Background Knee ligament injuries are common in elite rugby union players and are associated with performance limitations. However, comparative data on long-term performance and career patterns after isolated anterior cruciate ligament (ACL) versus medial collateral ligament (MCL) injuries remain limited. Methods A retrospective review of elite rugby union players who sustained an isolated partial or complete ACL or MCL tear from 2013 to 2025 was performed. Data were collected from rugby databases and media reports, and included player demographics, injury characteristics, and performance metrics. A Wilcoxon signed rank test was used to compare pre-injury and post-injury performance metrics, with a p value < 0.05 determined as statistically significant. Results Twenty-eight players sustained ACL injuries and 23 sustained MCL injuries. At 9.8 ± 3.1 months, 96.4% of ACL-injured players returned to sport, while 100% of MCL-injured players returned at 1.9 ± 2.1 months. ACL-injured players demonstrated significant declines in games played, tries, and points scored in the season following injury. Over time, performance largely stabilized, but total seasons played decreased. Players with MCL injuries demonstrated short-term performance declines but played a. similar number of seasons before and after injury. Re-injury occurred in 17.9% of ACL cases and 13.0% of MCL cases, with greater re-injury frequency and shorter intervals between injuries in the ACL cohort. Conclusion ACL injuries in elite rugby union players were associated with longer return to sport (RTS) times and fewer post-injury seasons despite recovery of performance metrics. MCL injuries allowed faster RTS and preserved career length but were associated with decreased performance. Re-injury led to further performance decline in both cohorts. These findings highlight distinct patterns of career and performance impact following ACL versus MCL injury in elite rugby union players. Level of evidence IV

Background Management of moderate-to-large (1-2.9 cm 2 ) osteochondral lesions of the talus (OLT) remains challenging due to the transition from reparative to replacement surgical strategies and the absence of high-level comparative evidence guiding treatment selection. Methods An international panel of experts participated in a modified Delphi consensus process during the International Congress on Cartilage Repair of the Ankle (ICCRA) meetings held in 2017 and 2025. Survey rounds and structured discussions were used to generate and refine consensus statements. Consensus strength was categorized as consensus (51%-74%), strong consensus (75%-99%), or unanimous (100%), and levels of evidence were graded according to established criteria. Results Consensus statements were developed for autologous osteochondral transplantation (AOT), osteochondral allograft transplantation (OCA), scaffold-based cartilage restoration techniques, and emerging extracellular matrix and juvenile cartilage allograft strategies. Autologous osteochondral transplantation was supported as a primary treatment option for cystic, uncontained, and revision lesions, with emphasis on graft continuity and appropriate depth. Osteochondral allograft transplantation was recommended for larger or uncontained lesions and in cases where autograft is contraindicated, with preference for fresh, size-matched grafts used within 28 days. Scaffold-based techniques were identified as viable alternatives in select primary and revision settings, although not superior to AOT for larger lesions. Extracellular matrix cartilage allograft (ECMA) and particulate juvenile cartilage allograft transplantation (PJCAT) potentially enhance cartilage restoration. Conclusion The ICCRA consensus provides a structured, evidence-informed framework for the surgical management of moderate-to-large OLT. Although multiple treatment strategies demonstrate clinical utility, the current literature remains heterogeneous with limited high-level evidence. Further prospective and comparative studies are warranted to better define optimal indications and long-term outcomes for each approach. Level of Evidence: V, Expert consensus

