Inspiratory Muscle Performance Research Articles

Role of the Inspiratory Muscles on Functional Performance From Critical Care to Hospital Discharge and Beyond in Patients With COVID-19.

The role of inspiratory muscle performance in functional performance in patients with coronavirus disease 2019 (COVID-19) is poorly understood. The purpose of this study was to perform a longitudinal examination of inspiratory and functional performance from intensive care unit (ICU) discharge (ICUD) to hospital discharge (HD) and symptoms at HD and 1month after HD in patients with COVID-19. Thirty patients (19 men, 11 women) with COVID-19 were included. Examination of inspiratory muscle performance at ICUD and HD was performed with an electronic manometer, which provided the maximal inspiratory pressure (MIP) and several other inspiratory measures. Examination of dyspnea and functional performance was performed at ICUD and HD with the Modified Borg Dyspnea Scale and the 1-minute sit-to-stand test (1MSST), respectively. The mean age was 71 (SD = 11) years, the mean length of ICU stay was 9 (SD = 6) days, and the mean length of hospital stay was 26 (SD = 16) days. Most of the patients were diagnosed with severe COVID-19 (76.7%) and had a mean Charlson Comorbidity Index of 4.4 (SD = 1.9), reflecting high comorbidity. The mean MIP of the entire cohort increased minimally from ICUD to HD (from 36 [SD = 21] to 40 [SD = 20] cm H2O), reflecting predicted values for men and women at ICUD and HD of 46 (25%) to 51 (23%) and 37 (24%) to 37 (20%), respectively. The 1MSTS score increased significantly from ICUD to HD (9.9 [SD = 7.1] vs 17.7 [SD = 11.1]) for the entire cohort but remained far below population-based reference values (2.5th percentile) for the majority of patients at ICUD and HD. At ICUD, MIP was found to be a significant predictor of a favorable change in 1MSTS performance (β = 0.308; odds ratio = 1.36) at HD. A significant reduction in inspiratory and functional performance exists in patients with COVID-19 at both ICUD and HD, with a greater MIP at ICUD being a significant predictor of a greater 1MSTS score at HD. This study shows that inspiratory muscle training may be an important adjunct after COVID-19.

Inspiratory Muscle and Functional Performance of Patients Entering Cardiac Rehabilitation after Cardiac Valve Replacement.

Limited research has examined inspiratory muscle performance (IMP) and functional performance (FP) of patients after valve replacement surgery (VRS). The purpose of this study was to examine IMP as well as several measures of FP in patients post-VRS. The study results of 27 patients revealed that patients undergoing transcatheter VRS were significantly (p = 0.01) older than patients undergoing minimally invasive or median sternotomy VRS with the median sternotomy VRS group performing significantly (p < 0.05) better than the transcatheter VRS group in the 6-min walk test, 5x sit-to-stand test, and sustained maximal inspiratory pressure. The 6-min walk test and IMP measures in all groups were significantly (p < 0.001) lower than predicted values. Significant (p < 0.05) relationships were found between IMP and FP with greater IMP being associated with greater FP. Pre-operative and early post-operative rehabilitation may improve IMP and FP post-VRS.

A temporal examination of inspiratory muscle strength and endurance in hospitalized COVID-19 patients

BackgroundThe two most common symptoms associated with COVID-19 are dyspnea and fatigue. One possible cause of such symptoms may be inspiratory muscle weakness. ObjectivesThe purpose of this study was to examine inspiratory muscle performance (IMP) from intensive care unit discharge (ICUD) to hospital discharge (HD) in patients with COVID-19 hypothesizing that IMP would be markedly depressed at both ICUD and HD. MethodsIMP was examined at ICUD and HD via the PrO2 device (PrO2 Health, Smithfield, RI) which provided the maximal inspiratory pressure (MIP), sustained MIP (SMIP), inspiratory duration (ID), and fatigue index test (FIT). Patient symptoms were assessed at ICUD, HD, and 1-month post-HD. Results30 patients (19 men, 11 women) with COVID-19 were included. The mean±SD age, BMI, and length of ICU and hospital stay was 71±11 yrs, 27.9 ± 6.3 kg/m, 9 ± 6 days, and 26±16 days, respectively. The mean±SD MIP, SMIP, ID, and FIT of the entire cohort at ICUD vs HD were 36±21 vs 40±20 cm H2O, 231±157 vs 297±182 PTU, 8.8 ± 4.2 vs 9.5 ± 4.6 s, and 9.0 ± 9.4 vs 13.1 ± 12.3, respectively, with only SMIP and FIT significantly greater at HD (p=.006 and 0.03, respectively). SMIP at HD was significantly related to resting dyspnea at HD (r=-0.40; p=.02). The SMIP and FIT of men were found to increase significantly from ICUD to HD, but no measure of IMP in the women increased significantly from ICUD to HD. At least one COVID-19-related symptom was present 1 month after HD with the most persistent symptoms being fatigue, cough, and dyspnea in 47%, 40%, and 37% of the patients, respectively. ConclusionsA significant reduction in IMP exists in patients with COVID-19 at both ICUD and HD and no measure of IMP in women was observed to increase significantly from ICUD to HD. Impaired inspiratory muscle endurance rather than strength was associated with greater dyspnea at HD.

