Rib Cage Research Articles

Stone Man Syndrome: A Rare and Debilitating Genetic Disorder with a Misguided Immune Response

Stone Man Syndrome, also known as Fibrodysplasia Ossificans Progressiva(FOP), is a rare genetic disorder characterized by progressive bone formation and connective tissue ossification. The condition affects approximately 1 in 2 million people worldwide and typically becomes apparent during early childhood. Individuals with Stone Man Syndrome experience the formation of extra bone in their muscles, tendons, and ligaments, which eventually leads to joint immobility and skeletal abnormalities. The condition progresses gradually and often leads to the fusion of the spinal column and rib cage, resulting in respiratory problems and limited mobility. FOP is caused by a mutation in the ACVR1 gene, which encodes a protein involved in bone formation and repair. The mutation leads to the activation of a specific signalling pathway, causing the body to produce excess bone tissue in response to injury or trauma. Currently, there is no cure for Stone Man Syndrome, and treatment options are limited. Physicians can only manage the symptoms of the condition and help patients maintain mobility through physical therapy, pain management, and surgery. However, surgery can be risky due to the risk of triggering new bone formation. The diagnosis of Stone Man Syndrome is typically based on clinical evaluation and genetic testing. Early diagnosis is critical to developing effective treatment plans and providing support for patients and their families. In conclusion, Stone Man Syndrome is a rare genetic disorder characterized by the progressive formation of extra bone tissue, leading to joint immobility and skeletal abnormalities. Although there is currently no cure for the condition, early diagnosis and management of symptoms can improve patients’ quality of life.

A Study to Assess the Effectiveness Of Structured Teaching Programme on Knowledge Regarding Hand Exercise in Prevention of AV Fistula Dysfunction among Hemodialysis Patient In Selected Hospital, Tumkur

Health is wealth; this phrase is very popular because happiness lies in the health of man. Good health helps to develop charm, grace, and happy mind. Kidneys are a pair of bean shaped organs located either side of the lower back just below the rib cage. Renal failure is the severe impairment or total lack of kidney function. Chronic Renal Failure (CRF) develops insidiously overtime and necessitates the initiation for long term survival.1 Dialysis is used to remove fluid and uremic waste products from the body when the kidneys are not able to do so. It is the best method to use arteriovenous fistula (AVF) as a vascular access. Compared to other vascular access such as venous catheter and a synthetic graft, arteriovenous fistula is most used method as it has fewer complications. Complications can occur even if we are careful, but are much less common if you take a few precautions. Hand exercise is essential to perform in prevention of AV fistula dysfunction. The aim of the study was to assess the effectiveness of Structured Teaching Programme on knowledge regarding Hand exercise among Hemodialysis patients in selected hospital, Tumkur.Methods: n evaluative approach with pre-experimental one group pre-test post-test design was used with purposive sampling technique to select the sample (N=50). A structured knowledge questionnaire was used to assess the Knowledge and STP was administered to find its effectiveness. The collected data was analyzed by using Descriptive statistics like mean, median and standard deviation, and inferential statistics like paired and independent‘t’ test was included to test the hypothesis and Chi-square test was included to test the association of knowledge scores with demographic variables.Results: The mean percentage of post-test knowledge score (79.09 %) was higher than the mean percentage of pre-test knowledge score (36.54%). The calculated’ value [t (49) = 21.01] is greater than the table value (0.05, 49df) = 1.96. It showed a significant difference between mean pre- and post- test knowledge scores. Calculated x2 values are showed no significant association between any of the variables with their post-test knowledge scores. Therefore, no significant association was found between these other variables and post-test knowledge level of Hemodialysis patients.
 Interpretation & Conclusion: The findings of the study showed that there was a deficit in knowledge ofHemodialysis patients before administration of STP. The results indicated that the STP is effective in increasingthe knowledge of Hemodialysis patients on Hand exercise.

