Thor Einar Gjerstad Andersen

• Peek, Kerry; Ross, Andrew; Andersen, Thor Einar; Meyer, Tim; Dahlén, Sara & Georgieva, Julia [Vis alle 9 forfattere av denne artikkelen] (2024). Heading in football: a systematic review of descriptors, definitions, and reporting methods used in heading incidence studies. Science and medicine in football. ISSN 2473-3938. doi: 10.1080/24733938.2024.2362191.
• Harøy, Joar; Bache-Mathiesen, Lena Kristin & Andersen, Thor Einar (2024). Lower HAGOS subscale scores associated with a longer duration of groin problems in football players in the subsequent season. BMJ Open sport & exercise medicine. ISSN 2055-7647. 10(2). doi: 10.1136/bmjsem-2023-001812.
• Thorarinsdottir, Solveig; Amundsen, Roar; Larmo, Arne Feilberg; Pedersen, Roar; Andersen, Thor Einar & Bahr, Roald [Vis alle 7 forfattere av denne artikkelen] (2024). Groin injuries in women's premier league football in Norway: A two-season prospective cohort study describing clinical and imaging characteristics. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 34(4). doi: 10.1111/sms.14611.
• Amundsen, Roar; Thorarinsdottir, Solveig; Larmo, A.; Pedersen, R.; Andersen, Thor Einar & Møller, Merete [Vis alle 7 forfattere av denne artikkelen] (2024). #ReadyToplay: hamstring injuries in women’s football–a two-season prospective cohort study in the Norwegian women’s premier league. Science and medicine in football. ISSN 2473-3938. doi: 10.1080/24733938.2024.2305389.
• Dunlop, Gordon; Ivarsson, Andreas; Andersen, Thor Einar; Brown, Susan; O’Driscoll, Gary & Lewin, Colin [Vis alle 11 forfattere av denne artikkelen] (2024). 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. Journal of Sports Sciences. ISSN 0264-0414. doi: 10.1080/02640414.2024.2307764.
• Amundsen, Roar; Thorarinsdottir, Solveig; Clarsen, Benjamin Matthew; Andersen, Thor Einar; Møller, Merete & Bahr, Roald (2023). #ReadyToPlay: health problems in women's football-a two-season prospective cohort study in the Norwegian premier league. British Journal of Sports Medicine. ISSN 0306-3674. 58(1), s. 4–11. doi: 10.1136/bjsports-2023-107141. Vis sammendrag

  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. We calculated average weekly prevalence, incidence and burden of all health problems reported. Results: We included 294 players (age: 22±4 years) from 11 teams. Response rate to the weekly questionnaire was 79%. On average, 32% (95% CI: 31% to 33%) of the players reported at least one health problem at any time and 22% (95% CI: 21% to 23%) reported a substantial health problem negatively affecting their training volume or performance. The overall incidence was 10.7 health problems per 1000 hours of football exposure. Sudden-onset injuries were most severe (68% of the total time loss), followed by gradual-onset injuries (25%) and illnesses (8%). Thigh was the most common injury location (26%), while knee injuries were most severe, causing 42% of the total injury time loss. Anterior cruciate ligament (ACL) injuries alone caused 30% of the total injury time loss. Conclusion: One in five players had a health problem negatively affecting their training volume or performance at any time. Sudden-onset injuries represented the most burdensome health problem. Thigh injuries were most frequent, while knee injuries, ACL injuries especially, were most severe.

• Waldén, Markus; Mountjoy, Margo; McCall, Alan; Serner, Andreas; Massey, Andrew & Tol, Johannes L. [Vis alle 16 forfattere av denne artikkelen] (2023). Football-specific extension of the IOC consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020. British Journal of Sports Medicine. ISSN 0306-3674. 57(21), s. 1341–1350. doi: 10.1136/bjsports-2022-106405. Vis sammendrag

  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. The Fédération Internationale de Football Association Medical Scientific Advisory Board established a panel of 16 football medicine and/or science experts, two players and one coach. With a foundation in the IOC consensus statement, the panel performed literature reviews on each included subtopic and performed two rounds of voting prior to and during a 2-day consensus meeting. The panel agreed on 40 of 75 pre-meeting and 21 of 44 meeting voting statements, respectively. The methodology and definitions presented in this comprehensive football-specific extension should ensure more consistent study designs, data collection procedures and use of nomenclature in future epidemiological studies of football injuries and illnesses regardless of setting. It should facilitate comparisons across studies and pooling of data.

