A 90 minute soccer match induces eccentric hamstring muscles fatigue

Background/Purpose of the study. Hamstring injuries are the most prevalent muscle injuries in both amateur and professional soccer (football) players. Eccentric strength deficits and muscle strength imbalances have been associated with an increased risk of muscle injuries. The current study is a non-randomised observational study investigating whether fatigue significantly reduces peak eccentric strength of the hamstring muscle group. Methods. Twenty-two right leg dominant professional football players participated in this study. None were injured or were rehabilitating from an injury at the time of testing. The eccentric strength of the hamstring muscles was determined using the Nordic exercise on a Norbord device prior to a 90 minute soccer match and after its end. Results. There was a significant decrease in eccentric strength at the end of the match (before the match: M = 306.91, SD = 59.26; after the match: Mean = 277.77 ± SD = 60.35 p =.000, Cohen’s d =.50). The imbalance in eccentric hamstring muscle strength between dominant and non-dominant limb before the match remained unchanged after its end. Conclusions. A professional football match significantly impacts on the ability of players to produce high speed eccentric strength in the hamstring muscle groups. Resistance to fatigue and eccentric strength, particularly at high speeds, are considerable factors in conditioning of professional soccer players. Eccentric muscle strength fatigue of the hamstring muscle group after a 90 min soccer match may provide a possible explanation for the greater risk of hamstring injuries under fatigue conditions. © 2021, CIC Edizioni Internazionali s.r.l.. All rights reserved

The Effect of Ball Heading and Subclinical Concussion On the Neuromuscular Control Of The Lower Limb: A Systematic Review

# Background Soccer is unique among sports because it is the only sport that involves purposeful use of the head to control, pass, or shoot the ball. Over the previous five years, a relationship between lower extremity (LE) injury and sports related concussion (SRC) has been established in various sporting populations. Athletes at the high school, collegiate, and professional levels have demonstrated a greater risk for sustaining a LE injury post SRC. The purpose of this systematic review was to examine the relationship of the SRC with the incidence of LE injuries. # Methods Ten databases were searched with the following keywords: Lower limb, ball heading, neuromuscular control, concussion, MEDLINE, Ovid MEDLINE(R) Daily, and Ovid MEDLINE(R), EMBASE, and Scopus. The search was limited to English-language and peer-reviewed publications, until 15/12/2022. The PEDro scale was used for the assessment of the risk of bias among the included studies. All included papers were qualitatively analyzed. # Results A total of 834 studies were identified and 10 articles (four concussion-MSK biomechanics, six concussion-MSK injury) were included in the qualitative analyses. Included papers ranged from low to high quality. Due to the heterogeneous nature of the included study designs, quantitative meta-analysis was unable to be performed. All four of the included concussion-MSK biomechanics studies demonstrated, to some degree, that worse cognitive performance was associated with lower extremity MSK biomechanical patterns suggestive of greater risk for MSK injury. Among the six injury related studies, two investigations failed to determine group differences in cognitive performance between subsequently injured and non-injured athletes. # Conclusion More research is needed to better understand the relationship of SRC and lower extremity injuries and the extent to which they are related to concussions and/or repetitive neurotrauma after ball heading sustained in soccer. # Level of Evidence

Ecological and Specific Evidence-Based Safe Return To Play After Anterior Cruciate Ligament Reconstruction In Soccer Players: A New International Paradigm

Existing return to play (RTP) assessments have not demonstrated the ability to decrease risk of subsequent anterior cruciate ligament (ACL) injury after reconstruction (ACLR). RTP criteria are standardized and do not simulate the physical and cognitive activity required by the practice of sport. Most RTP criteria do not include an ecological approach. There are scientific algorithms as the "5 factor maximum model" that can identify risk profiles and help reduce the risk of a second anterior cruciate ligament injury. Nevertheless, these algorithms remain too standardized and do not include the situations experienced in games by soccer players. This is why it is important to integrate ecological situations specific to the environment of soccer players in order to evaluate players under conditions closest to their sporting activity, especially with high cognitive load. One should identify high risk players under two conditions: Clinical analyses commonly include assessments such as isokinetic testing, functional tests (hop tests, vertical force-velocity, profile), running, clinical assessments (range of motion and graft laxity), proprioception and balance (Star Excursion Balance Test modified, Y-Balance, stabilometry) and psychological parameters (kinesophobia, quality of life and fear of re-injury). Field testing usually includes game simulation, evaluation under dual-task conditions, fatigue and workload analysis, deceleration, timed-agility-test and horizontal force-velocity profiles. Although it seems important to evaluate strength, psychological variables and aerobic and anaerobic capacities, evaluation of neuromotor control in standard and ecological situations may be helpful for reducing the risk of injury after ACLR. This proposal for RTP testing after ACLR is supported by the scientific literature and attempts to approximate the physical and cognitive loads during a soccer match. Future scientific investigation will be required to demonstrate the validity of this approach. # Level of Evidence

Mechanical and Contractile Properties of Knee Joint Muscles after Sports-Related Concussions in Women Footballers