A Secondary Analysis of Short- and Long-Term Variability of Inspiratory Muscle Performance in People Living With SCI.

To explore the expected variability in repeated short-term (ST) and long-term (LT) inspiratory muscle performance (IMP) in individuals with chronic spinal cord injury (SCI). Maximal inspiratory pressure (MIP), sustained MIP (SMIP), and inspiratory duration (ID) were collected from 22 individuals with chronic SCI (C1-T9, American Spinal Injury Association Impairment Scale [AIS] A-C) over 18 months. ST data were collected four times within 2 weeks (n = 19). LT data were collected at two time points at least 7 months apart (n = 20). SMIP was the most reliable IMP assessment with an intraclass correlation coefficient (ICC) of 0.959, followed by MIP (ICC 0.874) and ID (ICC 0.689). The ID was the only ST measure to have a significant difference [MIP: F(3, 54) = 2.5, p = .07; SMIP: F(3, 54) = 1.3, p = .29; ID: F(1.4, 25.6) = 4.8, p = .03]. Post hoc analysis showed the mean day 1 ST ID measure was significantly different from both days 3 and 4. The percent change of ID from day 3 to day 6 was 11.6%. No LT measures differed significantly [mean change (SD) [95% CI] for MIP: 5.2 cm H2O (18.8) [-3.6, 13.9], p = .235; SMIP: 60.9 pressure time unit (166.1) [-16.9, 138.6], p = .118; ID: 0.1 s (2.5) [-1.1, 1.3], p = .855]. These data provide a foundation for understanding normal variance in ST and LT IMP in the SCI population. Change in MIP function outside 10% is likely a true and meaningful change and may help clinicians recognize individuals with SCI at risk for respiratory compromise. Future studies should explore changes in MIP and SMIP that are associated with meaningful functional changes.

Feasibility of inspiratory muscle training to improve pulmonary and respiratory muscle function, and for attenuating sleep apnea symptoms in children and adolescent with obstructive sleep apnea and obesity: Case report

Background: Studies have demonstrated a potential risk of pulmonary and respiratory muscle dysfunction in individuals with obstructive sleep apnea (OSA) and/or obesity. Inspiratory muscle training (IMT) is an adjunct intervention designed to improve respiratory muscle strength, decrease severity of OSA, and to enhance sleep quality in adults with OSA. However, its effects on children with OSA and obesity are still largely unknown. Objectives: This case report aims to show the feasibility and the effects of IMT on pulmonary and respiratory muscle function and sleep apnea symptoms of children and adolescents with OSA and obesity. Case description: Four children and one adolescent who were diagnosed with OSA and classified as obesity underwent IMT with training load at 60% of the individual’s maximal inspiratory pressure (MIP) for 12 weeks. Results: No adverse effects occurred during evaluation and IMT. The participants’ compliance with IMT varied from 77.4% to 100%. After 12-week of IMT, MIP and maximal voluntary ventilation (MVV) increased from baseline, varying from 8.0% to 83.5% and 0.1% to 36.1%, respectively. Scores in the Sleep Related Breathing Disorder-Pediatric Sleep Questionnaire (SRBD-PSQ) tended to decrease rapidly at week 3. Thereafter, participants responded differently toward the end of IMT. Changes in pulmonary function variables were not observed. Conclusion: Improvements in respiratory muscle strength, endurance, and SRBD-PSQ scores occurred after IMT, suggesting the feasibility of IMT for increasing inspiratory muscle performance and for ameliorating sleep apnea symptoms in children and adolescents with OSA and obesity. However, pulmonary function was unaffected by IMT