• Moen, Christian; Andersen, Thor Einar; Clarsen, Benjamin Matthew; Madsen-Kaarød, Gitte & Dalen-Lorentsen, Torstein (2023). Prevalence and burden of health problems in top-level football referees. I Della Villa, F & Susta, D (Red.), Football Medicine - The Pursuit of Excellence - Abstract book. Calzetti Maricci editori. ISSN 9788860286871. s. 617–618.
• Amundsen, Roar; Thorarinsdottir, Solveig; Larmo, Arne; Pedersen, R.; Andersen, Thor Einar & Møller, Merete [Vis alle 7 forfattere av denne artikkelen] (2023). Hamstring injuries in the Norwegian women's Premier League. I Della Villa, F & Susta, D (Red.), Football Medicine - The Pursuit of Excellence - Abstract book. Calzetti Maricci editori. ISSN 9788860286871. s. 210–211.
• Andersen, Thor Einar (2023). Merit of video analysis. I Della Villa, F & Susta, D (Red.), Football Medicine - The Pursuit of Excellence - Abstract book. Calzetti Maricci editori. ISSN 9788860286871.
• Harøy, Joar; Bache-Mathiesen, Lena Kristin & Andersen, Thor Einar (2023). Pre-season HAGOS scores associated with the number of weeks with groin problems. I Della Villa, F & Susta, D (Red.), Football Medicine - The Pursuit of Excellence - Abstract book. Calzetti Maricci editori. ISSN 9788860286871.
• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar; Dalen-Lorentsen, Torstein; Tabben, Montassar; Chamari, Karim & Clarsen, Benjamin Matthew [Vis alle 7 forfattere av denne artikkelen] (2023). A new statistical approach to training load and injury risk: separating the acute from the chronic load. Biology of Sport. ISSN 0860-021X. 41(1), s. 119–134. doi: 10.5114/biolsport.2024.127388. Fulltekst i vitenarkiv Vis sammendrag

  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. A men’s Qatar Stars League football cohort (1 465 players, 1 977 injuries), where training load was defined as the number of minutes of activity, and a Norwegian elite U-19 football cohort (81 players, 60 injuries), where training load was defined as the session rating of perceived exertion (sRPE). Mixed logistic regression was run with training load on the current day (acute load) and cumulative past training load estimated by distributed lag non-linear models (chronic load) as independent variables. Injury was the outcome. An interaction between acute and chronic training load was modelled. In both football populations, we observed that the risk of injury on the current day for different values of acute training load was highest for players with low chronic load, followed by high and then medium chronic load. The slopes varied substantially between different levels of chronic training load, indicating an interaction. Modelling acute and chronic loads separately in regression models is a suitable statistical approach for analysing the association between relative training load and injury risk in injury prevention research. Sports scientists should also consider the potential for interactions between acute and chronic load.

• Vagle, Markus; Dalen-Lorentsen, Torstein; Moksnes, Håvard; Harøy, Joar; Bjørneboe, John Andreas & Andersen, Thor Einar (2023). Physical Performance Profiles in Norwegian Premier League Female Football: A Descriptive Study. International Journal of Sports Physiology and Performance (IJSPP). ISSN 1555-0265. 18(7), s. 695–703. doi: 10.1123/ijspp.2022-0360. Fulltekst i vitenarkiv
• Zein, Muhammad Ikhwan; Reurink, Gustaaf; Verhagen, Evert; Kerkhoffs, Gino M.M.J.; van der Horst, Nick & Goedhart, Edwin [Vis alle 12 forfattere av denne artikkelen] (2022). Study on Hamstring Re-injury Prevention (SHARP): protocol for an international multicentre, randomised controlled trial. BMJ Open. ISSN 2044-6055. 12(11). doi: 10.1136/bmjopen-2022-065816.
• Dalen-Lorentsen, Torstein; Andersen, Thor Einar; Thorbjørnsen, Christian; Brown, Michael; Tovi, David & Braastad, Anders [Vis alle 11 forfattere av denne artikkelen] (2022). Injury characteristics in Norwegian male professional football: A comparison between a regular season and a season in the pandemic. Frontiers in Sports and Active Living. ISSN 2624-9367. 4. doi: 10.3389/fspor.2022.915581. Fulltekst i vitenarkiv Vis sammendrag

  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. We invited all teams having participated in both seasons to export their injury data. Only teams that used the same medical staff to register injuries in both seasons were included, and to maximize data comparability between seasons, we applied a time-loss injury definition only. Seven of 13 teams agreed to participate and exported their injury data. Both seasons had 30 game weeks, but the 2020 season was 57 days shorter than the 2019 season. The match injury incidence did not differ significantly [incidence rate ratio 0.76 (0.48–1.20; p = 0.24) in the 2020 season compared to the 2019 season. Furthermore, we found no differences in the number of injuries, days lost to injury, matches missed to injury, or injury severity. We could not detect any differences between the two seasons, suggesting the congested match calendar combined with the safety measures in the 2020 season can be a safe alternative in future seasons.

