Download or read book The Influence of Interlimb Differences on Anterior Cruciate Ligament Injury Risk Factors in Female Collegiate Soccer Athletes written by Eric Kevin Greska and published by . This book was released on 2012 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ACL Injuries in the Female Athlete written by Frank R. Noyes and published by Springer. This book was released on 2018-09-07 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt: This successful book, now in a revised and updated second edition, reviews all aspects of anterior cruciate ligament (ACL) injuries in female athletes, with the focus on complete, noncontact ACL injuries. The opening section discusses anatomy and biomechanics and explains the short- and long-term impacts of complete ACL ruptures, including long-term muscle dysfunction and joint arthritis. Risk factors and possible causes of the higher noncontact ACL injury rates in female athletes compared with male athletes are then discussed in depth. Detailed attention is devoted to neuromuscular training programs and their effectiveness in reducing noncontact ACL injury rates in female athletes, as well as to sports-specific ACL injury prevention and conditioning programs of proven value. Rehabilitation programs after ACL injury and reconstruction that reduce the risk of a future injury are explored, and the concluding section looks at worldwide implementation of neuromuscular ACL injury prevention training and future research directions. The book will be of value to orthopedic surgeons, physical therapists, athletic trainers, sports medicine primary care physicians, and strength and conditioning specialists.

Download or read book ACL Injuries in the Female Athlete written by Frank R. Noyes and published by Springer Science & Business Media. This book was released on 2013-01-04 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nearly a million anterior cruciate ligament (ACL) injuries occur each year worldwide, causing long-term problems in the knee joint. This textbook examines the short- and long-term impacts of ACL injuries on the basis of hundreds of published studies. Risk factors for such injuries are explored using data from hypothesis-driven investigations, and possible causes of the higher risk of noncontact ACL injuries in female athletes are analyzed. Neuromuscular training programs shown to reduce the rate of these injuries in female athletes are described in step-by-step detail with the aid of numerous color photographs and video demonstrations. In addition, detailed descriptions are provided for rehabilitation programs to be used after ACL reconstruction in order to reduce the risk of a future injury. The book will be of value to orthopedic surgeons, physical therapists, athletic trainers, sports medicine primary care physicians, and strength and conditioning specialists.

Download or read book The Effects of a Novel Core Stability Training Program on Neuromuscular Anterior Cruciate Ligament Risk Factors in Female Collegiate Soccer Players written by Alexis Camacho and published by . This book was released on 2019 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Anterior cruciate ligaments injuries make up nearly half of all lower extremity injuries in sports. Female athletes, particularly those involved in soccer, are at even higher risk of injury than their male counterparts due to neuromuscular, physiological, and anatomical risk factor differences. Poor neuromuscular control of the core can cause poor mechanics of the lower extremity leading to an increased risk of ACL injury. Biomechanical variables such as vertical ground reaction force, knee abduction moments, and knee flexion during a side-cut are key risk factors that can be altered by a core stability training intervention. A 3-Dimensional analysis of these variables during a 90° side-cut task was conducted across three time points (pre, mid, post-training program). Subjects (n = 9) were randomly assigned to either the control (n = 4) or intervention (n = 5) group. Plank tests were also conducted at each testing session to assess core stability. The intervention group participated in three sessions a week for a duration of 8 weeks of core stability training. No significant differences were seen in peak knee flexion, peak abduction moment, vertical ground reaction force, and plank times (p = 0.876, p = 0.369, p = 0.748, p = 0.057, respectively). On a case-by-case basis, the intervention group had minor biomechanical improvements similar to previous research, but a limited sample size may not be a true reflection of the positive effects the intervention could have had with a larger sample size.

