Footballscience.net
As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases.
Following studies were retrieved for this week:
#1 Prediction of defensive success in elite soccer using machine learning - Tactical analysis of defensive play using tracking data and explainable AI
Reference: Sci Med Footb. 2023 Jul 21. doi: 10.1080/24733938.2023.2239766. Online ahead of print.
Authors: Leander Forcher, Tobias Beckmann, Oliver Wohak, Christian Romeike, Ferdinand Graf, Stefan Altmann
Summary: The interest in sports performance analysis is rising and tracking data holds high potential for game analysis in team sports due to its accuracy and informative content. Together with machine learning approaches one can obtain deeper and more objective insights into the performance structure. In soccer, the analysis of the defense was neglected in comparison to the offense. Therefore, the aim of this study is to predict ball gains in defense using tracking data to identify tactical variables that drive defensive success. We evaluated tracking data of 153 games of German Bundesliga season 2020/21. With it, we derived player (defensive pressure, distance to the ball, & velocity) and team metrics (inter-line distances, numerical superiority, surface area, & spread) each containing a tactical idea. Afterwards, we trained supervised machine learning classifiers (logistic regression, XGBoost, & Random Forest Classifier) to predict successful (ball gain) vs. unsuccessful defensive plays (no ball gain). The expert-reduction-model (Random Forest Classifier with 16 features) showed the best and satisfying prediction performance (F1-Score (test) = 0.57). Analyzing the most important input features of this model, we are able to identify tactical principles of defensive play that appear to be related to gaining the ball: press the ball leading player, create numerical superiority in areas close to the ball (press short pass options), compact organization of defending team. Those principles are highly interesting for practitioners to gain valuable insights in the tactical behavior of soccer players that may be related to the success of defensive play.
#2 Finite element brain deformation in adolescent soccer heading
Reference: Comput Methods Biomech Biomed Engin. 2023 Jul 21;1-11. doi: 10.1080/10255842.2023.2236746. Online ahead of print.
Authors: Colin M Huber, Declan A Patton, Jalaj Maheshwari, Zhou Zhou, Svein Kleiven, Kristy B Arbogast
Summary: Finite element (FE) modeling provides a means to examine how global kinematics of repetitive head loading in sports influences tissue level injury metrics. FE simulations of controlled soccer headers in two directions were completed using a human head FE model to estimate biomechanical loading on the brain by direction. Overall, headers were associated with 95th percentile peak maximum principal strains up to 0.07 and von Mises stresses up to 1450 Pa, and oblique headers trended toward higher values than frontal headers but below typical injury levels. These quantitative data provide insight into repetitive loading effects on the brain.
#3 Determining the effect of one decade on fitness of elite Austrian youth soccer players using propensity score matching
Reference: Front Sports Act Living. 2023 Jul 5;5:1186199. doi: 10.3389/fspor.2023.1186199. eCollection 2023.
Authors: Christoph Gonaus, Erich Müller, Thomas Stöggl, Jürgen Birklbauer
Summary: Current trends in attacking strategies and increases in external workload have led to a need for fast and well-conditioned athletes in modern soccer. More recently, progressions in speed, coordination, power and endurance were found over a decade in elite Austrian youth players. However, possible confounders such as relative age, maturation, learning effects, and academy philosophy may have influenced these changes. The present study aimed to determine the decade effect on fitness under statistical control of players' exact age, height, body mass, test location as well as total number of pretests and time interval between test and pretest. Players annually completed a battery of anthropometric, general and soccer-specific fitness tests. MANCOVA was calculated to identify the overall impacts of the covariates on fitness. To balance the covariates of initially 2,530 "former" (2002 to 2005) and 2,611 "recent" (2012 to 2015) players, 1:1 nearest neighbor propensity score (PS) matching was used, resulting in 587 U13, 573 U14, 475 U15, 325 U16, 262 U17, and 129 U18 matched pairs. The decade effect on fitness was assessed by independent t-tests and Cohen's d separately at each age group. Superior performances of recent players were found for linear sprint across all age categories (d = 0.154-0.476) as well as for agility (d = 0.125-0.340) and change-of-direction speed (d = 0.172-0.466) in U15 to U18. Reaction speed increased in U13 (d = 0.288) and U15 (d = 0.310). Flexibility reduced over the decade in all age categories (d = -0.151 to -0.589) and upper-limb power decreased (d = -0.278 to -0.347) in U13 and U14. Balancing the covariate distribution via PS matching generally confirmed previous findings, with fitness decade effects reflecting the athletic needs for modern soccer. Since fitness performance changed over time, reference values should be periodically updated. Coaches favor both physical and cognitive fast players nowadays. Thus, training should target all aspects of speed, without disregarding flexibility, upper-limb power and other preventive strategies that keep the players on the pitch.
