Effect of protective taping on knee eversion angle and jump height during single-leg vertical jumps in patients with anterior cruciate ligament reconstruction.

[Purpose] Taping is often performed to prevent injury and injury recurrence. However, it is unclear how taping affects landing and jumping kinematics in patients undergoing anterior cruciate ligament reconstruction. Therefore, this study aimed to determine the kinematic effects caused by taping during single-leg vertical jumps in patients with anterior cruciate ligament reconstruction. [Participants and Methods] Ten young patients who underwent anterior cruciate ligament reconstruction were included. The maximum knee joint flexion angle, peak value of the vertical component of the floor reaction force, maximum knee joint eversion angle, and jumping height during a single-leg vertical jump were measured using a three-dimensional motion analyzer and compared among the following three groups: without taping, with protective taping using elastic tape, and with protective taping using non-elastic tape. [Results] There were no significant differences in the peak value of the vertical component of the floor reaction force or the maximum knee joint flexion angle among the three groups. The maximum knee joint eversion angle and jumping height were significantly lower in the elastic tape and non-elastic tape groups than in the non-taping group. [Conclusion] Anterior cruciate ligament taping does not affect the magnitude of the impact on the body and can decrease knee joint eversion. However, jumping height was lower in the two taping groups than in the no-taping group. There were no significant differences in the items studied between the two taping groups.

Proprioceptive Reweighting and Postural Control are Impaired Among Elite Athletes Following Anterior Cruciate Ligament Reconstruction.

Background: After anterior cruciate ligament reconstruction (ACLR), the risk of recurrence can reach 20%, partially due to poor postural control and impaired sensory processing. Lack of flexibility in proprioceptive postural strategy has recently been shown to be a potential risk factor for ACL injury. Hypothesis/Purpose: This study aimed to compare proprioceptive reweighting and postural control between ACLR and controls elite athletes. It has been hypothesized that athletes with ACLR exhibit impaired proprioceptive reweighting and poor postural control. Study design: Cross-sectional study. Methods: Fifty-two ACLR and 23 control elite athletes (50 males and 25 females, mean age 24.7 years) were included. Proprioceptive reweighting was determined using the evolution of proprioceptive weighting (eRPW), calculated from the center of pressure (CoP) displacements generated by tendon vibration during bilateral standing tasks on firm and foam surfaces. An eRPW <95% classified individuals as flexible (i.e., able to reweight proprioceptive signals from the ankle to the lumbar region), whereas an eRPW >105% classified individuals as rigid (i.e., maintaining an ankle dominant strategy). CoP velocity (vCoP) and CoP ellipse area (EA) were used to characterize postural control. Independent sample t-test and a Chi-squared test were used to compare eRPW, vCoP, EA, and the proportion of flexible and rigid athletes between groups. Results: The eRPW was higher in the ACLR group (100.9±58.8 vs. 68.6±26.6%; p=0.031; Rank biserial correlation=0.314; medium), with a greater proportion of rigid athletes than in the control group (38.5 vs. 4.4%; p=0.010), reflecting lower proprioceptive reweighting. The ACLR group had greater EA on foam surface (8.0±4.6 vs. 6.3±4.4cm²; p=0.019), revealing poorer postural control. Conclusion: Elite athletes with ACLR showed impaired proprioceptive reweighting and poor postural control on an unstable surface. This reflects an inability to adapt proprioceptive weighting when balance conditions are changing and suboptimal postural strategies. Level of Evidence: 3b.

Alterations in mechanical properties of rabbit collateral ligaments eight weeks after anterior cruciate ligament transection.