Inspiratory Muscle Performance Is Related to Seated Balance Function in People With Spinal Cord Injury: An Observational Study

ObjectiveTo examine the relationship between inspiratory muscle performance (IMP) and functional sitting balance (FSB) in persons with chronic spinal cord injury (SCI). We hypothesized that a moderate correlation would be found between IMP and FSB and that individuals with better balance would have better IMP. DesignThe SCI-specific modification of the Function in Sitting Test (FIST-SCI) measured FSB. The IMP measures included (1) maximal inspiratory pressure (MIP), (2) sustained MIP (SMIP), and (3) inspiratory duration. Upper extremity motor score (UEMS) and level of injury (LOI) were taken from International Standards for Neurological Classification of Spinal Cord Injury examinations. Spearman correlational analyses assessed relationships among these factors in the sample (N=37). Mann-Whitney U tests explored differences between 2 comparison group pairs (tetraplegia group [TG] vs paraplegia group [PG]; independent transfer group [ITG] vs assisted transfer group [ATG]). Regression analysis examined variables predictive of FSB in the TG. SettingResearch facility. ParticipantsVolunteers with tetraplegia (n=21, American Spinal Injury Association Impairment Scale (AIS) A=8, B=7, C=6) and paraplegia (n=16, AIS A=9, B=4, C=3) (N=37). InterventionNot applicable. Main Outcome MeasuresIMP, LOI, UEMS, FIST-SCI. ResultsUEMS, MIP, SMIP, and LOI had moderate to high correlations with FIST-SCI scores (ρ=0.720 (P<.001), 0.480 (P=.003), 0.467 (P=.004), 0.527 (P=.001), respectively). UEMS, MIP, and FIST-SCI scores were higher in the PG and ITG than the TG and ATG, respectively (PG vs. TG P values=<.001, .008, .002, respectively, and ITG vs. ATG P values=<.001, .032, <.001, respectively). Further, SMIP and UEMS predicted FIST-SCI balance scores in the TG, accounting for 55% of total variance (P<.001) (FIST-SCI=11.88+0.03 [SMIP]+0.425 [UEMS]). ConclusionsThe relationship between IMP and balance appears preserved after SCI. FSB was predicted, in part, via UEMS and SMIP in the TG. Future research should focus on the effect of SCI-based breathing interventions on FSB.

Abstract 13852: Key Value of Inspiratory Muscle Performance and Training in a Home-Based Program to Improve Functional Capacity in Older Heart Failure Patients

Introduction: Patients with heart failure (HF) often have reduced exercise tolerance. Exercise training has putative value but is often limited by poor adherence or the effects of frailty. Baseline inspiratory muscle performance (IMP) may predict exercise limitation, and inspiratory muscle training (IMT) may have important clinical benefit, including offsetting the metaboreflex which may improve functional capacity by reducing sympathetic peripheral vasoconstriction induced by respiratory fatigue. We hypothesize that low IMP is an important predictor of exercise performance in older adults with HF and that IMT may be an effective home-based training program. Methods: Thirty-four male patients with HF (age and left ventricular ejection fraction of 69±7 years and 37±11%, respectively) were randomized into IMT (n=11) or aerobic and/or strength training (AST; n=23) for a 12-week home-based program. IMT was performed progressively from 50-85% of maximal inspiratory pressure (MIP) with the PrO 2 device (Smithfield, RI) which tracked data and adherence for comparison to AST regimens of cycle ergometry/walking and strength training individually advanced to achieve moderate to high intensities. Study endpoints included MIP, peak oxygen uptake (VO 2 ), 6-minute walk distance (6MWD), 30-second sit-to-stand (STS), grip strength, and leg strength (endurance, 1-rep max, and power). Results: IMT was well-tolerated with greater adherence (92±10% vs 79±34%) and a significantly greater MIP rise (25.3±25.0% vs 3.6±11.0%, p&lt;0.05). Baseline MIP greater than the median of 66 cmH 2 O across all exercise forms (n=18) was associated with significantly greater baseline and post-intervention peak VO 2 (16.4±5.0 vs 12.9±3.9 and 17.5±5.3 vs 13.4±3.1, p&lt;0.05) and was significantly correlated positively to change in 6MWD, STS, grip strength, and leg strength (r=0.352-0.504, p&lt;0.05). Conclusion: Home-based IMT significantly improved IMP and greater baseline IMP was associated with greater cardiorespiratory fitness, functional capacity, and trainability in older HF patients due likely to metaboreflex attenuation and greater adherence. Further study is needed to assess IMP and IMT performed alone or combined with AST regimens to address the growing HF population.

