Don't forget to mind the mind: a prospective cohort study over 12 months on mental health symptoms in active professional male footballers.

Aims: We examined the prevalence and incidence of mental health symptoms (MHS) in active professional male footballers over a 12-month period and investigated if MHS was associated with severe injuries or surgeries.

Participants And Methods: Football Players Worldwide (FIFPRO) affiliated national unions invited active professional male football players to participate in the study. MHS was operationalised in symptoms of anxiety, disordered eating, depression, distress, sleep disturbance, alcohol misuse and drug misuse, all being assessed with validated questionnaires.

Heading in football: a systematic review of descriptors, definitions, and reporting methods used in heading incidence studies.

The primary objective of this systematic review was to describe the number and type of heading descriptors used in all published studies which report on heading incidence in football. The secondary objective was to detail the data collection and reporting methods used in the included studies to present heading incidence data. Eligible studies were identified through searches of five electronic databases: Ovid MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science, using a combination of free-text keywords (inception to 12th September 2023).

Lower HAGOS subscale scores associated with a longer duration of groin problems in football players in the subsequent season.

Introduction: Groin injuries represent a considerable problem in football. Although the Adductor Strengthening Programme reduced groin injury risk, players can still experience groin symptoms throughout the season. This study aimed to determine whether preseason Copenhagen Hip and Groin Outcome Score (HAGOS) and a history of previous injury can identify individuals at risk of having a longer duration of groin problems the subsequent season, using an 'any physical complaint' definition of injury.

Examination of the validity of the Injury-Psychological Readiness to Return to Sport (I-PRRS) scale in male professional football players: A worldwide study of 29 professional teams.

Perceived confidence is an important dimension of an athlete's psychological readiness to return-to-play. However, there is no established and validated tool to evaluate confidence in professional football. This study aimed to provide preliminary evaluation of the internal structure of the Injury-Psychological Readiness to Return-to-Sport scale (I-PRRS) in a cohort of injured male professional footballers.

A new statistical approach to training load and injury risk: separating the acute from the chronic load.

The relationship between recent (acute) training load relative to long-term (chronic) training load may be associated with sports injury risk. We explored the potential for modelling acute and chronic loads separately to address current statistical methodology limitations. We also determined whether there was any evidence of an interaction in the association between acute and chronic training loads and injury risk in football.

#ReadyToPlay: health problems in women's football-a two-season prospective cohort study in the Norwegian premier league.

Objectives: To describe the prevalence, incidence and burden of all health problems in the Norwegian women's premier league.

Methods: During the 2020 and 2021 seasons, players in the Norwegian women's premier league reported all health problems (sudden-onset injuries, gradual-onset injuries and illnesses) weekly, using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. Team medical staff diagnosed reported problems using the Sport Medicine Diagnostic Coding System.

Physical Performance Profiles in Norwegian Premier League Female Football: A Descriptive Study.

Purpose: To map anthropometric and physical performance profiles in Norwegian premier league female football players.

Methods: During preseason, the physical qualities of 107 players were tested on Keiser leg press, countermovement jump, 40-meter sprint, and agility. Descriptive statistics were presented as mean (SD) and median [interquartile range].

Football-specific extension of the IOC consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020.

Several sports have published consensus statements on methods and reporting of epidemiological studies concerning injuries and illnesses with football (soccer) producing one of the first guidelines. This football-specific consensus statement was published in 2006 and required an update to align with scientific developments in the field. The International Olympic Committee (IOC) recently released a sports-generic consensus statement outlining methods for recording and reporting epidemiological data on injury and illness in sport and encouraged the development of sport-specific extensions.

Adductor Strengthening Programme is successfully adopted but frequently modified in Norwegian male professional football teams: a cross-sectional study.

Objectives: Groin injuries represent a substantial problem in male football, with the Adductor Strengthening Programme (ASP) being the only exercise programme demonstrated to significantly reduce the risk of groin problems. We aimed first, to use the Reach Adoption Effectiveness Implementation Maintenance (RE-AIM) framework to investigate attitudes, beliefs and behaviour to the ASP among primary delivery agents of injury prevention exercises in Norwegian male professional football teams. Second, we aimed to identify a real-world application of the ASP protocol used in a professional team setting.

Handling and reporting missing data in training load and injury risk research.

Purpose: To map the current practice of handling missing data in the field of training load and injury risk and to determine how missing data in training load should be handled.

Methods: A systematic review of the training load and injury risk literature was performed to determine how missing data are reported and handled. We ran simulations to compare the accuracy of modelling a predetermined relationship between training load and injury risk following handling missing data with different methods.

Study on Hamstring Re-injury Prevention (SHARP): protocol for an international multicentre, randomised controlled trial.

Introduction: Previous studies showed that the Nordic hamstring exercise (NHE) effectively prevents primary hamstring injury. However, no study investigated the secondary preventing effect of the NHE on hamstring reinjury. The primary purpose of this study is to investigate the effectiveness of the NHE for preventing hamstring reinjury after return to play (RTP) following a hamstring injury in football players.

