Comparison of the respiratory responses to external resistive loading and bronchoconstriction.

The effects of resistive loads applied at the mouth were compared to the effects of bronchospasm on ventilation, respiratory muscle force (occlusion pressure), and respiratory sensations in 6 normal and 11 asthmatic subjects breathing 100% O2. External resistive loads ranging from 0.65 to 13.33 cm H2O/liter per s were applied during both inspiration and expiration. Bronchospasm was induced by inhalation of aerosolized methacholine. Bronchospasm increased ventilation, inspiratory airflow, respiratory rate, and lowered PACO2. External resistive loading, on the other hand, reduced respiratory rate and inspiratory flow, but left ventilation and PACO2 unaltered. FRC increased to a greater extent with bronchospasm than external flow resistive loads. With both bronchospasm and external loading, occlusion pressure increased in proportion to the rise in resistance to airflow. However, the change in occlusion pressure produced by a given change in resistance and the absolute level of occlusion pressure at comparable levels of airway resistance were greater during bronchospasm than during external loading. These differences in occlusion pressure responses to the two forms of obstruction were not explained by differences in chemical drive or respiratory muscle mechanical advantage. Although the subjects' perception of the effort involved in breathing was heightened during both forms of obstruction to airflow, at any given level of resistance the sense of effort was greater with bronchospasm than external loading. Inputs from mechanoreceptors in the lungs (e.g., irritant receptors) and/or greater stimulation of chest wall mechanoreceptors as a result of increases in lung elastance may explain the differing responses elicited by the two forms of resistive loading.     

Adherence to home-based inspiratory muscle training in individuals with chronic obstructive pulmonary disease

BackgroundChronic obstructive pulmonary disease (COPD) is an incurable progressive illness characterized by airflow limitation and respiratory failure. Inspiratory muscle training (IMT) combined with pulmonary rehabilitation increases inspiratory muscle strength and endurance, and it decreases dyspnoea. Little is known about IMT adherence, and in the present study, we aimed to evaluate adherence to home-based IMT used with automatic internet-based feedback, in patients with chronic obstructive pulmonary disease.MethodThe adherence was evaluated at an individual level by completing a before-and-after comparison between two groups. Over a 12-week study period, the participants performed two daily sessions of 30 breaths with a mechanical threshold loading training device. They were randomly assigned to either a group of people who self-reported their perceived exertion during breathing and who received automatic internet-based feedback regarding their next threshold loadings, or a group of people who performed IMT with 30% maximal inspiratory pressure and who received no feedback.ResultsThe group of patients who self-reported their perceived exertion showed significantly better training adherence compared with the group of patients who received no feedback.ConclusionAdherence was greater among patients who self-reported their perceived breathing exertion and received automatic internet-based feedback on the next threshold loadings compared with patients who self-reported training sessions without feedback.     

Does mechanical threshold inspiratory muscle training promote recovery and improve outcomes in patients who are ventilator-dependent in the intensive care unit? The IMPROVE randomised trial

BackgroundIn patients who are ventilator-dependent in the intensive care unit, inspiratory muscle training may improve inspiratory muscle strength and accelerate liberation from the ventilator, but optimal training parameters are yet to be established, and little is known about the impact of inspiratory muscle training on quality of life or dyspnoea. Thus, we sought to ascertain whether inspiratory muscle training, commenced while ventilator-dependent, would improve outcomes for patients invasively ventilated for 7 days or longer.MethodsIn this randomised trial with assessor blinding and intention-to-treat analysis, 70 participants (mechanically ventilated ≥7 days) were randomised to receive once-daily supervised high-intensity inspiratory muscle training with a mechanical threshold device in addition to usual care or to receive usual care (control). Primary outcomes were inspiratory muscle strength (maximum inspiratory pressure % predicted) and endurance (fatigue resistance index) at ventilator liberation and 1 week later. Secondary outcomes included quality of life (SF-36v2, EQ-5D), dyspnoea, physical function, duration of ventilation, and in-hospital mortality.ResultsThirty-three participants were randomly allocated to the training group, and 37 to the control group. There were no statistically significant differences in strength (maximum inspiratory pressure) (95% confidence interval [CI]: −7.4 to 14.0) or endurance (fatigue resistance index) (95% CI: −0.003 to 0.436). Quality of life improved significantly more in the training group than in the control group (EQ-5D: 17.2; 95% CI: 1.3–33.0) (SF-36-PCS: 6.97; 95% CI: 1.96–12.00). Only the training group demonstrated significant reductions in dyspnoea (−1.5 at rest, −1.9 during exercise). There were no between-group differences in duration of ventilation or other measures. In-hospital mortality was higher in the control group than in the training group (9 vs 4, 24% vs 12%, p = 0.23).ConclusionsIn patients who are ventilator-dependent, mechanical threshold loading inspiratory muscle training improves quality of life and dyspnoea, even in the absence of strength improvements or acceleration of ventilator liberation.     