BackgroundThe management of osteochondral lesions of the talus (OLT) is challenging, with 2 main options being conservative and surgical management. Orthobiologic therapies come to bridge the gap between these 2 options; however, inconsistencies in indication, composition, and heterogeneous evidence limit clinical decision-making. To address these challenges, 3 International Congress Meetings on Cartilage Repair of the Ankle were convened in Pittsburgh, USA (2017), Dublin, Ireland (2019), and New York, USA (2025) to establish agreement on the role of conservative management and injectable orthobiologic strategies in the treatment of OLT.MethodsSeventy-five multidisciplinary experts from over 25 countries and 1 territory participated in a structured Delphi-based consensus process. Blinded surveys, structured questionnaires, and in-person discussions were used to develop and refine statements, supported by literature review and graded evidence (A1-E). Consensus strength was defined as consensus (51%-74%), strong consensus (75%-99%), or unanimous (100%)ResultsIn total, 29 consensus statements were achieved across the 3 meetings. Strong agreement was reached regarding indications and expected outcomes of conservative management, including the role of immobilization and appropriate timing for surgical intervention. Orthobiologic injections, including platelet-rich plasma, concentrated bone marrow aspirate, and hyaluronic acid, were considered appropriate in select patients with persistent symptoms, although no superiority was demonstrated among formulations, preparation methods, or injection strategies. When used as adjuncts to surgical procedures, orthobiologics may improve radiological outcomes, with limited evidence for improvement in clinical outcomes. Technical considerations, including preferred harvest sites and a lack of standardized preparation protocols, were identified, along with key principles for patient counselingConclusionThese international consensus statements establish a standardized framework for the conservative management and use of injectable orthobiologic therapies in OLT. By clarifying indications, technical considerations, and current limitations, this work aims to improve consistency in clinical practice, guide treatment decision-making, and inform future research.

Background Osteochondral lesions of the tibial plafond (OLTPs) are considerably less common than osteochondral lesions of the talus (OLT), and the terminology, prognostic factors, and treatment strategies for these lesions remain poorly characterized. Methods Experts participated in a structured Delphi-based consensus process during the International Consensus Meeting on Cartilage Repair of the Ankle (ICCRA) meeting held in 2019. Blinded surveys, structured questionnaires, literature review, and in-person discussions were used to develop and refine statements. Consensus strength was defined as consensus (51-74%), strong consensus (75-99%), or unanimous (100%). Results A total of 11 consensus statements were developed addressing terminology, prognostic factors, and management of OLTP, all of which achieved strong consensus. Unanimous agreement was reached on the terminology “osteochondral lesion of the tibial plafond.” Key prognostic factors included lesion characteristics, cystic changes, kissing lesions, and hindfoot alignment. Nonoperative treatment may be considered in asymptomatic or nondisplaced lesions, whereas surgical treatment may be indicated for symptomatic or progressive lesions. Bone marrow stimulation was recommended for small, non-cystic lesions; osteochondral transplantation was supported for larger or cystic lesions. Associated pathology such as kissing lesions and malalignment should be addressed concurrently, and salvage procedures may be considered in advanced cases. Conclusion These international consensus statements establish practical guidance for the assessment and management of OLTP by integrating current evidence with expert opinion. By outlining key prognostic considerations and treatment pathways, these recommendations aim to reduce variability in clinical practice and provide a foundation for future investigation in this challenging pathology. Level of Evidence: V, expert consensus

BACKGROUND:Acute Achilles tendon ruptures (AATRs) are devastating injuries for athletes, yet outcomes in elite rugby union players remain poorly characterized. HYPOTHESIS:Elite rugby union players who sustain AATRs will demonstrate significantly reduced performance metrics postinjury compared with preinjury levels. STUDY DESIGN:Retrospective case series. LEVEL OF EVIDENCE:Level 4. METHODS:A retrospective review of elite rugby union players who sustained Achilles ruptures from 2013 to 2025 was performed. Data, including player demographics, injury characteristics, and performance metrics, were collected from rugby databases and media reports. A Wilcoxon signed rank test was used to compare pre- and postrupture performance metrics. Effect size was calculated using matched-pairs rank-biserial correlation, with median paired differences and 95% CIs. A P value <0.05 was determined as statistically significant. RESULTS:A total of 52 elite rugby union players with a median age of 28 years were identified. Overall, 80.8% of players returned to play (RTP) at a median time of 8.5 months. In the season immediately after injury, games played, tries, tries per game, points, and points per game were all significantly lower than preinjury values (all P ≤ 0.003; r = -0.49 to -0.61). Across all seasons, games per season, tries per season, tries per game, points per season, and points per game were significantly lower after injury (all P < 0.001; r = -0.47 to -0.72). CONCLUSION:AATRs in elite rugby union players were associated with significant declines in performance metrics in both the immediate postinjury season and across subsequent seasons. These findings highlight the substantial performance impact of AATRs and support the need for improved position-specific prevention strategies and targeted postinjury rehabilitation protocols. CLINICAL RELEVANCE:Clinicians can use these findings to counsel rugby athletes and teams on prognosis, treatment decisions, and realistic performance expectations after AATRs.