Abstract 13927: Sustained Maximal Inspiratory Pressure: A Novel Measure of Inspiratory Muscle Performance and Its Relationship to Physiology and Function in Heart Failure

Introduction: The sustained maximal inspiratory pressure (SMIP) is a novel measure of inspiratory muscle performance that reflects the ability of the inspiratory muscles to maintain force over time from residual volume (RV) to total lung capacity (TLC) and has been described as single-breath work capacity. In chronic obstructive pulmonary disease SMIP has been found to be more highly correlated to a greater number of physiologic and functional measures than maximal inspiratory pressure (MIP). This study examined the relationship of SMIP and MIP to a variety of physiologic and functional measures in patients with heart failure (HF). Methods: Fifty male Veterans (mean±SD age, BMI, LVEF = 69.9±8.0 years, 33.6±7.2 kg/m 2 , 40.1±14.4%, respectively) with HF underwent measurement of MIP and SMIP with the PrO2 device (Smithfield, RI) which were measured from RV during initial inhalation and to TLC, respectively. Pulmonary function and maximal expiratory pressure (MEP) were also assessed. Exercise capacity was assessed via cardiopulmonary exercise testing (CPET) and leg strength testing. Physical function was assessed with grip strength, 6-minute walk distance (6MWD), and sit-to-stand test (STS). Results: The mean±SD MIP and SMIP were 66.3±24.8 cmH 2 O and 351.3±151.4 PTU, respectively. Both MIP and SMIP were significantly (p&lt;0.05) correlated to many physiologic (r=.33-.48) and functional measures (r=.38-.62) with the greatest correlate to MIP being MEP (r=.58) and the greatest correlate to SMIP being FEV 1 (r=.62). The greatest physiologic correlate to MIP and SMIP was CPET peak tidal volume with identical r-values (.48). Absolute and relative peak oxygen consumption (pVO 2 ) were correlated to both MIP and SMIP with identical r-values for absolute pVO 2 (.33) and slightly higher r-values between MIP and relative pVO 2 (.37 vs .34). The greatest functional correlate to MIP and SMIP was leg strength/endurance (r=.53 and .46, respectively) followed by STS (r=.52 and .45, respectively) and 6MWD (r=.49 and .45, respectively). Conclusions: MIP and SMIP are significantly correlated in a positive direction to many physiologic and functional measures supporting the role of inspiratory muscle training and further study of SMIP and MIP in HF.

Inspiratory Muscle Performance and Anthropometric Measures—Novel Assessments Related to Pulmonary Function in People with Spinal Cord Injury: A Pilot Study

ObjectiveTo investigate the feasibility and validity of using the novel axillary:umbilical (A:U) ratio and sustained maximal inspiratory pressure (SMIP) as supplementary measures in the assessment of respiratory function in people with spinal cord injury. DesignPilot study with a single day of data collection. All measurements were taken with participants in their personal wheelchairs to best represent normal functioning and positioning for each individual. SettingResearch institution. ParticipantsA convenience sample of 30 community dwelling volunteers with chronic spinal cord injury (C2-T12, American Spinal Injury Association Impairment Scale A-D) participated. InterventionsNot applicable. Main Outcome MeasuresParticipants underwent anthropometric measurements (trunk height, abdominal circumference, axillary circumference) and assessment of inspiratory muscle performance, incluidng maximal inspiratory pressure, SMIP, and inspiratory duration, as well as standard pulmonary function tests. ResultsThe A:U ratio and SMIP were recorded for all participants. The SMIP was significantly related to more respiratory performance measures than the maximal inspiratory pressure (P<.05) and the A:U ratio was significantly related to more respiratory performance measures than any other anthropometric measure (P<.05). Additionally, an A:U ratio cutoff point detected individuals with a peak expiratory flow ≥ 80% of their predicted value with a sensitivity and specificity of 85.7% and 91.3%, respectively (area under the curve: 0.92). ConclusionsIt is feasible to capture the A:U Ratio and SMIP in individuals with spinal cord injury. Further, the strong significant relationships of SMIP and the A:U ratio to respiratory performance measures suggests their clinical importance in the pulmonary assessment and risk stratification of people with chronic spinal cord injury.