Anterior cruciate ligament (ACL) injury is a common knee ligament injury among young, active adults; however, little is known about its impact on the viscoelastic properties of the knee joint's collateral ligaments. This study aimed to characterize and compare the viscoelastic properties of rabbit collateral ligaments in healthy control knees, injured knees, and knees contralateral to the injured knees. Unilateral anterior cruciate ligament transection was performed on six New Zealand white rabbits to create an ACL injury model. Medial and lateral collateral ligaments (MCL and LCL) were collected from the injured and contralateral knees eight weeks after ACL transection. Ligaments were also harvested from both knees of four unoperated rabbits. The ligaments underwent tensile stress-relaxation testing at strain levels of 2, 4, 6, and 8 %, and a sinusoidal loading test at 8 % strain with 0.5 % strain amplitude using frequencies of 0.01, 0.05, 0.1, 0.5, 1, and 2 Hz. The results showed that collateral ligaments of ACL-transected knees relaxed slower compared to control knees. Sinusoidal testing revealed that contralateral knee LCLs had significantly higher storage and loss modulus across all test frequencies. The results indicate that contralateral knee LCLs become stiffer compared to LCLs from control and ACL-transected knees, while LCLs from ACL-transected knees become less viscous compared to LCLs from control and contralateral knees. This study suggests that knee ligaments undergo adaptations following an ACL injury that may affect the mechanics of the ACL-transected knee, which should be considered in biomechanical and rehabilitation studies of patients with an ACL injury.

ACL injury characteristics in badminton : A registry study with prospectively collected data on sports related epidemiology and injury mechanism of 539 badminton players.

Background: Over recent years, more anterior cruciate ligament (ACL) ruptures in badminton players have occurred. Little is known about the injury mechanism in badminton. The hypothesis is that most ACL injuries occur with single leg landings on the non-dominant leg in the backhand side or with lunge movements in the forehand side on the dominant leg. To inform prevention strategies the aim of this study was to investigate the mechanism of ACL injuries in badminton, specifically if ACL injuries occur in certain positions on the badminton court and/or with certain movements. Secondary aims were to investigate differences among gender, age groups and between recreational and tournament players. Methods: The study, ACL Denmark, investigate ACL ruptures in a cohort of 90.610 participants diagnosed between 2000 and 2018. Of those, 539 participants reported ACL rupture during badminton and filled in an online questionnaire in December 2021-January 2022 on the injury mechanism and other injury characteristics. Data is presented as numbers, percentage, means (SD) and median (IQR) with chi square test or Fischers exact test for dichotomous outcomes. Results: Most participants played badminton (n = 435, 81 %) as primary sport and 155 (29 %) reported to play on a competitive level (Tegner score 8). The rear court (n = 285, 40 %) was the most frequent location of injury but with a high percentage on the front and midcourt (n = 154, 22 %). The rear court was more prevalent among players aged 18-29 (p < 0.001). The most prevalent movement preceding the ACL injury was the scissor kick jump on the rear court (100, 19 %) followed by lunge at the net (70, 13 %) and lunge at the rear court (69, 13 %). One hundred and six players (15 %) were injured preceded by a deceptive shot from the opponent. The dominant leg was mainly injured in the forehand side and the non-dominant leg mainly in the backhand side. Conclusion: The most prevalent movement preceding the ACL injury was the lunge followed by the scissor kick jump. The rear court was the primary location of ACL injury in badminton and the dominant knee has a higher risk of injury in the forehand side and the non-dominant knee in the backhand side. More focus on the technical performance of lunge and scissor kick jumps and development of a badminton specific ACL injury prevention program is needed in badminton.

Preliminary identification of somatic mutations profile in ACL injury.

Anterior cruciate ligament (ACL) injury is a common orthopedic disease with a high incidence, long recovery time, and often requiring surgical treatment. However, the susceptibility factors for ACL injury are currently unclear, and there is a lack of analysis on the differences in the ligament itself. Previous studies have focused on germline mutations, with less research on somatic mutations. To determine the role of somatic mutations in ACL injuries, we recruited seven patients between the ages of 20 and 39 years diagnosed with ACL injuries, collected their peripheral blood, injured ligament ends, and healthy ligament ends tissues, and performed exome sequencing with gene function enrichment analysis. We detected multiple gene mutations and gene deletions, which were only present in some of the samples. Unfortunately, it was not possible to determine whether these somatic mutations are related to ligament structure or function, or are involved in ACL injury. However, this study provides valuable clues for future in-depth research.

A Robotic Clamped-Kinematic System to Study Knee Ligament Injury.