• Stensø, Joakim Schanke; Andersen, Thor Einar & Harøy, Joar (2022). Adductor Strengthening Programme is successfully adopted but frequently modified in Norwegian male professional football teams: a cross-sectional study. BMJ Open. ISSN 2044-6055. 12(9). doi: 10.1136/bmjopen-2021-060611. Fulltekst i vitenarkiv Vis sammendrag

  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.

• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar; Dalen-Lorentsen, Torstein; Clarsen, Benjamin Matthew & Fagerland, Morten (2022). Assessing the cumulative effect of long-term training load on the risk of injury in team sports. BMJ Open sport & exercise medicine. ISSN 2055-7647. 8(2). doi: 10.1136/bmjsem-2022-001342. Fulltekst i vitenarkiv Vis sammendrag

  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). Different scenarios of the effect of sRPE on injury risk and the effect of relative sRPE on injury risk were simulated. These scenarios assumed that the probability of injury was the result of training load exposures over the previous 4 weeks. We compared seven different methods of modelling training load in their ability to model the simulated relationship. We then used the most accurate method, the distributed lag non-linear model (DLNM), to analyse data from Norwegian youth elite handball players (no. of players=205, no. of health problems=471) to illustrate how assessing the cumulative effect of training load can be done in practice. Results: DLNM was the only method that accurately modelled the simulated relationships between training load and injury risk. In the handball example, DLNM could show the cumulative effect of training load and how much training load affected health problem risk depending on the distance in time since the training load exposure. Conclusion: DLNM can be used to assess the cumulative effect of training load on injury risk.

• Moen, Christian; Andersen, Thor Einar; Clarsen, Benjamin Matthew; Madsen-Kaarød, Gitte & Dalen-Lorentsen, Torstein (2022). Prevalence and burden of health problems in top-level football referees. Science and medicine in football. ISSN 2473-3938. doi: 10.1080/24733938.2022.2055782. Fulltekst i vitenarkiv
• Sandmo, Stian Bahr; Matyasova, Katarina; Filipcik, Peter; Cente, Martin; Koerte, Inga Katharina & Pasternak, Ofer [Vis alle 10 forfattere av denne artikkelen] (2022). Changes in circulating microRNAs following head impacts in soccer. Brain Injury. ISSN 0269-9052. 36(4), s. 560–571. doi: 10.1080/02699052.2022.2034042. Fulltekst i vitenarkiv Vis sammendrag

  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. 89 samples were screened to detect microRNAs expressed after each exposure. Identified microRNAs were then validated in 98 samples to determine consistently deregulated microRNAs. Deregulated microRNAs were further explored using bioinformatics to identify target genes and characterize their involvement in biological pathways. Results: Accidental head impacts led to deregulation of eight microRNAs that were unaffected by high-intensity exercise; target genes were linked to 12 specific signaling pathways, primarily regulating chromatin organization, Hedgehog and Wnt signaling. Repetitive headers led to deregulation of six microRNAs that were unaffected by high-intensity exercise; target genes were linked to one specific signaling pathway (TGF-β). High-intensity exercise led to deregulation of seven microRNAs; target genes were linked to 31 specific signaling pathways. Conclusion: We identified microRNAs specific to accidental head impacts and repetitive headers in soccer, potentially being useful as brain injury biomarkers.

• Vagle, Markus; Dalen-Lorentsen, Torstein; Moksnes, Håvard; Harøy, Joar; Bjørneboe, John Andreas & Andersen, Thor Einar (2021). Fysisk prestasjonsevne blant norske elite kvinnefotballspillere - en deskriptiv studie. I Nyheim, Kurt Tomas (Red.), Book of Abstract - Idrettsmedisinsk høstkongress 2021. NIMF.
• Christensen, Karl Bang; Clausen, Mikkel Bek; King, Enda; Franklyn-Miller, Andrew; Harøy, Joar & Andersen, Thor Einar [Vis alle 8 forfattere av denne artikkelen] (2021). 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. British Journal of Sports Medicine. ISSN 0306-3674. 56(6), s. 333–339. doi: 10.1136/bjsports-2021-104412. Vis sammendrag

  Background: 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.

• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar; Clarsen, Benjamin & Fagerland, Morten Wang (2021). Handling and reporting missing data in training load and injury risk research. Science and medicine in football. ISSN 2473-3938. doi: 10.1080/24733938.2021.1998587. Vis sammendrag

  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. The simulations were based on a Norwegian Premier League men’s football dataset (n = 39). Internal training load was measured with the session Rating of Perceived Exertion (sRPE). External training load was the total distance covered measured by a global positioning systems (GPS) device. Results: Only 37 (34%) of 108 studies reported whether training load had any missing observations. Multiple Imputation using Predicted Mean Matching was the best method of handling missing data across multiple scenarios. Conclusion: Studies of training load and injury risk should report the extent of missing data, and how they are handled. Multiple Imputation with Predicted Mean Matching should be used when imputing sRPE and GPS variables.

• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar; Dalen-Lorentsen, Torstein; Clarsen, Benjamin Matthew & Fagerland, Morten (2021). Not straightforward: modelling non-linearity in training load and injury research. BMJ Open sport & exercise medicine. ISSN 2055-7647. 7(3), s. 1–9. doi: 10.1136/bmjsem-2021-001119. Fulltekst i vitenarkiv Vis sammendrag

  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. Simulations were carried out to compare the ability of seven methods to model non-linear relationships, using visualisations, root-mean-squared error and coverage of prediction intervals as performance metrics. Results: No relationships were identified in the football cohorts; however, a J-shaped relationship was found between sRPE and the probability of injury on the same day for elite youth handball players (p<0.001). In the simulations, the only methods capable of non-linear modelling relationships were the quadratic model, fractional polynomials and restricted cubic splines. Conclusion: The relationship between training load and injury risk should be assumed to be non-linear. Future research should apply appropriate methods to account for non-linearity, such as fractional polynomials or restricted cubic splines. We propose a guide for which method(s) to use in a range of different situations.

• Jones, Steven; Mullen, Rich; Clair, Zoe; Wrigley, Russ; Andersen, Thor Einar & Williams, Morgan (2021). Field based lower limb strength tests provide insight into sprint and change of direction ability in academy footballers. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. doi: 10.1111/sms.14039. Fulltekst i vitenarkiv Vis sammendrag

  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. Participants (n = 146; age 14.2 ± 2.2 years; stature 166.3 ± 15.4 cm; body mass 55.6 ± 15.6 kg) performed maximal countermovement jump (CMJ), Nordic hamstring strength (NHS), isometric hip adductor (ADD)/abductor (ABD), 5 m, 10 m, 20 m sprints, and modified 505 agility test. All strength measures were allometrically scaled to account for body weight. Between-limb differences were reported as imbalance scores. Principal component analysis reduced sprint and COD variables to a single “running ability” component score. Scaled strength and imbalance, when controlled for age, were associated with “running ability” (adjusted R2 = 0.78, p < 0.001). Significant effects on “running ability” included the following: age, CMJ impulse, NHS, and hip-ADD. When the sprint and COD variables were explored independently, age and CMJ-impulse were featured in all sprint and COD models. For 10 m and 20 m sprint distances, hip-ADD emerged as a significant effect. Mean 505 performance was explained by age, CMJ-impulse, hip-ADD, but also with the addition of NHS. Our findings suggest that insight into the underpinning strength qualities of “running ability” of academy footballers can be obtained from a suite of field-based tests.

• Dalen-Lorentsen, Torstein; Ranvik, Andreas M.; Bjørneboe, John Andreas; Clarsen, Benjamin Matthew & Andersen, Thor Einar (2021). Facilitators and barriers for implementation of a load management intervention in football. BMJ Open sport & exercise medicine. ISSN 2055-7647. 7(2), s. 1–9. doi: 10.1136/bmjsem-2021-001046. Fulltekst i vitenarkiv Vis sammendrag

  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. The questionnaires used were based on similar studies using the Reach, Effectiveness, Adoption, Implementation and Maintenance framework. Results: We recorded answers from 250 players and 17 coaches. Most players (88%) reported that scientific evidence showing improved performance from the intervention measures is a key facilitator to completing the intervention. Similarly, coaches reported that the most important facilitator was scientific evidence that the preventive measures were effective (100%). Players reported that the coach’s attitude to preventive measures was important (86%), and similarly, 88% of coaches reported that the player’s attitude was important. Conclusions: By having a mutual positive attitude towards the intervention, players and coaches can positively contribute to each other’s motivation and compliance. Both players and coaches reported scientific evidence for load management having injury-preventive and performance-enhancing effect and being time efficient as important facilitators.

