. The strength and endurance measurements were performed before the start of belt use, and after 1 and 2 months. The SB group increased the trunk flexor strength by 13% (p less than or equal to 0.01) after 2 months. The WB group increased the trunk flexor strength and endurance by 12% and 29%, respectively (p less than or equal to 0.001). No significant decrease of trunk muscle strength and endurance was found at the end of the follow-up period.  相似文献   

15.
BACKGROUND: Intrinsic positive end expiratory pressure (PEEPi) constitutes an inspiratory threshold load on the respiratory muscles, increasing work of breathing. The role of continuous positive airway pressure (CPAP) in alleviating PEEPi in patients with severe stable chronic obstructive pulmonary disease is uncertain. This study examined the effect of CPAP on the inspiratory threshold load, muscle effort, and lung volume in this patient group. METHODS: Nine patients were studied at baseline and with CPAP increasing in increments of 1 cm H(2)O to a maximum of 10 cm H(2)O. Breathing pattern and minute ventilation (I), dynamic PEEPi, expiratory muscle activity, diaphragmatic (PTPdi/min) and oesophageal (PTPoes/min) pressure-time product per minute, integrated diaphragmatic (EMGdi) and intercostal EMG (EMGic) and end expiratory lung volume (EELV) were measured. RESULTS: Expiratory muscle activity was present at baseline in one subject. In the remaining eight, PEEPi was reduced from a mean (SE) of 2.9 (0.6) cm H(2)O to 0.9 (0.1) cm H(2)O (p<0.05). In two subjects expiratory muscle activity contributed to PEEPi at higher pressures. There were no changes in respiratory pattern but I increased from 9.2 (0.6) l/min to 10.7 (1.1) l/min (p<0.05). EMGdi remained stable while EMGic increased significantly. PTPoes/min decreased, although this did not reach statistical significance. PTPdi/min decreased significantly from 242.1 (32.1) cm H(2)O.s/min to 112.9 (21.7) cm H(2)O.s/min). EELV increased by 1.1 (0.3) l (p<0.01). CONCLUSION: High levels of CPAP reduce PEEPi and indices of muscle effort in patients with severe stable COPD, but only at the expense of substantial increases in lung volume.  相似文献   

16.
Objectives: The purpose is to study the effect of inspiratory muscle training on aerobic capacity, respiratory muscle strength and rate of perceived exertion in paraplegics.

Study Design: Randomized controlled trial.

Settings: Rehabilitation department in Indian Spinal Injuries Centre, New Delhi.

Participants: A sample of 30 paraplegics (T1-T12) were randomly allocated into two groups: inspiratory muscle training (IMT) group and control group.

Interventions: The IMT group received inspiratory muscle training for 15 minutes 5 times a week for 4 weeks whereas the control group was given breathing exercises.

Outcome measures: Maximal inspiratory pressure(MIP), maximal expiratory pressure (MEP), modified Borg’s scale (MBS), 12 minute wheelchair aerobic test (12MWAT), multistage fitness test (MSFT), and 6 minutes push test (6MPT).

Results: Out of 30 participants, 27 completed the study. The results show that after four weeks of IMT training, there were significant improvements in mean change scores of IMT group as compared to control group. Participants in IMT group performed better on 12MWAT (P?=?0.001), MSFT (P?=?0.001) and 6MPT (P?=?0.001). Improvements in MIP scores (P?=?0.001), MEP scores (P?=?0.001) and MBS scores (P?=?0.004) were also seen in IMT group.