#4 The Effect of COVID-19 on Home Advantage in Women's Soccer: Evidence From Swedish Damallsvenskan
Reference: Am Behav Sci. 2023 Sep;67(10):1168-1178. doi: 10.1177/00027642221118259. Epub 2022 Aug 23.
Authors: Alex Krumer, Vetle A O Smith
Summary: Most studies of the effect of COVID-19 restrictions on home advantage have been conducted on men's soccer, with the women's game lacking scientific attention. The present study fills this gap by investigating games in Swedish Damallsvenskan women's soccer league. Comparing games in the 2019 and 2020 seasons, we find a slight, but not statistically significant reduction in home advantage in games without crowds in terms of goals scored and points achieved. However, unlike in most studies on men's soccer, we find that away teams received significantly more yellow cards in games without crowds compared to games with crowds. We discuss our results in the context of the findings in men's soccer.
#5 Pre-sleep feeding, sleep quality, and markers of recovery in division I NCAA female soccer players
Reference: J Int Soc Sports Nutr. 2023 Dec;20(1):2236055. doi: 10.1080/15502783.2023.2236055.
Authors: Casey E Greenwalt, Elisa Angeles, Matthew D Vukovich, Abbie E Smith-Ryan, Chris W Bach, Stacy T Sims, Tucker Zeleny, Kristen E Holmes, David M Presby, Katie J Schiltz, Marine Dupuit, Liliana I Renteria, Michael J Ormsbee
Download link: https://www.tandfonline.com/doi/epdf/10.1080/15502783.2023.2236055?needAccess=true&role=button
Summary: Pre-sleep nutrition habits in elite female athletes have yet to be evaluated. A retrospective analysis was performed with 14 NCAA Division I female soccer players who wore a WHOOP, Inc. band - a wearable device that quantifies recovery by measuring sleep, activity, and heart rate metrics through actigraphy and photoplethysmography, respectively - 24 h a day for an entire competitive season to measure sleep and recovery. Pre-sleep food consumption data were collected via surveys every 3 days. Average pre-sleep nutritional intake (mean ± sd: kcals 330 ± 284; cho 46.2 ± 40.5 g; pro 7.6 ± 7.3 g; fat 12 ± 10.5 g) was recorded. Macronutrients and kcals were grouped into high and low categories based upon the 50th percentile of the mean to compare the impact of a high versus low pre-sleep intake on sleep and recovery variables. Sleep duration (p = 0.10, 0.69, 0.16, 0.17) and sleep disturbances (p = 0.42, 0.65, 0.81, 0.81) were not affected by high versus low kcal, PRO, fat, CHO intake, respectively. Recovery (p = 0.81, 0.06, 0.81, 0.92), RHR (p = 0.84, 0.64, 0.26, 0.66), or HRV (p = 0.84, 0.70, 0.76, 0.93) were also not affected by high versus low kcal, PRO, fat, or CHO consumption, respectively. Consuming a small meal before bed may have no impact on sleep or recovery.