BackgroundThe evaluation of osteochondral lesions of the talus (OLT) has long been limited by variability in imaging protocols, lesion measurement techniques, and clinical utility of radiographic classification systems. To address these challenges, 3 International Congress Meetings on Cartilage Repair of the Ankle were convened in Pittsburgh, USA (2017), Dublin, Ireland (2019), and New York, USA (2025) to establish agreement on the work-up, diagnostic imaging, and radiographic classification systems for OLT.MethodsSeventy-five multidisciplinary experts from over 25 countries and 1 territory participated in a structured Delphi-based consensus process. Blinded surveys, structured questionnaires, and in-person discussions were used to develop and refine statements, supported by literature review and graded evidence (A1-E). Consensus strength was defined as consensus (51%-74%), strong consensus (75%-99%), or unanimous (100%).ResultsIn total, 19 consensus statements were achieved across the 3 meetings. Strong agreement was reached for first-line use of weight-bearing radiographs and complementary use of magnetic resonance imaging (MRI) and computed tomography for lesion characterization. Standardized assessment of lesion size in 3 planes and localization using a 9-zone grid were endorsed. Diagnostic arthroscopy was considered to have limited routine value in the setting of advanced imaging. Post-treatment imaging recommendations clarified indications for radiographs and cross-sectional imaging and emphasized the limited correlation between imaging findings and clinical function. Computed tomography-based classification systems were considered more useful for guiding treatment decisions than plain radiographic or MRI-based systems.ConclusionThese international consensus statements establish a standardized imaging-based framework for the evaluation and classification of OLT, improving consistency in diagnosis, treatment planning, and clinical reporting.

Objective: To determine the ‘normal’ career longevity of male professional soccer players, and the factors that affect this in order to provide a baseline against which career longevity after injury can be measured. 2- To demonstrate how these results can be used by comparing them with published career longevity rates after anterior cruciate ligament reconstruction (ACLR). Methods: Match play data for the entire careers of 4117 male soccer players playing in the top four English football leagues between 1992 and 2023 was utilised. Players were grouped into ability levels and their “still playing” rates, and career trajectory tracked according to age. Univariate and multivariate analyses were used to determine differences by playing position and ability and Kaplan–Meier survival curves were generated. The findings were compared with published results from the lead author’s cases after ACLR according to the comparable age and league level. Results: Goalkeepers had a longer overall career length than outfield players (12.4 ± 4.9 vs. 11.6 ± 4.7 years, p = <0.01). Outfield players in the English Premier League (EPL) and those also playing internationally (EPL + I) play for longer overall and longer at their highest level (14.8 ± 3.3 and 7.5 ± 5.0 years) than lower league players (League 2: 6.2 ± 4.1 and 2.9 + 2.2 years). At 5 years, EPL + I and EPL outfield players have a 60% and 40% probability of continuing to play at their highest level respectively compared to less than 20% in The Championship and below. At 10 years this is 40% and 18% respectively compared to <2% in the lower leagues. ‘Still playing’ rates after ACLR are up to 12.9% lower than average for 30 year old footballers. Discussion: Career duration in footballers is affected by the position played and ability level. Career longevity and performance data is provided in a usable format for easy comparisons with studies reporting career longevity, and illustrated in the case of ACL reconstruction outcomes in professional footballers.