The Impact of Yoga on Inspiratory Muscle Performance in Veterans with COPD: A Pilot Study.

Chronic obstructive pulmonary disease (COPD) causes respiratory muscle weakness that leads to disabling dyspnea and poor functional performance. Therapies are often geared to improve inspiratory muscle performance. Yoga has been shown to improve exercise capacity, quality of life, and some pulmonary function measures in COPD, but little research has examined the effects of yoga training on inspiratory muscle performance. The purpose of this study was to investigate the effects of yoga training on inspiratory muscle performance in military veterans using the Test of Incremental Respiratory Endurance (TIRE). A prospective pilot study examined a 6-week yoga training program consisting of asana (poses) and pranayama (controlled breathing). Subjects had baseline inspiratory muscle weakness. The TIRE measured inspiratory muscle performance via the PrO2 device, providing maximal inspiratory pressure, sustained maximal inspiratory pressure, and inspiratory duration. Secondary measures included 6-minute walk distance, St. George Respiratory Questionnaire, Hospital Anxiety and Depression Scale, and spirometry. Mean age and BMI of subjects were 67 ± 3.6 years and 20.7 ± 3.3, respectively. The majority of subjects had severe (28.7%) or very severe (57.1%) COPD. Statistically significant improve m e n t s were seen in maximal inspiratory pressure (39.0 ± 14.1 cmH2O to 56.4 ± 20.6 cmH2O) and sustained maximal inspiratory pressure (244.1 ± 100.6 PTU to 308.1 ± 121.2 PTU). No statistically significant improvements we re observed in 6-minute walk distance, St. George Respiratory Questionnaire, Hospital Anxiety and Depression Scale, or spirometry. Yoga training has the potential in improve inspiratory muscle performance in veterans with severe to very severe COPD who present with inspiratory muscle weakness. This is of importance because improving inspira-tory muscle performance has been shown to improve COPD outcomes.

Effects of Inspiratory Muscle Training in Older Adults.

Inspiratory muscle training (IMT) has been widely applied to different populations, including the general population of older adults. In addition to increasing inspiratory muscle strength, other benefits of IMT in the health of this population have been reported. The primary aim of this study was to review the effects of IMT on the general parameters of health (eg, respiratory, functional, physical, and other variables) in older adults (≥ 60 y), and the secondary aim was to analyze the main IMT protocol used in the studies. We searched the MEDLINE, PEDro, SciELO, and LILACS databases to identify relevant randomized controlled clinical trials, and we assessed their methodological quality according to the PEDro scale. The Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines were used to guide the development of the protocol for this systematic review. The search yielded 7 studies involving 248 participants from 917 titles. The main outcomes investigated in response to IMT were related to the respiratory, functional, and physical variables. The results indicate that IMT promotes an increase of inspiratory muscle strength and diaphragmatic thickness in older adults. There was heterogeneity in the protocols described for this population with respect to the total training time (4-8 weeks), intensity (30-80% of the maximum inspiratory pressure), and weekly frequency (5 or 7 sessions). The reviewed studies revealed a positive trend for the effectiveness of IMT in improving inspiratory muscle performance in elderly subjects. More randomized studies are needed to evaluate other outcomes (eg, functional capacity, exercise capacity, cardiac autonomic control, quality of life, and others) to provide robust evidence that this training modality can promote improvements in health parameters in this population. In addition, the usual IMT prescription in this population is based on sets and repetitions, of mild to moderate intensity, performed on most days of the week, for ≥ 4 weeks.

