Responsiveness and minimal important change of specific and generic patient-reported outcome measures for back patients: the Norwegian Neck and Back Register.

PURPOSE: To evaluate responsiveness and minimal important change (MIC) of Oswestry Disability Index (ODI), pain during activity on a numeric rating scale (NRSa) and health related quality of life (EQ-5D) based on data from the Norwegian neck and back registry (NNRR). METHODS: A total of 1617 patients who responded to NNRR follow-up after both 6 and 12 months were included in this study. Responsiveness was calculated using standardized response mean and area under the receiver operating characteristic (ROC) curve. We calculated MIC with both an anchor-based and distribution-based method. RESULTS: The condition specific ODI had best responsiveness, the more generic NRSa and EQ-5D had lower responsiveness. We found that the MIC for ODI varied from 3.0 to 9.5, from 0.4 to 2.5 for NRSa while the EQ5D varied from 0.05 to 0.12 depending on the method for calculation. CONCLUSION: In a register based back pain population, the condition specific ODI was more responsive to change than the more generic tools NRSa and EQ5D. The variations in responsiveness and MIC estimates also indicate that they should be regarded as indicative, rather than fixed estimates.

Symptom burden and follow-up of patients with neck and back complaints in specialized outpatient care: a national register study.

Back and neck pain are common in the population, especially among immigrants. In Norway's specialist care system, treating these patients typically involves a multidisciplinary approach based on the biopsychosocial model. However, language and cultural differences may create barriers to participation. Immigrants are often underrepresented in clinical studies, but a register-based approach can enhance their participation in research. This study aimed to compare both the symptom burden, and treatment, among Norwegians, non-Norwegians, and patients requiring translator service for back and neck pain within the Norwegian specialist care system. The Norwegian neck and back registry is a National Quality Register, established in 2012 and fully digitized in late 2020. The baseline data includes demographics and patient recorded outcome measures including Oswestry Disability Index, Fear-Avoidance Beliefs, pain rating on a numeric rating scale, Hopkins Symptom Checklist and EuroQol five-dimensional questionnaire on health related quality of life. During the two-year study period, a total of 14,124 patients were invited, and 10,060 (71%) participated. Norwegian patients reported less pain, better function assessed by Oswestry Disability Index, lower fear avoidance beliefs, less emotional distress, and higher health related quality of life compared to non-Norwegians. We found that patients with female gender, who were younger, more educated and exhibited fear-avoidance behavior were significantly more likely to receive multidisciplinary treatment. We found no difference in the proportion of Norwegian and non-Norwegian patients receiving multidisciplinary treatment [odds ratio (OR) 1.02 (95% confidence interval (CI) 0.90-1.16)]. However, patients needing a translator were less likely to receive multidisciplinary treatment compared to those who didn't require translation [OR 0.41 (95% CI (0.25-0.66)]. We found that non-Norwegian patients experience a higher symptom burden compared to Norwegian. We found that both non-Norwegians and patient in need of translator were to a greater extent recommended treatment in primary health care. The proportion of non-Norwegians patients receiving multidisciplinary treatment was similar to Norwegians, but those needing a translator were less likely to receive such treatment.

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]. 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.

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. 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.

Introducing a new method to record injuries during military training: a prospective study among 296 young Norwegian conscripts.