Knee ligament injury is among the most common sports injuries and is associated with long recovery periods and low return-to-sport rates. Unfortunately, the mechanics of ligament injury are difficult to study in vivo, and computational studies provide limited insight. The objective of this study was to implement and validate a robotic system capable of reproducing natural six degree-of-freedom clamped-kinematic trajectories on human cadaver knees (meaning that positions and orientations are rigidly controlled and resultant loads are measured). To accomplish this, we leveraged the field's recent access to high-fidelity bone kinematics from dynamic biplanar radiography (DBR), and implemented these kinematics in a coordinate frame built around the knee's natural flexion-extension axis. We assessed our system's capabilities in the context of ACL injury, by moving seven cadaveric knee specimens through kinematics derived from walking, running, drop jump, and ACL injury. We then used robotically simulated clinical stability tests to evaluate the hypothesis that knee stability would be only reduced by the motions intended to injure the knee. Our results show that the structural integrity of the knee was not compromised by non-injurious motions, while the injury motion produced a clinically relevant ACL injury with characteristic anterior and valgus instability. We also demonstrated that our robotic system can provide direct measurements of reaction loads during a variety of motions, and facilitate gross evaluation of ligament failure mechanisms. Clamped-kinematic robotic evaluation of cadaver knees has the potential to deepen understanding of the mechanics of knee ligament injury.

Posterior tibial slope angle in contact versus non-contact anterior cruciate ligament injuries.

BACKGROUND: Increased Posterior Tibial Slope (PTS) angle has been reported to be a risk factor for primary anterior cruciate ligament (ACL) tears. However, it is unknown whether increased PTS has an associated increased risk for non-contact versus contact ACL injury. PURPOSE: The purpose of this study is to determine whether patients with non-contact ACL injury have a higher PTS angle than those with contact ACL injury. METHODS: A total of 1700 patients who underwent primary ACL reconstruction between January 2011 and June 2023 at a single academic institution were initially included. Electronic medical records were reviewed for demographic information as well as evidence that the patient sustained a contact or non-contact ACL injury. Patients in the contact cohort were propensity score matched to patients in the non-contact cohort by age, sex and BMI. Additionally, patients in the contact cohort were then propensity score matched to a control group of patients with intact ACLs also by age, sex and BMI. RESULTS: One hundred and two patients with contact injury were initially identified and 1598 patients with non-contact injuries were identified. Of the 102, 67 had knee X-rays that were suitable for measurement. These 67 contact injury patients were propensity score matched to 67 noncontact patient and 67 patients with intact ACLs based on age, sex and BMI. There were no significant differences between contact and non-contact cohorts in age (28.7±6.3 vs. 27.1±6.5, p = 0.147), sex (Female: 36.0% vs. 34.3%, p = 0.858), or BMI (26.7±5.6 vs 26.1±3.4, p = 0.475). There was no significant difference in PTS angle between contact versus non-contact ACL injury patients (11.6±3.0 vs.11.6±2.8, p = 0.894). There was a significant difference in PTS between the contact ACL injury and the intact cohort (11.6±3.0 vs. 10.0±3.9, p = 0.010) and the non-contact ACL injury and the intact cohort (11.6±2.8 vs. 10.0±3.9, p = 0.010). CONCLUSION: There was no significant difference in the degree of PTS between patients who sustained contact versus non-contact ACL injuries. Additionally, there was a significantly increased PTS in both the contact and non-contact ACL injury cohorts compared to patients with intact ACLs.

Graft Failure and Contralateral ACL Injuries After Primary ACL Reconstruction: An Analysis of Risk Factors Using Interpretable Machine Learning.

Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) can be successful in restoring knee stability. However, secondary ACL injury, either through graft failure or contralateral injury, is a known complication and can significantly impact the ability of a patient to return successfully to previous activities. Purpose: To develop and internally validate an interpretable machine learning model to quantify the risk of graft failure and contralateral ACL injury in a longitudinal cohort treated with ACLR. Study Design: Case-control study; Level of evidence, 3. Methods: An established geographic database of >600,000 patients was used to identify patients with a diagnosis of ACL rupture between 1990 and 2016 with a minimum 2-year follow-up. Medical records were reviewed for relevant patient information and 4 candidate machine learning algorithms were evaluated for prediction of graft failure and contralateral ACL injury in patients after ACLR as identified either on magnetic resonance imaging or via arthroscopy. Performance of the algorithms was assessed through discrimination, calibration, and decision curve analysis. Model interpretability was enhanced utilizing global variable importance plots and partial dependence curves. Results: A total of 1497 patients met inclusion criteria. Among them, 140 (9.4%) had graft failure and 128 (8.6%) had a contralateral ACL injury after index surgery at a median follow-up of 140.7 months (interquartile range, 77.2-219.2 months). The best performing models achieved an area under the receiver operating characteristics curve of 0.70 for prediction of graft failure and 0.67 for prediction of contralateral ACL injury, outperforming a logistic regression fitted on the identical feature set. Notable predictors for increased risk of graft failure included younger age at injury, body mass index (BMI) <30, return to sports <13 months, initial time to surgery >75 days, utilization of allograft, femoral/tibial fixation with suspension/expansion devices, concomitant collateral ligament injury, and active or former smoking history. Predictors of contralateral ACL injury included greater preoperative pain, younger age at initial injury, BMI <30, active smoking history, initial time to surgery >75 days, history of contralateral knee arthroscopies, and involvement in contact sports. Conclusion: Less than 18% of all patients who undergo ACLR should be expected to sustain either a graft failure or contralateral ACL injury. Machine learning models outperformed logistic regression and identified greater preoperative pain, younger age, BMI <30, earlier return to higher activity, and time to surgical intervention >75 days as common risk factors for both graft failure as well as contralateral ACL injury after ACLR. Surgeon-modifiable risk factors for graft failure included allograft and femoral/tibial fixation with a suspension/expansion combination.

The influence of menstrual cycle phase on isokinetic knee flexor and extensor strength in female soccer players: a pilot study.

The prevalence of anterior cruciate ligament injury in female soccer players has been attributed to hormonal fluctuations during the menstrual cycle (MC), with injury incidence greatest during the follicular phase. Eight, eumenorrheic, collegiate soccer players (19.5 ± 0.75 years, 1.62 ± 4.90 cm, 61.12 ± 7.6 kg mean ± SD) completed eccentric knee flexor and concentric knee extensor trials at 60 and 240°·s-1 during the follicular, ovulation and luteal phases of their MC. Peak torque and corresponding angle of peak torque were maintained across all phases of the MC, irrespective of testing modality and speed (p ≥ 0.149). Strength ratios defined using peak torque were also not sensitive to MC phase (p ≥ 0.933). However, Functional Range in eccentric knee flexion was significantly lower during the follicular phase (p = 0.017), at both testing speeds. This supports epidemiological observations but highlights the importance of analysing isokinetic data beyond the peak of the strength curve. Interpretation of isokinetic data should therefore focus on points of "weakness" as opposed to maximum strength, whilst (p)rehabilitative strategies should consider strength through range of motion, and at different speeds. Eccentric hamstring strength was observed to decrease significantly at the higher speed, contrary to observations in elite male players, and potentially reflecting a differential training adaptation.

The Impact of Age and Gender on Anterior Cruciate Ligament Injuries and Associated Knee Lesions: A Retrospective Study.

OBJECTIVES: This study aimed to evaluate the anterior cruciate ligament (ACL)-associated lesions in knee sports injuries in magnetic resonance imaging (MRI) and the effect of genders and ages on the patterns of the associated lesions in Arar, Northern Border region, Saudi Arabia. METHODS: This retrospective cohort study enrolled MRI of knee sports injuries with diagnosed ACL lesions during the period from January 2018 to December 2023 in Prince Abdulaziz Bin Musaed Hospital and Alkhibrah Health Center in Arar. RESULTS: A total of 505 knee MRI images were enrolled in the study. There were 104 (20.5%) females and 401 (79.5%) males with an average age of 34.5 years (range: 10-85 years) in this study. ACL lesions were reported in 191 (37.8%) cases. ACL was reported to be associated with other knee lesions in 185 (96.8%) cases. Joint effusion and posterior horn medial meniscus (PHMM) lesions were the most associated lesions found in 112 (58.9%) and 108 (56.5%) cases, respectively. Aging was found to significantly increase the incidence of PHMM and joint effusion associated with ACL tears, with estimated relative risks of 1.4 and 1.5 (odds ratio: 2.19 and 2.6), respectively. Also, the female gender was found to significantly increase the incidence of PHMM and associated ligament injuries with estimated relative risks of 1.5 and 4.1 (odds ratio: 3.6 and 5.1), respectively. CONCLUSION: Tears of ACL are prevalent patterns of knee sports injuries with different types of associated injuries, which can be affected by the ages and genders of the patients.