Respiratory Function Assessment through Kinematic Analysis of Chest Wall Movements: Effects of Position and Gender.

The effect of position and gender on chest movements and respiratory volumes is controversial and investigated in only a few studies. This study aimed to investigate the effects of position and gender on the breathing pattern during four different positions in healthy individuals. In this cross-sectional study, twenty-eight (14 males, 14 females) healthy individuals participated aged 20-45 years. The optoelectronic plethysmography (OEP) method was used for the three-dimensional evaluation of chest wall motions and the compartmental analysis of the breathing pattern in supine, sitting, standing, and active straight leg raised (ASLR) positions. Volume changes in different parts of the chest wall were also measured. Position affected total and compartmental respiratory volumes in both genders. Respiratory volumes decreased in the supine position compared to sitting and standing. Total and abdominal respiratory volumes also decreased in females when comparing supine positions with the ASLR. A higher pulmonary rib cage contribution was identified in females, and males exhibited higher abdominal rib cage volume compared with females. The breathing pattern was affected by position and gender, and the respiratory volumes increased in more upright positions, perhaps due to a greater gravitational load. The ASLR decreases the respiratory volume, which is probably due to increased postural demand.

Postmortem calpain changes in longissimus muscle from Lanyu native and Kaohsiung crossbred black pigs.

The purpose of this study was to compare postmortem calpain changes in porcine muscle between Lanyu native (n= 10) and Kaohsiung crossbred (50% Meishan and 50% Duroc, n= 10) black pigs. Longissimus dorsi (LM) muscles (4th to 10th ribs) from both sides of carcasses were hot-sectioned in 30 min postmortem, vacuum-packaged, and stored at 5°C. LM samples from the left side of carcasses were sampled at 0 (30 min postmortem), 3, 6, 12, 24, 48, and 72 h of storage. The 24 and 72 h samples of shear force measurement were taken from the LM at the 8th and 10th ribs of the right side of carcasses, respectively. Our results showed that the decreases in calpain-1 activity, desmin content, and shear force were slower (P< 0.05) in Lanyu native black pig than in Kaohsiung crossbred black pig samples. Therefore, postmortem proteolysis and tenderization were more limited in LM from Lanyu native pigs than from Kaohsiung crossbred pigs.

Two Cases of Kittens Treated Surgically for Cranial Growth Plate Fracture of the Seventh Cervical Vertebra

Two kittens with cranial growth plate fractures of the seventh cervical vertebra were treated with a ventral median cervical approach to repair the fracture and fixed using titanium screws and polymethylmethacrylate. In both cases, postoperatively osteophyte formation progressed gradually in the ventral part of the fifth cervical vertebra, and in one case, deformity was observed in the thoracic cage and thoracic cranial region. Although the etiology of the fractures is unknown, no implant failure or loosening was observed after surgery, the clinical symptoms improved, and these kittens were able to walk, suggesting that the technique described in this study may be an effective treatment option.

Soft body reconstruction of a reptile fossil by the nondestructive elemental mapping with a newly designed XRF

AbstractVertebrate fossils usually consist only of mineralized skeletons and rarely preserve soft body parts. However, the buried soft body releases the degraded material into the surrounding sediments. The degraded material can be preserved as invisible signals of some chemicals or authigenic minerals, which can be revealed by the elemental distribution of the fossils' surface and their surrounding rock. As a method for surface elemental mapping, X‐ray fluorescence (XRF) measurement requires the samples to be ground and polished as a mirror‐like plane that keeps a stable distance of X‐ray source‐sample‐detector. This destructive pretreatment is undesirable for precious fossils. To rectify this problem, a nondestructive XRF for element mapping of the fossils' 3D surface is newly invented. The new equipment can follow the 3D shape model to keep the distance for every XRF scanned point. We performed the element mapping of Ca and Fe on the surface of a marine sauropterygian fossil (Keichousaurus hui) and its surrounding sediments, and found that the soft tissue around the thoracic cage is thicker than the abdomen. The abnormal elemental distribution on the area of the angular and surangular of the skull can be explained as unprofessionally prepared. In addition, this research found that elemental mapping revealed the invisible signals of the paleoenvironment around fossils and information for the reconstruction of soft‐tissue anatomy. We also give an example that based on the wide application of the “Internet of Things” and “Industrial Network,” the design and development of specialized equipment for paleontologists' requirements are going simple.

