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Objective: A few video analysis studies have been published in recent years, but none specifically on Spanish football. We aimed to describe the mechanisms, situational patterns, biomechanics and neurocognitive errors related to anterior cruciate ligament (ACL) injuries in professional Spanish football matches., Methods: We identified 167 consecutive ACL injuries across 12 seasons of the top two leagues in Spanish football. 115 (69%) injury videos were analysed for mechanism and situational pattern, while biomechanical analysis was possible in 81 cases. Neurocognitive errors were investigated for all non-contact injuries. Three independent reviewers evaluated each video. ACL injury epidemiology-month, timing within the match and pitch location at the time of injury was also documented., Results: More injuries occurred in defensive (n=68, 59%) than offensive (n=48, 41%) (p<0.01) playing situations. 16 (14%) injuries were direct contact, 49 (43%) indirect contact and 50 (43%) non-contact. Most injuries (89%) occurred during four main situational patterns: (1) pressing/tackling (n=47, 47%); (2) tackled (n=23, 23%); (3) landing from a jump (n=12, 12%) and regaining balance after kicking (n=6, 6%). Injuries generally involved a knee-dominant loading strategy in the sagittal plane with abducted hip and knee valgus. Of the non-contact injuries, 39 (78%) were deemed to involve a neurocognitive error. More (58%) injuries occurred in the first half of matches (p<0.01)., Conclusions: ACL injuries in Spanish football occurred similarly with non-contact and indirect contact mechanisms (44%). Four in five non-contact injuries involved a neurocognitive error. Most injuries occurred during four previously identified situational patterns, with more injuries earlier in the match., Competing Interests: None declared., (Copyright © Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract: Hill, V, Patterson, S, Buckthorpe, M, and Legg, HS. The acute effects of a preload upper-body power exercise on 50-m freestyle performance in youth swimmers. J Strength Cond Res 38(7): 1295-1299, 2024-This study aimed to investigate the acute effects of a medicine ball slam and the optimal recovery time required to induce a postactivation performance enhancement (PAPE) response on 50-meter freestyle swimming performance. Twenty-four (13 female, 11 male) competitive, adolescent swimmers (mean ± SD: age, 16.7 ± 1.2 years; height, 173.3 ± 6.7 cm; mass, 63.1 ± 6.4 kg) participated in a randomized crossover study. After the PAPE intervention (3 × 5 medicine ball slams), subjects had 1-minute, 4-minute, and 8-minute recovery periods before a 50-m maximal freestyle swim. A 1-way repeated-measures ANOVA revealed that different recovery times elicited changes in 50-m performance (F = 12.12, p < 0.0005). After 4 minutes of recovery, 50-m performance was 1.6% (0.47 seconds) faster (95% confidence interval [CI] [0.17-0.77], p < 0.001). When the data were split by sex, after 4 minutes of recovery, 50-m performance was 2% (0.64 seconds) faster for women (95% CI [0.279-0.998], p < 0.001). In conclusion, an upper-body power exercise, before performance, can induce a PAPE response and enhance 50-m freestyle performance after a 4-minute recovery period., (Copyright © 2024 National Strength and Conditioning Association.)

Purpose: To describe the injury mechanism and situational patterns of severe (absence >28 days) hamstring muscle injuries in professional male and female football (soccer) players., Methods: The data for males were sourced from Serie A clubs participating in both national and international competitions from 2018 to 2021. For the female cohort, hamstring injuries were identified during matches of the top national/international competitions from 2017 to 2023. Video footage was obtained, and three raters categorised injury mechanisms and situational patterns. Injuries were also examined according to the month, minute and location., Results: A total of 129 severe hamstring injuries were identified, with 64 occurring in females and 65 in males. Video analysis was possible for 29 (45%) female cases and 61 (94%) male cases. Female injuries had longer lay-off times (97.8 ± 77.1 days) than males (39.6 ± 20.9 days). Females had a higher proportion of indirect contact injuries (34%) than males (13%) and a lower proportion of non-contact injuries (66% vs. 87%). Four situational patterns were identified: running was the most common for both sexes, representing 59% of female injuries and 41% of male injuries. Over-stretching injuries were split across open and CKC scenarios but collectively explained nearly half (48%) of male injuries but only one in five (21%) female injuries. Kicking injuries had a higher proportion in females (17%) than males (10%). Injuries were more common in the second half for females and the first half for males., Conclusion: Females had a higher proportion of indirect contact, running and kicking injuries and a lower proportion of non-contact and stretch-type injuries than males. Understanding injury patterns can inform tailored prevention programs, considering sex-specific differences., Level of Evidence: Level IV., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Competing Interests: Competing interests: None declared.