限制吸气流速对吸气肌训练的临床价值

目的探讨慢性阻塞性肺疾病(COPD)缓解期患者在阈压力负荷吸气肌训练中限制吸气流速的临床价值。方法作者自行设计一种可限制吸气流速的阈压力负荷吸气肌训练仪,应用于临床测试A、B组共33例COPD缓解期患者,压力为25%最大口腔吸气压(MIP),限定吸气流速<0.05和＜0.8L/s,每天训练40min。结果6周后,患者MIP、负荷吸气时间、12min最大行走距离均显著增加(P＜0.01),常规肺功能无明显改善。16例对照组应用普通的阈压力负荷吸气肌训练仪,结果上述指标均无显著改善(P＞0.05)。结论在阈压力负荷吸气肌训练中限制吸气流速,形成稳定的呼吸方式,可在较低的压力负荷下,获得较好的临床效果。     

Inspiratory muscle training improves performance of a repeated sprints ability test in professional soccer players

BackgroundInspiratory muscle training (IMT) is an important method of attenuating both respiratory and peripheral effort perceptions, consequently improving neuromuscular performance and resulting in greater improvements in exercise capacity than exercise training alone.ObjectiveThe aim of this study was to investigate the effects of IMT on exercise tolerance, repeated sprint ability (RSA) performance, maximal inspiratory pressure (MIP), and peak inspiratory flow (PIF) in a cohort of professional male soccer players.MethodsTwenty-two healthy male professional soccer players (18.3 ± 1.4 years; 174.5 ± 6.1 cm; 70.5 kg ± 4.6 kg; body fat 10.1 ± 4.2%) from a club in the Brazilian first division soccer league participated in this study. IMT consisted of 15 and 30 self-paced inspiratory breaths (each to 50% maximal static inspiratory pressure [P₀]) in the 1-and 2-week intervention period, respectively. IMT was performed prior to soccer training (1 sets.d⁻¹; 6 d.wk⁻¹) with repeated sprint ability (RSA) assessed pre- and post- the 2-week period of IMT.ResultsStatistical analyses identified a significant (p < 0.001) decrease in sprint time post-IMT. Additionally, RSA_best, RSA_mean, total sprint time and percentage of RSA performance decrement (RSA _{% dec}) also showed significant decreases (p < 0.0001) post-IMT. Additional measures including MIP and PIF were also significantly elevated (p < 0.0002) following the 2-week period of IMT.ConclusionIn conclusion, our results raise two important issues. Firstly, IMT demonstrated enhanced inspiratory muscle strength in professional soccer players. Secondly, this increase in inspiratory muscle efficiency led to a decrease in sprint time and improved exercise tolerance. We recommend that a standard training protocol be developed and tested in an experimental and control group with a large representative sample.     

Effects of core stability training program on trunk muscle endurance in deaf children: A preliminary study

IntroductionSport participation is an important for deaf children as participants experience physical, psychological and social benefits; however, the beneficial effect of core stability training on core muscle endurance is unclear. The present study aimed to examine the effects of an 8-week core stability exercise training program on endurance of trunk muscles in deaf children.MethodsTwenty male deaf students (age, 16.5 ± 0.65 y; body mass, 62.08 ± 5.39 kg; BMI, 22.33 ± 2.24 kg/m²) volunteered to participate in this study and were randomly assigned to experimental (EXP, n = 10) and control (CON, n = 10) groups. The subjects in the EXP group performed 3 times a week for 8 weeks period of core stability training program and tested trunk muscle endurance including prone bridge, supine bridge and flexor endurance tests at pre and post 8 weeks intervention.ResultsThe CON group did not show any significant change after training period (p > 0.05). The EXP group showed significantly changes in core stability muscle endurance tests following the 8-week core stability training program (p < 0.05). In addition, the EXP group indicated statistically significant changes than the CON group in truck muscle endurance (p < 0.05).ConclusionsThe results indicated that core stability training program improved trunk muscle endurance. Therefore, this training approach can be recommended in deaf rehabilitation programs to improve trunk muscle endurance.     