Desempenho tecnológico de cortes diferentes de carne de coelho no processamento de produtos cárneos curados cozidos prontos para consumo

Abstract There is a worldwide demand for new protein sources through environmentally responsible production, and rabbit farming is a sustainable activity. Therefore, this study aimed to characterize meat from different cuts of rabbit carcasses and evaluate their use in the processing of restructured cured cooked ready-to-eat (RTE) products. Rabbit raw meats from different cuts were technologically characterized, and the RTE products were processed from the meats of the entire carcass (RABB), hind legs (RHIND), loin (RLOIN), and foreleg, thoracic cage, and flank (RBACK). Restructured pork cooked ham (PHAM) was used as the reference. Rabbit raw meat from different anatomical parts difered in proximate composition, total collagen and heme-pigment content, water-holding capacity, and CIE color, afecting the characteristics of processed products. RBACK products had higher fat content (5.46%), cooking and reheating losses (7.50% and 5.61%), and poor hardness and chewiness (11.1 N and 17.37 N×mm). Higher values of lightness (L* ~70.27), hue (h ~68.61°), and a slight cured color were observed in RLOIN, with a pale yellowish color described by sensory evaluation. RABB and RHIND were correlated with the sensory attributes of traditional PHAM, being preferred more often and with greater purchase intent than RLOIN and RBACK. It is concluded that cooked ham development from whole carcass meat (RABB) is a potential opportunity for the rabbit industry to ofer value-added technological products of high quality to consumers.

Thoracic Tumors in Children and their Long-Term Outcomes: A Single-Center Experience.

This study aims to review our experience in children with thoracic tumors managed by different surgical approaches, and to evaluate their long-term outcomes in relation to their functional status and quality of life. This is a retrospective study (2011-2021). Children <18 years with tumors of the thorax (lung, mediastinum, and thoracic cage) were included. All included were diagnosed, managed, and followed up based on a departmental protocol. Children alive were followed up annually to monitor the development of chest wall/spinal deformities and assessed regarding their quality of life (Lansky play-performance scale) and pulmonary functions. Information regarding their demography, clinical presentations, diagnosis, treatment administered, outcome, and follow-up details were collated and analyzed. Twenty-two children with thoracic tumors were included (2011-2021). Of which, 6/22 are benign and 16/22 are malignant lesions. About 14/22 children are alive on a regular follow-up until 2021, with a mean follow-up of 6 years (benign) and 6.25 years (malignant). About 3/22 children with malignant tumors requiring thoracotomy with rib resections developed scoliosis with a severely restrictive pattern on pulmonary functions, having a mild-to-moderate restriction of play on quality of life grading. Early follow-up of children who have undergone various surgical approaches for thoracic tumors based on the quality of life assessment and pulmonary function tests helps in planning early intervention if needed, especially in those who have undergone thoracotomy with rib resections, thereby improving their long-term functional status.