#6 Factors Associated with Children's Physical Activity During Youth Soccer Practices
Reference: Res Q Exerc Sport. 2023 Jul 19;1-7. doi: 10.1080/02701367.2023.2225563. Online ahead of print.
Authors: Emily R Shull, Kerry McIver, Alexander C McLain, Eva Monsma, Russell R Pate
Summary: The aim was to identify practice and social contextual factors that associate with physical activity (PA) levels of children during their participation in a youth soccer program. Twenty-seven youth soccer teams serving children ages 6-11 years participated. Research staff directly observed and recorded PA intensity and practice and social contextual factors using momentary time-sampling procedures. Each team was observed for 1 practice, during which approximately 6 children were each observed for twenty 30-s observation blocks (10-s observation, 20-s recording). In total, children were observed for 3,102 intervals. Multilevel logistic regression analyses were conducted to describe associations between PA intensity and practice and social contexts. Interaction terms were introduced into the models to determine if the associations differed across girls-only, boys-only, and coed teams. A total of 158 children were observed across the 27 teams. Children were more likely to engage in moderate or vigorous PA while performing fitness (Odds Ratio [OR], 9.9, 95% CI = 5.34-18.04), game (OR, 4.0, 95% CI = 2.88-5.66), warm-up (OR, 2.8, 95% CI = 1.85-4.11), and drill (OR, 1.9, 95% CI = 1.41-2.67) activities compared to tactic/instructional activities. The associations between PA intensity levels and practice and social contexts did not differ across girls-only, boys-only, and coed teams. Fitness activities and full-team game play were associated with higher PA intensity levels during children's participation in youth soccer practices. Youth sport practice protocols can be modified to increase children's physical activity.
#7 Effects of peripheral electromagnetic stimulation after an eccentric exercise-induced delayed-onset muscle soreness protocol in professional soccer players: a randomized controlled trial
Reference: Front Physiol. 2023 Jul 3;14:1206293. doi: 10.3389/fphys.2023.1206293. eCollection 2023.
Authors: Hugo Keriven, Alberto Sánchez-Sierra, Diego Miñambres-Martín, Ángel González de la Flor, Guillermo García-Pérez-de-Sevilla, Diego Domínguez-Balmaseda
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10351376/pdf/fphys-14-1206293.pdf
Summary: The aim was to examine the effects of peripheral electromagnetic stimulation in male professional soccer players on markers of Delayed Onset Muscular Soreness (DOMS), induced by a protocol of exercise (60 min of eccentric and plyometric). A randomized controlled trial with fourty-five professional soccer players aged 22.33 ± 4.82 years participated in the study. Twenty-three participants were assigned to the experimental group with peripheral electromagnetic stimulation (5 stimulations of 5 s at 100 HZ with 55 s of rest for a total of 5 min of treatment) and the remaining 22 participants were assigned to the control group. Pain pressure threshold (PPT) of the vastus medialis, the Visual Analogue Scale-Fatigue (VAS-F), half squat (HS) test and the maximum voluntary contraction of the quadriceps were assessed. All evaluations were performed before and after 1 h of the eccentric exercise induced DOMS, as well as at post 24-48, and 72 h. Group-by-time interaction was observed in PPT of the vastus medialis (p = 0.040) with a medium effect size (η2 p = 0.069). From 48 to 72 h the experimental group showed an increase of PPT compared to control group (p = 0.015). There was no group-by-time interaction for HS, quadriceps strength and VAS-F (p > 0.05). Peripheral electromagnetic stimulation in male professional soccer players did not produce significant improvements in the power and strength of the lower limbs but decreased the peripheral sensitization of the vastus medialis after eccentric exercise protocol.
#8 Effects of dietary supplements on athletic performance in elite soccer players: a systematic review
Reference: J Int Soc Sports Nutr. 2023 Dec;20(1):2236060. doi: 10.1080/15502783.2023.2236060.