Feasibility of intercostal blood flow measurement by echo-Doppler technique in healthy subjects

Intercostal artery blood flow supplies the external and internal intercostal muscles, which are inspiratory and expiratory muscles. Intercostal blood flow measured by the echo-Doppler (ED) technique has not previously been reported in humans. This study describes the feasibility of this measurement during free and loaded breathing in healthy subjects. Systolic, diastolic and mean blood flows were measured in the eighth dorsal intercostal space during free and loaded breathing using the ED technique. Flows were calculated as the product of the artery intraluminal surface and blood velocity. Ten healthy subjects (42 ± 13·6 years) were included. Integrated electromyogram (iEMG), arterial pressure, cardiac frequency and breathing pattern were also recorded. Mean blood flows were 3·5 ± 1·2 ml min⁻¹ at rest, 6 ± 2·6 ml min⁻¹ while breathing through a combined inspiratory and expiratory resistance and 4·0 ± 1·3 ml min⁻¹ 1 min after unloading. Diastolic blood flow was about one-third the systolic blood flow. The changes in blood flows were consistent with those in iEMG. No change in mean blood flow was observed between inspiration and expiration, suggesting a balance in the perfusion of external and internal muscles during breathing. In conclusion, ED is a feasible technique for non-invasive, real-time measurement of intercostal blood flow in humans. In healthy subjects, mean blood flow appeared tightly matched to iEMG activity. This technique may provide a way to assess the vascular adaptations induced by diseases in which respiratory work is increased or cardiac blood flow altered.     

Pilates method on pulmonary function and range of motion after coronary artery bypass grafting: A clinical trial

IntroductionCoronary artery bypass grafting (CABG) can compromise pulmonary function and range of motion (ROM) of the shoulder and knee joints due to median sternotomy and saphenectomy, the Pilates method being a strategy for reducing loss.ObjectiveTo evaluate the effect of applying the Pilates method on pulmonary function and ROM in patients undergoing CABG.Methodology: This is a clinical trial. Patients were evaluated preoperatively at discharge from the hospital for shoulder flexion and abduction and knee flexion-extension. In addition, vital capacity(VC), maximum inspiratory pressure(MIP), expiratory pressure(MEP) and peak expiratory flow(PEF) were evaluated. Upon discharge from the Intensive Care Unit (ICU), they were divided into a control group(CG) that received conventional assistance and Pilates(PG) was increased with Pilates method techniques.Results40 patients were analyzed, 25 were men(61%), with a mean age of 66 ± 7 years. At the end, the left shoulder abduction in the CG was 105±9vs115 ± 8 in the PG(p = 0.03), the right shoulder abduction in the CG 104 ± 11vs116 ± 10 in the PG(p < 0.001) and right knee flexion in the CG 78 ± 13vs92 ± 9 in the PG(0.002). In relation to MIP, the CG had a loss of 32 ± 8 while the PG 18 ± 10cmH2O(p < 0.001), the worsening MEP was 31 ± 9(CG)vs29 ± 11cmH2O(PG)(p = 0.53), the VC in the CG reduced 8±9vs6±8 in the PG(p = 0.23) and the PEF reduced 107 ± 5 in the GCvs83 ± 88 in the PG(p = 0.09).ConclusionIt is concluded that the Pilates method decreased the loss of ROM and maximum inspiratory pressure in patients undergoing coronary artery bypass grafting.     