Download or read book Neuromechanical Analysis of Anterior Cruciate Ligament Risk Factors in Female Collegiate Soccer Athletes written by Nelson Cortes and published by . This book was released on 2010 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book One Anterior Cruciate Ligament injury is enough written by Anne Fältström and published by Linköping University Electronic Press. This book was released on 2016-08-31 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Background: Anterior cruciate ligament (ACL) injury is a severe and common injury, and females have 2-4 times higher injury risk compared to men. Return to sport (RTS) is a common goal after an ACL reconstruction (ACLR), but only about two thirds of patients RTS. Young patients who RTS may have a 30-40 times increased risk of sustaining an additional ACL injury to the ipsi- or contralateral knee compared with an uninjured person. Aims: The overall aim of this thesis was to increase the knowledge about female football players with ACLR, and patients with bilateral ACL injuries, and to identify predictors for additional ipsi- and/or contralateral ACLR. Methods: This thesis comprises four studies. Study I and II were cross-sectional, including females who sustained a primary ACL rupture while playing football and underwent ACLR 6–36 months prior to study inclusion. In study I, 182 females were included at a median of 18 months (IQR 13) after ACLR. All players completed a battery of questionnaires. Ninety-four players (52%) returned to football and were playing at the time of completing the questionnaires, and 88 (48%) had not returned. In study II, 77 of the 94 active female football players (from study I) with an ACLR and 77 kneehealthy female football players were included. A battery of tests was used to assess postural control (the Star excursion balance test) and hop performance (the one-leg hop for distance, the five jump test and the side hop). Movement asymmetries in the lower limbs and trunk were assessed with the drop vertical jump and the tuck jump using two-dimensional analyses. Study III, was a cohort study including all patients with a primary ACLR (n=22,429) registered in the Swedish national ACL register between January 2005 and February 2013. Data extracted from the register to identify predictors for additional ACLR were: patient age at primary ACLR, sex, activity performed at the time of ACL injury, primary injury to the right- or left knee, time between injury and primary ACLR, presence of any concomitant injuries, graft type, Knee injury and Osteoarthritis Outcome Score and Euroqol Index Five Dimensions measured pre-operatively. Study IV was cross-sectional. In this study, patient-reported knee function, quality of life and activity level in 66 patients with bilateral ACL injuries was investigated and outcomes were compared with 182 patients with unilateral ACLR. Results: Factors associated with returning to football in females were; short time between injury and ACLR (0–3 months, OR 5.6; 3–12 months OR 4.7 vs. reference group >12 months) and high motivation (study I). In all functional tests, the reconstructed and uninvolved limbs did not differ, and players with ACLR and controls differed only minimally. Nine to 49% of the players with ACLR and controls had side-to-side differences and movement asymmetries and only one fifth had results that met the recommended guidelines for successful outcome on all the different tests (study II). Main predictors for revision and contralateral ACLR were younger age (fourfold increased rate for <16 vs. >35-year-old patients), having ACLR early after the primary injury (two to threefold increased rate for ACLR within 3 months vs. >12 months), and incurring the primary injury while playing football (study III). Patients with bilateral ACL injuries reported poorer knee function and quality of life compared to those who had undergone unilateral ACLR. They had a high activity level before their first and second ACL injuries but an impaired activity level at follow-up after their second injury (study IV). Conclusions: Female football players who returned to football after an ACLR had high motivation and had undergone ACLR within one year after injury. Players with ACLR had similar functional performance to healthy controls. Movement asymmetries, which in previous studies have been associated with increased risk for primary and secondary ACL injury, occurred to a high degree in both groups. The rate of additional ACLR seemed to be increased in a selected group of young patients who desire to return to strenuous sports like football quickly after primary ACLR. Sustaining a contralateral ACL injury led to impaired knee function and activity level.

Download or read book The influence of fatigue on injury risk in male youth soccer written by Michal Lehnert and published by Palacký University Olomouc. This book was released on with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents information regarding changes in lower limb injury risk factors when fatigue is present, and the role of genetics in injury risk in male youth soccer. As many internal risk factors are modifiable, information presented both in the theoretical part of the book and original research studies focuses on the influence of acute, residual and accumulated fatigue on physiological mechanisms are presented to aid sports scientists and coaches to understand the age related effects of fatigue on such factors. This information can help coaches monitor fatigue related responses and be able to create efficient training programmes during important periods of growth and maturation. This will help to enhance performance and reduce injury risk in youth male soccer.