Background: Improving our understanding of the situations and biomechanics that result in an anterior cruciate ligament (ACL) injury in basketball players may support the design of more effective programs to mitigate the risk of injury., Purpose: To (1) describe the mechanisms, situational patterns, and gross biomechanics (kinematics) of ACL injuries in professional basketball matches using video analysis and (2) document the distribution of ACL injuries according to player position, phase of the match, and location on the court., Study Design: Case series; Level of evidence, 4., Methods: A total of 38 ACL injuries in professional male European basketball leagues from the 2013-2014 to 2019-2020 seasons were identified. There were 36 (95%) injury videos analyzed for injury mechanisms and situational patterns, while biomechanical analysis was possible in 32 cases. Overall, 3 independent reviewers evaluated each video. Data according to player position (n = 38), phase of the match (n = 38), and location on the court (n = 36) were evaluated., Results: More injuries occurred while attacking (n = 25 [69%]) than defending (n = 11 [31%]). There was 1 (3%) direct contact injury, 21 (58%) indirect contact injuries, and 14 (39%) noncontact injuries. Most injuries (83%) occurred during 3 main situations: offensive cut (n = 17 [47%]), landing from a jump (n = 8 [22%]), and defensive cut (n = 5 [14%]). Injuries generally involved knee flexion (with minimal hip/trunk flexion and reduced plantarflexion) in the sagittal plane and knee valgus loading in most cases (75%). A similar number of injuries occurred during the first (53%) and second (47%) halves of the match, with a higher prevalence in the second (37%) and fourth (34%) quarters. Half of the injuries occurred during the first 10 minutes of effective playing time. More injuries occurred in guards (58%), and 73% of all injuries occurred in the scoring zone., Conclusion: Indirect contact was the main injury mechanism found in male professional basketball players. The offensive cut was the most common situational pattern. Biomechanical analysis confirmed a multiplanar mechanism, with knee loading in the sagittal plane accompanied by dynamic valgus. More injuries occurred in the first 10 minutes of a player's effective playing time, within the scoring zone, and among guards., Competing Interests: The authors have declared that there are no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto. Ethical approval was not sought for the present study., (© The Author(s) 2024.)

Introduction: Return to play related research is increasing rapidly, with two recent competency-based frameworks offering conceptualised support for on-field rehabilitation (OFR) decision-making. It is still unknown, however, who is responsible for OFR and how they typically select, monitor, and progress OFR processes., Aims: The purpose of this study was to investigate current OFR practice within English professional football to support practitioners with decision-making and highlight opportunities for future research related to the design, monitoring, and progression of OFR., Methods: Sixty-nine practitioners responsible for the design and implementation of OFR at 69 clubs (75% of the English Premier League and Football League) responded to a survey containing 30 questions (14 open and 16 closed)., Results: The main findings were that therapists (physiotherapists/sports therapists) have the largest influence on OFR, followed by physical performance coaches (sports scientists/strength and conditioning coaches), technical coaches and medical doctors. There was more agreement for the ordering of specific OFR drills earlier in the process when activities are easier to control. The most frequently reported objective monitoring tool was global positioning systems (GPS), with functional/clinical experience/expertise remaining subjectively vital. GPS outputs ( e.g ., sprint metrics and accelerations/decelerations) were most used for between session decision-making, with verbal communication being key for within session decision-making., Conclusion: Future research should use evidence of current practice, such as drill design and monitoring techniques, to explore drill-level analysis and give practitioners greater insights into which stage of current OFR frameworks specific drills fall, and how they might be more objectively progressed/regressed.

Context: Evidence is emerging that core neurocognitive functions such as working memory and inhibitory control (ie, motor-response and attentional inhibition) are linked to the anterior cruciate ligament (ACL) injury risk. Research has been conducted in laboratory settings, but the contribution of neurocognition to actual ACL injuries under real-world conditions is unknown., Objective: To describe the possible neurocognitive errors involved in noncontact ACL injury mechanisms., Design: Case series., Setting: Soccer matches., Patients or Other Participants: A total of 47 professional male soccer players., Main Outcome Measure(s): Three independent reviewers evaluated 47 videos of players sustaining noncontact ACL injuries. Neurocognitive errors in inhibitory control were operationalized as follows: (1) motor-response inhibition was scored when a player demonstrated poor decision-making and approached the opponent with high speed that reduced the ability to stop or change the intended action and (2) an attentional error was scored when a player shifted his selective attention away from the relevant task to irrelevant stimuli., Results: Of 47 noncontact ACL injuries, 26 (55%) were related to a pressing-type injury, 19 (73%) of which involved a deceiving action made by the opponent, suggesting poor inhibitory control of the defender. Of the remaining 21 noncontact ACL injuries (45%), 16 (76%) could be attributed to attentional errors. Agreement among the 3 raters was very good for all items except poor decision-making, which showed fair to good agreement (Fleiss κ = 0.71). Interrater reliability was excellent (intraclass correlation coefficient = 0.99-1.00)., Conclusions: Errors in motor-response inhibitory control and attentional inhibition were common during noncontact ACL injury events in professional male soccer players. The interrater agreement in detecting neurocognitive errors in general was very good., (© by the National Athletic Trainers’ Association, Inc.)