Monitoring of Volume of Air in Inhalation From Triflo Using Video Processing

Breathing exercise training with a flow-oriented incentive spirometer (or Triflo) is important in lung expansion rehabilitation for patients with lung surgery or pulmonary injury. In this article, we propose a novel technique to estimate the volume of air inhaled and the sustained inhalation time based on video processing. The proposed technique combines a randomized circle detection algorithm to detect the three balls in Triflo tubes and a normalized cross-correlation algorithm to track these three balls that rise due to inhalation. The values of inhalation and the sustained inhalation time intervals are automatically recorded as screenshots on a personal computer for later analysis by a doctor. Three major experiments were conducted to verify the advantages of this proposed system. The first experiment evaluated the performances of both the ball detection and the tracking algorithms showing 3.68% error. The second experiment applied the proposed method implemented, so that it displays in plots the changes in the inhalation rate, as the training of a postoperative volunteer progressed. In the last experiment, a healthy subject employs Triflo to test the inhalation training format for lung volume regeneration with three levels of difficulty, to record the number of successful breathing maneuvers. When the data are displayed in rate versus time plots, a graph can help a doctor to appropriately plan the training program for the benefit of patients, because a more adaptable therapy can be realized and varying degrees of difficulty can be implemented. In addition, the patients can comfortably practice in home-based rehabilitation, seeing the improvements in the inspiratory muscle performance in computer screenshots.

Exercise Induced Laryngeal Obstruction in a Collegiate Runner: A Case Report of a Novel Therapy

A 23-year-old male Division I distance runner presented with several years of exertional stridor (high-pitched inspiratory noise caused by airflow obstruction), previously diagnosed as exercised-induced laryngeal obstruction (EILO), a condition formerly known as vocal cord dysfunction and exercised-induced paradoxical vocal fold motion. Over the course of roughly 3 years, the patient had previously failed conventional and invasive respiratory therapies for EILO including respiratory retraining, inspiratory muscle training, reflux suppression, allergy suppression, amitriptyline, performance psychology, and injection of botulinum toxin to the larynx. At a referral center that specializes in the treatment of EILO, the patient's diagnosis was confirmed through the use of a new procedure called continuous laryngoscopy during exercise. He underwent three sessions of a unique procedure called therapeutic laryngoscopy during exercise (which relies on real-time laryngoscopy footage as biofeedback during exercise) and learned novel breathing techniques to address the problem. It is common to misdiagnose exercise induced respiratory problems based on patients-described symptoms alone. Athletic trainers should be able to recognize EILO cases and feel comfortable contacting and collaborating with expert providers on appropriate treatment. This case is also important in that it documents a treatment failure of laryngeal injection of botulinum toxin for EILO, something not previously reported in the literature.

Higher serum levels of systemic inflammatory markers are linked to greater inspiratory muscle dysfunction in COPD.

Chronic obstructive pulmonary disease (COPD) is associated with an inflammatory response that becomes more pronounced in acute exacerbations. Considerable attention has recently focused on the value of several inflammatory mediators in predicting worsening of COPD-related symptoms. Whereas respiratory muscle dysfunction is also widely present in this population, little is known about how systemic inflammation relates to inspiratory muscle dysfunction in COPD. Fifty-three males with mild-to-very severe airflow obstruction underwent blood sampling for 23 inflammatory markers, including acute-phase proteins, cytokines and adipokines. Inspiratory muscle performance was assessed via the test of incremental respiratory endurance, providing measures of maximal (MIP) and sustained maximal (SMIP) inspiratory pressures. The mean ± SD MIP and SMIP were 75.32±19.62 cmH2 O and 406.15±124.55 PTU. MIP negatively correlated with CRP, SAA and cystatin C (r-values from -0.333 to -0.378, P < 0.02), while SMIP was inversely related to SAA and cystatin C (r = -0.534 and r = -0.396, P = 0.00). Significant differences in CRP, SAA, cystatin C and PARC were also found between subjects with and without inspiratory muscle weakness. No additional significant relationships were observed between either MIP or SMIP and other inflammatory markers in the study. MIP and SMIP are markedly reduced with greater degrees of inflammation in COPD as expressed by higher levels of CRP, SAA and cystatin C. Future research is needed to further examine the above findings and determine the impact of systemic inflammation along with its underlying mechanisms on inspiratory muscle function in COPD.

Assessment of Maximum Dynamic Inspiratory Pressure.

