Yawning is a stereotyped orofacial-respiratory behaviour whose physiological role remains uncertain. Because cerebrospinal fluid (CSF) movement contributes to solute transport and waste removal and is strongly influenced by respiratory pressure dynamics, the study evaluated whether contagious yawning alters neurofluid flow relative to normal and gaping deep breathing, and whether contagious yawning kinematics are reproducible within individuals. In a single MRI session in healthy adults, real-time phase-contrast imaging at the upper cervical level (C3) was combined with mid-sagittal real-time cine imaging to quantify CSF and internal jugular venous flows during normal breathing, forceful oral inspirations (gaping deep breaths), yawns, and stifled yawns, and to derive tongue-motion trajectories. Both gaping deep breaths and yawns increased CSF and venous flow compared with normal breathing; despite similar flow magnitudes, yawns more frequently produced co-directional caudal CSF and jugular outflow during inspiration, whereas gaping deep breaths typically showed counter-directional CSF-venous flow. Contagious yawning also elicited a marked internal carotid inflow increase (up to 43%) during the gaping/early expiratory phase that was not apparent during both deep and normal breathing. Yawning kinematics were highly reproducible within individuals across repeated events, indicating a stable motor sequence consistent with brainstem pattern-generator control. These observations show that yawning is not simply an intensified breath but a distinct cardiorespiratory manoeuvre that reorganizes neurofluid flow. The inspiratory alignment of CSF with venous outflow during yawns suggests a transient caudal advection that could influence solute transport and heat exchange within the cranial-cervical system, motivating targeted mechanistic studies with simultaneous airway pressure, thoraco-abdominal motion, and cervical venous pressure measurements.

Muscle forces are difficult to measure in vivo, so the force-generating capacity of muscles is commonly inferred from muscle architecture. It is often assumed, implicitly or explicity, that a muscle’s maximum force-generating capacity is proportional to physiological cross-sectional area (PCSA), and that a muscle’s operating range is proportional to mean optimal fascicle length. Here, we examined the effect of muscle architecture (PCSA and fascicle length) on muscle function (maximal isometric force and operating range) using a three-dimensional finite element model which accounts in a mechanically consistent way for muscle deformation and other complexities of muscle contraction. By varying architectural properties independently, it was shown that muscle force-generating capacity does not scale by the same factor as PCSA, and that operating range does not scale by the same factor as optimal fascicle length. For instance, 3-fold independent variation of mean optimal fascicle length caused the maximum isometric force-generating capacity of the muscle to vary from 83% to 105% of the force predicted by PCSA alone. Non-uniformities in fascicle length that develop as the muscle deforms during contraction reduce muscle force and operating range. Thus, a three-dimensional finite element model that satisfies fundamental physical constraints predicts that the maximum force-generating capacity of skeletal muscle depends on factors other than PCSA, and that operating range depends on factors other than optimal fascicle length. These findings have implications for how the force-generating properties of animal muscles are scaled to human muscles, and for how the functional capacity of muscles is predicted from muscle architecture.

How cerebrospinal fluid (CSF) circulates around the brain and spine is important to understand solute transport and the mechanisms of CSF flow disorders. It has recently been shown that respiratory-associated spinal CSF flows are influenced by intrathoracic and abdominal pressures, as well as by cranial blood volume. The mechanism of this remains unclear, and we hypothesise that differences in thoracic and lumbar pressures during respiration drive spinal epidural blood volume changes, which in turn drive CSF movement. We tested this hypothesis using a simple model of the whole spinal subarachnoid space (SSAS) and deformed the boundaries of the SSAS to simulate the effect of changes in epidural venous blood volumes. The model showed that the direction of cervical CSF flow depended on the relative difference in the volumes of the thoracic and lumbar SSAS. When the volume increase of the thoracic SSAS was the same or larger than the reduction of the lumbar SSAS, cervical CSF was drawn caudally, but when the change in thoracic SSAS was smaller, cervical CSF was displaced cranially. These models showed that the direction of cervical CSF flow was sensitive to small differences in the thoracic and lumbar SSAS. Since the SSAS volume change depends on the intrathoracic and abdominal pressures that drive venous blood through the epidural veins, these models suggest that respiratory manoeuvres that produce a large pressure gradient across the diaphragm are more likely to draw CSF caudally from the cranium into the SSAS.