Short period of high-intensity inspiratory muscle training improves inspiratory muscle strength in patients with chronic kidney disease on hemodialysis: a randomized controlled trial

BackgroundChronic kidney disease is a complex disease that impacts multiple organs and systems (including musculoskeletal and cardiorespiratory) leading to reduction of functional capacity.ObjectiveThe aim of this study was to investigate the effect of a short period of high intensity inspiratory muscle training on maximum inspiratory pressure, functional capacity and endothelial function of chronic kidney disease patients on hemodialysis.MethodsThis randomized controlled trial enrolled 25 patients who were allocated into two groups: intervention (IMTG = 14) and control (CG = 11) groups. Intervention patients received the exercise protocol over a period of 5 weeks, 6 times per week, with each session consisting of 5 sets of 10 repetitions with an initial load of 50% progressing to 70% of maximum inspiratory pressure , measured weekly. The primary outcome was inspiratory muscle strength and the secondary outcomes were functional capacity and endothelial function evaluated before and after the training protocol.ResultsThe inspiratory muscle training induced a marked improvement in maximum inspiratory pressure which was evident after the training period (mean difference 19.0 cmH₂O – 95%CI 0.4–37.5; IMTG: 102 ± 25.7 cmH₂O vs CG: 83 ± 19.2; p = 0.046). The magnitude of maximum inspiratory pressure improvement was 33.5% at the end of the protocol for the IMTG. Functional capacity and endothelial function did not vary between or within groups.ConclusionA short period of high-intensity inspiratory muscle training for five weeks was able to improve inspiratory muscle strength of chronic kidney disease patients on hemodialysis (ClinicalTrials.gov registration NCT03082404).     

Effects of mouthpiece shape and expiratory threshold loading on contraction of the lateral abdominal muscles: A cross-sectional study

BackgroundExpiratory tasks may facilitate transversus abdominis (TrA) activity for spinal stabilization. The purpose of this study was to verify whether a combination of pursed-lip breathing (PLB) and use of an expiratory threshold loading (ETL) device to increase expiratory resistance would promote TrA contraction comparable to that for a stabilization exercise.MethodsTwenty healthy men performed expiratory tasks or an abdominal drawing-in maneuver (ADIM). Expiratory tasks comprised combinations of ETL settings with 0%, 5%, or 15% of maximum expiratory pressure, and mouthpieces with a normal shape or pursed-lip shape. B-mode ultrasound imaging of the TrA, internal oblique, and external oblique muscles was performed to determine percentage changes in muscle thickness. Percentage changes among tasks were statistically compared for each muscle.FindingsTrA thickness increased with normal lips at 15% ETL, with PLB with 5% ETL, and with ADIM (p < 0.01 each). Internal oblique thickness increased under all PLB conditions (p < 0.01 each). No significant differences in external oblique thickness were seen for any tasks. The total thickness of the lateral abdominal muscles was significantly increased not only for 15% ETL tasks and ADIM, but also for PLB with 5% ETL (p < 0.02 each).InterpretationThese results indicated that PLB with 5% ETL could facilitate the same level of TrA activity as the ADIM. PLB with 5% ETL was the only task that simultaneously increased overall lateral abdominal muscles, including the internal obliques, and might be readily applicable in clinical situations.     

Dissimilar perceptual response between trained women and men in resistance training to concentric failure: A quasi-experimental study

PurposeThis study compared sex-related affective responses during resistance training performed to concentric failure.MethodsThe study was a non-randomized trial (quasi-experimental study). Well-trained young participants were allocated into two groups according to sex (Women, n = 7, 21.1 ± 6.0 years, 57.6 ± 5.0 kg; and Men, n = 7, 28.3 ± 5.7 years, 88.3 ± 11.4 kg). Participants visited the laboratory three times: 1) 12-repetition maximum; 2–3) resistance training to concentric failure sessions. Perceptual measures were assessed before, during, and immediately after the resistance training sessions. The following were assessed: a) rating of perceived exertion for effort (RPE-E) and discomfort (RPE-D), b) feeling scale, c) physical activity affect scale (PAAS), d) felt arousal scale, and e) physical activity enjoyment scale (PACES).ResultsHigh levels of RPE-E and RPE-D were reported without between-groups differences (p > 0.218). Women reported a reduction in the feeling scale (p = 0.001) whereas men did not (p > 0.680). Larger effect sizes were observed for women compared to men in the felt arousal scale and PAAS (negative affect and fatigue). Feeling scale and felt arousal scale data plotted in a circumplex model of affect indicated a transition to high-activation and unpleasant-affect only for the women. There was good reliability between results from sessions 1 and 2.ConclusionsTraining to concentric failure resulted in negative changes in affective perceptual responses only for women. This type of training should be used with caution since it may change the affect perception and reduce training adherence in women. Further studies are needed using larger sample sizes, different resistance-training exercises, and diverse training methods.     