Outcomes following anterior cruciate ligament reconstruction (ACLR) need improving, with poor return-to-sport rates and a high risk of secondary re-injury. There is a need to improve rehabilitation strategies post-ACLR, if we can support enhanced patient outcomes. This paper discusses how to optimise the early-stage rehabilitation process post-ACLR. Early-stage rehabilitation is the vital foundation on which successful rehabilitation post-ACLR can occur. Without high-quality early-stage (and pre-operative) rehabilitation, patients often do not overcome major aspects of dysfunction, which limits knee function and the ability to transition through subsequent stages of rehabilitation optimally. We highlight six main dimensions during the early stage: (1) pain and swelling; (2) knee joint range of motion; (3) arthrogenic muscle inhibition and muscle strength; (4) movement quality/neuromuscular control during activities of daily living (5) psycho-social-cultural and environmental factors and (6) physical fitness preservation. The six do not share equal importance and the extent of time commitment devoted to each will depend on the individual patient. The paper provides recommendations on how to implement these into practice, discussing training planning and programming, and suggests specific screening to monitor work and when the athlete can progress to the next stage (e.g. mid-stage rehabilitation entry criteria)., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Objective: The objective of this study is to describe the mechanism of injury and situational patterns (based on ball possession and playing action leading to injury) of severe (lay-off time >28 days) lower limb muscle injuries in professional male football (soccer) players during match play., Methods: Players experiencing a severe muscle injury of the lower limb during Italian first (Serie A) division male football matches over three consecutive seasons (2018-2021) were identified. Video footage was obtained and three raters independently categorised injury mechanism and situational patterns using a standardised checklist. Injury epidemiology (month), timing of injuries within the match and location of injuries on the pitch were also examined., Results: We identified 121 lower limb severe muscle injuries. Videos of sufficient quality were available for 103 (85%) cases, including 61 (60%) hamstring, 17 (16%) calf, 16 (15%) adductor and 9 (9%) quadricep muscle injuries. Nearly two-thirds of injuries involved the dominant/kicking leg (n=65, 63%). Eighty-five (83%) injuries were non-contact and 18 (17%) indirect contact. Four main situational patterns were identified and accounted for 88% of injuries: (1) running/acceleration (n=35, 34%); (2) closed kinetic chain stretching (n=21, 20%); (3) open kinetic chain stretching (n=19, 18%) and (4) kicking (n=16, 16%), with differences between muscle groups. 71% of injuries occurred in the first half of the match (p<0.01), with a gradual increase through the first half., Conclusion: Most severe muscle injuries during football matches were non-contact and occurred in the first half during running/acceleration, open and closed kinetic chain stretching, or kicking., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Background: Achilles tendon rupture (ATR), while rare in football, is a severe career-threatening injury associated with long-layoff times. To date, no study has documented ATR's mechanism in professional football players., Aim: To describe the mechanisms, situational patterns and gross biomechanics (kinematics) of ATR injuries in professional male football players., Methods: Eighty-six (n=86) consecutive ATR injuries in professional football players during official matches were identified. Sixty (70%) injury videos were identified for mechanism and situational pattern, with biomechanical analysis feasible in 42 cases. Three independent reviewers evaluated the injury videos. Distribution of ATR during the season, the match play and on the field were also reported., Results: Fifty (n=50, 83%) injuries were classified as non-contact and 10 (17%) as indirect contact. ATRs are injuries occurring during accelerations; three main situational patterns were identified: (1) forward acceleration from standing (n=25, 42%); (2) cross-over cutting (n=15, 25%) and (3) vertical jumping (n=11, 18%). Biomechanically, ATR injuries were consistent with a multiplanar loading at the injury frame consisting of a slightly flexed trunk (15.5°), extended hip (-19.5°), early flexed knee (22.5°) and end-range dorsiflexed (40°) ankle in the sagittal plane and foot pronation; 27 (45%) ATRs occurred in the first 30 min of effective match time., Conclusions: All ATRs in professional football were either non-contact (83%) or indirect contact (17%) injuries. The most common situational patterns were forward acceleration from standing, cross-over cutting and vertical jumping. Biomechanics was consistent and probably triggered by a multiplanar, although predominantly sagittal, loading of the injured Achilles tendon., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The outcome after ACL reconstruction (ACLR) is in general disappointing with unacceptable number of athletes that do not return to pre-injury level of sports, high re-injury rates, early development of osteoarthritis and shorter careers. Athletes after ACLR have high expectation to return to sports which is in contrast with the current outcomes. The aim of this manuscript is to present an overview of factors that are needed to be incorporated and to personalize the rehabilitation process for an athlete who has undergone an ACLR., (© 2022. The Author(s).)