Синдром крыловидной лопатки

Since A. Velpeau [1] first described a case of isolated paralysis of the anterior serratus muscle leading to the development of winged scapula syndrome, it has been shown that this lesion leads to shoulder joint dysfunction and the development of pain syndrome. Correct movement and positioning of the scapula relative to the rib cage is essential for proper shoulder joint function and positioning of the upper extremity in space. Weakness and loss of biomechanics of scapula motion leads to difficulty in lifting the upper extremity as well as lifting weights. According to the literature, the most common causes of winged scapula syndrome are injuries of the long thoracic nerve (paralysis of the anterior serratus muscle) and the spinal accessory nerve (paralysis of the trapezius muscle). The number of cases of anterior serratus muscle paralysis ranges from 0.0026 to 0.21% [2]. Most authors focus on nerve damage leading to paralysis of the anterior dentate and trapezius muscles. However, in 1930, S. Fichet described the development of winged scapula syndrome as a result of traumatic detachment of the muscles surrounding the scapula [3]. Traumatic detachment of the anterior serratus, trapezius, and rhomboid muscles is an important and understudied problem leading to shoulder joint dysfunction and development of winged scapula. The aim of the review is to study the main injuries leading to the development of wing-shaped scapula syndrome, as well as the main methods of diagnosis and treatment of this pathology.

Ultrassom diafragmático após manobra de estabilização costal manual em recém-nascidos prematuros: ensaio clínico

Abstract Introduction The manual rib cage stabilization maneu-ver (MRCSM) is a physical therapy intervention that promotes stabilization of the zone of apposition of the diaphragm, facilitating the contraction of this muscle and the work of breathing. Objective To evaluate by diaphragm ultrasound the diaphragmatic excursion in premature newborns before and after MRCSM. Methods Before-after clinical trial assessing by diaphragm ultra-sound the effectiveness of MRCSM in the amplitude of diaphragmatic excursions. Results The study sample consisted of 48 premature newborns born at a mean gestational age of 33.0 ± 2.8 weeks with a mean birth weight of 1,904.1 ± 708.9 grams. The newborns were classified in three groups: without respiratory distress syndrome (RDS; n = 26), with RDS (n = 15) and with apnea (n = 7) as a cause of admission to the neonatal intensive care unit (NICU). The measurements of diaphragmatic excursion and thickening were similar in newborns without or with RDS or apnea and there was a significant increase in the amplitude of diaphragmatic excursions after MRCSM (p &lt; 0.001; effect size &gt; 0.68) and less diaphragmatic thickening at exhalation in all of them. The diaphragm thickening fraction was 0.50 (0.33 - 0.72), and the diaphragm thickening rate was 0.04 (0.03 - 0.07). These measurements showed no significant variation with the presence or absence of RDS or apnea (p &gt; 0.05). No significant variations in heart rate (p = 0.30), respiratory rate (p = 0.79), and peripheral oxygen saturation, consid-ering newborns in ambient air (p = 0.17) compared with baseline. Conclusion The MRCSM was effective, safe, and increased the amplitude of diaphragmatic excursion and thickness in premature newborns at one week of age, regardless of the presence or absence of RDS or apnea as a cause of admission to the NICU.

Military Clinical Strategist to International Health Investor.

Virtual reality (VR) is emerging as a groundbreaking tool in the treatment of congenital heart diseases. This innovative technology offers a transformative approach by creating immersive, interactive, and personalized environments for both patients and healthcare professionals. In the pediatric cardiology institute in Safra Children's hospital in Sheba Medical Center in Israel, VR is being utilized for patient education, pre-operative planning, and intraoperative guidance. Patients can explore 3D visualizations of their own hearts, gaining a better understanding of their condition and proposed treatments. Surgeons and medical teams benefit from VR simulations that enhance their surgical planning and decision-making processes observing complex cases and evaluating printed models. Furthermore, Augmented reality AR can be employed in the operating room for observing the rib cage and reviewing the patient anatomy. The 3D visualization program is led by the Engineering in Medicine (EiM) tech-lab which cooperates with different specialties in the hospital including plastic surgery, ENT, ObGyn and more. The most critical topic addressed by the lab, cooperating with engineers from the Israeli Institute of technology deals with registration of the holographic image on the real patient body allowing intra-operative guidance. (Presented at the 2008th Meeting, September 27, 2023).

