Pathophysiologie von COVID-19 und deren mögliche Bedeutung für Long-COVID

Ende 2019 wurde erstmals ein neues Virus der Corona-Familie, das severe acute respiratory syndrome coronavirus 2 (kurz SARS-CoV-2) beschrieben, welches die coronavirus disease 2019 (kurz COVID-19) verursacht. Nachdem es initial galt, zuerst einmal die akuten durch das SARS-CoV2 hervorgerufenen Veränderungen näher zu evaluieren, zeigten sich schnell klinische Hinweise, dass auch persistierende Veränderungen und somit klinische Beschwerden durch das SARS-CoV-2 hervorgerufen werden können. Neben den Veränderungen des Immunsystems scheint auch das Gefäß-System und hierbei vor allem das Endothel eine entscheidende Rolle zu spielen. Da diese beiden Systeme nahezu ubiquitär im menschlichen Körper vorkommen, sind die Langzeitfolgen (auch bekannt als Long-COVID) entsprechend vielfältig. Hierbei wird bis zu einer Dauer von 3-4 Wochen von einem akuten COVID-19, einer Dauer zwischen 4 und 12 Wochen von einem postakuten COVID-19 und einer Dauer über 12 Wochen von einem chronischen COVID oder Long-COVID gesprochen. In dem vorliegenden Review sollen die zugrundeliegenden Pathophysiologien/-mechanismen sowie die relevantesten hieraus resultierenden klinischen Veränderungen dargestellt werden. = At the end of 2019, a new virus of the corona family, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 for short), which causes the coronavirus disease 2019 (COVID-19 for short), was released for the first time. After the initial task was to first evaluate the acute changes caused by the SARS-CoV2 in more detail, clinical indications quickly emerged that persistent changes and thus clinical complaints can also be caused by the SARS-CoV-2. In addition to the changes in the immune system, the vascular system and especially the endothelium seem to play a decisive role. Since these two systems occur almost ubiquitously in the human body, the long-term consequences (also known as long COVID) are correspondingly diverse. Here, up to a duration of 3-4 weeks is spoken of an acute COVID-19, a duration between 4 and 12 weeks of a post-acute COVID-19 and a duration of 12 weeks of a chronic COVID or long COVID. In the present review, the underlying pathophysiologies / mechanisms as well as the most relevant resulting clinical changes are to be presented

Do athletes benefit from preoperative physical therapy before ACL-reconstruction?

Successful return to sport (RTS) and competition (RTC) rates are important factors when evaluating the successfulness of anterior cruciate ligament reconstruction (ACLR). Although functional outcomes are mostly satisfying after rehabilitation, a great proportion of athletes does not return to their preoperative level of performance. Low preoperative leg symmetry index in the strength development of quadriceps and hamstring muscles, female sex, older age, fear of reinjury, low self-efficacy and long waiting times without any intervention between injury and surgery can predict lower RTS rate after ACLR. Preoperative physical therapy addressing potential risk factors may improve RTS in elite and amateur athletes. Although athletes usually show high functional performance after injury, prehabilitation may – nevertheless – enhance successful RTC. Identifying risk factors for not RTS after ACLR can contribute to the decision on modality of prehabilitation and timing for surgery. The development of evidence-based guidelines considering preoperative patient- and knee function-related state could provide additional information regarding necessity for prehabilitation. = Die erfolgreiche Rückkehr in den Trainings- und Wettkampfbetrieb ist ein wichtiger Faktor der Evaluation nach einer vorderen Kreuzbandrekonstruktion (VKBR). Obwohl die funktionellen Ergebnisse nach der Rehabilitation meist zufriedenstellend sind, kehrt ein großer Teil der Athletinnen1 nicht zu ihrem präoperativen Leistungsniveau zurück. Ein niedriger Leg Symmetry Index (LSI) in der Kraftentwicklung der Quadrizeps- und Knieflexoren, weibliches Geschlecht, höheres Alter, Angst vor einer erneuten Verletzung, geringe Selbstwirksamkeit und lange Wartezeiten zwischen Verletzung und Operation können zu einer niedrigeren Return-sports-(RTS)-Rate nach VKBR führen. Eine präoperative Physiotherapie oder Prähabilitation, die auf potenzielle Risikofaktoren eingeht, kann die Wahrscheinlichkeit für RTS bei Profi- und Amateursportlerinnen verbessern. Obwohl die Athletinnen in der Regel auch nach einer Verletzung eine hohe funktionelle Leistungsfähigkeit zeigen, könnte eine Prähabilitation dennoch eine erfolgreiche Rückkehr in den Sport unterstützen. Die Identifizierung von Risikofaktoren, die eine Rückkehr in den Trainings- und Wettkampfbetrieb nach einer Ruptur des vorderen Kreuzbandes verhindern, kann zur Entscheidung über den Zeitpunkt der Operation beitragen. Die Entwicklung evidenzbasierter Leitlinien unter Berücksichtigung des präoperativen patienten- und kniebezogenen Status könnte zusätzliche Informationen dazu liefern, ob eine Prähabilitationsphase angebracht ist