Conclusion: Both groups showed significant improvements, however inspiratory muscle training was seen to be more effective than deep breathing exercises for improving aerobic capacity, respiratory muscle strength and rate of perceived exertion in paraplegics.  相似文献   

17.
This research project was undertaken as a component of a comprehensive assessment of the University of Connecticut's freshman football team. The purpose of this study was to identify weaknesses in the neck musculature and note any relationships between strength differences and cervical spine stability. Neck muscle strength was evaluated using isometric contractions for the motions of flexion, extension, and right and left lateral flexion. Statistical correlations were derived for each of the 28 male subjects, who were divided into two groups of 14 linemen and 14 runningbacks. A Human Performance Regulator, which electrically evaluates neuromuscular force produced during an isometric contraction, was used to measure the force applied. A typical weightlifting power rack was used as a stabilization platform. The data recorded indicates that there are significant differences between the neck muscle strength of the two groups, as well as differences in neck muscle strength of individuals between their right and left sides. Looking at these muscular differences and their relationship to cervical vertebrae alignment during lateral flexion, the authors contend that blocking or tackling with the head in a laterally flexed position, to supposedly hit with the shoulder, places the cervical spine in a structurally weak position lacking muscular support, and predisposes the athlete to cervical spine injuries. J Orthop Sports Phys Ther 1987;8(7):351-356.  相似文献   

18.
19.
Inspiratory mechanical loads were applied to the airway continuously for 5 min in healthy young adult volunteers maintained in a near steady-state of halothane anesthesia 1.1 MAC. The loads, both flow resistive and elastic in nature, had been selected to reduce the first loaded tidal volume approximately 10, 30 or 50%--these being designated "small," "medium," and "large" loads, respectively. The actual magnitudes of resistive load were 8 +/- 1, 21 +/- 3, and 48 +/- 6 cmH2O X l-1 X s, and of elastic load 6 +/- 1, 18 +/- 1, and 41 +/- 5 cmH2O X l-1 (mean +/- SEM). All loads caused an immediate reduction of ventilation proportional to the size of the load. This was followed by a gradual recovery of ventilation toward control values over approximately 2 min and then nearly stable ventilation for the rest of the loading period. Respiratory frequency was unchanged throughout. At 5 min of loading, ventilation and PaCO2 had been nearly steady for 3 min and O2 uptake and CO2 output at the airway were unchanged from control, suggesting the establishment of a near steady respiratory state. With the small and medium loads of both types, ventilation and PaCO2 in this near steady-state were not detectably different from control. With the large loads, however, ventilation was significantly reduced and PaCO2 slightly increased. The end-expiratory position of the chest wall and the relative contributions of the rib cage and abdomen-diaphragm to ventilation, as estimated by anteroposterior chest wall magnetometers, were not consistently altered by any load.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
IntroductionSystemic sclerosis/scleroderma (SSc) is a chronic autoimmune disease with connective tissue, multi-organ, and multisystem involvement. The disease has three main characteristics, namely vasculopathy, fibrosis, and autoimmunity. The effect of high-intensity interval training (HIIT) in aerobic exercise on other rheumatic diseases has been studied, for example in patients with rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA). The purpose of this work is to investigate the effectiveness of HIIT of aerobics exercise on improving the inspiratory muscle, quality of life and functional ability for systemic sclerosis subjects.Material and methodsThe study was conducted on patients with confirmed systemic sclerosis who met the inclusion criteria. The research was carried out for 12 months in the outpatient clinic and gait laboratory of the Department of Physical Medicine and Rehabilitation.ResultsAfter HIIT in aerobic exercise, we found significant changes in inspiratory muscle (SNIP values 45.67 [30.92] vs. 54.25 [22.71]), handgrip (13.14 [4.42] vs. 15.63 [4.08]), walking speed (184.70 [26.86] vs. 246.6 [12.30]), metabolic equivalent (3.53 [0.30] vs. 4.21 [1.25]) and Scleroderma-Specific Health Assessment Questionnaire Disability Index for all visual analog scale (VAS) domains except Disability Index. Exercise approaches are characterized by repeated cycles of exercise interrupted by rest. For a range of clinical conditions, HIIT in aerobic exercise is known to remedy blood vessel function.ConclusionsOur results suggest that HIIT in aerobic exercise has improved functional ability, respiratory muscle strength, and quality of life in SSc subjects. Training twice a week in a 12-week HIIT program is considered to be safe for this population. We have to consider internal and external factors that influenced the result. A larger sample and further exploration of the feasibility of combined exercise in SSc patients should be the focus for future research.  相似文献   

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