Download or read book Incidence and Prevention of Injury of the Anterior Cruciate Ligament in Females written by Arielle E. Gillie and published by . This book was released on 2011 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: According to the American College of Sports Medicine, women are two to eight times more likely to sustain an anterior cruciate ligament injury than men at the same level of performance. This high incidence of women with an ACL injury is thought to be due to a number of gender differences. This study examines the research that has been conducted to determine the reason for the disproportionate incidence of anterior cruciate ligament in female population. The study encompasses anatomical structure of the knee joint, structural differences in the male and female knee, hormonal influences, biomechanical influences, neuromuscular influences, and strategies for prevention. If intrinsic and extrinsic risk factors for women can be determined and altered, then steps can be taken to reduce the risk of an anterior cruciate ligament injury in women.

Download or read book Gender Differences in Risk Factors Related to Anterior Cruciate Ligament Injuries in Intercollegiate Soccer Players written by April Marie Reed and published by . This book was released on 1998 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anterior Cruciate Ligament Injuries in the Female Athlete written by Karen Ocwieja and published by . This book was released on 2009 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Female athletes have become the poster children for anterior cruciate ligament (ACL) injuries in recent years. This has lead to increased attention from research. There is now a vast amount of articles about ACL injuries and the library keeps growing. The purpose of this thesis is to review the current literature on ACL injury related to etiology, pathology and prevention. Through my research an additional topic arose. This is highlighted in a further section, psychosocial factors. Original research was conducted to gain a preliminary look at how playing multiple sports at one time, or specializing in one sport in high school, affects injury rates and what was the greatest influence on the decision to play club sports. The results from the literature review revealed that valgus stress at the knee and the imbalance between the force couple of the hamstrings and quadriceps are the most responsive to correction through training. The research supports that by correcting those two etiological risk factors female athletes can reduce their risk for ACL injury. Additional research is needed to look at how psychosocial factors [are] related to ACL injuries"--Abstract.

Download or read book Assessing and Modifying Neuromuscular Risk Factors for Anterior Cruciate Ligament Injury in Female Athletes written by Joanne Parsons and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Injury to the anterior cruciate ligament (ACL) may have consequences for an athlete in the form of pain, decreased activity levels and early-onset osteoarthritis. Female athletes are at increased risk of injury, perhaps because of differences in neuromuscular function. Methods of identifying risk factors and effective prevention strategies for ACL injury have traditionally involved athletes of high school age or older. However by that age, the opportune time to intervene may have passed. This thesis involves a sequence of studies which measures the neuromuscular function of younger athletes, aged 10-14 years. First, the reliability of measuring strength and power of the lower extremity on an isokinetic dynamometer was explored. Torque and power of the hip flexors and knee extensors were the only measures with acceptable reliability. Conversely, peak velocity of all the tested hip and knee movements demonstrated acceptable reliability. A high amount of variability was found with all test movements, and so alternate tests should be used if measuring an individual athlete's ability. From the data collected within the reliability study, a sex comparison was undertaken to determine if neuromuscular power differed at this young age. It was determined that girls and boys between 10 and 14 years of age do not differ in terms of knee or hip movement velocity or power. There is evidence to suggest that sex differences exist by adulthood; further research is required to determine when the disparity becomes apparent. The final project was to determine whether strength training would improve the manner in which young female athletes land from a jump; a common ACL injury mechanism. This randomized controlled trial found no difference between the intervention group who trained their legs, and the control group who trained their arms. However those athletes with the poorest landings appeared to improve their movement pattern regardless of training regime. This thesis contributes to the literature by providing evidence for measurement protocols for young athletes, introducing neuromuscular power instead of strength into the investigation of contributing factors to injury, and by furthering the examination of strength training as an effective component of prevention programs.