Clinical-epidemiological evaluation of victims of thoracic trauma in a reference hospital in Aracaju-SE.

thoracic trauma is defined as anything that involves the rib cage, the musculoskeletal framework that houses the heart, lungs, pleurae and mediastinal structures. It can be superficial or immediately lifethreatening for victims. In Brazil, most assistance is due to urban violence. evaluate the clinical and epidemiological aspect of patients who are victims of thoracic trauma treated at Hospital de Urgência de Sergipe, Aracaju/SE, Brazil. cross-sectional, observational and prospective study, carried out for eleven months, with 100 polytraumatized patients. A semi-structured form was applied, and the data were systematized, analyzed and statistically tested considering a 5% margin of error. Results: 85% of the patients were male, with a mean age of 39.3 and an age range of 30 to 49 years; 57% of them had incomplete primary education, 70% had a family income of up to 2 minimum wages and 41% were from Greater Aracaju. As for the mechanism of trauma, 33% were car-related, with blunt trauma as the main mechanism, and rib fractures as the main consequence. Among penetrating injuries, CWI (26%) and GSW (21%) were the most prevalent, with hemothorax being the main consequence. Most patients underwent thoracostomy (59%). the profile found was of young men, victims of urban violence. The thoracostomy was resolving in most cases and should be instituted promptly when necessary. A smaller number of patients may require thoracotomy, especially in the presence of hemodynamic instability.

Effect of Neck Rehabilitation Exercise and Breathing Exercise on Visual Complaints in Individuals with Idiopathic Chronic Neck Pain

Background: Neck pain is one of the most common musculoskeletal disorders and a leading cause of disability. Chronic neck pain causes hyperalgesia in soft tissues around the neck, and in severe cases, it leads to restriction of daily life activities. The excessive stress caused by the chronic pain leads to cervico-ocular gain, leading to a mismatch of reflexes that determine the gaze and vision. Chronic neck pain also alters the cervicothoracic kinematic change and length-tension changes in neck muscles and leads to decreased thoracic cage mobility. This leads to respiratory insufficiency in patients with chronic neck pain, which is similar to the changes that occur in cases of a neuromuscular disorder. Objective: The objective of this study was to find the effect of neck rehabilitation exercises and breathing exercises on visual complaints in individuals with idiopathic chronic neck pain. Materials and Methods: Thirty individuals with idiopathic chronic neck pain of both sexes ranging from 20 to 35 years were included according to the selection criteria and divided into two groups. Group A (n = 15) received the intervention for neck pain, whereas Group B (n = 15) did not receive any interventions. Outcome Measures: Neck disability Index, Visual Complain Index and NPRS are used as outcome measures. Results: Statistical analysis was done using SBM SPSS software version 20, which showed that there was a significant improvement in NDI in the experimental group (P &lt; 0.05). Conclusion: This study concludes that there is a significant effect of neck rehabilitation exercises and breathing exercises on visual complaints in individuals with idiopathic chronic neck pain.

Перспективы использования дыхательных тренажёров у больных с травматическими повреждениями

Chest injuries sustained during armed conflict have a high mortality rate and are accompanied by pulmonary dysfunction. Pulmonary contusion is manifested by rupture of pulmonary parenchyma, atelectasis, and hemorrhages in pulmonary parenchyma. The treatment strategy for such patients includes anesthesia, management of acute respiratory failure, treatment of infectious complications, sanation of airways, and rehabilitation measures. One of the goals of such interventions is the elimination of respiratory biomechanics disorders. It is recommended to use respiratory exercisers with a threshold level of resistance for the process of inhalation and exhalation to train respiratory muscles. At the Main Military Clinical Hospital named after N.N. Burdenko the possibility of application of the respiratory simulator "Universal-2011" as a therapeutic physical training tool in the hospital phase of treatment of patients with thoracic trauma was studied. The efficacy of the carried activities was evaluated by functional tests of tolerance to hyper- and hypocapnia of Stange and Gench and the assessment of thoracic cage excursion. The experience of using a respiratory exerciser was observed to be positive. All 25 patients fulfilled the planned program with the achievement of improvement of external respiratory function and exercise tolerance.