Objectives: To establish agreement in National team contexts when players transition from club to National team about (i) what medical and physical information to collect, (ii) how to use information (iii) identifying challenges to collection and (iv) collection methods., Design: Delphi survey., Methods: A series of sequential online questionnaires were sent to heads of medical and performance of the 32 National teams following the FIFA 2018 World Cup. Two separate Delphi's; 'Medical' and 'Physical' were administered. The 'Medical' respondent was the person responsible for player health. 'Physical' referred to the person responsible for physical performance. Content analyses were performed, with subsequent rounds designed according to responses of the previous. Agreement was considered at ≥70%., Results: Twenty-three Medical (72%) and 14 (44%) Physical heads participated in Round 1 (3 rounds total). Seventeen Medical and 12 Physical respondents completed all rounds. Medical information agreed upon injury epidemiology, screening and injury treatment strategies. Physical information included training/match-loads, fatigue, wellness and current exercise programmes. Both Medical and Physical agreed information should be used to plan and individualise player programmes. Additionally medical information should guide coaches' national team selection. Communication, willingness to share and quality/completeness of information were agreed as main challenges. Medical and Physical respondents agreed a standardised reporting form and electronic shared database as best option to collect information., Conclusions: Our findings highlight the importance of health and performance information exchange between national and club teams. Further, this exchange should be cooperative, symbiotic and a two-way process to assist with improving player health., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

Objective: To describe the mechanisms, situational patterns, and biomechanics (kinematics) of medial collateral ligament (MCL) injuries in professional male soccer players., Design: Case series., Methods: Fifty-seven consecutive MCL injuries across 2 seasons of professional soccer matches were identified. We obtained and reviewed 37 of 57 (65%) injury videos to establish the injury mechanism, situational pattern, and knee flexion angle. We used detailed biomechanical analysis to assess the indirect and noncontact injuries. Injury layoff times, timing of injuries during the match, and location of the injuries on the pitch were also reported., Results: Twenty-three (62%) injuries were direct contact, 9 (24%) were indirect contact, and 5 (14%) were noncontact. Three main sprain mechanisms were noted: (1) direct contact/blow to the knee (n = 16), (2) contact to the leg or foot (lever like) (n = 7), and (3) sliding (n = 9). Seventy-three percent of MCL injuries occurred during 2 main situations: (1) pressing/tackling (n = 14, 38%) and (2) being tackled (n = 13, 35%). For indirect and noncontact injuries, knee valgus loading (100% of cases), hip abduction (73% of cases), and external foot rotation (92% of cases) were prominent injury kinematics, often with lateral trunk tilt (median, 10°; 64% of cases) and rotation (64% of cases). Knee flexion angles were higher for indirect and noncontact injuries (median, 100°) than for direct-contact injuries (median, 22°; P <.01)., Conclusion: Nearly two thirds of MCL injuries occurred after direct contact; 1 in every 4 MCL injuries occurred after indirect contact. Three sprain mechanisms characterized MCL injuries: (1) blow to the knee, (2) contact to the leg or foot (lever like), and (3) sliding. J Orthop Sports Phys Ther 2021;51(12):611-618. Epub 16 Nov 2021. doi:10.2519/jospt.2021.10529 .

Background: Anterior cruciate ligament (ACL) injuries represent a significant burden to rugby players. Improving our understanding of the patterns and biomechanics that result in ACL injury may aid in the design of effective prevention programs., Purpose: To describe, using video analysis, the mechanisms, situational patterns, and biomechanics of ACL injuries in professional rugby matches. Further aims were to document injuries according to pitch location and timing within the match., Study Design: Case series; Level of evidence, 4., Methods: A total of 62 ACL injuries were identified in players of the 4 most important rugby leagues across 4 consecutive seasons. We analyzed 57 (92%) injury videos for injury mechanism and situational patterns; biomechanical analysis was performed on indirect and noncontact ACL injuries only (38 cases available). Three reviewers independently evaluated each video., Results: More injuries occurred while attacking than defending (41 [72%] vs 16 [28%]; P < .01). Regarding mechanism, 18 (32%) injuries were direct contact; 15 (26%), indirect contact; and 24 (42%), noncontact. Most direct contact injuries involved being tackled directly to the knee (n = 10). Three situational patterns were identified for players who had a noncontact or indirect contact injury: offensive change of direction (COD) (n = 18), being tackled (n = 10), and pressing/tackling (n = 8). Injuries generally involved a knee-loading strategy in the sagittal plane, which was accompanied by knee valgus loading in most cases (94%). Overall, 73% of injuries occurred during the first 40 minutes of effective playing time., Conclusion: Most ACL injuries in professional male rugby players happened through a noncontact or indirect contact mechanism (68%). Three situational patterns were described, including offensive change of direction, being tackled, and pressing/tackling. Biomechanical analysis confirmed a multiplanar mechanism, with a knee-loading pattern in the sagittal plane accompanied by dynamic valgus. As most injuries occurred in the first 40 minutes, accumulated fatigue appears not to be a major risk factor for ACL injury., Competing Interests: The authors have declared that there are no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2021.)