Download or read book Differential Biomechanical Effects of an ACL Injury Prevention Program in Women s Basketball and Soccer Players written by Jeffrey Bruce Taylor and published by . This book was released on 2016 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Anterior cruciate ligament (ACL) injury prevention programs are considerably less successful in women's basketball than women's soccer. Despite different sport-specific demands (e.g. more jumping and frontal plane movements in basketball), ACL injury prevention programs have been uniformly administered in both sports and predominantly emphasize improving high-risk biomechanics during sagittal plane tasks. As such, injury prevention programs may not provide the appropriate stimulus to reduce ACL injury risk during the high-risk demands associated with women's basketball. Thus, the purpose of this study was to 1) compare the fundamental movement profiles in adolescent female basketball and soccer players during a variety of jump landing tasks, 2) assess whether an established ACL injury prevention program affects lower extremity biomechanics during sagittal vs. frontal plane and double- vs. single-leg landings, and 3) analyze the extent to which female basketball and soccer players respond differently to a uniform ACL injury prevention program. A repeated measures experimental design was used in this study. Middle- and high-school aged female basketball and soccer teams were cluster-randomized into intervention (basketball, n=21; soccer, n=27) and control (basketball, n=21; soccer, n=28) groups. Three-dimensional biomechanical analysis was performed during double- and single-leg sagittal and frontal plane tasks before and after the completion of an established 6-week ACL injury prevention program. Biomechanical variables of interest were those that have been theorized to influence ACL injury risk, including hip flexion, adduction, internal rotation, and knee flexion, abduction, internal rotation and external rotation peak angles, excursions, and peak normalized external joint moments. At baseline, basketball players exhibited relatively stiff landings, with less hip and/or knee excursion than soccer players. Sport differences were especially apparent as jump landing tasks increased in difficulty, with the single-leg, frontal plane jump landing eliciting the most differences. During this task, basketball players landed with decreased hip adduction angles (p.001), decreased hip flexion (p=.03), and knee flexion (p=.01) excursions, and increased hip internal rotation (p=.003) and greater relative knee external rotation (p=.001) excursions. Additionally, forces differed between sports during the single-leg frontal plane jump landing, with basketball players showing increased knee abduction (p=.003) and decreased hip adduction (p=.001) and knee external rotation (p.001) moments. Across sports, no significant biomechanical changes were identified after the training program in any of the sagittal or frontal plane jump landing tasks (p.05). However, limited evidence suggested that biomechanical changes were not the same across all tasks, as participants in the intervention group showed relative decreases in knee abduction moments during the double-leg sagittal plane landing compared to the single-leg sagittal plane landing (p=.005). Additionally, women's basketball and soccer players largely exhibited similar biomechanical adaptations after training. No significant differences in biomechanical adaptations were identified between sports during the drop vertical jump, double-leg sagittal plane, or double- and single-leg frontal plane tasks (p.05). During the single-leg sagittal plane jump landing task, basketball players in the intervention group exhibited increased peak knee abduction angles (p=.004) and excursions (p=.003) after training compared to the basketball control group (p=.01) and soccer intervention group (p=.01). These results indicate that the discrepancy in the success of ACL injury prevention programs in basketball and soccer players may not be a function of sport-specific responses to training. Instead, basketball players appear to utilize distinct fundamental movement strategies during a variety of jump landing tasks compared to soccer, and therefore, current prevention programs may not successfully address these sport-specific movement differences. Specifically, basketball players land in potentially higher-risk positions, with decreased levels of hip and knee flexion excursion, and elements of dynamic lower extremity valgus, which are especially prevalent during high level basketball-specific tasks, including jump landings on a single-leg and in the frontal plane. However, 6-weeks of offseason training using a warm-up based ACL injury prevention program does not appear to provide adequate volume or intensity to modify the high-risk movement patterns used during these tasks. Thus, to improve the success of future programs in the basketball population, exercise prescription may need to incorporate higher levels of more intense technique training that emphasizes soft landings during basketball-specific frontal plane and single-leg jumping activities."--Abstract from author supplied metadata.