BACKGROUND:In March 2010, New South Wales (NSW), Australia, introduced legislation mandating age-appropriate restraints for child passengers up to 7 years. This study aims to evaluate its impact on child injury rates using linked hospital and death data. METHODS:An interrupted time series using random effects quasi-Poisson regression analysed hospital-admitted injury rates in child passengers (0-14 years) in NSW, Australia, from July 2001 to March 2019. Hospital administration data were divided into prelegislation, legislation and postlegislation periods, with the legislative period spanning November 2007 to December 2011, accounting for a 6-month adaptation and enforcement grace period. RESULTS:Injury rates in children under 14 were reduced postlegislation compared with prelegislation. The average injury rate was 33% lower for children directly affected by the legislation (aged 1-6 years, incidence rate ratio (IRR)=0.67, 95% CI: 0.57 to 0.79), 25% lower for children aged 7-10 years (IRR=0.75, 95% CI: 0.65 to 0.85) and 20% lower for children aged 11-14 years (IRR=0.80, 95% CI: 0.68 to 0.94). Compared with children aged 11-14, the injury rate for other age groups decreased, though with large uncertainty in these estimates. CONCLUSIONS:The findings suggest a decrease in injuries among child passengers following legislation mandating age-appropriate restraints up to 7 years. However, similar reductions among older children and substantial uncertainty in estimates using the oldest children as controls limit attribution of the effect solely to the legislation. Combined with observational studies showing increased restraint use among children under 12 years old, the results indicate an overall postlegislation improvement in child passenger safety in NSW, Australia.

Measurements of muscle architecture are crucial for understanding muscle function but are often difficult to obtain in human muscles in vivo. This study aimed to create population-averaged atlases of human rotator cuff muscle shape and muscle fibre orientations from anatomical magnetic resonance images (MRI) and diffusion-weighted images (DWI) and to utilise these atlases to predict muscle fibre orientations from anatomical MRI data alone. An image registration framework was applied to coregister anatomical MRI and DWI data of 11 male and 9 female subjects into sex-specific common spaces, forming the basis for the atlases. The accuracy of registration was quantified using Dice coefficients, angular correlation coefficients (ACCs) and angular differences. The same metrics were used to assess the capability of the atlases to predict fibre orientations for subjects not included in the atlas construction, via leave-one-out cross-validation. The results showed that individual male and female image data were accurately registered into their respective atlas spaces, with high Dice coefficients (0.888 ± 0.002 for males, 0.856 ± 0.021 for females) and consistent angular alignment as evidenced by the ACCs and angular differences. Predicted fibre orientations for out-of-sample subjects closely matched those derived from DWI images, exhibiting improved smoothness and coverage (ACC: 0.909 ± 0.011 for males, 0.942 ± 0.011 for females; angular difference: 13.8° ± 1.3° for males, 11.2° ± 1.2° for females). These findings demonstrate that population-averaged atlases enhance muscle architecture reconstructions and enable the accurate prediction of muscle fibre orientations using only anatomical MRI scans in younger individuals without shoulder injuries.

Diagnosis of a glioblastoma (GBM) brain tumor is associated with very poor prognosis. Currently, few preclinical models used to identify new therapies address the soft brain tissue environment and GBM mechanoresponses, which are implicated in disease progression. Understanding the GBM biomechanical landscape is critical to deriving improved preclinical models and magnetic resonance elastography (MRE) holds promise to address this gap. Due to technical and feasibility issues for MRE of patient tumors at scale, most studies only report on small cohorts of patients, thus limiting the conclusions that may be drawn from individual studies. To thus gain a better overview, we have undertaken a systematic review and meta-analysis of the reported tissue viscoelastic property values from studies of both healthy brain and brain tumors, with a particular focus on delineating measurements relative to MRE transducer vibration frequency. Based on these analyses, healthy white matter consistently appears stiffer than gray matter. Further, analyses of pooled healthy brain tissue measurements vs human GBM suggested that, overall, the GBM has the same stiffness as the surrounding healthy tissue. This contrasted with mouse models of GBM, where the tumors appear softer than brain tissue. The limited number of studies of human GBM in situ is a caveat to these conclusions and MRE analyses of larger GBM patient cohorts are urgently needed. Meanwhile, the information from this analysis can be used to guide engineering of improved preclinical models with features that recapitulate the in vivo brain tissue environment.