Authors: Rodrigo Abreu, Catarina B Oliveira, Júlio A Costa, João Brito, Vitor H Teixeira
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10355692/pdf/RSSN_20_2236060.pdf
Summary: Dietary supplements are widely used among athletes, and soccer players are no exception. Nevertheless, evidence supporting the use of dietary supplements aiming to enhance performance in soccer is somewhat contradictory, scarce, or even nonexistent. Thus, the present study aimed to systematically review and synthesize the effects of dietary supplements on athletic performance (e.g. distance covered, sprinting, jump performance) in elite soccer players. Studies enrolling highly trained, elite, and world-class soccer players using dietary supplements were searched in MEDLINE/PubMed, Web of Science, Scopus, and EBSCO databases in June 2022. In total, 1043 studies were identified, and 18 met the eligibility criteria. The studies evaluated the impacts on athletic performance of several dietary supplements, including caffeine, creatine, protein, beverages with carbohydrates and electrolytes, tart cherry juice, nitrate-rich beetroot juice, sodium bicarbonate with minerals, yohimbine, and a proprietary nutraceutical blend. Caffeine supplementation in doses between 3 and 6 mg/kg of body mass may improve jump height and sprint ability, particularly in female players, but individual response to caffeine must be considered. Creatine may improve sprint, agility, and in female players, jump performance. Protein supplementation can improve sprint and jump performance between matches, especially if protein ingested from food is not up to recommendations. Beverages containing carbohydrates and electrolytes can be used as part of the strategies to achieve carbohydrate intake during training and match-days but used alone do not benefit athletic performance. Tart cherry juice might be useful for maintaining athletic performance after matches that produce higher force loss and exercise-induced muscle damage, although polyphenols from the diet might attenuate the effects of tart cherry supplementation. Nitrate-rich beetroot concentrate can attenuate performance decrease in the days following matches. Further investigation with sodium bicarbonate alone is necessary, as supplementation protocols with elite players included other substances. Finally, the available data does not support yohimbine supplementation or the use of Resurgex Plus® to improve athletic performance in elite soccer players. Still, more well-designed research with elite soccer players is needed to improve support and advice regarding the use of dietary supplements for athletic performance enhancement.
#9 Quality of Life of Following Mild Traumatic Brain Injury in Youth Soccer Players Title Page
Reference: J Athl Train. 2023 Jul 18. doi: 10.4085/1062-6050-0011.23. Online ahead of print.
Authors: Scott L Rosenthal, Tess S Simpson, Michael W Kirkwood, Robin L Peterson
Summary: Pediatric mild traumatic brain injuries (mTBI) represent an evolving field of interest in youth athletics. While most players recover within 4 weeks, some have symptoms that last longer. Little is known about youth health-related quality of life (HRQoL) following mTBI. The aim was to characterize youth HRQoL following soccer-related mTBI and to identify predictors of individual differences in HRQoL recovery. Soccer players, ages 8-17 years, who sustained mTBI (n=23), orthopedic injuries (OI, n=24), or remained uninjured (n=23) during a single season participated in this study. HRQoL was assessed via the Pediatric Quality of Life Version 4.0 and post-concussive symptomatology via the Health and Behavior Index. Serial assessments occurred at 24-48 hours, 7 days, 30 days and 90 days post-injury via telephone interview. Seven days post-injury, the mTBI and OI groups had poorer Total HRQoL (F[2,67] =11.35, p<0.001) than uninjured controls. At 7 days, the mTBI group had the poorest Psychosocial HRQoL, while OI had the poorest Physical HRQoL. Differences between the mTBI group and uninjured controls resolved by 30 days. Within the mTBI group, players with significant post-concussive symptoms at 7 days had poorer Total (F[1,21]=23.071, p<=0.001; F[1,21]=5.798, p=0.028), Psychosocial (F[1,21]=16.488, p=<0.001; F[1,21]=5.050, p=0.039), and Physical HRQoL (F[1,21]=21.671, p=<0.001; F[1,21]=5.119, p=0.038) at 7 and 30 days than players with minimal symptoms, and these differences resolved by 90 days. As a groups, youth soccer players who sustained mTBI had transient impairments in HRQoL that resolved by 30 days. A subset of players with significant post-concussive symptoms at 7 days post-injury have poorer HRQoL for at least 30 days post-injury than those whose post-concussive symptoms had resolved within a week of injury. This suggests ongoing recovery in this subset at 30 days and potential utility of HRQoL as a measure of recovery.
