Joar Harøy’s research while affiliated with Norwegian School of Sport Sciences and other places

Objectives To evaluate the use and modification of the Copenhagen Adduction Exercise in football (soccer) teams, including the reasons for modification and alternate injury-prevention strategies. Methods In this cross-sectional study, staff members from a convenience sample of 50 male elite, academy and amateur football teams in Norway, Germany and Austria completed an online questionnaire focussing on the implementation of the Copenhagen Adduction Exercise. Fourteen of the staff members also completed an interview. Results Forty-two teams (84%) reported using the Copenhagen Adduction Exercise, but the majority (65%) had modified the original programme. Modifications included changes to sets, repetitions, progressions and frequency and were particularly common among elite teams. The main reasons for modifications were managing overall player load, experiences and beliefs and individualisation. Despite modifications, all teams followed the basic principles of the original programme. Conclusion The adoption of the Copenhagen Adduction Exercise by football teams is high, but the vast majority of teams modify the programme. Despite these modifications, the basic principles of the programme are maintained.

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. Methods Preseason HAGOS score and weekly groin problems were registered with the Oslo Sports Trauma Research Center Overuse questionnaire during one full season in 632 male semiprofessional adult players. Results The prognostic model showed a decreased number of weeks with groin problems for each increase in HAGOS score for ‘groin-related quality of life’ (QOL) (IRR=0.99, p=0.003). A 10-point higher ‘QOL’ score predicted 10% fewer weeks of groin problems. Additionally, previous hip/groin injury was associated with a 74% increase in the number of weeks with symptoms (p<0.001). Conclusion The HAGOS questionnaire applied preseason can detect players at risk of getting more weeks with groin problems the following season. The ‘QOL’ subscale seems to be the superior subscale for estimating subsequent groin problem duration. While HAGOS appears promising in identifying players at risk, previous groin injury is the most robust indicator, showing a substantial 74% increase in weeks with symptoms.

Background Apophyseal load-related injuries in the lower extremities are unique to children and adolescents, often resulting in reduced participation in football. Objective To investigate the prevalence, incidence, and characteristics of apophyseal load-related injuries in male youth academy football players. Design A prospective cohort study. Setting A Norwegian Premier League club’s youth male academy. Participants A total of 58 players from the U-14, U-16, and U-19 teams accepted the invitation to participate. Fifty-two players completed the full study period. Interventions Players reported all health problems, injuries, and illnesses using the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H2) during 42 weeks of the 2022 season. The players who reported symptoms from the pelvis, hip, groin, knee, or heel were assessed by a sports physiotherapist (SR), using a standardized clinical examination protocol. Subsequently, they were categorized as having an apophyseal load-related injury or not. Main outcome measurements We calculated the average weekly prevalence and overall injury incidence of apophyseal load-related injuries, and we investigated their characteristics. Results The players’ average weekly response rate of the OSTRC-H2 was 91%. The average weekly prevalence of self-reported health problems was 37%. Clinically diagnosed apophyseal load-related injuries had an average weekly prevalence of 12% and the overall injury incidence was 4.6 injuries per 1000 training and match hours. A total of 37 players were assessed using the standardized clinical examination protocol, and we diagnosed 31 apophyseal load-related injuries in 21 players. Complaints from the adductor (pubic) apophyses was most common with ten cases (32%). The U-14 team constituted 55% of all apophyseal load-related injuries. Conclusion Youth male academy players exhibited a notable prevalence and incidence of apophyseal load-related injuries, with complaints from the adductor (pubic) apophysis being most frequent. This warrants a need for injury prevention strategies targeting these injuries in youth players.

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]. Pearson correlations analyses were made for all performance tests, and results presented as R value with 95% CIs. Results: The female players were 22 (4) years of age, stature 169.0 (6.2) cm, body weight 65.3 (6.7) kg; force 2122 (312) N, power 1090 (140) W, sprint 40 m 5.75 (0.21) seconds, agility dominant 10.18 (0.32) seconds, nondominant 10.27 (0.31) seconds, and countermovement jump 32.6 (4.1) cm. Outfield players were faster and more agile than goalkeepers, a difference of 40 m, agility of dominant, and nondominant leg, respectively: 0.20 [0.09-0.32], 0.37 [0.21-0.54], and 0.28 [0.12-45]; P < .001. Goalkeepers and central defenders were taller and heavier compared with fullbacks, central midfielders, and wide midfielders (P ranging from <.02). A difference was found between dominant and nondominant legs for the agility test, showing that players are faster when changing direction with the dominant leg. Conclusions: Our study presents anthropometric and physical performance profiles of Norwegian premier league female football players. We found no difference for the physical qualities strength, power, sprint, agility, and countermovement jump between any outfield playing positions in female premier league players. There was a difference between outfield players and goalkeepers for sprint and agility.