Demographic and Injury Characteristics as Potential Risk Factors for Anterior Cruciate Ligament Injuries: A Multicentric Cross-Sectional Study.

Background: Anterior cruciate ligament (ACL) injuries are prevalent and can have debilitating consequences, with various factors potentially influencing their occurrence. This multicentric study aimed to comprehensively analyze the epidemiological characteristics of ACL injuries. We hypothesized that specific patient characteristics, such as age, sex, body mass index (BMI), and sports involvement, would be associated with distinct injury patterns and risk profiles. Methods: This cross-sectional study analyzed the medical records of 712 patients aged 15-60 diagnosed with ACL rupture. Data on demographics, injury mechanisms, associated injuries, graft type, and sports involvement were collected. Results: The majority of patients were male (93.1%), aged 15-30 years (80.2%), and overweight (66.7%). Autografts were the predominant graft choice (96.07%). Associated injuries were present in 79.5% of cases, with medial meniscus ruptures being the most common (37.36%). Sports-related (49.3%) and non-sports-related (50.7%) injuries were nearly equal, with non-contact injuries more prevalent (71.1%). In the sports-related subgroup, associated injuries emerged as a significant risk factor for ACL rupture (p = 0.014, OR = 1.596, 95% CI: 1.101-2.314), whereas non-contact mechanisms showed borderline significance (OR = 0.75, p = 0.09). Moreover, younger athletes were more susceptible to sports-related injuries (p = 0.024), with football being the primary sport involved. Conclusions: This study identified a high prevalence of concomitant injuries with ACL injury, which increased the risk of ACL injury, particularly in sports-related cases. Age-related differences in injury patterns highlight the need for age-appropriate preventive measures, especially for younger athletes participating in high-risk sports. This underscores the need for comprehensive injury assessment, targeted prevention strategies, and optimized clinical management approaches tailored to different populations' specific characteristics and risks.

Characterization of bone marrow edema patterns among patients with Segond fracture in the setting of acute anterior cruciate ligament injury: A comparative MRI study.

PURPOSE: The purpose of this study is to investigate the anatomic distribution of bone marrow edema on MRI among patients who sustained a Segond fracture compared to those with an isolated ACL tear. METHODS: A retrospective cohort study was performed of patients aged 18-40 years old who presented with an acute isolated ACL tear between January 2012 and May 2022. Two blinded readers reviewed all knee MRIs to assess bone marrow edema using the Whole-Organ Magnetic Resonance Imaging Score and the area of each sub-compartment was scored. RESULTS: There were 522 patients in the final analysis, of which 28 patients (5.4%) were identified to have a Segond fracture. The Segond group demonstrated significantly greater rates of WORMS grades 2 and 3 in the central lateral femoral condyle, as well as the anterior, central, and posterior lateral tibial plateau. Furthermore, the Segond group demonstrated significantly greater rates of WORMS grades 2 and 3 in the central medial femoral condyle and the anterior medial tibial plateau. Bone edema at the central lateral femoral condyle (R = 0.034, p = 0.019) and central tibial plateau (R = 0.093, p = 0.033) were significantly correlated with lateral meniscus tears, while the edema in the posterior medial femoral condyle was correlated with medial meniscus tears (R = 0.127, p = 0.004). CONCLUSION: Patients who present with ACL tear and a concomitant Segond fracture demonstrate significantly more extensive bone marrow edema in both the medial and lateral compartments of the knee compared to patients with an isolated ACL tear.

Think fast, stay healthy? A narrative review of neurocognitive performance and lower extremity injury.