#10 Cognitive Function and Heading Frequency Among Retired Professional Soccer Players-Heading for Clarity?
Reference: JAMA Netw Open. 2023 Jul 3;6(7):e2324368. doi: 10.1001/jamanetworkopen.2023.24368.
Authors: Peter Ueda
Download link: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2807344
#11 Heading Frequency and Risk of Cognitive Impairment in Retired Male Professional Soccer Players
Reference: JAMA Netw Open. 2023 Jul 3;6(7):e2323822. doi: 10.1001/jamanetworkopen.2023.23822.
Authors: Shima Espahbodi, Eef Hogervorst, Tara-Mei Povall Macnab, Ahmed Thanoon, Gwen Sacha Fernandes, Bonnie Millar, Ashley Duncan, Maria Goodwin, Mark Batt, Colin W Fuller, Gordon Fuller, Eamonn Ferguson, Tobias Bast, Michael Doherty, Weiya Zhang
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10352859/?report=reader
Summary: Although professional soccer players appear to be at higher risk of neurodegenerative disease, the reason remains unknown. The aim was to examine whether heading frequency is associated with risk of cognitive impairment in retired professional soccer players. A UK nationwide cross-sectional study was conducted between August 15, 2020, and December 31, 2021, in 459 retired male professional soccer players older than 45 years and registered with the Professional Footballers' Association or a League Club Players' Association. Data on heading frequency in 3 bands-0 to 5, 6 to 15, and more than 15 times per match or training session and other soccer-specific risk factors, such as player position and concussion-were collected through a self-reported questionnaire. Cognitive impairment was defined using the Telephone Interview for Cognitive Status-modified as scores of less than or equal to 21. Hopkins Verbal Learning Test, verbal fluency, and independent activities of daily living were also assessed. Test Your Memory and physician-diagnosed dementia/Alzheimer disease were self-reported via the questionnaire. Adjusted odds ratios (AORs) with 95% CIs were calculated. Of 468 retired male professional soccer players who completed questionnaires (mean [SD] age, 63.68 [10.48]; body mass index, 27.22 [2.89]), 459 reported heading frequency: 114 headed 0 to 5 times, 185 headed 6 to 15 times, 160 headed more than 15 times per match, and 125 headed 0 to 5 times, 174 headed 6 to 15 times, and 160 headed more than 15 times per training session during their careers. The prevalence of cognitive impairment was 9.78% (0-5 times), 14.78% (6-15 times), and 15.20% (>15 times) per match (P = .51). Compared with players reporting 0 to 5 headers per match, the AORs were 2.71 (95% CI, 0.89-8.25) for players reporting 6 to 15 headers per match and 3.53 (95% CI, 1.13-11.04) for players reporting more than 15 headers per match (P = .03 for trend). Corresponding AORs for heading frequency per training session were 2.38 (95% CI, 0.82-6.95) for those reporting 6 to 15, and 3.40 (95% CI, 1.13-10.23) for those reporting more than 15 in comparison with those who reported 0 to 5 (P = .03 for trend). Concussion involving memory loss was also associated with a greater risk of cognitive impairment (AOR, 3.16; 95% CI, 1.08-9.22). Similar results were observed with other cognitive tests and self-reported physician-diagnosed dementia/Alzheimer disease. The findings of this study suggest that repetitive heading during a professional soccer career is associated with an increased risk of cognitive impairment in later life. Further study is needed to establish the upper threshold for heading frequency to mitigate this risk.