Inspiratory muscle strength has been considered an important marker of ventilatory capacity and a predictor of global performance. A new tool has become available for dynamically evaluating the maximum inspiratory pressure (the S-Index). However, the proper assessment of this parameter needs to be determined. Thus, the aim of the present study was to investigate the number of inspiratory maneuvers necessary to reach a maximum and reliable S-Index and the influence of inspiratory muscle warm-up on this assessment. We performed a retrospective study from the database of 432 healthy subjects who underwent S-Index tests and inspiratory muscle warm-up or sham. The effect of repeated maneuvers on the S-Index and the impact of inspiratory muscle warm-up were analyzed by using the intraclass correlation coefficient and unpaired t test. We analyzed 81 subjects, (55% men), mean ± SD age 38.1 ± 9.6 y, 43 subjects in the inspiratory muscle warm-up group. Maximum and reliable S-Indexes were reached at the eighth maneuver in both groups preceding inspiratory muscle warm-up or sham, 102 cm H2O (95% CI 95-109 cm H2O); intraclass correlation coefficient 0.96; P < .001. Only the inspiratory muscle warm-up group presented a significant increase in the S-Index after warm-up, 13.5 cm H2O (95% CI 10-17), P < .001. Eight maneuvers were necessary to reach maximum and reliable values of the S-Index preceding inspiratory muscle warm-up or sham. Moreover, inspiratory muscle warm-up preceding S-Index assessment improved inspiratory muscle performance.

The BODE index and inspiratory muscle performance in COPD: Clinical findings and implications.

Objectives:The Test of Incremental Respiratory Endurance is a novel testing method that provides a unique examination of one’s inspiratory muscle strength, work and endurance. Little is known about the relationship between inspiratory muscle performance and mortality risk in obstructive lung disease. We examined the relationship between the Test of Incremental Respiratory Endurance measures and the Body-mass index, airflow Obstruction, Dyspnea and Exercise index in chronic obstructive pulmonary disease.Methods:In all, 70 males with mild-to-very severe chronic obstructive pulmonary disease (mean ± standard deviation of 70.2 ± 5.9 years) underwent measurements of body-mass index, spirometry, dyspnea and a 6-min walk test from which the Body-mass index, airflow Obstruction, Dyspnea and Exercise score was calculated. The Test of Incremental Respiratory Endurance provided measures of maximal inspiratory pressure, sustained maximal inspiratory pressure and inspiratory duration.Results:All Test of Incremental Respiratory Endurance parameters inversely correlated with the Body-mass index, airflow Obstruction, Dyspnea and Exercise score: maximal inspiratory pressure (r = −0.355, p = 0.00), sustained maximal inspiratory pressure (r = −0.426, p = 0.00) and ID (r = −0.278, p = 0.02), with sustained maximal inspiratory pressure displaying the highest correlation. Independent significant correlations were also observed between the sustained maximal inspiratory pressure and all Body-mass index, airflow Obstruction, Dyspnea and Exercise score components, except for body-mass index. Finally, sustained maximal inspiratory pressure was significantly different among the Body-mass index, airflow Obstruction, Dyspnea and Exercise index quartiles.Discussion:The significant association between the Body-mass index, airflow Obstruction, Dyspnea and Exercise score and inspiratory muscle performance, in particular sustained maximal inspiratory pressure, suggests that these measures may have a potential prognostic value in the evaluation of chronic obstructive pulmonary disease.

Acute responses of breathing techniques in maximal inspiratory pressure

The purpose of the present study was to examine the effect of three breathing techniques [normal breath (NB), breath holding (BH) and intermittent breath holding (IBH)] on finswimmers’ heart rate (HR), arterial oxygen saturation (SpO2) and maximum inspiratory pressure (PImax). Ten young finswimmers (15.8 ± 0.5 years) performed 8 × 25 m freestyle leg kick trials under the three different breathing occasions (NB, BH and IBH). HR, SpO2 and PImax were recorded immediately after the end of each test. The results showed lower SpO2 values immediately after the end of IBH technique in correlation with the other breathing techniques (IBH: 88 ± 0.9%; BH: 93.3 ± 0.7%; NB: 98.3 ± 0.3%; p < 0.001). Additionally, HR was higher after IBH compared to the other breathing techniques (IBH: 177 ± 4.2 bpm−1; BH: 165.7 ± 7.9 bpm−1; NB: 158.3 ± 2.2 bpm−1, p < 0.001) and PImax was also higher after the IBH compared to the other two techniques (IBH: 168.3 ± 5.3 cmH2O; BH: 166 ± 11 cmH2O; NB: 161.7 ± 11.4 cmH2O; p < 0.05). The data from the present study support that BH and even more so IBH training acutely increase the inspiratory muscles strength. This is an important training tool to improve the inspiratory muscle performance in athletes.