BACKGROUND: Lower extremity (LE) injury has been problematic in athletic populations. While previous research has identified biomechanical and neuromuscular risk factors, more recent efforts have determined that neurocognitive performance (NP) may influence LE injury risk. OBJECTIVES: To describe the present findings pertaining to the relationship between NP and LE injury. This review described potential cerebral neural mechanisms underpinning LE injury with a particular emphasis on the role of vision in sensorimotor integration. Lastly, newer technology such as stroboscopic eyewear, smartboards, and virtual/augmented reality were discussed for their utility in assessing and training NP. METHODS: Narrative review that described NP and LE injury, as well as plausible mechanisms and training interventions. RESULTS: NP appears to influence both LE biomechanics and LE injury risk. Athletes with worse NP demonstrated decreased knee flexion and increased frontal plane knee loading compared to better performing athletes. Most studies determined an association between NP and LE injury risk. Visual motor reaction time, processing speed, and working memory appear to be useful NP measures for identifying athletes at risk for LE injury. Various brain regions including the precuneus and lingual gyrus may be implicated as neural signatures for LE injury. While recently developed technology offer promise, far-transfer effects to LE injury risk reduction have yet to be substantially investigated. CONCLUSIONS: NP should be considered an important component for identifying LE injury risk. Sports scientists and clinicians may consider a variety of assessments and interventions to quantify and train NP in conjunction with previously established protocols.

ACL Injury Etiology in Its Context: A Systems Thinking, Group Model Building Approach.

Background/Objectives: Given the complex nature of Anterior Cruciate Ligament (ACL) injury, it is important to analyze its etiology with suitable approaches in order to formulate intervention strategies for effective prevention. The present study employs system thinking techniques to develop a Causal Loop Diagram (CLD) Model for investigating the risk factors for ACL Injury (CLD-ACLI), through a Group Model Building approach. Methods: A two-stage procedure was applied involving a comprehensive literature review followed by several systems thinking group-modeling co-creation workshops with stakeholders. Results: Based on input from experts and stakeholders, combined with the latest scientific findings, the derived CLD-ACLI model revealed a series of interesting complex nonlinear interrelationships causal loops between the likelihood of ACL injury and the number of risk factors. Particularly, the interaction among institutional, psychological, neurocognitive, neuromuscular, malalignment factors, and trauma history seem to affect neuromuscular control, which subsequently may alter the biomechanics of landing, predisposing the ACL to injury. Further, according to the proposed CLD-ACLI model, the risk for injury may increase further if specific environmental and anatomical factors affect the shear forces imposed on the ACL. Conclusions: The proposed CLD-ACLI model constitutes a rigorous useful conceptual presentation agreed upon among experts on the dynamic interactions among potential intrinsic and extrinsic risk factors for ACL injury. The presented causal loop model constitutes a vital step for developing a validated quantitative system dynamics simulation model for evaluating ACL injury-prevention strategies prior to implementation.

Neurocognitive demands reduce jump distance and coordination variability of the injured leg in athletes after anterior cruciate ligament reconstruction.

PURPOSE: The study aimed to evaluate the impact of neurocognitive reliance on jump distance and lower extremity kinematics in individuals who had undergone anterior cruciate ligament reconstruction (ACLR). This was achieved by comparing hop performance under standard and neurocognitive conditions. METHODS: Thirty-two patients after ACLR and 32 healthy controls (CTRL) participated. Both groups performed a single-leg hop for distance (SLHD) and two neurocognitive hop tests, each designed to evaluate distinct aspects of neurocognition. The neurocognitive tests included the reaction SLHD (R-SLHD), measuring reaction to a central stimulus and working memory SLHD (WM-SLHD) assessing response to a memorized stimulus amidst distractor stimuli. Distances were assessed for the three-hop tests. In addition, joint kinematics were collected to calculate lower extremity coordination of the lower extremity. SLHD performance was defined as the mean hop distance per condition per leg for each participant and was analyzed using a mixed ANOVA with condition and leg as the within-subjects factors and the group (ACLR or CTRL) as the between-subjects factor. Differences in joint coordination variability were analyzed using two-sample t-test statistical parametric mapping (SPM) with linear regression. RESULTS: The WM-SLHD resulted in a significantly decreased jump distance compared with the standard hop test both for ACLR and CTRL. Furthermore, the leg difference within the ACLR group increased under higher cognitive load as tested with the WM-SLHD, indicating leg-specific adaptations in lower extremity coordination. CONCLUSIONS: Neurocognitive single-leg hop tests resulted in reduced jump distance in CTRL and ACLR. The neurocognitive hop test revealed changes in coordination variability for the CTRL and the uninjured leg of ACLR individuals, whereas the injured leg's coordination variability remained unaltered, suggesting persistent cognitive control of movements post-ACLR. LEVEL OF EVIDENCE: Level III.