The effects of respiratory muscle training on improvement of the internal and external thoraco-pulmonary respiratory mechanism in COPD patients

IntroductionChronic obstructive pulmonary disease (CPOD) is a severe, incapacitating pathology. Inspiratory and/or expiratory muscle training may favorably impact the indicators of both specific and general improvement with regard to this disease. We are hypothesizing that when combined with bronchial decluttering, this training will have a beneficial effect on lung function and quality of life in these patients.MethodFourty COPD subjects classified Gold I and Gold II and aged 60.38 ± 8.02 years were divided into four groups of 10. Three of the groups were trained with the help of Threshold^® tools used for (1) inspiratory, (2) expiratory and (3) inspiratory and expiratory purposes; their training supplemented the decluttering and lower limb muscle exercise that the 4th group concurrently received. The patients underwent 16 rehabilitation sessions over an 8-week period. The variables consisted in: (1) forced expiratory volume in 1 s (FEV1) and spirometrically measured peak expiratory and inspiratory flow rates (PEFR and PIFR); (2) fatigability, dyspnea, heart rate and walking distance evaluated during the 6-minute walk test; (3) maximum inspiratory pressure and (4) maximum expiratory pressure as assessed by the Threshold^® tools and (5) the signs of quality of life in terms of the Saint-George's respiratory questionnaire (SGRQ) score.ResultsOnly in group 1, there was significant improvement with regard to FEV1 and PEFR. There was no PIFR modification in any of the groups. On the other hand, signs of quality of life scores along with dyspnea, fatigability and heart rate showed significant improvement in the three experimental groups, and significant improvement in maximum inspiratory pressure was observed in groups 1 and 3.DiscussionWhen associated with decluttering techniques, diaphragmatic rehabilitation and lower limb muscle exercise along with psychological support and educational efforts, respiratory muscle training is beneficial when compared with the usual protocols in rehabilitation of COPD patients.     

Inspiratory muscle strength training improves weaning outcome in failure to wean patients: a randomized trial

Introduction

Most patients are readily liberated from mechanical ventilation (MV) support, however, 10% - 15% of patients experience failure to wean (FTW). FTW patients account for approximately 40% of all MV days and have significantly worse clinical outcomes. MV induced inspiratory muscle weakness has been implicated as a contributor to FTW and recent work has documented inspiratory muscle weakness in humans supported with MV.

Methods

We conducted a single center, single-blind, randomized controlled trial to test whether inspiratory muscle strength training (IMST) would improve weaning outcome in FTW patients. Of 129 patients evaluated for participation, 69 were enrolled and studied. 35 subjects were randomly assigned to the IMST condition and 34 to the SHAM treatment. IMST was performed with a threshold inspiratory device, set at the highest pressure tolerated and progressed daily. SHAM training provided a constant, low inspiratory pressure load. Subjects completed 4 sets of 6-10 training breaths, 5 days per week. Subjects also performed progressively longer breathing trials daily per protocol. The weaning criterion was 72 consecutive hours without MV support. Subjects were blinded to group assignment, and were treated until weaned or 28 days.

Results

Groups were comparable on demographic and clinical variables at baseline. The IMST and SHAM groups respectively received 41.9 ± 25.5 vs. 47.3 ± 33.0 days of MV support prior to starting intervention, P = 0.36. The IMST and SHAM groups participated in 9.7 ± 4.0 and 11.0 ± 4.8 training sessions, respectively, P = 0.09. The SHAM group's pre to post-training maximal inspiratory pressure (MIP) change was not significant (-43.5 ± 17.8 vs. -45.1 ± 19.5 cm H₂O, P = 0.39), while the IMST group's MIP increased (-44.4 ± 18.4 vs. -54.1 ± 17.8 cm H₂O, P < 0.0001). There were no adverse events observed during IMST or SHAM treatments. Twenty-five of 35 IMST subjects weaned (71%, 95% confidence interval (CI) = 55% to 84%), while 16 of 34 (47%, 95% CI = 31% to 63%) SHAM subjects weaned, P = .039. The number of patients needed to be treated for effect was 4 (95% CI = 2 to 80).