Download or read book Women s Health in Sports and Exercise written by William E. Garrett and published by American Academy of Orthopedic Surgeons. This book was released on 2001 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses training methods, injury risks and the effects of exercise on physical and emotional health.

Download or read book Prevention of Noncontact ACL Injuries written by Letha Y. Griffin and published by Academy. This book was released on 2001 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This important work will help you understand: the epidemiology of noncontact ACL injuries; risk factors for injuries; the "at-risk" athlete; neuromuscular prevention programs; their influence on injury rates. Supported by the American Orthopaedic Society for Sports Medicine, the National Athletic Trainers Association Research and Education Foundation, the National Collegiate Athletic Association, and the Orthopaedic Research and Education Foundation.

Download or read book CORE PERFORMANCE MEASURES AND BODY SEGMENT KINEMATICS FOLLOWING KNEE JOINT LOADING AMONG FEMALE COLLEGIATE ATHLETES written by Matthew Armistead and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Women participating in sports are three-times more likely to suffer anterior cruciate ligament (ACL) injury than men. Consequently, incidence of injury varies among different sports in which women engage; specifically, womens ice hockey players display a markedly lower rate compared with lacrosse, and field hockey. While the inherent dynamics of individual sports influence incidence, modifiable factors may also contribute to these disparate ACL injury rates, and represent variables that clinicians could address to reduce risk. Core strength, and endurance are such variables proposed to be related to ACL injury risk, and intervention programs targeted at improving these measures are suggested to curb incidence. During dynamic movement tasks in sports, such as landing, lesser measures of core performance may cause the center of mass to shift in a manner that heightens knee valgus angle, which may load the ACL, and result in injury. Landing represents a common non-contact mechanism of ACL injury, and biomechanical approach to studying body segment responses to knee joint loading; thus, the aim of this study was to compare core performance, and kinematic landing profiles among Division-I collegiate female student-athletes participating in ice hockey, lacrosse, and field hockey. We hypothesized that ice hockey players would demonstrate greater core performance measures as well as lesser lateral trunk lean, and knee valgus angles upon landing compared with lacrosse, and field hockey. The outcomes of this study demonstrate that ice hockey players demonstrate greater core performance measures, which may influence body segment kinematics associated with knee loading mechanisms that result in ACL injury. Practitioners that operate in competitive athletics may use these data to identify modifiable factors, like core performance, in an effort to potentially improve body segment responses to destabilizing loads imparted to the knee joint for diminishing ACL injury risk in collegiate womens sports.

Download or read book Greater Breast Support Reduces Common Biomechanical Risk Factors Associated with Anterior Cruciate Ligament Injury written by Hailey Benton Fong and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To examine the effects of breast support on trunk and knee joint biomechanics in female collegiate athletes during a double-limb landing task.Methods: Fourteen female athletes completed five landings in three different sports bra conditions: no support, low support, and high support. 3D kinematics and ground reaction forces were recorded simultaneously. Visual 3D was used to calculate trunk and knee joint angles and moments. Custom software determined discrete trunk and knee joint variables. A repeated measures analysis of covariance with post-hoc t-tests compared landing biomechanics by condition.Results: Greater breast support was associated with reducation in knee flexion and knee valgus angles as well as increases in knee varus moments. Greater breast support was associated with greater trunk flexion angles at initial contact and greater peak trunk flexion angles. Conclusions: Lower levels of breast support are associated with knee joint and trunk biomechanical profiles suggested to increase ACL injury risk. .