• Jones, Steven; Clair, Zoe; Wrigley, Russ; Mullen, Rich; Andersen, Thor Einar & Williams, Morgan (2021). Strength development and non-contact lower limb injury in academy footballers across age groups. Scandinavian Journal of Medicine & Science in Sports. ISSN 0905-7188. 31(3), s. 679–690. doi: 10.1111/sms.13889. Vis sammendrag

  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. Furthermore, this study: reports normative strength data of emerging field-based tests that can be easily deployed in football academies; explores the effect of age on injury occurrence; and highlights the number of days lost from injury in male youth footballers. Assessments of hip adductor, abductor, and eccentric knee flexor strength were obtained from 195 academy football players during pre-season and at the end of season. In-season injuries were recorded by medical staff. Those footballers who sustained non-contact lower limb injury were compared with those who did not sustain a non-contact lower limb injury. No between-group differences were observed for any strength assessments when controlled for pre-season measures. Stronger footballers at pre-season experienced strength loses, while those weaker players gained strength across the season. Hip strength development was impaired in older age group footballers. Sustaining a non-contact lower limb injury had minimal impact on strength development. In the absence of in-season lower limb strength monitoring, development in academy youth footballers may not progress as expected, and in particular, stronger and older youth athletes may benefit from individualized strength training.

• Dalen-Lorentsen, Torstein; Andersen, Thor Einar; Bjørneboe, John Andreas; Vagle, Markus; Martin, Kevin Nordanger & Kleppen, Michael [Vis alle 8 forfattere av denne artikkelen] (2021). A Cherry, Ripe for Picking: The Relationship Between the Acute-Chronic Workload Ratio and Health Problems. Journal of Orthopaedic and Sports Physical Therapy. ISSN 0190-6011. 51(4), s. 162–173. doi: 10.2519/jospt.2021.9893. Fulltekst i vitenarkiv Vis sammendrag

  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. The relationship between players' training load and health was analyzed using a range of different definitions of ACWR and health problems. We used 21-day and 28-day chronic periods, coupled and uncoupled calculations, and the exponentially weighted moving average and rolling average. Acute-chronic workload ratio data were categorized as low, medium, or high, using predefined categories and z scores. We compared medium to high, medium to low, and low to high categories. The outcome was defined in 3 ways: “all health problems,” “all injuries,” and “new noncontact injuries.” We performed random-effects logistic regression analyses of all combinations, for a total of 108 analyses. Results: We recorded 6250 athlete-days and 196 health problems. Of the 108 analyses performed, 23 (21%) identified a statistically significant (P<.05) association between the ACWR and health problems. A greater proportion of significant associations were identified when using an exponentially weighted moving average (44% of analyses), when comparing low to high categories (33%), and when using the “all health problems” definition (33%). Conclusion: The relationship between the ACWR and health problems was dependent on methodological approach.