INTRODUCTION: Most epidemiological studies in the field of military medicine have been based on data from medical records and registries. The aims of this study were to test a self-reporting injury surveillance system commonly used in sports medicine in a military setting, and to describe the injury pattern among Norwegian army conscripts during a period of military training. METHOD: A total of 296 conscripts in His Majesty the King's Guard were asked to report all injuries each week for 12 weeks, using a modification of the Oslo Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H2). We recorded all injuries irrespective of their need for medical attention or consequences for military participation. In addition, we retrieved data on injuries recorded by military physicians in the medical record from the Norwegian Armed Forces Health Register. RESULTS: The mean weekly response rate was 74%. A total of 357 injuries were recorded, of which 82% were only captured through the OSTRC-H2 and 3% only in the medical records. The average weekly prevalence of injury was 28% (95% CI: 25% to 31%), and 10% (95% CI: 8% to 12%) experienced injuries with a substantial negative impact on training and performance. The greatest injury burden was caused by lower limb injuries, with knee and foot injuries as the predominant injury locations. CONCLUSION: The OSTRC-H2 is suitable for use in a military setting and records substantially more injuries than the standard medical record. The prevalence of injuries among conscripts is high and comparable with many elite sports.

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. 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. TRIAL REGISTRATION NUMBER: Trial registration number.

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. 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. J Orthop Sports Phys Ther 2021;51(4):162-173. Epub 20 Jan 2021. doi:10.2519/jospt.2021.9893.

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. METHODS: We cluster-randomised 34 elite youth football teams (16 females, 18 males) to an intervention group (18 teams) and a control group (16 teams). Intervention group coaches planned all training based on published ACWR load management principles using a commercially available athlete management system for a complete 10-month season. Control group coaches continued to plan training as normal. The prevalence of health problems was measured monthly in both groups using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. RESULTS: The between-group difference in health problem prevalence (primary outcome) was 1.8%-points (-4.1 to 7.7 %-points; p=0.55) with no reduction in the likelihood of reporting a health problem in the intervention group (relative risk 1.01 (95% CI 0.91 to 1.12); p=0.84) compared with the control group. CONCLUSIONS: We observed no between-group difference, suggesting that this specific load management intervention was not successful in preventing health problems in elite youth footballers. TRIAL REGISTRATION NUMBER: ISRCTN18177140.

Role of illness in male professional football: not a major contributor to time loss.

BACKGROUND: There are limited data on the nature, type and incidence of illness in football. Previous studies indicate that gastrointestinal and respiratory tract illnesses are most common. AIM: To describe the incidence and burden of illness in male professional football. METHODS: Over the 4-year study period, 2011-2014, 73 professional football teams in Europe participated, with a total of 1 261 367 player-days recorded. All time-loss illnesses were recorded by the medical staff of each club. A recordable illness episode was any physical or psychological symptom (not related to injury) that resulted in the player being unable to participate fully in training or match play. RESULTS: A total of 1914 illness episodes were recorded. The illness incidence was 1.5 per 1000 player-days, meaning that, on average, a player experienced an illness episode every second season, with a median of 3 days absence per illness episode. Severe illness (absence >4 weeks) constituted 2% of all illnesses. Respiratory tract illness was the most common (58%), followed by gastrointestinal illness (38%). Respiratory tract illness, gastrointestinal illness and cardiovascular illness caused the highest illness burden. CONCLUSIONS: The illness incidence among male professional football players is low compared with the injury incidence. We found that the highest illness burden was caused by illness to the respiratory tract, gastrointestinal tract and cardiovascular system.

No association between surface shifts and time-loss overuse injury risk in male professional football.

OBJECTIVES: To investigate frequent surface shifts and match play on an unaccustomed surface as potential risk factors for injury in Scandinavian male professional football. DESIGN: Prospective cohort study. METHODS: Thirty two top-division clubs (16 Swedish, 16 Norwegian) were followed during seasons 2010 and 2011. The influence from (1) number of surface shifts (between artificial turf and grass) during five-match sequences, and (2) match play on an unaccustomed surface (other surface than on the home venue) on subsequent overuse injury risk was evaluated with generalized estimating equations (GEE). GEE results are presented with risk ratios and 95% confidence interval (CI). Injury rate was expressed as time loss injuries/1000h, and compared between groups with a rate ratio and 95% CI. RESULTS: No association was found between the number of surface shifts and subsequent overuse injury risk (risk ratio 1.01, 95% CI 0.91-1.12). Furthermore, no difference was seen in subsequent overuse injury risk after match play on unaccustomed compared with accustomed surface (risk ratio 1.04, 95% CI 0.78-1.38). Grass clubs (grass installed at home venue) had a lower match injury rate when playing away matches on artificial turf compared with away matches on grass (rate ratio 0.66, 95% CI 0.40-0.89). CONCLUSIONS: This study showed no association between surface shifts or playing matches on an unaccustomed surface and time-loss injury risk in professional football, suggesting that clubs and players can cope with such surface transitions.