The purpose of this study was to determine if women footballers have an increased lack of neuromuscular control of the knee joint after a concussion compared to a healthy cohort tested with tensiomyography (TMG). Forty-one female collegiate footballers were enrolled in this study from which there were 20 with a history of sports-related concussions (SRCs) and 21 control subjects. Results from the SRC group had significantly higher Tc (ms) (z = −5.478, p = 0.000) and significantly lower Dm (mm) (z = −3.835, p = 0.000) than the control group in the case of the rectus femoris muscle. The SRC group had significantly higher Tc (ms) (z = −2.348, p = 0.016) and significantly lower Dm (mm) (z = −4.776, p = 0.000) than the control group in the case of the vastus medialis muscle. The SRC group had significantly higher Tc (ms) (z = −5.400, p = 0.000) and significantly lower Dm (mm) (z = −4.971, p = 0.000) than the control group in the case of the vastus lateralis muscle. The SRC group had significantly higher Tc (ms) (z = −5.349, p = 0.000) than the control group in the case of the biceps femoris muscle response, whereas no significant difference was found in Dm (mm) (z = −0.198, p = 0.853) between the groups. The results of the current study may have implications for current practice standards regarding the evaluation and management of concussions and can add valuable information for knee prevention programs as well

The impact of body mass index on post resuscitation survival after cardiac arrest: A meta-analysis

Background: Observational studies examining the association between body mass index (BMI) and the outcome of cardiac arrest (CA) shows controversial results. Methods: We reviewed literature for studies assessing the impact of BMI on survival and neurological outcome following CA. Eligible studies were subsequently meta-analyzed and pooled odds ratios and their corresponding 95% confidence intervals for post CA survival and neurological status were derived. Results: A total of 7 studies with 24,651 patients were evaluable for this meta-analysis. The studies were also categorized by location of the CA and the use of therapeutic hypothermia. Our results suggested that BMI between 25 and 29.9 kgr/m2had a favorable impact on survival after CA (OR = 1.172, 95% CI, 1.109-1.236) in comparison to normal weight subjects. Likewise, overweight patients presented increased odds for a favorable neurological outcome after CA (OR = 1.112, 95% CI, 1.020-1.213). On the contrary, underweight subjects presented decreased odds of surviving after CA as compared to normal BMI subjects (OR = 0.781, 95% CI, 0.652-0.935). Finally, BMI >30 kgr/m2was not associated with improved survival or neurological outcome as compared to BMI 18.5-24.9 kgr/m2. Conclusions: Overweight patients have a favorable prognosis after CA in terms of both survival and neurological outcome. This effect was amplified when the analysis is restricted in in-hospital cardiac arrest and in patients non-treated with therapeutic hypothermia

Triiodothyronine levels in acute pulmonary embolism predict in-hospital mortality

Objective: To assess the thyroid function in patients with acute pulmonary embolism, in order to evaluate the prognostic value of thyroid hormones. Methods: We studied 31 consecutive patients with acute pulmonary embolism. Measured variables upon admission included the ratio of the partial pressure of oxygen in arterial blood to the inspired oxygen fraction (PaO2/FiO2), acute physiology and chronic health evaluation II score, risk stratification indices and plasma levels of triiodothyronine, free thyroxine, and thyroid stimulating hormone. Results: Plasma levels of triiodothyronine were below normal level in 7 patients (22.6%). Plasma triiodothyronine correlated with PaO2/FiO2 (P < 0.05) and with acute physiology and chronic health evaluation II score (P < 0.01). In four patients (12.9%) who died, triiodothyronine levels were significantly lower (P < 0.01) than that in patients who survived. In contrast both groups had similar levels of free thyroxine, and thyroid stimulating hormone. Moreover, triiodothyronine levels negatively correlated with serum markers of right ventricular dysfunction. Accordingly, in multivariate logistic regression analysis, the only factors independently associated with an increased risk of death were triiodothyronine and PaO2/FiO2. Conclusions: Our preliminary data suggest that low plasma triiodothyronine is an independent predictor of in-hospital death in patients with acute pulmonary embolism

Intrinsic graft laxity variation with open kinetic chain exercise after anterior cruciate ligament reconstruction: A non-randomized controlled study

International audienc

Implementing Velocity-Based Training to Optimize Return to Sprint After Anterior Cruciate Ligament Reconstruction in Soccer Players: A Clinical Commentary

International audienceAfter anterior cruciate ligament reconstruction (ACLR), return to sprint is poorly documented in the literature. In soccer, return to sprint is an essential component of return to play and performance after ACLR. The characteristics of running in soccer are specific (velocity differences, nonlinear, intensity). It is important to address these particularities, such as curvilinear running, acceleration, deceleration, changes of direction, and variations in velocity, in the patient’s rehabilitation program. Force, velocity, and acceleration capacities are key elements to sprint performance. Velocity-based training (VBT) has gained much interest in recent years and may have a role to play in optimizing return to play and return to sprint after ACLR. Force, velocity, and acceleration can be assessed using force-velocity-power and acceleration-speed profiles, which should inform rehabilitation. The purpose of this commentary is to describe a velocity-based return to sprint program which can be used during ACLR rehabilitation