Se alle arbeider i Cristin

• Dalen-Lorentsen, Torstein; Bjørneboe, John Andreas; Harøy, Joar & Andersen, Thor Einar (2024). We stand with the players: a call to action for the football community. British Journal of Sports Medicine. ISSN 0306-3674. doi: 10.1136/bjsports-2023-108041.
• Bjørneboe, John Andreas; Andersen, Thor Einar & Dahlén, Sara (2024). Brain health in female football players.
• Bahr, Roald & Andersen, Thor Einar (2024). OSTRC & IHS presentations.
• Andersen, Thor Einar (2024). Rehabilitering etter commotio i idretten (Idrettsmodellen).
• Andersen, Thor Einar (2024). Akutt vurdering av hodetraume i idretten.
• Andersen, Thor Einar (2024). Workshop: Prevention of growth-related groin and pelvic injuries in youth athletes.
• Dijkstra, H. Paul; Mc Auliffe, Seán; Ardern, Clare L.; Kemp, Joanne L.; Mosler, Andrea Britt & Price, Amy [Vis alle 20 forfattere av denne artikkelen] (2023). Infographic. Oxford consensus on primary cam morphology and femoroacetabular impingement syndrome—natural history of primary cam morphology to inform clinical practice and research priorities on conditions affecting the young person’s hip. British Journal of Sports Medicine. ISSN 0306-3674. 57(6), s. 382–284. doi: 10.1136/bjsports-2022-106094.
• Andersen, Thor Einar & Harøy, Joar (2023). Femuroacetabular impingement hos unge idrettsutøvere (15-30 år): Tverrfaglig utredning og rehabilitering på Idrettens helsesenter - hvem sendes til ortopeden? .
• Andersen, Thor Einar (2023). Femuroacetabular impingement hos unge idrettsutøvere (15-30 år): Hva er femuroacetabular impingent (FAI)?
• Knapstad, Anders & Andersen, Thor Einar (2023). Forebygging av Hamstring Re-skade hos fotballspillere – det norske bidraget til «the SHARP study».
• Rygh, Simen; Andersen, Thor Einar & Harøy, Joar (2023). Hva er forekomsten av vekst-relaterte skader i underekstremitetene hos fotballspillere i et ungdomsakademi?
• Thorarinsdottir, Solveig; Amundsen, Roar; Larmo, Arne Feilberg; Pedersen, Roar; Andersen, Thor Einar & Bahr, Roald [Vis alle 7 forfattere av denne artikkelen] (2023). Groin injuries in womens premier league football in Norway.
• Thorarinsdottir, Solveig; Amundsen, Roar; Clarsen, Benjamin Matthew; Andersen, Thor Einar; Møller, Merete & Bahr, Roald (2023). #ReadyToPlay. Health problems in womens premier leage football.
• Andersen, Thor Einar (2023). Introduction to training load and injury risk research and best practice.
• Andersen, Thor Einar (2023). Hva er nytt om hodeskader i idrett 6th International Concussion Conference 2022?
• Andersen, Thor Einar (2023). Trauma – pelvis, limbs Head, face.
• Andersen, Thor Einar (2023). Opening & introduction .
• Holtzhausen, Louis; Dahlén, Sara; Sandmo, Stian Bahr & Andersen, Thor Einar (2023). Paneldiskusjon: Next steps in concussion awareness, diagnostics and management.
• Andersen, Thor Einar (2023). Nytt fra Amsterdam Concensus conference on sports related concussion.
• Andersen, Thor Einar (2023). Håndtering av hodeskade i idrett.
• Andersen, Thor Einar (2023). Hodeskader i idrett.
• Moen, Christian; Andersen, Thor Einar; Clarsen, Benjamin Matthew; Madsen-Kaarød, Gitte & Dalen-Lorentsen, Torstein (2023). Prevalence and burden of health problems in top-level football referees.
• Amundsen, Roar; Thorarinsdottir, Solveig; Larmo, Arne; Pedersen, R.; Andersen, Thor Einar & Møller, Merete [Vis alle 7 forfattere av denne artikkelen] (2023). Hamstring injuries in the Norwegian women's Premier League.
• Andersen, Thor Einar (2023). Merit of video analysis.
• Harøy, Joar; Bache-Mathiesen, Lena Kristin & Andersen, Thor Einar (2023). Pre-season HAGOS scores associated with the number of weeks with groin problems.
• Thorarinsdottir, Solveig; Amundsen, Roar; Bahr, Roald; Andersen, Thor Einar; Larmo, Arne & Pedersen, R. [Vis alle 7 forfattere av denne artikkelen] (2023). Groin injuries in women's Premier League football in Norway. I Della Villa, F & Susta, D (Red.), Football Medicine - The Pursuit of Excellence - Abstract book. Calzetti Maricci editori. ISSN 9788860286871.
• Thorarinsdottir, Solveig; Amundsen, Roar; Bahr, Roald; Andersen, Thor Einar; Larmo, Arne & Pedersen, R. [Vis alle 7 forfattere av denne artikkelen] (2023). Groin injuries in women's Premier League football in Norway.
• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar; Dalen-Lorentsen, Torstein; Tabben, Montassar; Chamari, Karim & Clarsen, Benjamin Matthew [Vis alle 7 forfattere av denne artikkelen] (2023). A new methodological approach to training load and injury risk.
• Thorarinsdottir, Solveig; Amundsen, Roar; Clarsen, Benjamin Matthew; Andersen, Thor Einar; Møller, Merete & Bahr, Roald (2022). INJURIES AND ILLNESS IN ELITE WOMEN’S FOTBALL IN NORWAY – A TWO-YEAR PROSPECTIVE COHORT STUDY .
• Andersen, Thor Einar (2022). Hodeskader i idrett – Workshop.
• Andersen, Thor Einar (2022). Hodeskader i idrett.
• Amundsen, Roar; Thorarinsdottir, Solveig; Clarsen, Benjamin Matthew; Andersen, Thor Einar; Møller, Merete & Bahr, Roald (2022). Health problems in the elite women`s football league in Norway - a prospective cohort study.
• Amundsen, Roar; Thorarinsdottir, Solveig; Pedersen, Roar; Larmo, Arne; Andersen, Thor Einar & Møller, Merete [Vis alle 7 forfattere av denne artikkelen] (2022). Hamstringsskader i elite kvinnefotball.
• Bahr, Roald & Andersen, Thor Einar (2022). The Oslo Sports Trauma Research Center (OSTRC), The Norwegian School of Sport Sciences.
• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar & Fagerland, Morten (2022). Modelling non-linearity in training load and injury risk research: A simulation study.
• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar & Fagerland, Morten (2022). Estimating cumulative protracted time-lagged effects of training load on sports injury.
• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar & Fagerland, Morten (2022). Developments in injury prevention methodology research – missing data in training load.
• Andersen, Thor Einar (2022). Hvor farlig er det å heade?
• Dalen-Lorentsen, Torstein; Bjørneboe, John Andreas; Vagle, Markus; Clarsen, Benjamin Matthew; Fagerland, Morten & Andersen, Thor Einar (2021). Kan styring av treningsbelastning redusere helseproblemer? En cluster-randomisert kontrollert studie av 482 junior-elite fotballspillere av begge kjønn.
• Dalen-Lorentsen, Torstein; Andersen, Thor Einar; Thorbjørnsen, Christian; Brown, Michael; Tovi, David & Braastad, Anders [Vis alle 11 forfattere av denne artikkelen] (2021). Skadedata fra eliteserien i fotball: Er det forskjeller mellon en vanlig sesong og en sesong i pandemien?
• Stensø, Joakim; Andersen, Thor Einar & Harøy, Joar (2021). Attitudes, beliefs, and behaviour to the adductor strengthening programme in male professional football - successfully adopted, but usually modified . British Journal of Sports Medicine. ISSN 0306-3674. 55. doi: 10.1136/bjsports-2021-IOC.389.
• Moen, Christian; Andersen, Thor Einar; Clarsen, Benjamin Matthew; Madsen-Kaarød, Gitte & Dalen-Lorentsen, Torstein (2021). Prevalence and burden of health problems in top-level football referees. British Journal of Sports Medicine. ISSN 0306-3674. 55. doi: 10.1136/bjsports-2021-IOC.387.
• Sandmo, Stian Bahr; Filipcik, Peter; Cente, Martin; Hanes, Jozef; Andersen, Thor Einar & Straume-Næsheim, Truls Martin [Vis alle 7 forfattere av denne artikkelen] (2021). Biomarkers in serum after head impact exposure in football. British Journal of Sports Medicine. ISSN 0306-3674. 55. doi: 10.1136/bjsports-2021-IOC.14.
• Sandmo, Stian Bahr; McIntosh, Andrew S.; Andersen, Thor Einar; Koerte, Inga K. & Bahr, Roald (2021). Evaluation of in-ear sensor systems for quantifying head impacts in youth football . British Journal of Sports Medicine. ISSN 0306-3674. 55. doi: 10.1136/bjsports-2021-IOC.11.
• Sandmo, Stian Bahr; Andersen, Thor Einar; Koerte, Inga K. & Bahr, Roald (2021). Head impact exposure in youth football – are current interventions hitting the target? . British Journal of Sports Medicine. ISSN 0306-3674. 55, s. A5–A6. doi: 10.1136/bjsports-2021-IOC.12.
• Andersen, Thor Einar (2021). Stressbrudd hos idrettsutøvere.
• Andersen, Thor Einar (2021). Sub- concussive head impacts in football.
• Andersen, Thor Einar (2021). Overview of the hamstring tendon.
• Andersen, Thor Einar (2021). The Oslo Sports Trauma Research Centre (OSTRC), The Norwegian School of Sport Sciences – Current Football Medicine Projects at OSTRC.