Inspiratory Muscle Performance of Former Smokers and Nonsmokers Using the Test of Incremental Respiratory Endurance.

Smoking has potential deleterious effects on respiratory muscle function. Smokers may present with reduced inspiratory muscle strength and endurance. We compared inspiratory muscle performance of nonsmokers with that of former smokers without overt respiratory problems via the Test of Incremental Respiratory Endurance. This study was performed on 42 healthy subjects between the ages of 30 and 79 y (mean ± SD of 56.5 ± 14.4 y). Fourteen male and 7 female former smokers were matched to nonsmokers based on sex, age, height, and weight. Subjects completed a questionnaire about their health and current smoking status. Testing included the best of 3 or more consistent trials. The Test of Incremental Respiratory Endurance measurements included maximal inspiratory pressure measured from residual volume as well as sustained maximal inspiratory pressure and inspiratory duration measured from residual volume to total lung capacity during a maximal sustained inhalation. No significant difference in inspiratory performance of the entire group of former smokers compared with nonsmokers was found. However, separate sex analyses found a significant difference in sustained maximal inspiratory pressure between male former smokers and nonsmokers (518.7 ± 205.0 pressure time units vs 676.5 ± 255.2 pressure time units, P = .041). We found similar maximal inspiratory pressure between former smokers and nonsmokers via the Test of Incremental Respiratory Endurance, but the significant difference in sustained maximal inspiratory pressure between male former smokers and nonsmokers suggests that the sustained maximal inspiratory pressure may have greater discriminatory ability in assessing the effects of smoking on inspiratory muscle performance. Further investigation of the effects of smoking on inspiratory performance via the Test of Incremental Respiratory Endurance is warranted.

Inspiratory Muscle Performance is Significantly Related to Agility and Speed in Collegiate Tennis Players

The Illinois Agility Test (IAT) measures sport agility by combining multi-directional skills with sprints. The Test of Incremental Respiratory Endurance (TIRE) evaluates inspiratory muscle strength and endurance via Maximal Inspiratory Pressure (MIP) and Sustained Maximal Inspiratory Pressure (SMIP). The relationship between athletic agility and inspiratory muscle performance (IMP) is unclear. PURPOSE: To examine the association between IMP and IAT results of Collegiate Tennis Players (CTP). METHODS: IMP of 7 male CTP (mean ± SD age = 20.3 ± 0.8 years, height = 186.2 ± 3.4 cm, and weight = 77.7 ± 6.5 kg) and 8 female CTP (age = 20.9 ± 0.8 years, height = 168.9 ± 6.2 cm, and weight = 64.7 ± 6.5 kg) was assessed via TIRE with the best of 3–5 trials providing MIP [measured from residual volume (RV)] and SMIP (measured from RV to total lung capacity). The IAT was performed twice with a 10-min rest between trials. The first and last intervals of the IAT comprised sprints to and from cones set 10 m apart, while the second interval involved weaving back and forth through four cones placed 3.3 m apart. A custom mobile app and tablet were used to time each IAT interval. RESULTS: MIP and SMIP of men were significantly (p<.05) greater than women (134.5 ± 19.4 vs. 99.5 ± 35.3 cm H2O and 791.1 ± 193.9 vs. 471.7 ± 162.8 PTU, respectively). Men were significantly (p<.05) faster during all IAT intervals and had a significant (p<.05) negative correlation between MIP and last sprint times of both trials (r = - .77 and - .89, respectively). In women, significant (p<.05) negative correlations existed between weaving time and SMIP of the first trial (r = - .77) and MIP and SMIP of the second trial (r = - .93 and - .89, respectively). CONCLUSIONS: IMP was significantly correlated to IAT time in CTP but gender differences existed. The correlation between MIP and last sprints in men suggests that men depend on IMP for speed. MIP and SMIP were related to the weave interval in women suggesting that women depend more on IMP for agility. Stronger correlations existed between IMP and IAT during the second IAT trials suggesting that greater IMP provides less susceptibility to performance decrement associated with fatigue. Greater IMP may provide greater balance and contribute to greater agility in women and speed in men, resulting in improved performance in CTP.

Core Strength/Endurance and Inspiratory Muscle Performance - Are They Related?

Core Strength/Endurance and Inspiratory Muscle Performance - Are They Related?