It is important to optimise the functional recovery process to enhance patient outcomes after major injury such as anterior cruciate ligament reconstruction (ACLR). Restoring movement quality during sporting-type movements is important prior to return-to-sport (RTS) after ACLR. Alterations in movement quality during an array of functional tasks are common amongst ACLR patients at or near the time of RTS and are associated with worse outcomes after ACLR. The inability to correct movement issues prior to RTS is likely due to the use of incomplete programmes or a lack of volume and intensity of movement re-training programmes. Although most clinicians and researchers understand that re-training movement after ACLR is important (e.g., the 'why'), there is often a disconnect with understanding the 'how' and 'what' of movement re-training post ACLR. The aim of this paper was to discuss factors relevant to movement dysfunction and re-training after ACLR and provide recommendations for clinicians to restore movement quality of patients after ACLR, prior to RTS. The paper recommends: (i) considering the factors which influence the expression of movement quality, which revolve around individual (e.g., neuromuscular, biomechanical, sensorimotor and neurocognitive factors), task-specific and environmental constraints; (ii) incorporating a three-staged movement re-training approach aligned to the ACLR functional recovery process: (1) addressing the neuromuscular and biomechanical and sensorimotor control factors which affect movement quality and motor learning, (2) including a progressive movement re-training approach to re-learn an array of functional tasks optimising coordination and motor learning (3) performing the final aspect of rehabilitation and movement training on the field, in realistic environments progressively simulating the sporting movement demands and environmental constraints; and (iii) effectively designing the movement programme for optimal load management, employing effective coach and feedback techniques and utilising qualitative movement analysis for transition between exercises, stages and for RTS., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This paper presents a four-stage plyometric program to be undertaken as part of criterion-based rehabilitation for athletes with anterior cruciate ligament reconstruction (ACLR). After ACLR, the patient experiences alterations of joint mobility, gait and movement patterns, neuromuscular function and general physical fitness. Plyometric training is an important component for neuromuscular and movement re-conditioning after ACLR. Effective use of plyometrics can support enhancements in explosive sporting performance, movement quality and lower risk of injury. Plyometric training, as a component of the ACL functional recovery process, can aid in restoring function and supporting timely return to sport. However, few patients undertake or complete a plyometric program prior to return-to-sport. To truly impact individual patients, a stronger focus on research implementation is needed from researchers to translate efficacious interventions into practice. In designing a plyometric program, it is important to match the specific plyometric tasks to the functional recovery status of the ACLR patient. To do this, it is important to understand the relative intensity of plyometrics tasks, align these tasks to the ACL functional recovery process and monitor the athlete as part of criterion based rehabilitation. Plyometric intensity is based on the intensity of efforts, the vertical and/or horizontal momentum prior to ground contact, the ground contact time and the surface or environment on which they are performed on/in. Furthermore, how the person technically performs the task will influence joint loading. There should be a gradual increase in task intensity and specificity throughout the program, with all tasks used for both neuromuscular and motor control re-conditioning. The aim of this paper is to provide recommendations to clinicians on how to design and implement plyometric training programs for the ACLR patient, as part of the functional recovery process., Level of Evidence: 5., Competing Interests: The authors report no conflict of interests relevant to the content of this review.

Competing Interests: Competing interests: None declared.

Background: Female soccer players are particularly susceptible to anterior cruciate ligament (ACL) injuries, accounting for 16% to 43% of the injury burden during the season. Despite the advancements in injury prevention programs, the rate of ACL injuries continues to rise., Purpose: To provide a comprehensive description of the mechanisms, situational pattern, and biomechanics of ACL injuries in women's soccer., Study Design: Case series; Level of evidence, 4., Methods: We identified 57 consecutive ACL injuries that occurred in matches of 6 top female leagues across 3 seasons (2017-2020). A total of 35 (61%) injury videos were analyzed for the mechanism and situational pattern, while biomechanical analysis was possible in 29 cases. Three independent reviewers evaluated each video. The distribution of ACL injuries according to month, timing within the match, and field location at the time of injury was also reported., Results: In the 35 injury videos, there were 19 (54%) noncontact injuries, 12 (34%) indirect contact injuries, and 4 (11%) direct contact injuries. We identified 3 main situations in players who suffered a noncontact/indirect contact injury: (1) pressing and tackling (n = 18), (2) regaining balance after kicking (n = 7), and (3) being tackled (n = 4). Biomechanical analysis indicated multiplanar mechanisms with frequent knee valgus loading (88%). Additionally, 64% of injuries occurred in the first half of matches and most frequently within the first 30 minutes., Conclusion: Female athletes showed remarkable similarities with elite male players in terms of the ACL mechanism and situational pattern of injury, and 88% of injuries involved no direct contact to the knee, with noncontact injuries being highly prevalent. Injuries occurred during 3 main situations, with accompanying alterations in multiplanar biomechanics. Interventions aimed at reducing ACL injuries in women's soccer should consider high-intensity defensive play at the beginning of a match. Instruction in the 3 main situations should be applied alongside appropriate neuromuscular training interventions.