Sport and exercise recommendations for pregnant athletes: a systematic scoping review

ObjectivesTo analyse the available evidence and identify gaps in current knowledge regarding physical activity volume and intensity and their effects on pregnancy outcomes in female athletes.DesignScoping review.Data sourcesA structured literature search of three electronic databases (Embase, PubMed and Web of Science) was conducted on 25 February 2022, and a rerun search was conducted on 8 September 2022.Eligibility criteriaStudies were eligible if they contained information on the relevant population (ie, elite or competitive amateur female athletes), intervention/exposure (ie, minimum of 10 hours of sport per week) and fetal and maternal outcomes. Eligible comparators included female recreational athletes and pregnant non-exercisers.Risk of biasThe risk of bias was evaluated with the National Institutes of Health (National Heart, Lung and Blood Institute) quality assessment tool.ResultsThe results revealed a discrepancy between the number of original research papers and the number of reviews and recommendations derived from them. The identified studies focused primarily on pregnant recreational athletes. Sixteen clinical studies met the inclusion criteria. No adverse effects on maternal or fetal outcomes were reported. Only during performance tests involving acute intensive exercise with the mother exercising at more than 90% of her maximal heart rate did some fetuses experience decelerations in heart rate.Summary/conclusionA lack of high-quality studies and direct evidence on pregnant elite and competitive amateur female athletes is evident. Further prospective observational cohort studies are needed using new monitoring methods (eg, non-invasive, wireless monitoring systems) aiming to gain a broader understanding of the stress tolerance of pregnant athletes and fetuses during exercise. Following that, interventional studies with stress tests in laboratory settings should be conducted. Therefore, technology plays a decisive role in gaining new knowledge and providing evidence-based recommendations on this topic.PROSPERO registration numberCRD42022309541

ARE THIGH MUSCLE ACTIVATION PATTERNS DURING DROP JUMPS DEPENDENT ON SEX AND FATIGUE? A PILOT STUDY IN COMPETITIVE SOCCER PLAYERS

The purpose of this study was to identify whether sex- and fatigue-dependent effects occur in muscle activation patterns during drop jumps. Therefore, 12 (5 female, 7 male) competitive soccer players performed five drop jumps (DJs) in a rested and fatigued state. Lactate, jump height, maximum knee flexion angle and the quadriceps to hamstring muscle activation ratio (QHGRF ratio) were compared via repeated-measures MANOVA, and effect sizes were used for interpretation. In the fatigued state, jump height and maximum knee flexion angles were reduced (large effect), and the left limb showed an non-significant medium effect towards an increased QHGRF ratio. Additionally, a sex-specific medium effect of the QHGRF ratio of the left limb indicates a higher QHGRF ratio for males. This indicates a tendency towards a quadriceps-dominant landing strategy in at least one limb

Health problems occurring in national-level female soccer players are different between leagues and throughout the season: a 6-month prospective cohort study

OBJECTIVES This study investigated the prevalence and severity of health problems in national-level female soccer players with respect to league and seasonality. METHODS In a prospective cohort study, 46 female soccer players aged 22.8±3.9 years playing in the three highest leagues in Switzerland were surveyed biweekly using the Oslo Sports Trauma Research Centre health problem (OSTRC-H) questionnaire. All definitions and measures followed the OSTRC-H-specific recommendations. The 6-month observation period included parts of the off-season and one half of the match season. RESULTS The average 2-weekly health problem prevalence was 37.3% (illnesses: 8.8%; sudden onset injuries-both acute and repetitive mechanisms: 19.7%; repetitive gradual onset injuries: 12.4%) and 25.1% for substantial problems as defined in the OSTRC-H context (7.3%; 12.0% and 7.3%, respectively). The absolute injury rates amounted to 148 injuries per 100 players per half season, of which 96 injuries per 100 players per half season were substantial. Female players in the 2nd and 3rd highest national leagues showed more gradual onset injuries (p<0.001) and fewer illnesses than those in the top league (p<0.05). At the same time, there were no league-specific differences in sudden onset injuries. Such injuries had a higher cumulative severity score than gradual onset injuries. Among sudden onset injuries, the ankle was the most affected body part, while the thigh was affected by for gradual onset injuries. The average 2-weekly health problem prevalence values steadily increased during the match season. CONCLUSION Among national-level female soccer players, the risk of health problems is relatively high and differs between leagues and across seasons