Chiari malformation is characterised by the herniation of the cerebellar tonsils through the foramen magnum. It is commonly assumed that the tonsils obstruct normal cerebrospinal fluid (CSF) flow, resulting in cough-associated headaches. However, the mechanisms that cause these headaches are unknown, leading to varied and often unsatisfactory treatment outcomes for patients with Chiari. In this study real-time phase contrast MRI (PC-MRI) was used to determine whether the tonsils restrict CSF flow during coughs, and shape models of the posterior fossa were used to identify morphological differences between patients with and without cough headache. Twenty Chiari patients with cough headache, seven without, and twelve age and sex matched controls underwent MR imaging of the head and neck. 3D models of the hindbrain, CSF and vertebrobasilar arteries were constructed from T1-weighted MRI. PC-MRI was collected at the foramen magnum and mid-C3 to measure CSF flow, plus arterial and venous flow. The shape models showed that the CSF space anterior to the pons was narrower in Chiari patients than in controls. Additionally, the CSF space around the vertebrobasilar arteries was more restricted in patients with cough headache than those without. The flow of CSF across the foramen magnum was not restricted, and CSF velocities were ∼2 times greater in Chiari patients than in controls. These findings suggest that overcrowding of the posterior fossa creates high velocity CSF flow across the pons, medulla, and vertebrobasilar arteries. This high velocity flow through the restricted CSF space may stress the cranial vasculature and contribute to headache.

BACKGROUND:Premature graduation to an adult seatbelt is common and detrimental to optimal crash protection. While there is an existing tool (the 5-step test) to support a parent's decision to graduate their child, its effectiveness is unknown. The aim of this study was to evaluate the 5-step test. METHOD:A randomised controlled design was used. Participants were parents of children aged 7-12 years. After exposure to information about the 5-step test or control material, participants assessed belt fit in three seating conditions and 'thought aloud' while making their assessment. Seating conditions provided a good, poor and partially good seatbelt fit based on the child's anthropometry. Participants were also assessed on their knowledge of good seatbelt fit criteria. RESULTS:Participants exposed to the 5-step test (n=18) had significantly improved their knowledge of the criteria required to achieve good seatbelt with, on average, 1.0 higher score in the 6-point assessment (95% CI 0.23 to 1.7, p=0.012) than those in the control group. There was also a greater percentage of participants in this group (44.4% intervention vs 27.8% control) who made accurate decisions about seatbelt fit, but this difference did not reach significance (OR 2.08, 95% CI 0.52 to 8.34). CONCLUSION:The results demonstrate that the 5-step test is effective in improving knowledge but are inconclusive about its effectiveness in promoting accurate decision-making. However, the proportion of participants making accurate decisions in the intervention group remained low. This suggests that parents may require greater assistance than what is currently provided.

The tongue is a muscular hydrostat whose complex fibre architecture enables its diverse functions in swallowing, speech, and breathing. Current understanding of the tongue's structure is largely based on ex vivo dissections, which are not directly linked to function. This study aimed to develop an anatomical atlas of the living human tongue incorporating detailed muscle architecture. The pharynx of 20 healthy volunteers (10 females) were imaged with 3T MRI, collecting mDIXON and diffusion-weighted images (DWI). Multichannel registration was used to align scans from individual participants into a common spatial reference frame to create a population-averaged tongue atlas. The atlas was able to reliably predict tongue muscle architecture of tongues not used in atlas construction, although accuracy varied with the image types used. The best performance, assessed with a local angular correlation coefficient (LACC), was achieved when both anatomical (mDIXON) and diffusion-weighted images were used (LACC = 0.66 ± 0.04; p ≪ 0.001), but acceptable accuracy was achieved when only anatomical images were used (LACC = 0.52 ± 0.04; p ≪ 0.001). Principal component analysis of a tongue statistical shape model based on the atlas identified that the largest source of variation in tongue muscle architecture was related to the position of the hyoid relative to the mandibular plane. A lower hyoid was more common in males (M: 13 mm, F: 9 mm; p = 0.009). This new atlas of in vivo tongue muscle architecture provides a new understanding of the relationships between the muscles and bony structures that may enable more accurate simulation of human living tongue function.