Three distinct mechanisms predominate in non-contact anterior cruciate ligament injuries in male professional football players: a systematic video analysis of 39 cases.

BACKGROUND: Current knowledge on anterior cruciate ligament (ACL) injury mechanisms in male football players is limited. AIM: To describe ACL injury mechanisms in male professional football players using systematic video analysis. METHODS: We assessed videos from 39 complete ACL tears recorded via prospective professional football injury surveillance between 2001 and 2011. Five analysts independently reviewed all videos to estimate the time of initial foot contact with the ground and the time of ACL tear. We then analysed all videos according to a structured format describing the injury circumstances and lower limb joint biomechanics. RESULTS: Twenty-five injuries were non-contact, eight indirect contact and six direct contact injuries. We identified three main categories of non-contact and indirect contact injury situations: (1) pressing (n=11), (2) re-gaining balance after kicking (n=5) and (3) landing after heading (n=5). The fourth main injury situation was direct contact with the injured leg or knee (n=6). Knee valgus was frequently seen in the main categories of non-contact and indirect contact playing situations (n=11), but a dynamic valgus collapse was infrequent (n=3). This was in contrast to the tackling-induced direct contact situations where a knee valgus collapse occurred in all cases (n=3). CONCLUSIONS: Eighty-five per cent of the ACL injuries in male professional football players resulted from non-contact or indirect contact mechanisms. The most common playing situation leading to injury was pressing followed by kicking and heading. Knee valgus was frequently seen regardless of the playing situation, but a dynamic valgus collapse was rare.

Video analysis of situations with a high-risk for injury in Norwegian male professional football; a comparison between 2000 and 2010.

BACKGROUND: A recent study from Norwegian male professional football found that the risk of acute match injuries increased from 2002 to 2007. OBJECTIVE: To compare the incidence of incidents with a propensity for injury, from the 2000 season to the 2010 season in Norwegian male professional football using video analysis. METHODS: We conducted a video analysis of incidents in Norwegian professional football. An incident was recorded if the match was interrupted by the referee, and the player lay down for more than 15 s, and appeared to be in pain or received medical treatment. We also conducted a video analysis of all player-to-player contact situations occurring during 30 randomly selected matches. RESULTS: A total of 1287 incidents were identified during the two seasons. The corresponding rate of incidents was 74.4 (95% CI 67.3 to 81.5) in the 2000 season and 109.6 (95% CI 102.3 to 116.9) in the 2010 season, a significant increase from 2000 to 2010 (rate ratio 1.47, 95% CI 1.31 to 1.66). We observed a significantly higher rate of opponent-to-player contact and non-contact incidents in the 2010 season, but no change in the proportion of fouls or sanctions awarded by the referee. The rate of player-to-player contact situations in both heading and tackling duels was lower during the 2010 season. CONCLUSIONS: We found an increased rate of non-contact and opponent-to-player contact incidents in both heading and tackling duels in the 2010 season compared with 10 years earlier, even if there was no increase in the frequency of player-to-player contact situations.

The Nordic Football Injury Audit: higher injury rates for professional football clubs with third-generation artificial turf at their home venue.