INTRODUCTION:Voice assessment and treatment involve the manipulation of all the subsystems of voice production, and may lead to production of respirable aerosol particles that pose a greater risk of potential viral transmission via inhalation of respirable pathogens (eg, SARS-CoV-2) than quiet breathing or conversational speech. OBJECTIVE:To characterise the production of respirable aerosol particles during a selection of voice assessment therapy tasks. METHODS:We recruited 23 healthy adult participants (12 males, 11 females), 11 of whom were speech-language pathologists specialising in voice disorders. We used an aerodynamic and an optical particle sizer to measure the number concentration and particle size distributions of respirable aerosols generated during a variety of voice assessment and therapy tasks. The measurements were carried out in a laminar flow operating theatre, with a near-zero background aerosol concentration, allowing us to quantify the number concentration and size distributions of respirable aerosol particles produced from assessment/therapy tasks studied. RESULTS:Aerosol number concentrations generated while performing assessment/therapy tasks were log-normally distributed among individuals with no significant differences between professionals (speech-language pathologists) and non-professionals or between males and females. Activities produced up to 32 times the aerosol number concentration of breathing and 24 times that of speech at 70-80 dBA. In terms of aerosol mass, activities produced up to 163 times the mass concentration of breathing and up to 36 times the mass concentration of speech. Voicing was a significant factor in aerosol production; aerosol number/mass concentrations generated during the voiced activities were 1.1-5 times higher than their unvoiced counterpart activities. Additionally, voiced activities produced bigger respirable aerosol particles than their unvoiced variants except the trills. Humming generated higher aerosol concentrations than sustained /a/, fricatives, speaking (70-80 dBA), and breathing. Oscillatory semi-occluded vocal tract exercises (SOVTEs) generated higher aerosol number/mass concentrations than the activities without oscillation. Water resistance therapy (WRT) generated the most aerosol of all activities, ∼10 times higher than speaking at 70-80 dBA and >30 times higher than breathing. CONCLUSIONS:All activities generated more aerosol than breathing, although a sizeable minority were no different to speaking. Larger number concentrations and larger particle sizes appear to be generated by activities with higher suspected airflows, with the greatest involving intraoral pressure oscillation and/or an oscillating oral articulation (WRT or trilling).

PURPOSE:To determine the 'normal' career longevity of male professional footballers and the factors that affect this in order to provide a baseline against which career longevity after injury can be measured. To demonstrate how these results can be used by comparing them with published career longevity rates after anterior cruciate ligament reconstruction (ACLR). METHODS:Match play data for the entire careers of 4117 male footballers playing in the top four English football leagues between 1992 and 2023 was utilised. Players were grouped into ability levels and their "still playing" rates, and career trajectory tracked according to age. Univariate and multivariate analyses were used to determine differences by playing position and ability and Kaplan-Meier survival curves were generated. The findings were compared with published results after ACLR according to the comparable age and league level. RESULTS:Goalkeepers had a longer overall career length than outfield players (12.4 ± 4.9 vs. 11.6 ± 4.7 years, p = <0.01).Outfield players in the English Premier League (EPL) and those also playing internationally (EPL + I) play for longer overall and longer at their highest level (14.8 ± 3.3 and 7.5 ± 5.0 years) than lower league players (League 2: 6.2 ± 4.1 and 2.9 + 2.2 years). At 5 years, EPL + I and EPL outfield players have a 60% and 40% probability of continuing to play at their highest level respectively compared to less than 20% in The Championship and below. At 10 years this is 40% and 18% respectively compared to <2% in the lower leagues. 'Still playing' rates after ACLR are up to 12.9% lower than average for 30 year old footballers. CONCLUSION:Career duration in footballers is affected by the position played and ability level. Career longevity and performance data is provided in a usable format for easy comparisons with studies reporting career longevity outcomes in professional footballers. LEVEL OF EVIDENCE:Level III, retrospective cohort study.