Download or read book Injury Prevention in Youth Football Players written by Hanna Lindblom and published by Linköping University Electronic Press. This book was released on 2019-10-08 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Background With 17–35% of all 14-year-olds in Sweden being active in football, injuries do occur, most frequently during match play. Based on knowledge of injury mechanisms and risk factors, different injury prevention exercise programmes (IPEPs) have been developed. In this thesis, the Swedish IPEP Knee Control was used as a model for injury preventive training. Aim The overall aim of this thesis was to improve our understanding of the effects of the Knee Control injury prevention exercise programme on sports performance and jump-landing technique, as well as exploring programme implementation and coach experiences of using the programme in youth football. Methods Studies I and IV were cluster-randomised trials focusing on the performance effects of Knee Control. Study I included four teams with 41 female youth football players (mean age 14). The intervention group used Knee Control twice weekly for 11 weeks, whereas the control group teams did their usual training. Knee Control includes six different exercises at four levels of difficulty and with partner exercises and is meant to be used during warm-up at every training session. Performance was tested using a battery of balance, agility, jump and sprint tests at baseline and follow-up at an indoor venue. Study IV had a similar set-up but included two different interventions: Knee Control and a new, further-developed version of the programme, Knee Control+, which were studied during an eight-week intervention involving eight youth football teams, four male, four female (mean age 14), with 77 players. Similar, but not identical, performance tests were used in Study IV, along with drop vertical jumps and tuck jump assessment to assess jump-landing technique. Studies II and III focused on the implementation context. Study II was questionnaire based, using the RE-AIM framework covering the reach, effectiveness, adoption, implementation and maintenance of Knee Control. Coaches for female youth teams (n=352), one representative of the national football association and representatives of eight district football associations responded to web-based questionnaires. Data collection was performed two years after the nation-wide implementation of Knee Control started. Study III was a qualitative study that followed up on the results of Study II. Interviews were conducted with 20 coaches for female football teams and analysed using qualitative content analysis. The interviews focused on factors that affected the adoption and use of Knee Control. All 20 coaches had experience of Knee Control. Results Limited positive effects were seen on jump-landing technique in girls, with the total tuck jump assessment score improving, as well as two separate criteria, the number of jumps accomplished during the 10-second test and additionally an increased knee-flexion angle upon landing from a drop vertical jump. No improvements on the performance tests were found in either Study I or Study IV. Both studies, however, suffered from low player compliance with the IPEPs and as a result low training dosage. No major differences in results were seen between Knee Control and Knee Control+ in Study IV. Study II showed that 91% of the responding coaches were familiar with Knee Control, they perceived the programme to be effective, 74% had started to use it, and it was fairly well maintained over time. However, only one third of the coaches used the programme every week and few used the whole programme. There were no formal policies for programme implementation and use in the district football associations and clubs. Study III showed that the coach was vital for programme use but needed social support, buy-in from players, resources and a feasible programme to facilitate programme adoption and use. When facing challenges with Knee Control implementation and use, the coaches did their best to work around these obstacles; for example, by modifying the programme content or dosage. Conclusions In conclusion, limited positive effects on jump-landing technique were seen in girls, potentially affecting risk factors for injury positively. No clinically meaningful effects from Knee Control or Knee Control+ were seen on performance tests as measured in the studies in either boys or girls. This may be related to the low training dosage. The high programme reach, perceived effectiveness, adoption and fairly high maintenance of Knee Control were positive. The modifications of