OBJECTIVE:Many children with physical disabilities need additional postural support when sitting and supplementary padding is used on standards approved child restraints to achieve this when traveling in a motor vehicle. However, the effect of this padding on crash protection for a child is unknown. This study aimed to investigate the effect of additional padding for postural support on crash protection for child occupants in forward facing child restraints.METHODS:Forty frontal sled tests at 49 km/h were conducted to compare Q1 anthropometric test device (ATD) responses in a forward-facing restraint, with and without additional padding in locations to increase recline of the restraint, and/or support the head, trunk and pelvis. Three padding materials were tested: cloth toweling, soft foam, and expanded polystyrene (EPS). The influence of padding on head excursion, peak 3 ms head acceleration, HIC15, peak 3 ms chest acceleration and chest deflection were analyzed.RESULTS:The influence of padding varied depending on the location of use. Padding used under the restraint to increase the recline angle increased head injury metrics. Toweling in multiple locations which included behind the head increased head excursion and chest injury metrics. There was minimal effect on injury risk measures with additional padding to support the sides of the head or the pelvis position. Rigid EPS foam, as recommended in Australian standards and guidelines, had minimal effect on injury metrics when used inside the restraint, as did tightly rolled or folded toweling secured to the restraint at single locations around the body of the child.CONCLUSIONS:This study does not support the use of postural support padding to increase recline of a forward-facing restraint or padding behind the head. Recommendations in published standards and guidelines to not use foam that is spongy, soft or easily compressed, with preference for secured firm foam or short-term use of tightly rolled or folded toweling under the child restraint cover is supported. This study also highlights the importance of considering the whole context of child occupant protection when using additional padding, particularly the change in the child's seated position when adding padding in relation to the standard safety features of the restraint.

Abstract Introduction A novel therapeutic application of optogenetic stimulation as a treatment for Obstructive Sleep Apnea (OSA) requires stimulation of the pharyngeal muscles synchronously with the onset of inspiration to maintain airway patency during sleep1. A sensor array in a removable oral appliance was developed to monitor physiological data; photoplethysmography, acceleration, temperature and audio to predict respiratory airflow. This could then deliver correctly timed stimulation pulses coinciding with inspiration onset as part of a potential therapy. Methods Twenty participants underwent daytime respiratory monitoring (flow, volume and mask pressure) with concurrent monitoring using the oral sensor appliance. Participants were coached to perform multiple breathing patterns; spontaneous, fast and slow breathing, apneas, coughs and snores in supine, left and right-side sleeping positions. Sensor data was used to train a Long Short-Term Memory (LSTM) deep learning model against airflow data to predict respiration waveforms. Results A LSTM deep learning model was trained on over 24,000 seconds of physiological data from the 20 participants to predict respiratory waveforms. The model successfully predicted 5-second respiratory waveforms from the preceding 10 seconds of physiological data with acceptable accuracy (Mean Squared Error = 0.078, Root Mean Squared Error = 0.278), enabling real-time targeted optogenetic stimulation timing. Discussion This study establishes a proof of concept for using an oral sensory appliance in conjunction with optogenetic therapy for OSA. Furthermore, the sensor array demonstrates promise as a potential platform for vital sign and sleep monitoring within the oral cavity.

Objective Incorrect use of child restraints is a long-standing issue, limiting the protection offered by child restraints in the event of a crash. Child restraint fitting services are a measure to reduce incorrect use but have limited reach and availability to underserved populations. Virtual child restraint fitting services have the potential to increase the reach and availability, but as with any digital intervention, need to be acceptable to users to be effective. The acceptability of such interventions has not been studied before. Methods Using a three-arm randomized controlled trial, this study evaluated the acceptability of: (1) a video with child restraint fitting advice (Control), (2) a traditional in-person child restraint fitting service (In-person), and (3) a virtual child restraint fitting service (Virtual). Additionally, the effectiveness in reducing incorrect use was evaluated. Results There was a significantly higher level of overall acceptability for the in-person service, and significantly fewer errors in child restraint use in this group compared to the control. There were no significant differences in overall acceptability or errors between the virtual service and the control. However in-depth analysis of the constructs of acceptability demonstrated participants in the in-person and virtual service groups held similar views on four of the seven constructs including the usefulness of the services and the impact of the service on comprehension of key information for correct restraint use. Areas where the views differed between these groups included perceived burden, appropriateness, and opportunity costs. Qualitative feedback suggested these negative perceptions on the virtual service may be remediated with some improvements to the technology. Conclusions Overall, child restraint fitting services provided virtually show promise as an alternative to in-person but attention to how services are provided via this technology, together with technology improvement, might be needed to fully realize its potential.