Optimization of heat transfer in mist/steam cooled square channel with kink angled rib turbulator

Optimization of heat transfer in mist/steam cooled square channel with kink angled rib turbulator

True Neurogenic Thoracic Outlet Syndrome with Elongated C7 Transverse Processes in a Hemiplegic Patient: A Case Report

Thoracic outlet syndrome (TOS) is caused by the compression of neurovascular structures in the thoracic cage. TOS can be classified into neurogenic TOS (NTOS) and vascular TOS. Congenital anomalies, such as cervical ribs and elongated C7 transverse processes, may be the cause of NTOS. NTOS can be subcategorized as either disputed NTOS or true NTOS. True NTOS, a very rare disease with a prevalence of about one in a million, is diagnosed by the weakness and atrophy of T1-innervated intrinsic muscles of the hand and corresponding electrodiagnostic abnormalities. We report a case of a 42-year-old patient, who presented with a 5-year history of clumsiness and 1 1-year history of weakness and atrophy in her right hand. The patient was diagnosed with true NTOS during comprehensive rehabilitation, which she received for left hemiplegia due to intracranial hemorrhage. Elongated bilateral C7 transverse processes were found on a radiological evaluation. True NTOS is often overlooked or mistaken for carpal tunnel syndrome, thus delaying the diagnosis and inevitably worsening outcomes. Therefore, an electrodiagnostic study is crucial for detecting true NTOS, rather than typical physical examinations such as the Roos stress test and Adson’s test.

Clinico–anatomical characteristic of the traffic trauma in the megapolis environment.Second report: anatomical verification of injuries

Objective.Verification of clinic–anatomical characteristics of trauma as a consequence of traffic accident in the megapolis environment.&#x0D; Materials and methods. Retrospective analysis of the data obtained was conducted in 1159 injured persons, who were traumatized as a consequence of a traffic accident in megapolis.&#x0D; Results.There was established, that as a result of traffic accident in the megapolis environment, the injured persons most frequently obtained trauma of the head – 68.31%, of thoracic cage – 57.07%, and of the extremities – 53.99%. The majority of the injured persons survived have had the trauma of the head (67.13%), of the thoracic cage (55.74%) and extremities (53.63%), while mostly rare – pelvic trauma (15.70%). Among the injured persons, who died, the head injuries was noted in 94.0%, thoracic trauma – in 86.0%, and abdominal injuries – in 76.0%.&#x0D; Conclusion.Trauma as a consequence of traffic accident in the megapolis environment constitutes a multicomponent injury (2.4 damages in every injured person). The result of the traumatic process course depends on the injury composition (in the injured persons survived, the combination coefficient was 2.3, while in the dead – 3.8) and on damage of a certain anatomic–functional local site.The head, thoracic and pelvic sites have constituted the most dangerous localizations.

Compound heterozygous splicing variants in KIAA0586 cause fetal short-rib thoracic dysplasia and cerebellar malformation: Use of exome sequencing in prenatal diagnosis.

Short-rib thoracic dysplasia (SRTD) and Joubert syndrome (JS) are rare genetic ciliopathies, and individuals with either syndrome can manifest cerebellar malformation and variable developmental delays. However, neither of these conditions is easily diagnosed during pregnancy due to a limited fetal phenotype. Here, we investigated a fetus that was initially observed to have short limbs and polydactyly and discovered a compound heterozygous pathogenesis through exome sequencing (ES). Simultaneous trio-ES and chromosome microarray analysis was provided for the fetus. The presence and effects of these variants on splicing were further validated at the DNA and RNA levels. Only short limbs and post-axial polydactyly of the fetus were detected during the second trimester. Two variants (c.3940+1G>A and c.3303G>A), affecting splicing of KIAA0586, were identified from amniocytes through ES and validated by Sanger sequencing. More intensive fetal monitoring was applied, and the fetus was also found to have deformed cerebellar malformation and a constricted thoracic cage. Herein, we report the genetic pathogenesis of SRTD and/or JS associated with KIAA0586 in a fetus. The novel splicing variants observed expand the spectrum of KIAA0586 in SRTD and/or JS. Based on the genetic data and the distinct corresponding phenotypes discovered by imaging examination, a comprehensive diagnosis was made during pregnancy and more valuable prognostic information was provided for the parents.