Deadbug Bridging Performance in 6- to 15-Year-Old Competitive Alpine Skiers—A Cross-Sectional Study

In competitive alpine skiing, a superior antirotation and rear-chain stabilization capacity is essential to constantly remain in dynamic equilibrium while skiing and to counteract the ski-specific adverse loading patterns of the back. As such, skiers' trunk stabilization performance during deadbug bridging (DBB) exercises has been shown to be associated with both skiing performance and overuse complaints of the lower back in skiers under 16 years of age (U16). However, to date, little is known about the corresponding stabilization abilities in younger skiers, i.e., 6- to 15-year-old skiers. As part of a biomechanical field experiment during a national off-snow fitness competition, a total of 101 youth competitive alpine skiers were tested with respect to their trunk stabilization performance during DDB exercise. The maximum contralateral displacement of the pelvic drop during leg lift (DBBdisplacement) was quantified using reflective markers and a motion capture system (Vicon, Oxford, UK). Potential age group and sex differences in DBBdisplacement were assessed using analysis of variance (ANOVA) at p < 0.05. Within each subgroup, the associations of DBBdisplacement with age, anthropometrics and maturity offset were analysed using Pearson's correlation (p < 0.05). Female skiers under 15 years of age (U15) showed better DBB performance than male U15 skiers, while there was no sex difference at the under 10-year (U10) level. In female U10 skiers, DBBdisplacement was moderately associated with body height, while in all other subgroups, no confounding associations with anthropometrics or biological maturation were found. Biomechanically quantifying DBB performance may be considered a feasible and nonconfounded screening test approach in young skiers older than 6 years. Body height may represent a confounding bias in exclusively the U10 female skier cohort and, therefore, should be considered when interpreting the test results. In summary, this study provided sport-specific normative reference data that may be of equal interest to both researchers and sport practitioners. Keywords: athletes; biological maturation; core stability; injury prevention; physical conditioning; physical fitness; skiing; testin

Primary Open Latarjet Procedure Results in Functional Differences but No Structural Changes in Subscapularis Muscle Quality vs the Healthy Contralateral Shoulder at Long-term Follow-up

BACKGROUND There are concerns that the Latarjet procedure results in loss of glenohumeral rotation and strength and in subscapularis dysfunction. The long-term effects of this procedure on subscapularis quality, glenohumeral rotation, and strength are unknown. PURPOSE/HYPOTHESIS To analyze the long-term effect of the primary open Latarjet procedure using a muscle-splitting approach on internal and external rotation and strength, as well as subscapularis muscle quality as compared with the healthy contralateral side. We hypothesized that the primary open Latarjet procedure is associated with a reduction of long-term shoulder strength and function and decreased subscapularis quality. STUDY DESIGN Case series; Level of evidence, 4. METHODS A total of 42 patients who underwent a primary open Latarjet procedure for recurrent anterior shoulder instability at a mean age of 26 years (range, 18-36) were reviewed after a mean follow-up of 8.4 years (range, 5-12). The subscapularis muscle volume and fat fraction of both shoulders were assessed. Bilateral active internal rotation (IR) and external rotation (ER), as well as IR and ER strength, were assessed by isokinetic testing (concentric, eccentric, and fatigability). RESULTS Active IR (0.6-point difference, P < .001) and ER (4° difference, P = .010) were significantly greater in healthy contralateral shoulders. The IR strength of the operated shoulder was significantly less than that of the healthy shoulder in concentric and eccentric testing (range of deficit, 4%-6%; P < .05). Also, the ER strength of the operated shoulder was significantly less than that of the healthy shoulder in concentric testing (11% deficit, P < .05). Subscapularis muscle volume was significantly greater in the operated shoulder (4% difference, P = .022), and there was no significant difference in fat fraction (P = .114). CONCLUSIONS The primary open Latarjet procedure was associated with significantly decreased active IR and ER and strength when compared with the healthy contralateral shoulder. The clinical influence of these findings is yet to be defined. There was no increased subscapularis muscle fatty degeneration but a minimal hypertrophy on the operated side at long-term follow-up

Screening Tests for Assessing Athletes at Risk of ACL Injury or Reinjury-A Scoping Review

