Towards Active Learning for Action Spotting in Association Football Videos

Association football is a complex and dynamic sport, with numerous actions occurring simultaneously in each game. Analyzing football videos is challenging and requires identifying subtle and diverse spatio-temporal patterns. Despite recent advances in computer vision, current algorithms still face significant challenges when learning from limited annotated data, lowering their performance in detecting these patterns. In this paper, we propose an active learning framework that selects the most informative video samples to be annotated next, thus drastically reducing the annotation effort and accelerating the training of action spotting models to reach the highest accuracy at a faster pace. Our approach leverages the notion of uncertainty sampling to select the most challenging video clips to train on next, hastening the learning process of the algorithm. We demonstrate that our proposed active learning framework effectively reduces the required training data for accurate action spotting in football videos. We achieve similar performances for action spotting with NetVLAD++ on SoccerNet-v2, using only one-third of the dataset, indicating significant capabilities for reducing annotation time and improving data efficiency. We further validate our approach on two new datasets that focus on temporally localizing actions of headers and passes, proving its effectiveness across different action semantics in football. We believe our active learning framework for action spotting would support further applications of action spotting algorithms and accelerate annotation campaigns in the sports domain.Comment: Accepted at CVSports'2

Characteristics of potential head injury situations at the FIFA World Cup Qatar 2022 TM

This exploratory video analysis study aimed to review characteristics of potential head injury situations during a men’s professional international football tournament. For 64 matches of the FIFA World Cup Qatar 2022™ FIFA analysts used match footage to record all potential head injury situations. A potential head injury situation was defined as a player staying down for more than 5 s and/or requesting medical attention, and where the body impact location included the player’s head. Characteristics were further recorded for match, player (i.e. player action including aerial duels), medical assessment, and outcome (e.g. substitution). Descriptive statistics are reported as well as Pearson’s Chi-squared test (or Fisher’s exact test) to explore potential head injury situations more likely to result in medical attention. In total, 149 potential head injury situations occurred in 56 matches (mean 2.33/match, range 0–6) involving 117 players. Eight matches resulted in no incidents. Aerial duels were the most frequent match characteristic leading to a potential head injury situation. Injury stoppage with on-pitch medical assessment occurred in 35 of the 149 potential head injury situations (23%), with pitch-side assessment also occurring in 15 situations (10%), resulting in four concussion substitutions. Players were more likely to require medical attention for potential head injuries sustained when the ball was loose (χ2 = 6.88; p = 0.038) when the injured player was jumping (FET p = 0.044) and for head-to-head contact (FET p = <0.001). Further exploration of aerial duels during match play which do and do not lead to potential and actual head injuries is recommended

Broadening our understanding of injury mechanisms to include at-risk situations: an overview of potential injuries at the FIFA men’s World Cup Qatar 2022TM

This study aims to examine and describe the characteristics of potential injury situations during a men’s professional international tournament quantified using the FIFA Football Language Medical Coding. A prospective study was conducted during the 64 matches of the FIFA World Cup Qatar 2022™, during which five analysts recorded potential injury situations from video analysis. ”Potential injuries” were recorded when players stayed down > 5 s and/or requested medical attention. Characteristics were further recorded for variables such as opponent’s action and body location. In total, 720 potential injury situations were recorded of which 139 required medical assessment. The actions which resulted in most potential injuries were running while receiving a pass (74; 10%), while passing the ball (59; 8%), and while progressing with the ball (48; 7%). Duels and ball progression led to a potential injury in 3.0% and 2.1% of all similar actions in total. Both aerial duels and ball progression led to an potential injury that required medical assessment on 0.4% of occasions. Most potential injuries involved the head (149; 21%), foot (120; 17%), or lower leg (110; 15%) with most medical assessments of the head (35; 25%), lower leg (17; 12%), and knee (15; 11%) with a median duration of 47 seconds (IQR 28–61). This study provides a detailed overview of match circumstances that may have a higher injury risk. Although some variables within the coding system need improvement to increase reliability, its use will allow a more detailed comparison of differences between high-risk player actions leading to injury and those that do not, which can improve future prevention strategies

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Muscle strength in adults with spinal cord injury: a systematic review of manual muscle testing, isokinetic and hand held dynamometry clinimetrics

Objectives The objectives of this systematic review were to synthesise the best available evidence regarding the clinimetrics for manual muscle testing (MMT), isokinetic dynamometry (ID) and hand held dynamometry (HHD) in the assessment of muscle strength in adults with spinal cord injury (SCI) and determine whether there is research evidence to recommend HHD as the standard tool for measuring muscle strength in adults with SCI. Inclusion Criteria: Only studies related to adults with SCI and MMT and/or ID and/or HHD were included. Search Strategy The search sought to identify any relevant English language published or unpublished studies via a three step search strategy. Methodological quality Two independent reviewers assessed the methodological quality of the studies using the quality evaluation tool consensus-based standards for the selection of health status instruments (COSMIN). Data collection An original data extraction form was developed to extract quantitative data from the included studies. Data synthesis It was not appropriate to conduct a meta-analysis due to the heterogeneity of the included studies. Therefore, the results are presented in narrative text including raw data as presented in the included studies as well as the contextual data. Results Eleven studies met the inclusion criteria of this systematic review. The results demonstrated that MMT showed varying inter-tester reliability over 10 muscle groups tested, ID demonstrated good reliability for the shoulder but not the elbow, HHD showed good reliability and validity for the upper limb and trunk, as well as good results for responsiveness and interpretability. Positive correlations were seen between MMT, ID and HHD particularly at the lower MMT grades. However, change in muscle strength scores seen on ID and HHD testing were not always correlated with changes in MMT grade. Significant overlapping of scores was seen between MMT and HHD particularly for grades 4 and 5 with MMT unable to detect subtle changes in muscle strength compared with dynamometry. Conclusions In conclusion, when considering the clinimetrics of the 3 methods for assessing muscle strength in adults with SCI there does appear to be support in the literature to recommend the wider application of HHD compared with MMT and ID.Thesis (M.Clin.Sc.) -- University of Adelaide, School of Translational Health Science, 2014