programme content and/or dosage were concerning but will hopefully decrease with a more user-friendly programme. Bakgrund I och med att 17–35% av alla 14-åringar i Sverige är aktiva inom fotboll så uppkommer en del skador, oftast i samband med matcher. Utifrån kunskap om skadesituationer och riskfaktorer för skador har olika skadeförebyggande träningsprogram utvecklats. I denna avhandling användes det svenska skadeförebyggande programmet Knäkontroll som modell för skadepreventiv träning. Syfte Det övergripande syftet var att öka förståelsen för effekterna av Knäkontroll på prestationsförmåga och hopp-landningsteknik, programmets implementering och tränarnas erfarenheter av att använda programmet inom svensk ungdomsfotboll. Metod Studie I och Studie IV var klusterrandomiserade studier som undersökte effekterna på prestationsförmågan av att träna Knäkontroll. Studie I inkluderade 41 flickfotbollsspelare (genomsnittsålder 14 år). Interventionsgruppen använde Knäkontroll två gånger per vecka i 11 veckor, medan kontrollgruppen tränade som vanligt. Knäkontroll involverar sex olika övningar på fyra svårighetsgrader och med tillhörande parövningar och ska användas vid uppvärmningen inför varje fotbollsträning. Prestationsförmågan testades inomhus med ett batteri av olika tester för balans, snabbhet, hopp- och sprintförmåga vid baslinje och uppföljning. Studie IV hade ett likartat upplägg men inkluderade två olika interventioner: Knäkontroll och en vidareutvecklad version av programmet, Knäkontroll+. Studien pågick åtta veckor i åtta fotbollslag (fyra pojk-, fyra flicklag) med 77 spelare (genomsnittsålder 14 år). Liknande test för prestationsförmåga användes som i studie I, men även drop vertical jumps och tuck jumps för att bedöma hopp-landningsteknik. Studie II och Studie III fokuserade på implementeringskontexten, det vill säga implementeringen av Knäkontroll ute i fotbollslag. Studie II var en enkätstudie som med hjälp av ramverket RE-AIM (reach, effectiveness, adoption, implementation and maintenance) utvärderade implementeringen av Knäkontroll. Tränare för flickfotbollslag (n=352), en representant för Svenska Fotbollförbundet och representanter för åtta distriktsförbund besvarade de webbaserade enkäterna. Datainsamlingen gjordes två år efter att den nationella implementeringen av Knäkontroll startade. Studie III var en kvalitativ studie som fördjupade resultaten av Studie II. Intervjuer genomfördes med tjugo tränare för flick- och damfotbollslag och analyserades med kvalitativ innehållsanalys. Intervjuerna fokuserade på faktorer som påverkade tränarnas upptag och användning av Knäkontroll. Alla tränare hade erfarenhet av Knäkontroll sedan tidigare. Resultat Begränsad positiv effekt sågs på hopp-landningsteknik bland flickorna i studie IV, med en förbättrad totalpoäng på tuck jumps, på två kriterier i tuck jump, ökat antal hopp under testets 10 sekunder samt en ökad knäflexionsvinkel vid landning från drop vertical jumps. Ingen förbättring av prestationsförmågan sågs i Studie I eller Studie IV. I båda studierna var spelarnas närvaro på fotbollsträningar låg, vilket även gav en låg träningsdos av Knäkontroll. Inga större skillnader i resultat sågs mellan Knäkontroll och Knäkontroll+ i Studie IV. Studie II visade att 91% av tränarna kände till Knäkontroll, att tränarna upplevde att programmet var effektivt, 74% hade också börjat använda programmet och användandet bibehölls också förhållandevis väl över tid. Däremot använde endast 1/3 av tränarna programmet varje vecka och få använde hela programmet. Det saknades riktlinjer för programmets implementering och användning inom distriktsförbund och klubbar. Studie III visade att tränaren var oumbärlig för programmets användning men behövde mer socialt stöd, intresse från spelarna och resurser utöver ett användarvänligt program för att underlätta det preventiva arbetet. När tränarna ställdes inför utmaningar gjorde de sitt bästa för att kringgå problemen, till exempel genom att modifiera programmets innehåll eller dosering, för att ändå kunna använda programmet. Konklusion Sammanfattningsvis sågs begränsade positiva effekter på hopplandningsteknik hos flickorna, vilket möjligen påverkar riskfaktorerna för skada positivt. Inga kliniskt meningsfulla effekter av Knäkontroll eller Knäkontroll+ sågs på prestationstesterna hos varken pojkar eller flickor. Detta kan vara relaterat till den låga träningsdosen. Knäkontrollprogrammets stora spridning, högt skattade effektivitet, höga upptag och förhållandevis goda bibehållande var positivt. De modifieringar av programmets innehåll och/eller dosering som sågs var oroväckande men kan förhoppningsvis minska av ett mer användarvänligt program.