Conclusions

An IMST program can lead to increased MIP and improved weaning outcome in FTW patients compared to SHAM treatment.

Trial Registration

ClinicalTrials.gov: NCT00419458     

Inspiratory muscle training in intensive care unit patients: An international cross-sectional survey of physiotherapist practice

BackgroundInspiratory muscle training is safe and effective in reversing inspiratory muscle weakness and improving outcomes in patients who have experienced prolonged mechanical ventilation in the intensive care unit (ICU). The degree of worldwide implementation of inspiratory muscle training in such patients has not been investigated.ObjectivesThe objectives of this study were to describe the current practice of inspiratory muscle training by intensive care physiotherapists and investigate barriers to implementation in the intensive care context and additionally to determine if any factors are associated with the use of inspiratory muscle training in patients in the ICU and identify preferred methods of future education.MethodOnline cross-sectional surveys of intensive care physiotherapists were conducted using voluntary sampling. Multivariate logistic regression analysis was used to identify factors associated with inspiratory muscle training use in patients in the ICU.ResultsOf 360 participants, 63% (95% confidence interval [CI] = 58 to 68) reported using inspiratory muscle training in patients in the ICU, with 69% (95% CI = 63 to 75) using a threshold device. Only 64% (95% CI = 58 to 70) of participants who used inspiratory muscle training routinely assessed inspiratory muscle strength. The most common barriers to implementing inspiratory muscle training sessions in eligible patients were sedation and delirium. Participants were 4.8 times more likely to use inspiratory muscle training in patients if they did not consider equipment a barrier and were 4.1 times more likely to use inspiratory muscle training if they aware of the evidence for this training in these patients. For education about inspiratory muscle training, 41% of participants preferred online training modules.ConclusionIn this first study to describe international practice by intensive care therapists, 63% reported using inspiratory muscle training. Improving access to equipment and enhancing knowledge of inspiratory muscle training techniques could improve the translation of evidence into practice.     

Interaction effects of different orders of resistance exercises and rest intervals on performances by young athletes

ObjectiveThe purpose of this study was to verify the acute effects of different exercise orders and rest intervals between sets on young athletes performance.MethodSixteen young male football players (73.2 ± 4.8 kg, 177.5 ± 5.1 cm, BMI 23.2 ± 1.1, 19.8 ± 0.9 years) completed six experimental strength training (ST) sessions with different exercise order sequences (A and B) and rest interval lengths (1 min, 3 min, and self-selected).In Sequence A the exercises were: bench press (BP), back squat (BS), biceps curl (BC) and plantar flexion (PF); while Sequence B was performed in the opposite order (i.e. PF, BC, BS and BP).The total work volume (TWV) per exercise (sets x repetitions x load) and per training session (sum of the TWV of all exercises) were evaluated for all ST sessions.ResultsBC and PF exercises presented higher TWV in sequence B (p ≤ 0.05). Already, the exercises BP, BS and PF presented higher TWV with 3 min and self-selected rest intervals (p ≤ 0.05). The 3-min and self-selected rest intervals presented higher values of TWV per training session compared to the 1-min rest interval (p ≤ 0.05).ConclusionThe exercise order influenced certain exercises (BC and PF), which presented higher TWV when positioned at the beginning of a sequence. While the longer rest intervals (3 min and self-selected) resulted in higher TWV per exercise (BP, BS and PF) and per training session. These results suggest that self-selected rest interval can be implemented to increase training efficiency in young athletes.     