Abstract Introduction Inspiratory-related genioglossus electromyography (EMG) activity is crucial to maintain upper airway patency during inspiration. Recent findings suggest variations in anterior/posterior genioglossus multiunit EMG activation during awake supine quiet breathing in healthy adults. However, whether such differences extend to EMG across oblique (middle) and horizontal (base) genioglossus compartments, and whether activation differ in obstructive sleep apnoea (OSA) is unclear. Methods Prior to in-lab polysomnography, intramuscular electrodes were placed into the horizontal and oblique compartments of the genioglossus in 9 controls (AHI≤5 events/hr) and 45 age- and BMI- matched OSA patients (AHI range 5-94.3 events/hr). Multiunit EMG patterns were classified as phasic or tonic during awake supine quiet nasal breathing. Phasic pattern recordings were quantitatively analysed (% maximum of swallowing or tongue protrusion). The effects of OSA status and genioglossus compartments were assessed through mixed linear analysis, controlling for nadir Pepi and repeated measures in participants. Results More than half (57.6%, n=106/184) of the recording sites had a phasic pattern. A more negative nadir Pepi correlated with reduced likelihood of tonic activity (OR: 0.819, P=0.042). Within phasic patterns, a more negative nadir Pepi correlated with increased peak EMG (beta=-0.847, P=0.011), phasic EMG (beta=-0.654, P=0.005), and tonic EMG (beta=-0.253, P=0.048). No significant effects of OSA status or genioglossus compartment on activity patterns or EMG measurements were observed. Conclusions No compartmental disparity in EMG or differences between OSA and non-OSA individuals were found. Understanding mechanisms driving efficient dilatory activity of the genioglossus compartments is pivotal to develop OSA treatments targeting pharyngeal muscle activity.

Abstract Introduction Obstructive sleep apnoea (OSA) patients are often sub-optimally treated due to poor tolerance and/or incomplete responses to established therapies. Our novel therapy sensitises upper airway muscles to light (optogenetics) and allows their activation during sleep. Previous work has demonstrated that an adeno-associated viral vector (AAV) driven by a muscle-specific promoter produces strong expression of light-sensitive proteins (opsins) in the tongue, and strong light-evoked muscle activation 3-weeks after administration. Here we determine whether this response persists over 12-weeks, and whether immunosuppression is required. Methods Rats received intralingual injections of the AAV. After 12-weeks, opsin expression in the tongue was quantified via confocal imaging. Light-evoked muscle activation was recorded in a model of sleep-associated muscle hypotonia. This was repeated in three additional groups of animals. Group 1 received rapamycin (4 mg/kg/day) and cyclosporin (5 mg/kg/day), group 2 received prednisolone (1 mg/kg/day, tapering 10%/week from week 9), and group 3 received daily vehicle intrapleural injections. Results Without immunosuppression, opsin expression decreased ~4-fold in the tongue between 3- and 12-weeks post-AAV administration (two-way RM ANOVA, p=0.01). Subsequently, light-evoked muscle-activation also declined (linear mixed model, time*stimulation, p<0.001). With rapamycin/cyclosporin administration, light stimulation at 12-weeks was able to increase muscle-activation ~2-fold (p<0.001). Prednisolone and vehicle administration did not facilitate light-evoked muscle-activation at 12-weeks (p>0.05; LMM, group*stimulation p<0.001). Discussion Rapamycin/cyclosporin administration allows persistent opsin expression and light-evoked muscle activation. As all existing clinically approved AAV-mediated gene therapies require initial immune suppression, this requirement is not a barrier to clinical translation of an optogenetics-based therapy for OSA.