#12 Streaming the beautiful game: exploring big tech's growing presence in the soccer industry
Reference: Front Sports Act Living. 2023 Jun 29;5:1156601. doi: 10.3389/fspor.2023.1156601. eCollection 2023.
Authors: Alexis Fakataulavelua, Markus Lang, Jérémy Moulard
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10339385/pdf/fspor-05-1156601.pdf
Summary: This study investigates the evolving role of major technology corporations-namely, Amazon, Apple, Microsoft, Facebook, Netflix, and Google-in the sports industry, with a specific focus on soccer. By employing a qualitative content analysis of media reports, scientific literature, and annual reports from 2000 to 2021, the research scrutinizes the varying approaches and investments of these tech giants in the domain of sports. The findings classify these companies into three distinct categories: (1) those actively securing broadcast rights for major competitions and leagues (Google, Facebook, Amazon); (2) those primarily producing and disseminating soccer documentaries (Netflix); and (3) those not directly engaging in media rights but advancing the technological aspects of clubs and leagues (Apple and Microsoft). This study underscores the escalating significance of Big Tech in reshaping the sports media landscape and calls for further research to comprehend the broader implications of their presence in sports broadcasting and fan engagement.
#13 Effects of combined plyometric, strength and running technique training program on change-of-direction and countermovement jump: A two-armed parallel study design on young soccer players
Reference: Gait Posture. 2023 Jul 1;105:27-34. doi: 10.1016/j.gaitpost.2023.06.025. Online ahead of print.
Authors: Ricardo Martín-Moya, Ana Filipa Silva, Filipe Manuel Clemente, Francisco Tomás González-Fernández
Summary: Players must be capable to have a good change-of-direction (COD) skill aiming to be the fastest as possible to react immediately to the opponent or even to help players to be more agile since COD is a physical determinant of agility. Thus, the aim of this study was to test the effects of a six-week combined training intervention in the COD and countermovement jump (CMJ) of young soccer players, while comparing with a control group only performing the regular field-based training sessions. A sample of 80 non-professional players (40 experimental group and 40 control group) between the ages of ten and twelve was taken [(Age: 10.70 ± 1.02)]. The tests that were carried out from the beginning to the end of the intervention were: CMJ test, 505COD Test and Illinois Test. Paired sample t-test was used for determining differences as a repeated measures analysis (pre- post). An ANCOVA test was performed using the pretest as a covariate and the times pre and post as factors. Repeated measures ANCOVA revealed significant influence of baseline level on the 5-0-5 COD (p = 0.001; ηp2=0.170), the Illinois (p = 0.018; ηp2=0.070) and the CMJ (p = 0.047; ηp2=0.050). Significant interactions group*time (p < 0.001; ηp2=0.137), 5-0-5 COD (p < 0.001; ηp2=0.274), and CMJ (p < 0.001; ηp2=0.392) were found, while no significant interactions were found in Illinois (p = 0.293; ηp2=0.014). The current research revealed that a combined training intervention consisting of strength training, plyometrics, and running techniques can be significantly beneficial for improving COD performance and CMJ.
#14 Lightweight Football Motion Recognition and Intensity Analysis Using Low-Cost Wearable Sensors
Reference: Appl Bionics Biomech. 2023 Jul 12;2023:2354728. doi: 10.1155/2023/2354728. eCollection 2023.