Isolation requirements for COVID-19 close contacts risked discouraging elite athletes and support staff from travelling to international sports events hosted in the UK during 2021.ObjectivesThe purpose of this study, in collaboration with the UK Health Security Agency, was to develop and implement a risk assessment and workplace daily testing approach in elite sporting events, for individuals who would otherwise be excluded by quarantine.MethodsLongitudinal study of athletes and staff identified as close contacts during travel (ie, flights, train) to specific international sports events. A risk assessment was undertaken, and participants were categorised as at ‘low’ or ‘high’ risk of developing SARS-CoV-2 based on their exposure circumstances. High-risk individuals remained in 10-day isolation, whereas those of low risk underwent daily symptom and lateral flow testing, enhanced workplace mitigation and selected work activities were permitted.ResultsOf 29 514 event personnel, 202 travel-related close contacts were reported to the study team, of which 126 were eligible from 40 events in 7 sports. Of the individuals assessed, 105 (83.3%) were classified as low risk, while 21 (16.7%) were classified as high risk. No low-risk individuals tested positive in over 280 rapid antigen tests.ConclusionInternational sports events rely on athlete and support staff availability, with economic consequences of event cancellation or postponement. Our study showed no detection of SARS-CoV-2 in low-risk close contacts, and enabled their sustained participation. This multidisciplinary intervention appears to have been effective, enabling large-scale event continuation, while minimising risk to athletes, employees and the wider public.

IMPORTANCE:Men have a higher risk of Achilles tendon (AT) injury, and the impact of morphological and mechanical sex differences may play a role. AIM:The aim of this study is to systematically review the literature to determine whether there are sex-specific differences in AT morphological and mechanical properties and analyze how these differences may impact AT injury in both men and women. EVIDENCE REVIEW:A systematic literature search of articles published between 2001 and 2021, in the MEDLINE, EMBASE, and Cochrane databases was performed during May 2022 according to PRISMA. The primary outcome measures included sex-related differences in the mechanical and morphological properties of the Achilles tendon. Secondary outcomes included impact of sex on Achilles tendon properties and adaptation. FINDINGS:Nineteen studies with a total of 1,143 participants (613 men and 530 women) were included in this systematic review. Men had increased measurements when compared with women in the following: AT length, thickness, cross-sectional area (CSA), stiffness, peak force, loading rate, and voluntary muscle contraction. Women had an increase in CSA deformation, strain, and compliance. CONCLUSIONS AND RELEVANCE:Our study demonstrates that men have an increased AT length, thickness, and CSA, indicating that men may be subjected biomechanically to higher loads in their day-to-day activities. In addition, men have lower deformation and compliance properties, along with increased AT stiffness, reducing their capacity to adapt during loading, potentially increasing their risk of injury. LEVEL OF EVIDENCE:IV.

Respiratory particles produced during vocalized and nonvocalized activities such as breathing, speaking, and singing serve as a major route for respiratory pathogen transmission. This work reports concomitant measurements of exhaled carbon dioxide volume (VCO2) and minute ventilation (VE), along with exhaled respiratory particles during breathing, exercising, speaking, and singing. Exhaled CO2 and VE measured across healthy adult participants follow a similar trend to particle number concentration during the nonvocalized exercise activities (breathing at rest, vigorous exercise, and very vigorous exercise). Exhaled CO2 is strongly correlated with mean particle number (r = 0.81) and mass (r = 0.84) emission rates for the nonvocalized exercise activities. However, exhaled CO2 is poorly correlated with mean particle number (r = 0.34) and mass (r = 0.12) emission rates during activities requiring vocalization. These results demonstrate that in most real-world environments vocalization loudness is the main factor controlling respiratory particle emission and exhaled CO2 is a poor surrogate measure for estimating particle emission during vocalization. Although measurements of indoor CO2 concentrations provide valuable information about room ventilation, such measurements are poor indicators of respiratory particle concentrations and may significantly underestimate respiratory particle concentrations and disease transmission risk.