It is important to optimise the functional recovery process to enhance patient outcomes after major injury such as anterior cruciate ligament reconstruction (ACLR). This requires in part more high-quality original research, but also an approach to translate existing research into practice to overcome the research to implementation barriers. This includes research on ACLR athletes, but also research on other pathologies, which with some modification can be valuable to the ACLR patient. One important consideration after ACLR is the recovery of hamstring muscle function, particularly when using ipsilateral hamstring autograft. Deficits in knee flexor function after ACLR are associated with increased risk of knee osteoarthritis, altered gait and sport-type movement quality, and elevated risk of re-injury upon return to sport. After ACLR and the early post-operative period, there are often considerable deficits in hamstring function which need to be overcome as part of the functional recovery process. To achieve this requires consideration of many factors including the types of strength to recover (e.g., maximal and explosive, multiplanar not just uniplanar), specific programming principles (e.g., periodised resistance programme) and exercise selection. There is a need to know how to train the hamstrings, but also apply this to the ACLR athlete. In this paper, the authors discuss the deficits in hamstring function after ACLR, the considerations on how to restore these deficits and align this information to the ACLR functional recovery process, providing recommendation on how to recover hamstring function after ACLR.

Background: A few small studies have reported on the mechanisms of ACL injury in professional male football., Aim: To describe the mechanisms, situational patterns and biomechanics (kinematics) of ACL injuries in professional male football matches., Methods: We identified 148 consecutive ACL injuries across 10 seasons of professional Italian football. 134 (90%) injury videos were analysed for mechanism and situational pattern, while biomechanical analysis was possible in 107 cases. Three independent reviewers evaluated each video. ACL injury epidemiology (month), timing within the match and pitch location at the time of injury were also reported., Results: 59 (44%) injuries were non-contact, 59 (44%) were indirect contact and 16 (12%) were direct contact. Players were frequently perturbed immediately prior to injury. We identified four main situational patterns for players who suffered a non-contact or an indirect contact injury: (1) pressing and tackling (n=55); (2) tackled (n=24); (3) regaining balance after kicking (n=19); and (4) landing from a jump (n=8). Knee valgus loading (n=83, 81%) was the dominant injury pattern across all four of these situational patterns (86%, 86%, 67% and 50%, respectively). 62% of the injuries occurred in the first half of the matches (p<0.01). Injuries peaked at the beginning of the season (September-October) and were also higher at the end of the season (March-May)., Conclusions: 88% of ACL injuries occurred without direct knee contact, but indirect contact injuries were as frequent as non-contact injuries, underlying the importance of mechanical perturbation. The most common situational patterns were pressing, being tackled and kicking., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Competing Interests: Competing interests: None declared.

There is a need to improve patient outcomes after anterior cruciate ligament reconstruction (ACLR). To do this likely involves a strong focus on optimizing rehabilitation processes and practices. Movement re-training is considered an important element of rehabilitation after ACLR, but there is a lack of knowledge on the 'how' and 'what' movement re-training should occur after ACLR. In its basic form, movement re-training after ACLR is about progressing a patient through gradually more demanding tasks from the point of being able to walk to being able to perform highly complex sports movements. However, there is a lack of guidance on when to implement certain tasks (e.g. when to begin running) and how to transition between tasks. This paper presents a 10 task progressions system which can form an important aspect of the movement-based re-training process, providing structure and patient autonomy. Monitoring knee function and movement and neuromuscular status to safely transition between these tasks is important. Although this task-based progression is designed for patients following a rehabilitation program after ACLR, it may have generalizability for all major lower limb injuries. The task-based progression was formed by combining theory, the best available evidence, and significant practice experience applied to movement re-training after ACLR. This approach supports patient autonomy, medical team communication and collaboration and can provide structure to the movement re-training process., (© 2020 by the Sports Physical Therapy Section.)

Outcomes following anterior cruciate ligament (ACL) reconstruction need improving, with poor return-to-sport rates and high risk of secondary re-injury. There is a need to improve rehabilitation strategies after ACL reconstruction, if we can support enhanced patient outcomes. This paper discusses how to optimise the mid-stage rehabilitation process after ACL reconstruction. Mid-stage is a difficult and vitally important stage of the functional recovery process and provides the foundation on which to commence late-stage rehabilitation training. Often many aspects of mid-stage rehabilitation (e.g. knee extensors isolated muscle strength) are not actually restored prior to return-to-sport. In addition, if we are to allow time for optimal late-stage rehabilitation and return-to-sport training, we need to optimise the mid-stage rehabilitation approach and complete it in a timely manner. This paper forms a key part of a strategy to optimise the ACL rehabilitation approach and considers factors more specific to mid-stage rehabilitation characterised in 3 areas: (1) muscle strength: muscle and joint specific, in particular at the knee level, with the knee extensors and flexors and distally with the triceps surae and proximally with the lumbo-pelvic-hip complex, as well as closed kinetic chain strength; (2) altered basic motor patterning (movement quality) and (3) fitness re-conditioning. In addition, the paper provides recommendations on how to implement these into practice, discussing training planning and programming and suggests specific screening to monitor work and when the athlete is able to progress to the next stage (e.g. late-stage rehabilitation criteria).