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. Design: A descriptive cross-sectional survey, using a questionnaire designed to cover all five dimensions of the RE-AIM framework. Setting: The top two divisions of Norwegian male professional football. Participants: 32 primary injury prevention delivery agents. Primary and secondary outcome measures: Primarily, the proportion of respondents being aware of the ASP and its effect; having adopted it; having implemented it as intended; and considering maintaining using it. Secondary, the most often used ASP modifications. Results: Twenty-nine (91%) participants responded. All (100%) respondents were aware of the ASP and its injury preventive effect. The two most stated reasons for using the ASP were its injury preventive effect and that it does not require equipment. The ASP was adopted by all (100%) delivery agents, but only 10% used it in accordance with the original protocol. The main modifications were that the players in 72% of the teams were instructed to perform a non-progressive number of repetitions during pre-season, and in 86% of the teams instructed to perform more sets, but fewer repetitions per set, during in season. In total, 97% of the delivery agents planned to continue using the ASP. Conclusion: The delivery agents have positive attitudes and beliefs to the ASP, but they frequently modify it. We identified and reported a real-world application of the ASP protocol.

Objective To provide consensus on how to plan, organize and implement exercise-based injury prevention program (IPP) in sports. Design Delphi. Setting LimeSurvey platform. Participants Experienced sports physical therapists from the International Federation of Sports Physical Therapy member countries. Main outcome measures Factors related to sports IPP planning, organization and implementation. Results We included 305 participants from 32 countries. IPP planning should be based on an athlete's injury history, on pre-season screening results, and on injury rates (respectively, 98%, 92%, 89% agreement). In total 97% participants agreed that IPP organization should depend on the athlete's age, 93% on the competition level, and 93% on the availability of low-cost materials. It was agreed that IPP should mainly be implemented in warm-up sessions delivered by the head or strength/conditioning coach, with physical training sessions and individual physical therapy sessions (respectively, 94%, 92%, 90% agreement). Conclusion Strong consensus was reached on (1) IPP based on the athlete's injury history, pre-season screening and evidence-based sports-specific injury rates; (2) IPP organization based on the athlete's age, competition level, and the availability of low-cost materials and (3) IPP implementation focussing on warm-up sessions implemented by the strength/conditioning coach, and/or individual prevention sessions by the physical therapist.

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. Methods We included individual responses to the Danish (n=157), English (n=146) and Norwegian (n=149) language versions of HAGOS from 452 athletes (median age 24 years old, range 20–28) with groin pain. Overall fit, model fit, individual item fit, local response dependence and measurement invariance was examined using confirmatory factor analysis and graphical Rasch models. Results The removal of seven misfitting items (S2, P1, P2, A4, SP1, SP5, Q3) resulted in 6 HAGOS subscales with acceptable psychometric properties. For the Symptoms, Pain and Sports subscales evidence of DIF was disclosed between the three different language-versions of HAGOS and conversion tables were created. Conclusions A revised HAGOS derived using modern test theory provides valid measurements for male multidirectional athletes with groin pain across different cultures and languages. Conversion tables must be applied to compare HAGOS scores from Danish, Norwegian and English language versions.

Background The Adductor Strengthening Programme (ASP) is the first groin specific prevention programme proven to reduce the risk of groin problems in male football. Widespread dissemination of the programme and its preventative effect is recommended, however, successful implementation require researchers acquiring comprehensive knowledge of the implementation context. Using the Reach Effectiveness Adoption Implementation Maintenance (RE-AIM) framework is recommended for this procedure. Objectives First, to investigate delivery agents’ attitudes, beliefs, and behaviour regarding the ASP using the RE-AIM framework. Second, to present a ‘best practice’ protocol based on the reported usage of the ASP in a professional team setting. Design Descriptive cross-sectional. Setting Norwegian male professional football teams. Participants The primary delivery agent of injury prevention exercise programmes in each team (n=32). Intervention Survey using a pilot tested questionnaire. Results Twenty-nine (91%) participants responded. All respondents (100%) were familiar with the ASP and its potential to mitigate the burden of groin problems. All delivery agents (100%) adopted the ASP, however, only 10% used it in accordance with the evidence-based protocol. The main modifications were that players in 72% of the teams were instructed to perform a non-progressive number of repetitions during pre-season, and 86% of the teams performed more sets, but fewer repetitions per set during in-season. In total, 97% of delivery agents planned to continue using the ASP in the subsequent season. The two most stated reasons for using the ASP, were first, its documented injury preventive effect and second, that it doesn’t require any additional equipment. Conclusion The delivery agents had positive attitudes and beliefs to the ASP. Moreover, they widely adopted and planned to maintain its usage in the next season. Most of the delivery agents modified the original ASP protocol, which warrant further investigations.