PurposeAnkle sprains remain the most common soft tissue injury presenting to Emergency Departments. Recently, there has been increased awareness and reporting of deltoid ligament injuries in association with injuries to the lateral ligament complex as well as with fibula fractures. This article reviews the currently available literature on the anatomy of the deltoid ligament, clinical and radiological diagnosis of injuries to the deltoid ligament and treatment recommendations.MethodsA literature review was conducted for keywords associated with deltoid ligament injuries. MEDLINE, PubMed and Embase databases were utilised for this search. Articles were included if involving an adult population, were English-language, were related to deltoid ligament injuries (with or without associated injuries) and reported on patho-anatomy, clinical or radiological diagnosis or treatment methods.ResultsA total of 93 articles were assessed for relevance from the database search, and 47 were included after the removal of irrelevant articles and duplicates. Several studies reported on the clinical findings of deltoid ligament injury, as well as the radiographic analysis. Arthroscopy was considered the gold standard of diagnosis, with authors reporting on the potential benefit of performing arthroscopic repair or reconstruction at the same time. There were no studies that provided a system for the classification of deltoid ligament injury or larger studies of treatment pathways. Long-term studies of the incidence of instability in deltoid ligament injuries were not available.ConclusionThere is limited evidence available regarding deltoid ligament injuries, particularly in terms of treatment options, either in isolation or with concomitant injuries. Long-term follow-up studies are needed to obtain more accurate data on the number of complications.Level of EvidenceLevel IV.

PURPOSE:The medial collateral ligament of the ankle, or deltoid ligament, can be injured in up to 40% of patients who sustain an ankle inversion sprain. Reporting injuries of the deltoid ligament is not easy due to confusion in the current anatomical descriptions, with up to 16 fascicles described, with variable frequencies. The purpose of this study was to clarify the anatomy of the deltoid ligament. METHODS:Thirty-two fresh-frozen ankle specimens were used for this study. Careful dissection was undergone until full visualization of the deltoid ligament was achieved and measurements taken. RESULTS:The deltoid ligament was found to have four constant fascicles in two layers. The superficial layer consists of the tibionavicular, tibiospring and tibiocalcaneal fascicles, while the deep layer consists of the tibiotalar fascicle. Measurements of these fascicles are given in detail. The tibiotalar fascicle and the anterior part of the tibionavicular fascicle were found to be intra-articular structures. CONCLUSION:The deltoid ligament has a constant number of fascicles divided into a superficial and a deep layer. This clarification of the anatomy and terminology of the deltoid ligament and its fascicles will help clinical view, diagnosis and (interdoctor)communication and treatment. The ligamentous fibres of the deep layer, as well as the anterior fibres of the superficial layer (tibionavicular fascicle) are intra-articular, which could negatively impact its healing capacity, explaining chronicity of these types of injuries. LEVEL OF EVIDENCE:Not applicable (cadaveric study).

Respiratory aerosols can serve as vectors for disease transmission, and aerosol emission is highly activity-dependent. COVID-19 severely impacted the performing arts due to concerns about disease spread by respiratory aerosols and droplets generated during singing and playing musical instruments. Aerosol generation from woodwind and brass performance is less understood compared to singing due to uncertainty about how the diverse range of musical instruments may impact respiratory aerosol concentrations and size distributions. Here, aerosol number and mass concentrations along with size distributions were measured for breathing, speaking, and playing four different woodwind and brass instruments by 23 professional instrumentalists. We find that a 1 dBA increase in sound pressure level corresponds to a similar to 10% increase in aerosol number concentration. The aerosol size distribution is consistent with that of breathing. Differences in aerosol emission across musical instruments can be partly explained by the loudness of performance. Measuring aerosol generation from single notes or simple songs may be sufficient to characterise the aerosol emission range during actual performance, provided a range of loudnesses are accessed. These results provide insight into the factors contributing to aerosol emission during musical performance and facilitate risk assessments associated with infectious respiratory disease transmission in the performing arts.