BACKGROUND: Previously, no difference in acute injury rate has been found when playing football on artificial turf (AT) compared with natural grass (NG). AIM: To compare acute injury rates in professional football played on AT and NG at the individual player level; and to compare, at club level, acute and overuse injury rates between clubs that have AT at their home venue (AT clubs) and clubs that have NG (NG clubs). METHODS: 32 clubs (AT, n=11; NG, n=21) in the male Swedish and Norwegian premier leagues were followed prospectively during the 2010 and 2011 seasons. Injury rate was expressed as the number of time loss injuries/1000 h and compared with rate ratio (RR) and 99% CI. RESULTS: No statistically significant differences were found in acute injury rates on AT compared with NG during match play (RR 0.98, 99% CI 0.79 to 1.22) or training (RR 1.14, 99% CI 0.86 to 1.50) when analysing at the individual player level. When analysing at the club level, however, AT clubs had a significantly higher acute training injury rate (RR 1.31, 99% CI 1.04 to 1.63) and overuse injury rate (RR 1.38, 99% CI 1.14 to 1.65) compared with NG clubs. CONCLUSIONS: At the individual player level, no significant differences were found in acute injury rates when playing on AT compared with NG. However, clubs with AT at their home venue had higher rates of acute training injuries and overuse injuries compared with clubs that played home matches on NG.

Lower incidence of arm-to-head contact incidents with stricter interpretation of the Laws of the Game in Norwegian male professional football.

BACKGROUND: Video analyses reveal that the rate of incidents with a propensity for injury caused by opponent-to-player contact has increased by about 50% from 2000 to 2010 in Norwegian male professional football. The aim of the study was to assess whether a stricter interpretation of the Laws of the Game (red cards for high elbows in heading duels and for late/two foot tackles) could reduce the potential for injuries in Norwegian male professional football. METHODS: A preintervention/postintervention design was employed, where the rate of incidents and injuries from the 2010 season (pre) was compared to the 2011 season (post). An incident was recorded if the match was interrupted by the referee, and the player lay down for more than 15 s, and appeared to be in pain or received medical treatment. Time-loss injuries were recorded by the medical staff of each club. RESULTS: A total of 1421 contact incidents were identified, corresponding to a rate of 92.7 (95% CI 86.0 to 99.4) in the 2010 season and 86.6 (95% CI 80.3 to 99.4) in the 2011 season, with no difference between the two season. We found a reduction in the incidence of total head incidents (rate ratio (RR) 0.81, 95% CI 0.67 to 0.99), and head-incidents caused by arm-to-head contact (RR 0.72, 95% CI 0.54 to 0.97). We found no difference in tackling characteristics or contact injury rate. CONCLUSIONS: We found no significant differences in the overall rate of incidents after the introduction of stricter rule enforcement. However, the rate of head and arm-to head incidents was lower in the 2011 season.

Risk of injury on third-generation artificial turf in Norwegian professional football.

BACKGROUND: Artificial turf is used extensively in both recreational and elite football in areas with difficult climatic conditions. OBJECTIVE: To compare the risk for acute injuries between natural grass (NG) and third-generation artificial turf (3GAT) in male professional football. study design: Prospective cohort study. METHODS: All injuries sustained by players with a first-team contract were recorded by the medical staff of each club, from the 2004 throughout the 2007 season. An injury was registered if the player was unable to take fully part in football activity or match play. RESULTS: A total of 668 match injuries, 526 on grass and 142 on artificial turf, were recorded. The overall acute match injury incidence was 17.1 (95% CI 15.8 to 18.4) per 1000 match hours; 17.0 (95% CI 15.6 to 18.5) on grass and 17.6 (95% CI 14.7 to 20.5) on artificial turf. Correspondingly, the incidence for training injuries was 1.8 (95% CI 1.6 to 2.0); 1.8 (95% CI 1.5 to 2.0) on grass and 1.9 (95% CI 1.5 to 2.2) on artificial turf respectively. No significant difference was observed in injury location, type or severity between turf types. CONCLUSION: No significant differences were detected in injury rate or pattern between 3GAT and NG in Norwegian male professional football.