Various tests are available to assess athletes for factors associated with their susceptibility and risk of anterior cruciate ligament (ACL) injury or reinjury; however, it is unclear which tests are clinically meaningful and what should be considered when using them. Therefore, the aim of this scoping review was to screen and summarize testing and to derive evidence-based recommendations for clinicians, practitioners and future research. Five databases were searched to identify studies addressing musculoskeletal morphology or functional-performance-related screening tests with a clear conceptual link or an evidence-based relationship to ACL (re)injury. A quality rating was carried out using the National Institutes of Health (NIH) Study-Quality Assessment Tool. Six different categories of common screening tests were identified: balance and postural control, gait- and running-related tests, joint laxity, joint morphology and anthropometrics, jump tests and strength tests. Predicting future injury in a complex, dynamic system based on a single screening test is methodologically challenging, which is also reflected in the highly controversial findings in the literature regarding potential associations between specific screening tests and the occurrence of ACL injuries and reinjuries. Nonetheless, various screening tests can provide clinically relevant information on ACL-(re)injury-related factors and help to provide tailored preventive measures. A selection of corresponding evidence-based recommendations is derived and presented in this scoping review

Association of Gene Variants with Seasonal Variation in Muscle Strength and Aerobic Capacity in Elite Skiers

Background: The training of elite skiers follows a systematic seasonal periodization with a preparation period, when anaerobic muscle strength, aerobic capacity, and cardio-metabolic recovery are specifically conditioned to provide extra capacity for developing ski-specific physical fitness in the subsequent competition period. We hypothesized that periodization-induced alterations in muscle and metabolic performance demonstrate important variability, which in part is explained by gene-associated factors in association with sex and age. Methods: A total of 34 elite skiers (20.4 ± 3.1 years, 19 women, 15 men) underwent exhaustive cardiopulmonary exercise and isokinetic strength testing before and after the preparation and subsequent competition periods of the World Cup skiing seasons 2015-2018. Biometric data were recorded, and frequent polymorphisms in five fitness genes, ACE-I/D (rs1799752), TNC (rs2104772), ACTN3 (rs1815739), and PTK2 (rs7460, rs7843014), were determined with specific PCR reactions on collected DNA. Relative percentage changes of cardio-pulmonary and skeletal muscle metabolism and performance over the two seasonal periods were calculated for 160 data points and subjected to analysis of variance (ANOVA) to identify hypothesized and novel associations between performance alterations and the five respective genotypes and determine the influence of age × sex. A threshold of 0.1 for the effect size (h2) was deemed appropriate to identify relevant associations and motivate a post hoc test to localize effects. Results: The preparation and competition periods produced antidromic functional changes, the extent of which varied with increasing importance for anaerobic strength, aerobic performance, cardio-metabolic efficiency, and cardio-metabolic/muscle recovery. Only peak RER (-14%), but not anaerobic strength and peak aerobic performance, and parameters characterizing cardio-metabolic efficiency, differed between the first and last studied skiing seasons because improvements over the preparation period were mostly lost over the competition period. A number of functional parameters demonstrated associations of variability in periodic changes with a given genotype, and this was considerably influenced by athlete "age", but not "sex". This concerned age-dependent associations between periodic changes in muscle-related parameters, such as anaerobic strength for low and high angular velocities of extension and flexion and blood lactate concentration, with rs1799752 and rs2104772, whose gene products relate to sarcopenia. By contrast, the variance in period-dependent changes in body mass and peak VO2 with rs1799752 and rs2104772, respectively, was independent of age. Likely, the variance in periodic changes in the reliance of aerobic performance on lactate, oxygen uptake, and heart rate was associated with rs1815739 independent of age. These associations manifested at the post hoc level in genotype-associated differences in critical performance parameters. ACTN3 T-allele carriers demonstrated, compared to non-carriers, largely different periodic changes in the muscle-associated parameters of aerobic metabolism during exhaustive exercise, including blood lactate and respiration exchange ratio. The homozygous T-allele carriers of rs2104772 demonstrated the largest changes in extension strength at low angular velocity during the preparation period. Conclusions: Physiological characteristics of performance in skiing athletes undergo training period-dependent seasonal alterations the extent of which is largest for muscle metabolism-related parameters. Genotype associations for the variability in changes of aerobic metabolism-associated power output during exhaustive exercise and anaerobic peak power over the preparation and competition period motivate personalized training regimes. This may help to predict and maximize the benefit of physical conditioning of elite skiers based on chronological characteristics and the polymorphisms of the ACTN3, ACE, and TNC genes investigated here