BackgroundIntrinsic foot muscles are known to support the medial longitudinal arch (MLA) and stabilize the foot, and they are activated with weight bearing and increased postural demand. Various types of intrinsic foot muscle training have been reported, but one of the most useful of these, the short foot exercise, is challenging to perform effectively and requires practice, making it difficult to implement in ordinary clinical settings.Research questionWhat are the differences in abductor hallucis longus (ABH) muscle activity and MLA angle during intrinsic foot muscle exercises that employ weight bearing and balancing conditions when they are performed with minimal practice?MethodsSixteen healthy volunteers performed nine different intrinsic foot muscle exercises, practiced once or twice. The exercises consisted of toe curl, short foot without pushing, short foot with pushing and toe spread exercises in sitting and standing positions, and single leg swing in a standing position. Each exercise was performed three times for five seconds. The activities of the ABH muscles were measured using surface electromyographic (EMG) sensors and the MLA angles during the exercises were captured using an optical motion tracking system. The integrals of the ABH EMG signals were calculated.ResultsDifferences in the integral and maximum of the ABH EMG signal were found between the exercises (p < 0.001). Post-hoc pair-wise analysis revealed that the EMG activity was larger during the swing exercise than in exercises other than toe spread, both in sitting and standing positions, and short foot exercise with pushing while standing. The minimum MLA angle during each exercise was smaller for the toe spread exercise in a sitting position than other exercises (p < 0.023).SignificanceA single leg swing exercise may be effective for self-exercise of intrinsic foot muscles, particularly when intensive supervised physiotherapy is not possible.

Transmission of an airborne disease can occur when an individual exhales respiratory particles that contain infectious pathogens. Surgical face masks are often used to reduce the amount of respiratory aerosol emitted into the environment by an individual while also lowering the concentration of particles the individual inhales. Respiratory aerosol generation is activity-dependent with high person-to-person variability. Moreover, mask fit differs among people. Here, we measure the efficacy of surgical masks (EN14683 Type IIR) in reducing both aerosol (0.3 - 20 mu m diameter) and droplet (20 - 1000 mu m diameter) emission during breathing, speaking and five speech and language therapy tasks performed by a human cohort. When participants wore a surgical face mask, measured particle number concentrations at the front of the mask were always lower than that for breathing without mitigation in place. For breathing and speaking, the through-mask filtration efficiencies were 80% and 87%, respectively, while for voice therapy tasks the through-mask filtration efficiencies ranged from 89% ("Hey!") to 95% (/a::/). Size-dependent through-mask filtration efficiencies were high (80 - 95%) for particles 0.5 - 2 mu m diameter, with masks filtering a greater fraction of larger particle sizes. For particle sizes >4 mu m diameter, filtration efficiencies of surgical face masks for all tested respiratory tasks were similar to 100%. Surgical face masks significantly reduced the number of particles emitted from all respiratory activities. These results have implications for developing effective mitigations for disease transmission through inhalation.

Purpose: The anatomy of the deltoid ligament is complex. There is agreement on the presence of superficial and deep layers but the number and frequency of fascicles remains controversial. Identifying injuries to specific components of the deltoid ligament may inform decision-making on their management. The anatomy was reviewed to establish the number and dimension of fascicles visible with three-dimensional (3D) volumetric magnetic resonance images (MRI). Methods: Twenty ankles from asymptomatic healthy volunteers were imaged with 3D volumetric MRI. The presence of individual fascicles was recorded and measured in 3D. Results: The median age of participants was 26 years (range: 20-37) of which 13 (65%) were female. All 20 ankles had a deltoid ligament formed of four fascicles in two layers: three fascicles in the superficial layer; tibionavicular (mean dimensions 22.5 x 10.0 x 2.4 mm), tibiospring (16.6 x 6.7 x 1.9 mm) and tibiocalcaneal (23.8 x 4.6 x 1.8 mm) and a deep layer consisting of the tibiotalar fascicle, which could be divided into two parts: anterior tibiotalar (mean dimensions 10 x 5.6 x 4.1 mm) and the significantly larger posterior tibiotalar (14.2 x 13.8 x 17.5 mm, p < 0.01). There were no additional fascicles observed. Conclusions: The deltoid ligament complex was consistently visualised as four fascicles (tibionavicular, tibiospring, tibiocalcaneal, tibiotalar) in two layers (superficial and deep) in all 20 ankles. The posterior part of the tibiotalar fascicle was the thickest of all the fascicles in the deltoid ligament. It is, therefore, possible to accurately identify the components of the deltoid ligament, and 3T MRI can be used to assess fascicle-specific injury, which will guide treatment and rehabilitation. Level of Evidence: Level III.