The influence of inspiratory muscle training on diaphragmatic mobility,pulmonary function and maximum respiratory pressures in morbidly obese individuals: a pilot study

Abstract

Purpose: To investigate whether 12 week inspiratory muscle training (IMT) has any impact on pulmonary function, maximum respiratory pressures and diaphragmatic mobility (DM) in morbidly obese subjects. Method: Thirty-one morbidly obese individuals were assessed. Volunteers were randomised into two groups. The IMT group (n?=?16) followed an IMT protocol for 12 weeks, with a training load of 30% of maximal inspiratory pressure (PImax). The control group (CG) (n?=?15) followed the same protocol but without inspiratory load. Results: A total of 14 subjects performed IMT for 12 weeks. Significant increases in PImax (?86.86?±??20.70?cmH₂O versus ?106.43?±??32.97?cmH₂O, p?<?0.05) and maximal voluntary ventilation (97.84?±?37.06?L/min versus 115.17?±?34.17?L/min, p?<?0.05) were observed in the IMT group when compared to baseline. However, only FIV₁ significantly differed between the IMT group and the CG after the 12 week protocol (3.35?±?0.96?L versus 2.22?±?1.07?L, respectively; p?<?0.05). No significant differences were found in DM after the IMT protocol was performed. Conclusion: IMT improved PImax and altered the FIV₁. These results suggest that the improvements in muscular respiratory efficiency were insufficient to mobilise the diaphragm and modify ventilation mechanics. Pre-operative IMT may be a valuable approach in obese patients for preventing post-operative pulmonary complications. http://clinicaltrials.org -- NCT01449643 -- The Influence of IMT on Diaphragmatic Mobility in Morbidly Obese.

• Implications for Rehabilitation Morbid Obesity

• Morbid obesity is a disabling condition that has a serious negative impact on lung function, respiratory muscle function and quality of life.

• Inspiratory Muscle Training (IMT) is a technique which aims to improve pulmonary expansion and to prevent post surgery complications on morbid obese individuals.

• This study shows significantly increased on maximal inspiratory pressure, maximal voluntary ventilation and promoted changes on spirometric variables after IMT.

     

Identification of anaerobic threshold by analysis of heart rate variability during discontinuous dynamic and resistance exercise protocols in healthy older men

The purposes of this study were to determine anaerobic threshold (AT) during discontinuous dynamic and resistive exercise protocols by analysing of heart rate variability (HRV) and blood lactate (BL) in healthy elderly subjects and compare the cardiovascular, metabolic and autonomic variables obtained from these two forms of exercise. Fourteen elderly (70 ± 4 years) apparently healthy males underwent the following tests: (i) incremental ramp test on cycle ergometer, (ii) one repetition maximum (1RM) leg press at 45°, (iii) a discontinuous exercise test on a cycle ergometer (DET‐C) protocol and (iv) a resistance exercise leg press (DET‐L) protocol. Heart rate, blood pressure and BL were obtained during each increment of exercise intensity. No significant differences (P>0·05) were found between methods of AT determination (BL and HRV) nor the relative intensity corresponding to AT (30% of maximum intensity) between the types of exercise (DET‐C and DET‐L). Furthermore, no significant differences (P>0·05) were found between the DET‐C and DET‐L in relation to HRV, however, the DET‐L provided higher values of systolic blood pressure and BL (P<0·05) from the intensity corresponding to AT. We conclude that HRV was effective in determination of AT, and the parasympathetic modulation responses obtained during dynamic and resistive exercise protocols were similar when compared at the same relative intensity. However, DET‐L resulted in higher values of blood pressure and BL at workloads beyond AT.     

Immediate effects of vibration biofeedback on ankle kinematics in people with chronic ankle instability

BackgroundPeople with chronic ankle instability are more inverted during initial contact and loading response which may increase the risk of subsequent ankle injuries. Vibration feedback gait retraining causes medial center of pressure shifts but its impact on ankle kinematics remains unknown. The purpose of this study was to understand kinematic ankle changes in people with chronic ankle instability following vibration feedback gait retraining.MethodsNineteen participants with chronic ankle instability walked with vibration feedback for 10 min on a treadmill and for one mile in the real-world. A vibration stimulus occurred at the lower leg when pressure under the 5th metatarsal exceeded a threshold. Three-dimensional kinematics of the ankle were recorded in the lab before and after training. Paired t-tests compared baseline and posttest ankle, hindfoot, and forefoot positions during initial contact and loading response for the lab and real-world conditions.FindingsAfter lab training the ankle (mean difference:-1.68 ± 1.62°, effect size:0.95) and forefoot (mean difference:-1.68 ± 1.67°, effect size:0.92) were more abducted. After real-world training, the ankle (mean difference:-1.19 ± 2.12°, effect size:0.54) and forefoot (mean difference:-1.87 ± 3.00°, effect size:0.63) were more everted. Similarly the ankle (mean difference:-2.37 ± 4.79°, effect size:0.46) and forefoot (mean difference:-2.78 ± 4.91°, effect size:0.51) were more abducted after real-world training.InterpretationVibration feedback decreases inversion and adduction during loading response. However, RW compared to lab training may have more beneficial frontal plane changes for people with chronic ankle instability.     