Outcomes after long-term injuries such as anterior cruciate ligament reconstruction (ACLR) need improving. One area which has received limited research attention is the use of aquatic therapy to optimize the functional recovery process after injury. There is still limited understanding of what the benefits of the pool can bring for rehabilitation and particularly what and when can be done in the pool after injury. This clinical commentary describes how the application of the properties of water can support the functional recovery process after ACLR. Here it is proposed that the main properties (density, hydrostatic pressure, buoyancy and viscosity) of aquatic therapy, if applied correctly to rehabilitation practices, can be used to achieve six primary goals after ACLR : 1) assist in the reduction of pain and swelling; 2) support the recovery of gait; 3) support the maintenance and/ or development of cardiovascular fitness; 4) help accelerate and optimize motor pattern retraining; 5) allow for earlier introduction of plyometrics and power training and 6) support the between session recovery and optimal load management, particularly in the later phases of rehabilitation. If implemented correctly, the presented phased protocol can support practitioners in implementing or delivering aquatic therapy rehabilitation services to their injured athletes. To support implementation, the authors have provided a specific protocol and supplementary videos for the use of aquatic therapy after ACLR., Level of Evidence: 5., Competing Interests: Conflict of interest: There were no funding sources for the paper. The authors report no conflict of interest., (© 2019 by the Sports Physical Therapy Section.)

Synopsis: This paper is part 2 of a 2-part series aimed at discussing the key elements of on-field rehabilitation training. In part 1, we described 4 pillars underpinning high-quality on-field rehabilitation: (1) restoring movement quality, (2) physical conditioning, (3) restoring sport-specific skills, and (4) progressively developing chronic training load. In part 2, we describe how the pillars contribute to a 5-stage on-field rehabilitation program to help injured players transition to team practice and match play. We use the example of a soccer player with ambitions to return to sport after anterior cruciate ligament reconstruction. The program moves through 5 field-based training stages: (1) linear movement, (2) multidirectional movement, (3) soccer-specific technical skills, (4) soccer-specific movement, and (5) practice simulation. The staged program is research based and facilitates communication, planning, control, and safety in return to sport following long-term injury. J Orthop Sports Phys Ther 2019;49(8):570-575. doi:10.2519/jospt.2019.8952 .

Synopsis: Outcomes following long-term injuries such as anterior cruciate ligament rupture are unsatisfactory. To improve outcomes, we must improve rehabilitation practices. One aspect of the return-to-sport process that has received limited attention is on-field rehabilitation. This article is part 1 of a 2-part series aimed at discussing the important elements of on-field rehabilitation and illustrating how they can be applied across a 5-stage on-field rehabilitation program following anterior cruciate ligament reconstruction. The intention of on-field rehabilitation is to support athletes in their transition back to sport after injury, from standard rehabilitation to return to the team or practice. In part 1, we describe 4 pillars of high-quality on-field rehabilitation: (1) restoring movement quality, (2) physical conditioning, (3) restoring sport-specific skills, and (4) progressively developing chronic training load. In part 2, we describe how these pillars may be combined into a 5-stage on-field rehabilitation program to help athletes transition to team practice and match play following anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 2019;49(8):565-569. doi:10.2519/jospt.2019.8954 .

Despite increased knowledge on anterior cruciate ligament (ACL) injury mechanisms, improved surgical techniques, improved understanding of ACL biomechanics and enhanced knowledge in rehabilitation practice, return-to-sport (RTS) rates and subsequent second ACL re-injury rates after ACL reconstruction are not optimal. This narrative review discusses factors that may be highly relevant for RTS training and testing after ACL reconstruction, but which have received limited research attention to date or do not form part of the standard approach to rehabilitation. These factors include (1) explosive neuromuscular performance; (2) movement quality deficits associated with re-injury risk, particularly the need to re-train optimal sport-specific movement patterns; (3) the influence of fatigue; and (4) a lack of sport-specific re-training prior to RTS, with particular attention to an insufficient development of chronic training load. In addition, incorporating performance re-training and ensuring an athlete has restored their sport-specific profile is important. The relevance of these variables for RTS training and testing is discussed, with a new recommended model of late-stage rehabilitation and RTS training presented. Additional testing to support RTS decision making is also presented. This paper contains important information for practitioners and researchers to support optimised late-stage rehabilitation and RTS programmes and RTS testing with a view to enhancing patient outcomes after ACL reconstruction.