• Andersen, Thor Einar (2021). Introduction: What is next in the collaboration? .
• Stensø, Joakim; Andersen, Thor Einar & Harøy, Joar (2021). Attitudes, beliefs, and behaviour to the Adductor Strengthening Programme in male professional football: Successfully adopted, but usually modified.
• Moen, Christian; Andersen, Thor Einar; Clarsen, Benjamin Matthew; Madsen-Kaarød, Gitte & Dalen-Lorentsen, Torstein (2021). Prevalence and burden of health problems in top-level football referees.
• Sandmo, Stian Bahr; Filipcik, Peter; Cente, Martin; Hanes, Jozef; Andersen, Thor Einar & Straume-Næsheim, Truls Martin [Vis alle 7 forfattere av denne artikkelen] (2021). Biomarkers in serum after head impact exposure in football.
• Sandmo, Stian Bahr; Andersen, Thor Einar; Koerte, Inga K. & Bahr, Roald (2021). Head impact exposure in youth football – are current interventions hitting the target?
• Sandmo, Stian Bahr; McIntosh, Andrew S.; Andersen, Thor Einar; Koerte, Inga K. & Bahr, Roald (2021). Evaluation of in-ear sensor systems for quantifying head impacts in youth football.
• Andersen, Thor Einar (2021). What are the symptoms and impairments?
• Andersen, Thor Einar (2021). The future of load management in injury prevention: Where to now?
• Andersen, Thor Einar (2021). Load management: The hottest topic in injury prevention.
• Vagle, Markus; Dalen-Lorentsen, Torstein; Moksnes, Håvard; Harøy, Joar; Bjørneboe, John Andreas & Andersen, Thor Einar (2021). Physical performance profiles in elite female football: a descriptive study.
• Bache-Mathiesen, Lena Kristin; Andersen, Thor Einar; Dalen-Lorentsen, Torstein; Clarsen, Benjamin Matthew & Fagerland, Morten (2021). A peek behind the study... [Tidsskrift]. BMJ Open Sport & Exercise Medicine.
• Spencer, Matthew; Wiig, Håvard; Andersen, Thor Einar & Luteberget, Live (2020). INDIVIDUAL RESPONSE TO EXTERNAL TRAINING LOAD IN ELITE FOOTBALL PLAYERS.
• Andersen, Thor Einar (2020). Overview of the hamstring tendon.
• Andersen, Thor Einar (2020). Prevention of muscle injuries in top level football - a Delphi study.
• Andersen, Thor Einar (2020). On-field management of acute musculo-skeletal trauma.
• Andersen, Thor Einar (2020). Skills and role of the physiotherapist within a football team.
• Bache-Mathiesen, Lena Kristin; Fagerland, Morten & Andersen, Thor Einar (2023). Improving the Methodology of Training Load and Injury Risk Research: An Analysis of Analyses. Norges idrettshøgskole.
• Dalen-Lorentsen, Torstein; Andersen, Thor Einar; Clarsen, Benjamin Matthew & Bjørneboe, John Andreas (2021). Training load and health problems in football: More complex than we first thought? Norges idrettshøgskole. ISSN 978-82-502-0597-0.
• Andersen, Thor Einar; Harøy, Joar & Stensø, Joakim Schanke (2021). Attitudes and beliefs regarding the Adductor Strengthening Programme among injury prevention delivery agents in Norwegian male elite football teams - a descriptive cross-sectional study . Norges idrettshøgskole.
• Andersen, Thor Einar; Harøy, Joar & Brun, Alexander (2021). Sammenheng mellom HAGOS i pre-season og rapporterte lyskeproblemer påfølgende sesong -en prospektiv kohortstudie blant mannlige fotballspillere fra Norges 2. og 3. nivå. Norges idrettshøgskole.
• Moen, Christian; Dalen-Lorentsen, Torstein & Andersen, Thor Einar (2021). Prevalence and burden of health problems in top-level football referees . Norges idrettshøgskole.
• Dalen-Lorentsen, Torstein; Bjørneboe, John Andreas; Vagle, Markus; Clarsen, Benjamin Matthew; Fagerland, Morten & Andersen, Thor Einar (2021). Kan styring av treningsbelastning redusere helseproblemer? En cluster-randomisert kontrollert studie av 482 junior-elite fotballspillere av begge kjønn. NIMF.
• Dalen-Lorentsen, Torstein; Andersen, Thor Einar; Thorbjørnsen, Christian; Brown, Michael; Tovi, David & Braastad, Anders [Vis alle 11 forfattere av denne artikkelen] (2021). Skadedata fra eliteserien i fotball -er det forskjeller mellom en vanlig sesong og en sesong i pandemien. NIMF.
• Larsen, Anders; Dalen-Lorentsen, Torstein & Andersen, Thor Einar (2020). Maskinlæring i profesjonell fotball . Norges idrettshøgskole.

Se alle arbeider i Cristin