Abstract Introduction Nocturnal swallowing and cortical arousals from sleep both produce rapid transient heartrate increases driven by autonomic activation. Obstructive Sleep Apnoea (OSA) is associated with autonomic dysfunction and cardiovascular diseases, however, the underpinning mechanisms remain unclear. Here, we examine autonomic activation associated with swallowing and arousals during sleep in OSA. Methods Overnight sleep with epiglottic pressure data from a previous study were analyzed using custom semi-automated analysis scripts to extract variables for swallows and arousals during sleep. The following variables were extracted: average heartrate 30 seconds prior to a swallow or arousal and, peak heartrate 10 seconds afterwards, plus data on associated arousals and arousal duration, respiratory events preceding the swallow(s). Results 53 datasets were analyzed, including 6 controls, 12 mild, 17 moderate and 18 severe OSA subjects, in total: 2794 swallows and 9147 arousals. Across all samples, heartrate elevation was greater when swallows occurred in close succession (21.4bpm vs 14.7bpm, p<0.0001). Arousals with swallows produced larger heartrate elevations (17.0bpm vs 10.7bpm, p<0.0001) and prolonged duration by 6 seconds compared to arousals without swallows. Arousals during Rapid Eye Movement (REM) sleep also produced a higher heartrate increase (16.4bpm vs 12bpm, p<0.0001). Notably, the severe OSA group exhibited reduced magnitude of swallow and arousal heartrate increases (18.4bpm vs 22.3bpm and 11.9bpm vs 12.9bpm, p<0.0001). Discussion Individuals with severe OSA exhibited diminished magnitude of heartrate elevation responses to swallows and arousals. This finding potentially advances our comprehension of the underlying mechanisms of OSA with association with cardiovascular diseases.

Background Transitioning a child prematurely from a booster seat to the vehicle seat with seatbelt is prevalent worldwide. This type of inappropriate restraint use can worsen the severity of injuries of children in a motor vehicle crash. Despite the availability of the 5-step test (a tool to aid parents in making transition decisions), there is a lack of research on its effectiveness in changing practice. The objective of this study was to evaluate the effectiveness of the 5-step test. Methods To assess the 5-step test, a randomised controlled design was employed. The study compared parents exposed to the 5-step test (intervention group) vs. legal requirements (control group). All resources were provided in written form. After exposure, parents were asked to evaluate the suitability of an adult seatbelt when observing their child (aged 7–12 years) in three distinct belt fit conditions: good, poor, and partially good fit. Parents were prompted to verbalise their thought processes while making the evaluation and were assessed on their knowledge regarding good seatbelt fit criteria. Results Participants exposed to the 5-step test (n=18) showed a statistically significant improvement in their understanding of the criteria for achieving a good seatbelt fit. On average, they scored 1.0 point higher on the 6-point assessment compared to the control group (95% CI 0.23–1.7, p=0.012). Despite this greater knowledge, there was no significant difference between the two groups' decisions about their child's seatbelt fit (OR 2.08, 95% CI 0.52–8.34). Qualitative analysis of the 'think aloud' data indicates that parents possess some understanding of how to accurately determine a safe seatbelt fit for their child, yet also demonstrate supplementary metrics influence their decision beyond information provided in the 5-step test. Conclusion The findings indicate that the 5-step test effectively enhances knowledge but offers inconclusive evidence regarding its ability to promote correct assessments about seatbelt fit. This implies that parents may need more support than is currently available, and merely grasping the essential criteria for safe seatbelt fit may not be sufficient for correct decision making. In future, user input should be incorporated into enhanced resources for parents guiding transition from booster seats.

Background In March 2010, new child restraint legislation was implemented in NSW, Australia which required child passengers up to the age of seven travelling in a motor vehicle to be restrained in an age-appropriate restraint. There is conflicting evidence for the impact of changes in legislation. Studies that fail to find reductions in injury may be limited due to short periods of follow-up, the types of datasets used, and use of methods that assume an abrupt, specified change time-point directly aligned with date of the law change. Objective To examine injury rates in child passengers before and after implementation of new child restraint legislation in NSW, Australia in March 2010, with a legislation time-period and a control group. Methods An interrupted time series (ITS) approach in SAS was used to investigate the trends in hospital admitted injury among children aged 0–14. The data used for this analysis was collected through linked administrative datasets between 1 July 2001 and 31 March 2019. Monthly injury admission number and rate were aggregated and adjusted to the population. The temporal data was split into three time periods: pre-legislation (July 2001 – October 2007), legislation (November 2007 – December 2011), and post-legislation (January 2012 – March 2019). Results Across the study period, there were 2940 injury cases. For each age group, 213 data-points/months over the study period were analysed. When comparing children aged 11–14 years and pre-legislation period, the injury rate for age-group zero, those 1–6 years, and 7–13 years reduced by 49% (IRR= 0.51, 95% CI= 0.12–2.12), 36% (IRR= 0.64, 95% CI= 0.30–1.37), and 37% (IRR= 0.63, 95% CI= 0.27–1.47), respectively, in the post-legislation period. Conclusions The lack of detailed information on the use of child restraints in each injury case, coupled with the small sample size of severe injury cases, may limit the conclusiveness of our findings. Future research analysing media and market reports could offer a more comprehensive understanding of the impact of legislation on child restraint usage at the population level.