The effects of fatigue on the relationship between ankle angle at initial contact and the knee and hip joints in landing: Assessing the risk of ACL injury.

BACKGROUND: Anterior cruciate ligament (ACL) injuries may correlate with lower limb angles and biomechanical factors in both dominant and non-dominant legs at initial contact (IC) post-landing. This study aims to investigate the correlation between ankle angles in three axes at IC and knee and hip joint angles during post-spike landings in professional volleyball players, both pre- and post-fatigue induction. RESEARCH QUESTION: To what extent does fatigue influence lower limb joint angles, and what is the relationship between ankle joint angles and hip and knee angles at IC during the landing phase following a volleyball spike? METHODS: Under conditions involving the peripheral fatiguing protocol, the lower limb joint angles at IC following post-spike landings were measured in 28 professional male volleyball players aged between 19 and 28 years, who executed the Bosco fatigue protocol both before and after inducing fatigue. A paired t-test was utilized to compare the joint angles pre- and post-fatigue in both dominant and non-dominant legs. Furthermore, Pearson's correlation test was conducted to explore the relationship between ankle angles at IC and the corresponding knee and hip joint angles. RESULTS: The findings of the study revealed that fatigue significantly increased hip external rotation and decreased knee joint flexion and external rotation in both the dominant and non-dominant legs (p < 0.05). Additionally, correlation analysis demonstrated that the ankle joint's positioning in the frontal and horizontal planes was significantly associated with hip flexion and external rotation at the IC, as well as with knee flexion and rotation (0.40 < r < 0.80). CONCLUSION: Fatigue increased hip external rotation and ankle internal rotation, weakening the correlation between these joints while strengthening the ankle-knee relationship, indicating a reduced hip control in jumps. This suggests a heightened ACL injury risk in the dominant leg due to the weakened ankle-hip connection, contrasting with the non-dominant leg.

Negative sentiments toward anterior cruciate ligament injury prevention outweigh positive awareness discussions on social media.

OBJECTIVES: The aim of this study is to understand the current public discussion surrounding anterior cruciate ligament (ACL) injury prevention on social media and determine factors that influence levels of public engagement. METHODS: We performed a qualitative and quantitative cross-sectional analysis of ACL injury prevention techniques discussed on social media via the Twitter application programming interface (API). The Twitter API was queried from inception to May 2023 using keywords related to ACL injury and prevention. We conducted a thematic analysis of the posts and performed a sentiment analysis using natural language processing. A multivariable regression model was used to identify metadata that predicted higher engagement (media, links, tagging, hashtags). RESULTS: A subset of 1823 unique posts was analyzed from 1701 unique accounts. Most posts were raising awareness about ACL injury prevention (n â€‹= â€‹733, 40.2%), followed by opinions on the topic (n â€‹= â€‹390, 21.4%), specific prevention techniques (n â€‹= â€‹289, 15.9%), personal experiences (n â€‹= â€‹272, 14.9%), and research (n â€‹= â€‹139, 7.6%). The majority consisted of posts from patients or caregivers (n â€‹= â€‹948, 55.7%), whereas healthcare providers accounted for 14.7% of posts. Posts containing media increased Tweet engagement count by an average of 6.1 (95% CI 2.8 to 9.4, p â€‹= â€‹0.00033) and posts discussing personal opinions increased engagement by 6.7 (95% CI 3.5 to 9.8, p â€‹= â€‹0.00004). On sentiment analysis of all included Tweets, 822 (45.1%) posts were positive, 309 (17.0%) were negative, and 692 (38.0%) were neutral. Sentiments expressed in posts related to ACL prevention were 2.8 times more negative compared to those discussing raising awareness. CONCLUSIONS: There is active discussion about ACL injury prevention on Twitter. The use of visual media increased public engagement. We identified a potential knowledge gap between the available prevention techniques and the perspectives of athletes, highlighting the need for healthcare professionals to enhance their engagement with ACL injury prevention on social media. LEVEL OF EVIDENCE: III.