Quality Criteria for Studies Assessing the Acute Effects of Heading:Results from a UEFA Expert Panel

There is increasing concern regarding the effects of heading in football on brain health including cognitive, behavioural and neuromotor function, with research suggesting an association between repeated ball-head impacts and neurodegenerative disease. While longitudinal studies to determine the long-term consequences of heading are challenging, there have been short-term ‘acute’ studies conducted, with some studies lacking appropriate methodology to ensure valid results. The Union of European Football Associations (UEFA) established a panel of experts to determine methodological recommendations for the conduct of studies that explore the acute effects of heading (defined as a single session of heading conducted either in a laboratory setting or following match play or a training session). The aim of this panel was to create quality criteria for acute heading studies that will form part of the eligibility assessment when applying for UEFA research funding (although the criteria can be applied to the conduct of acute heading research more widely). This process was deemed necessary to counter studies with poor methodological quality that used heading trials that did not accurately represent player exposure to ball-head impacts through football practice and match play (such as small sample sizes, unrealistically high heading exposure, and a lack of consideration of confounding variables). The panel identified core design decisions that authors should consider when designing and conducting acute heading research, with key methodological requirements for each domain pertaining to participants, heading trials, confounding variables, statistics and dependent/target variables and their measurement. After two rounds of reviews, the final list of quality criteria was agreed by the panel and will be applied to the next round of UEFA grant applications.</p

Head impact events in youth football in India and Australia, compared to FIFA Men's World Cup matchesPractical Implications:

Summary: Objectives: This observational study compared incidence and characteristics of head impact events in matches in male youth under-18 football within Australia and India, to the Men's FIFA World Cup™ (FWC). Methods: Ten match videos from Australia, India and the 2018 FWC (total n ​= ​30) were coded for head impact events (purposeful headers and unintentional head impacts), match result as well as incidence rates (IR) per 1000 match-hours for heading performance characteristics. One-Way ANOVAs were conducted to assess statistical significance of heading IR and other characteristics. Results: Purposeful headers (n ​= ​2734) were the most common head impact event (97%) with significantly more headers being completed by players from India (IR:3239) compared to Australia (IR: 2096) and FWC (IR: 2509). Most headers were completed during free play, via contact with the players forehead. Heading duels were more common in FWC matches (32%), than those in Australia (23%) or India (19%) (p ​< ​0.001). More headers occurred in the centre of the pitch (range 36–48%), with centre-backs completing the most headers across all groups (range 30–33%). Winning teams in India performed more headers from set-pieces than losing teams (p ​< ​0.001). In FWC matches, winning teams performed more headers in the defensive third compared to losing teams (p ​= ​0.02). Conclusion: Despite similar heading characteristics across both U18 groups and the FWC, players in India recorded higher heading incidence, suggesting that heading guidelines would benefit from being country and age specific

Effectiveness of a nonoperative tailored treatment and return to sport of a rugby union player after a cervical spine disc herniation: a case report

Abstract: BACKGROUND: This case report aims to illustrate the nonoperative rehabilitation of a rugby union player following a cervical spine disc herniation with neck pain and radicular pain. CASE PRESENTATION: A 23-year-old male rugby player presented with neck pain and radicular pain and was evaluated using clinical and neck-motor control assessments, self-report questionnaires, neck-strength, and magnetic resonance imaging. OUTCOME AND FOLLOW-UP: A well-structured rehabilitation program was followed to ensure early recovery and optimal functional outcome. The player was able to participate in full rugby training sessions without limitation. He returned to his previous level of performance, playing in the first team. DISCUSSION: This is the first case report of a rugby union player with an isolated disc herniation managed with nonoperative treatment. The treatment objectives, interventions, and assessments are provided in detail. JOSPT Cases 2023;3(4):260-266. Epub 25 September 2023. doi:10.2519/josptcases.2023.11886 pain. CASE PRESENTATION: A 23-year-old male rugby player presented with neck pain and radicular pain and was evaluated using clinical and neck-motor control assessments, self-report questionnaires, neck-strength, and magnetic resonance imaging. OUTCOME AND FOLLOW-UP: A wellstructured rehabilitation program was followed to ensure early recovery and optimal functional outcome. The player was able to participate in full rugby training sessions without limitation. He returned to his previous level of performance, playing in the first team. i DISCUSSION: This is the first case report of a rugby union player with an isolated disc herniation managed with nonoperative treatment. The treatment objectives, interventions, and assessments are provided in detail

The beautiful game for women: A spotlight on the 2023 Women's football medicine conference

Summary: The 9th FIFA Women's World Cup (FWWC) marked several milestones: the first hosted by two Nations, held in the Southern Hemisphere, comprising 32 teams, and >1.9million spectators (FWWC attendance record). The overwhelming success of the tournament stimulated huge public interest in women's football. The importance of maximising player health was apparent throughout the tournament with injuries and illnesses affecting team selection and performance, emphasising the need for continued focus on women's football player health. This short report summarises the key takeaway messages from the Women's Football Medicine Conference held online during the round stages of the 2023 FWWC