Authors: Qian Xie, Ning Jin, Shanshan Lu
Summary: In recent years, machine learning has been utilized in health informatics and sports science. There is a great demand and development potential for combining the Internet of Things (IoT) and artificial intelligence (AI) to be applied to football sports. The conventional teaching and training methods of football sports have limited collection and mining of real raw data using wearable devices, and lack human motion capture and gesture recognition based on sports science theories. In this study, a low-cost AI + IoT system framework is designed to recognize football motion and analyze motion intensity. To reduce the communication delay and the computational resource consumption caused by data operations, a multitask learning model is designed to achieve motion recognition and intensity estimation. The model can perform classification and regression tasks in parallel and output the results simultaneously. A feature extraction scheme is designed in the initial data processing, and feature data augmentation is performed to solve the small sample data problem. To evaluate the performance of the designed football motion recognition algorithm, this paper proposes a data extraction experimental scheme to complete the data collection of different motions. Model validation is performed using three publicly available datasets, and the features learning strategies are analyzed. Finally, experiments are conducted on the collected football motion datasets and the experimental results show that the designed multitask model can perform two tasks simultaneously and can achieve high computational efficiency. The multitasking single-layer long short-term memory (LSTM) network with 32 neural units can achieve the accuracy of 0.8372, F1 score of 0.8172, mean average precision (mAP) of 0.7627, and mean absolute error (MAE) of 0.6117, while the multitasking single-layer LSTM network with 64 neural units can achieve the accuracy of 0.8407, F1 score of 0.8132, mAP of 0.7728, and MAE of 0.5966.
#15 Isolated adductor longus avulsion in a young semi-professional football player: Imaging contribution and therapeutic considerations
Reference: J Clin Ultrasound. 2023 Jul 19. doi: 10.1002/jcu.23525. Online ahead of print.
Authors: Michele Abate, Luigi Sammarchi, Roberto Calà, Giacomo Milesi, Carmine Stefano Poerio, Riccardo Del Vescovo, Antonio Corvino, Andrea Delli Pizzi, Giulio Cocco, Vincenzo Salini
Download link: https://onlinelibrary.wiley.com/doi/epdf/10.1002/jcu.23525
Summary: Adductor longus injuries are usually observed at the proximal musculo-tendinous junction, but isolated tendinous ruptures (i.e., avulsion) at the origin on the pubic bone are uncommon. In this article, we report a new case of isolated adductor longus avulsion that occurred in a young athlete and was treated with conservative therapy. An 18 years old semi-professional football player, in the attempt to reach the ball with his right leg, reported acute pain and functional limitation in his left adductor area. Clinical examination showed tenderness on palpation associated with mild swelling. Manual strength testing of adductor muscles showed weakness and elicited moderate pain in the proximal groin region near the pubic bone. The diagnostic evaluations (ultrasound [3-14 MHz linear probe] and magnetic resonance imaging [1.5 Tesla magnetic field]), performed a few days after the event, showed a complete isolated avulsion of the proximal adductor longus tendon associated with a fluid collection, with a gap of about 9.5 mm from its insertion on the pubic bone. Degenerative alterations (sub-chondral sclerosis, bone edema, erosions, cortical irregularities, calcifications) were found. These findings were crucial in the treatment choice because conservative management is suggested when the gap is below 1 cm and when no important displacement of proximal torn tendon's end at dynamic ultrasound is appreciated. A structured rehabilitation protocol was implemented, allowing the player to come back to his full athletic activity after 146 days. Return to play was allowed when several subjective and objective parameters were fully satisfied (full hip range of motion, pain-free football-specific activities, less than a 5%-10% difference in hip adduction strength between the injured and uninjured legs, advanced anatomical healing of the adductor longus tendon seen on diagnostic exams, and Hip And Groin Outcome Score [HAGOS] scores similar to baseline data). This case report emphasizes the importance of diagnostic imaging and clinical assessments in the management of an adductor longus avulsion with short retraction (about 1 cm). Both imaging techniques are non-invasive and without risks, allow contra-lateral examination and may guide in the treatment choice; moreover, they significantly influence the post-care approach by enabling to fine-tune a safe return to full athletic activity with minor re-injury rate. While US can be used as primary imaging modality, MRI offers a higher level of accuracy.