Deoxygenation of inspiratory muscles during cycling,hyperpnoea and loaded breathing in health and disease: a systematic review

Assessing inspiratory muscle deoxygenation and blood flow can provide insight into anaerobic stress, recruitment strategies and mechanisms of inspiratory muscle limitation. Therefore, this review aimed to synthesize measurements of inspiratory muscle oxyhaemoglobin (O₂Hb), deoxyhaemoglobin (HHb), blood volume and flow of the inspiratory muscles acquired via near‐infrared spectroscopy (NIRS) during cycling, hyperpnoea and loaded breathing in healthy non‐athletes, healthy athletes and patients with chronic obstructive pulmonary disease (COPD) or chronic heart failure (CHF). Searches were performed on Medline and Medline in‐process, EMBASE, Central, Sportdiscus, PubMed and Compendex. Reviewers independently abstracted articles and assessed their quality using the modified Downs and Black checklist. Of the 644 articles identified, 21 met the inclusion criteria. Studies evaluated non‐athletes (n = 9), athletes (n = 5), COPD (n = 2) and CHF (n = 5). The sample was 90% male and 73% were non‐athletes and athletes. Interventions included cycle ergometry, hyperpnoea, loaded breathing, elbow flexor loading and combined loaded breathing and ergometry. Athletes and patients with CHF or COPD demonstrated deoxygenation of inspiratory accessory muscles that was often an opposite or exaggerated pattern compared to non‐athletes. O₂Hb decreased and HHb increased significantly in inspiratory muscles during cycle ergometry and loaded breathing with accentuated changes during combined ergometry and loaded breathing. During different regimens of hyperpnoea or loaded breathing, comparisons of inspiratory muscles demonstrated that the sternocleidomastoid deoxygenated more than the intercostals, parasternals or scalenes. Evaluating inspiratory muscle deoxygenation via NIRS can inform mechanisms of inspiratory muscle limitation in non‐athletes, athletes and patients with CHF or COPD.     

Flow generators for helmet CPAP: Which to prefer? A bench study

ObjectiveTo assess the different effect of filters’ application during helmet-CPAP delivered with three different flow generators on the delivered fresh gas flow, FiO₂, and the noise level inside and outside the helmet.MethodsIn a bench study, three flow generators (air-oxygen blender, turbine ventilator and Venturi system) were used to generate two different gas flows (60 L/min and 80 L/min), with a fixed FiO₂ at 0.6, to perform a helmet-CPAP on a manikin. Three different fixed PEEP valves (7.5, 10, and 12.5 cmH₂O) were applied at the expiratory port. Gas flow, FiO₂ and noise were recorded for each Flow-generator/Flow/PEEP combination, first without filter interposition and then after positioning a heat and moister exchanger filter (HMEF) at the helmet inlet port.ResultsThe application of the HMEF lead to a significant difference in the flow variation among the three flow generators (p < 0.001). Compared to baseline, the highest flow reduction was observed with the VENTURI (−13.4 ± 1.2 %, p < 0.001), a slight increase with the BLENDER (1.2 ± 0.5 %, p < 0.001), whereas no difference was recorded with the TURBINE (0.1 ± 0.6 %, p = 0.12). After HMEF was interposed, a significant FiO₂ variation was observed only with VENTURI (11.3 ± 1.8 %, p < 0.001). As for the noise, the TURBINE was the least noisy system, both with and without the filter interposition.ConclusionsFlow generators used to deliver helmet-CPAP have different characteristics and responses to HMEF interposition. Users should be aware of the effects on FiO₂ and flow of the different devices in order to make a precise setup of the circuit.