Abstract Introduction Post COVID-19 neurological sequelae (popularly termed “Long COVID”), which include chronic sleep disruption and “brain fog” are widespread; however, studies have not yet comprehensively evaluated the concurrent effects of these disruptions of neurocognitive function and their relationship to sleep disturbance. Methods Participants aged between 40-65, with no more than 2 cardiovascular risk factors were stratified into three groups of ten: Group 1 (pre-pandemic datasets), Group 2 (individuals recovered from COVID-19), and Group 3 (individuals diagnosed with Long COVID under the WHO criteria). Polysomnography (PSG), Multiple Sleep Latency Test (MSLT), participant surveys and neurocognitive testing, among other data, were collected. Results Control group 1 included more participants (70%) with obstructive sleep apnoea (OSA) compared to the Long COVID group, resulting in a markedly greater arousal index (ANOVA p=0.03), but no significant differences in percentage of Slow Wave Sleep (SWS) and Rapid Eye Movement (REM) sleep were observed between all three groups (ANOVA p=0.29). The Long COVID group displayed heightened daytime sleepiness, based on MSLT, Epworth Sleepiness Scores, and fatigue severity scores (Group 2: 28±10 vs Group 3:44±11, unpaired t-test p=0.01). Discussion Initial observations suggest sleep architecture (proportion of SWS and REM sleep) in Long COVID does not differ from controls, however the reduced sleep latency and elevated subjective fatigue suggest dysfunction of sleep in Long COVID which needs to be further explored.

All children travelling in motor vehicles must be properly secured in a size-appropriate child restraint. However, for many children with a disability, standard child restraints are not suitable, and health professionals or caregivers modify restraints. There is however little data characterising these modifications. This study examined the modifications used to assist with the restraint of children aged 0-16 years with additional needs in motor vehicles. Two anonymous online surveys, one for caregivers and one for health professionals on child restraint use and modifications to seating for children with disabilities were undertaken. The quantitative and qualitative data were analysed with descriptive statistics. Eighty-six responses were analysed (40 caregivers and 46 health professionals). The majority (95.7%) of health professionals and 22.5 percent of caregivers reported having used modifications. Additional padding for postural support was the most frequently used modification (47.7% health professionals, 10% caregivers). Specialised harnesses were the most frequently used accessory used by health professionals (47.8%), with cross chest straps most frequently used by the surveyed caregivers (10%). Challenges for children with disabilities using compliant child restraints continue to persist, despite the use of modifications. There is also a lack of evidence on the impact of the modifications on restraint performance, potentially placing children at risk.

Abstract Introduction The pterygomandibular raphe (PMR) is an aponeurotic junction in the lateral upper airway soft tissue that may be an anatomical marker to predict mandibular advancement splint (MAS) treatment success (Brown et al. 2021). We evaluated the feasibility of a novel ultrasound (US) protocol to assess these lateral soft tissues, particularly PMR. Methods 31 participants (n=19(61.3%) female) with and without obstructive sleep apnoea (OSA) underwent lateral upper airway ultrasound. Inclusion criteria were age 18-75 years and previous polysomnogram. Eight participants also underwent MRI. The anatomical landmarks of PMR were measured. Results Participants were middle aged (56.5±15.9 years), overweight or obese (BMI 29.4±6.4 kg/m2) and had moderate OSA (mean AHI 24.4±21.7 events/hour). PMR was detected in all subjects. Submandibular gland depth (4.8±1.2 mm), US-PMR depth (18.1±3.0 mm) and US-PMR width (2.4±0.4 mm) were measured (n=31), and tonsil depth was recorded (n=24, 19.5±3.8 mm). US-PMR width measurements of OSA (n=24, 2.5±0.3 mm) and non-OSA (n=7, 2.5±0.6 mm) subjects were not different (p>0.05). MRI-PMR width values were similar (OSA 3.1±0.9 vs. non-OSA 2.5±1.5 mm, p>0.05). The width of MRI-PMR (2.7±1.2 mm) compared to and US-PMR (2.8±0.5 mm) was not significantly different (p>0.05). Discussion This research highlights the potential of US as a useful tool to study lateral upper airway tissues, particularly the PMR. We plan to correlate these findings in a larger number of participants who have undergone both MRI and US to demonstrate the sensitivity, specificity and clinical utility of US.