Injury characteristics in Norwegian male professional football: A comparison between a regular season and a season in the pandemic.

The Coronavirus Disease-19 (COVID-19) pandemic forced the Norwegian male premier league football season to reschedule, reducing the fixture calendar substantially. Previous research has shown that a congested match schedule can affect injury rates in professional football. Therefore, we aimed to investigate whether the Norwegian premier league teams suffered more injuries in the more match congested 2020 season than in the regular 2019-season.

Assessing the cumulative effect of long-term training load on the risk of injury in team sports.

Objectives: Determine how to assess the cumulative effect of training load on the risk of injury or health problems in team sports.

Methods: First, we performed a simulation based on a Norwegian Premier League male football dataset (n players=36). Training load was sampled from daily session rating of perceived exertion (sRPE).

Prevalence and burden of health problems in top-level football referees.

Background: Top-level football referees take decisions during strenuous physical activity, and often under great mental pressure. Despite their central role in a football match, little is known about referees' health problems, particularly in female referees.

Aim: To investigate the prevalence and burden of health problems in female and male top-level referees.

Changes in circulating microRNAs following head impacts in soccer.

Aim: To explore the short-term effects of accidental head impacts and repetitive headers on circulating microRNAs, accounting for the effects of high-intensity exercise alone.

Methods: Blood samples were collected from professional soccer players at rest. Repeat samples were drawn 1 h and 12 h after three conditions: (1) accidental head impacts in a match, (2) repetitive headers during training, and (3) high-intensity exercise.

Validation of the Copenhagen Hip and Groin Outcome Score (HAGOS) using modern test theory across different cultures and languages: a cross-sectional study of 452 male athletes with groin pain.

Bkground: No studies have tested the validity of the Copenhagen Hip and Groin Outcome Score (HAGOS) using modern test theory, across different cultures and languages.

Objective: To validate the Danish, English and Norwegian versions of HAGOS and its six subscales (Symptoms (S, Item 1-7), Pain (P, Item 1-10), activities of daily living (Item 1-5), Sport and recreation (Sport/rec, Item 1-8), Participation in physical activity (item 1-2) and quality of life (item 1-5)) by evaluating differential item functioning (DIF) and measurement invariance across the three language versions in male multidirectional team athletes with groin pain. Second, to modify subscales depending on goodness-of-fit to the item response theory models and calculate conversion tables if language DIF was observed.

Not straightforward: modelling non-linearity in training load and injury research.

Objectives: To determine whether the relationship between training load and injury risk is non-linear and investigate ways of handling non-linearity.

Methods: We analysed daily training load and injury data from three cohorts: Norwegian elite U-19 football (n=81, 55% male, mean age 17 years (SD 1)), Norwegian Premier League football (n=36, 100% male, mean age 26 years (SD 4)) and elite youth handball (n=205, 36% male, mean age 17 years (SD 1)). The relationship between session rating of perceived exertion (sRPE) and probability of injury was estimated with restricted cubic splines in mixed-effects logistic regression models.

Field based lower limb strength tests provide insight into sprint and change of direction ability in academy footballers.

Conducting field-based strength assessments is embedded within football academy development processes. Yet, there is a limited understanding of how hip and groin strength assessments relate to vital game-based tasks such as sprinting and change of direction (COD) performance. Our aim was to explore field-based strength assessments and their relationships with both sprint and COD performance in male academy footballers.

Facilitators and barriers for implementation of a load management intervention in football.

Background: In a recent randomised controlled trial, we found that a commonly used training load management approach was not effective in preventing injuries and illnesses in Norwegian elite youth footballers.

Aim: To investigate players' and coaches' barriers and facilitators to a load management approach to prevent injuries and illnesses and their attitudes and beliefs of load management and injuries and illnesses in general.

Methods: We asked players and coaches about their views on injury risk in football, the benefits and limitations of load management in general and implementation of load management in football.

A Cherry, Ripe for Picking: The Relationship Between the Acute-Chronic Workload Ratio and Health Problems.

Objective: To investigate whether the relationship between the acute-chronic workload ratio (ACWR) and health problems varies when different methodological approaches are used to quantify it.

Design: Prospective cohort study.

Methods: An online questionnaire was used to collect daily health and training information from 86 elite youth footballers for 105 days.

Strength development and non-contact lower limb injury in academy footballers across age groups.

Non-contact lower limb injuries are common in academy football. Yet, the impact these injuries have on strength development in academy footballers remains unclear. This study aimed to investigate the impact of non-contact lower limb injury on hip, groin, and knee flexor strength development in male academy youth footballers.

Does load management using the acute:chronic workload ratio prevent health problems? A cluster randomised trial of 482 elite youth footballers of both sexes.

Background: The acute:chronic workload ratio (ACWR) is commonly used to manage training load in sports, particularly to reduce injury risk. However, despite its extensive application as a prevention intervention, the effectiveness of load management using ACWR has never been evaluated in an experimental study.

Aim: To evaluate the effectiveness of a load management intervention designed to reduce the prevalence of health problems among elite youth football players of both sexes.