Automatic 3D CT liver segmentation based on fast global minimization of probabilistic active contour.

Automatic liver segmentation from computed tomography (CT) images is an essential preprocessing step for computer-aided diagnosis of liver diseases. However, due to the large differences in liver shapes, low-contrast to adjacent tissues, and existence of tumors or other abnormalities, liver segmentation has been very challenging. This study presents an accurate and fast liver segmentation method based on a novel probabilistic active contour (PAC) model and its fast global minimization scheme (3D-FGMPAC), which is explainable as compared with deep learningmethods. The proposed method first constructs a slice-indexed-histogram to localize the volume of interest (VOI) and estimate the probability that a voxel belongs to the liver according its intensity. The probabilistic image would be used to initialize the 3D PAC model. Secondly, a new contour indicator function, which is a component of the model, is produced by combining the gradient-based edge detection and Hessian-matrix-based surface detection. Then, a fast numerical scheme derived for the 3D PAC model is performed to evolve the initial probabilistic image into the global minimizer of the model, which is a smoothed probabilistic image showing a distinctly highlighted liver. Next, a simple region-growing strategy is applied to extract the whole liver mask from the smoothed probabilistic image. Finally, a B-spline surface is constructed to fit the patch of the rib cage to prevent possible leakage into adjacent intercostaltissues. The proposed method is evaluated on two public datasets. The average Dice score, volume overlap error, volume difference, symmetric surface distance and volume processing time are 0.96, 7.35%, 0.02%, 1.17 mm and 19.8 s for the Sliver07 dataset, and 0.95, 8.89%, , 1.45 mm and 23.08 s for the 3Dircadb dataset,respectively. The proposed fully-automatic approach can effectively segment the liver from low-contrast and complex backgrounds. The quantitative and qualitative results demonstrate that the proposed segmentation method outperforms state-of-the-art traditional automatic liver segmentation algorithms and achieves very competitive performance compared with recent deep leaning-basedmethods.

Non-invasive assessment of fatigue and recovery of inspiratory rib cage muscles during endurance test in healthy individuals.

Fatigue is defined as loss of capacity to develop muscle force and/or velocity that is reversible at rest. We assessed non-invasively the fatigue and recovery of inspiratory rib cage muscles during two respiratory endurance tests in healthy individuals. The sniff nasal inspiratory pressure (SNIP) was assessed before and after two respiratory endurance tests: normocapnic hyperpnea (NH) and inspiratory pressure threshold loading (IPTL). Contractile (maximum rate of pressure development and time to peak pressure) and relaxation parameters (maximum relaxation rate [MRR], time constant of pressure decay [τ], and half relaxation time) obtained from sniff curves and shortening velocity and mechanical power estimated using optoelectronic plethysmography were analyzed during SNIP maneuvers. Respiratory muscle activity (electromyography) and tissue oxygenation (near-infrared spectroscopy-NIRS) were obtained during endurance tests and SNIP maneuvers. Fatigue development of inspiratory rib cage muscles was assessed according to the slope of decay of median frequency. Peak pressure during SNIP decreased after both protocols (p <0.05). MRR, shortening velocity, and mechanical power decreased (p <0.05), whereas τ increased after IPTL (p <0.05). The median frequency of inspiratory rib cage muscles (i.e., sum of sternocleidomastoid, scalene, and parasternal) decreased linearly during IPTL and exponentially during NH, mainly due to the sternocleidomastoid. Fatigue development behaved differently between protocols and relaxation properties (MRR and τ), shortening velocity, and mechanical power changed only in the IPTL.