The Gluteus Maximus (GM) muscle is the largest and most powerful in the human body. It plays an important role in optimal functioning of the human movement system as well as athletic performance. It is however, prone to inhibition and weakness which contributes to chronic pain, injury and athletic under-performance. As such, understanding how to assess and treat GM dysfunction is an important aspect of sports science and medicine, as it has relevance for injury prevention, rehabilitation and performance enhancement. Despite GMs considerable importance there is little research attempting to translate evidence into practice to support practitioners when faced with 'sleepy glutes'. This clinical commentary discusses the importance of GM for athletic performance and injury risk; factors which contribute to GM dysfunction and then provides evidenced informed approaches to assess and treat GM dysfunction. This can be used as part of rehabilitation or injury prevention practices as well as athletic performance training., Level of Evidence: 5.

Competing Interests: Competing interests: None declared.

One of the main priorities of rehabilitation after anterior cruciate ligament reconstruction (ACLR) surgery is the restoration of knee extensor muscle strength. Residual deficits in knee extensor muscle size and strength after injury are linked to poor biomechanics, reduced knee function, increased knee osteoarthritis risk, as well as heightened risk of re-injury upon return to sport. Most studies indicate that knee extensor muscle strength is typically not resolved prior to return to sport. This clinical commentary discusses strategies to optimize and accelerate the recovery of knee extensor strength post-surgery, with the purpose to support the clinician with evidence-based strategies to implement into clinical practice. Principally, two strategies exist to normalize quadriceps strength after surgery, 1) limiting strength loss after injury and surgery and 2) maximizing and accelerating the recovery of strength after surgery. Optimal preparation for surgery and a focused attempt to resolve arthrogenic muscle inhibition are essential in the pre and post-operative period prior to the inclusion of a periodized strength training program. Often voluntary strengthening alone is insufficient to fully restore knee extensor muscle strength and the use of electrical stimulation and where necessary the use of blood flow restriction training with low loads can support strength recovery, particularly in patients who are significantly load compromised and experience pain during exercise. Resistance training should employ all contraction modes, utilize open and closed kinetic chain exercise of both limbs, and progress from isolated to functional strength training, as part of a periodized approach to restoring neuromuscular function. Furthermore, thinking beyond the knee musculature and correcting core and hip dysfunction is also important to ensure an optimal knee extension strengthening program. The purpose of this clinical commentary is to provide a series of evidenced based strategies which can be implemented by clinicians responsible for the rehabilitation of patients after ACLR., Level of Evidence: 5.

This narrative and literature review discusses the relevance of Rate of Force Development (RFD) (the slope of the force time curve) for Return To Sport (RTS), its determinants and the influence of training practices on it expression, with the purpose to enhance clinicians' awareness of how RFD training may enhance RTS success. RFD is considered functionally more relevant than maximal muscle strength during certain very fast actions including rapid joint stabilisation following mechanical perturbation. Deficits in RFD are reported following conventional rehabilitation programmes despite full restoration of maximal strength, which may contribute to the less than satisfactory RTS outcomes reported in the literature. RFD determinants vary as a function of time from force onset with a diminishing role of maximal strength as the time available for force development decreases. Factors such as neural activation, fibre type composition and muscle contractile properties influence RFD also and to a much greater extent during the early periods of rapid force development. Conventional resistance training using moderate loads typical of most rehabilitation programmes is insufficient at restoring or enhancing RFD, thus incorporating periodised resistance training programmes and explosive training techniques in the final stages of rehabilitation prior to RTS is recommended., Level of Evidence: V.

The study aimed to assess the influence of fatigue induced by repeated high-force explosive contractions on explosive and maximal isometric strength of the human knee extensors and to examine the neural and contractile mechanisms for the expected decrement. Eleven healthy untrained males completed 10 sets of voluntary maximal explosive contractions (five times 3 s, interspersed with 2 s rest). Sets were separated by 5 s, during which supramaximal twitch and octet contractions [eight pulses at 300 Hz that elicit the contractile peak rate of force development (pRFD)] were evoked. Explosive force, at specific time points, and pRFD were assessed for voluntary and evoked efforts, expressed in absolute terms and normalized to maximal/peak force. Maximal voluntary contraction force (MVCF) and peak evoked forces were also determined. Surface EMG amplitude was measured from three superficial agonists and normalized to maximal compound action potential area. By set 10, explosive force (47-52%, P < 0.001) and MVCF (42%, P < 0.001) had declined markedly. Explosive force declined more rapidly than MVCF, with lower normalized explosive force at 50 ms (29%, P = 0.038) that resulted in reduced normalized explosive force from 0 to 150 ms (11-29%, P ≤ 0.038). Neural efficacy declined by 34%, whilst there was a 15-28% reduction in quadriceps EMG amplitude during voluntary efforts (all P ≤ 0.03). There was demonstrable contractile fatigue (pRFD: octet, 27%; twitch, 66%; both P < 0.001). Fatigue reduced normalized pRFD for the twitch (21%, P = 0.001) but not the octet (P = 0.803). Fatigue exerted a more rapid and pronounced effect on explosive force than on MVCF, particularly during the initial 50 ms of contraction, which may explain the greater incidence of injuries associated with fatigue. Both neural and contractile fatigue mechanisms appeared to contribute to impaired explosive voluntary performance., (© 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.)