Preventing Anterior Cruciate Ligament (ACL) Injuries in High School Sports Participants: An Executive Summary of the Inaugural Meeting of the National ACL Injury Coalition.

To address the increasing rates of anterior cruciate ligament (ACL) injury among young sports participants, the Hospital for Special Surgery (HSS) and the Aspen Institute convened a meeting of a new national coalition to make ACL injury prevention a fundamental aspect of youth sports. This executive summary outlines the National ACL Injury Coalition's goals as defined at its inaugural meeting held at HSS on March 27, 2023. Using a theory of change called "collective impact" designed to support collaboration and drive systems-level change, the coalition focused on 4 strategic priorities intended to reduce ACL injury rates in high school sports participants: widespread implementation of interventions (ensuring that student athletes are adequately trained), high-quality education (raising awareness among many stakeholders), equitable access (ensuring that all high school sports participants, regardless of the resources available at their schools, have access to injury prevention resources), and aligning stakeholders (uniting disparate entities-schools, sports clubs, parents, coaches, and others in these efforts). The group outlined short-range, medium-range, and long-range goals over a 3-year period, including the launch of an ACL injury prevention toolkit for use by adolescent sports participants and teams, athletic trainers, coaches, and other key stakeholders.

The Effect of Neurocognitive Training on Biomechanical Risk Factors Related to Anterior Cruciate Ligament Injury in Athletes: A Narrative Review.

CONTEXT: The best current evidence supports the effectiveness of neuromuscular training in reducing the risk of injury; however, the rate of anterior cruciate ligament (ACL) injuries is still high. Neurocognitive training (NT) has successfully improved biomechanical risk factors, but they have been considered in only a few studies. OBJECTIVE: To review the literature to determine the effect of NT on biomechanical risk factors related to ACL injury in athletes. EVIDENCE ACQUISITION: We searched PubMed, Google Scholar, Scopus, Science Direct, and the Physiotherapy Evidence Database from inception to August 2011. We included randomized controlled trials that used motor learning approaches and injury prevention programs to investigate kinematic and kinetic risk factors related to ACL injury. The quality of each clinical trial study was evaluated by the Physiotherapy Evidence Database scale. The eligibility criteria were checked based on the PICOS (population, intervention, comparison, outcome, and study type) framework. EVIDENCE SYNTHESIS: A total of 9 studies were included in the final analysis. Motor learning approaches include internal and external focus of attention, dual tasks, visual motor training, self-control feedback, differential learning, and linear and nonlinear pedagogy, combined with exercise programs. In most of the studies that used NT, a significant decrease in knee valgus; tibial abduction and external rotation; ground reaction force; and an increase in knee-, trunk-, hip-, and knee-flexion moment was observed. CONCLUSION: In classical NT, deviation from the ideal movement pattern especially emphasizing variability and self-discovery processes is functional in injury prevention and may mitigate biomechanical risk factors of ACL injuries in athletes. Practitioners are advised to use sport-specific cognitive tasks in combination with neuromuscular training to simulate loads of the competitive environment. This may improve ACL injury risk reduction and rehabilitation programs.

Patient-Reported Outcome Measures Used on Patients With Anterior Cruciate Ligament Injury.

Patient-reported knee-related rating scores and scales are widely used in reporting the clinical outcomes of anterior cruciate ligament (ACL) surgery. Understanding the psychometric properties of such measures is vital to recognizing the limitations that such measures may confer. The aim of this study was to review the available evidence as to the psychometric properties of patient-reported outcome measures (PROMs) used in ACL surgery. Eleven studies were identified, the majority being prospective cohort studies. Eight English, ACL-specific patient-reported outcome measures were identified and evaluated: Lysholm score, Tegner Activity Scale (TAS), Cincinnati score, ACL-Quality of Life (QOL) score, International Knee Documentation Committee (IKDC) Subjective Knee Form (SKF), Knee Injury and Osteoarthritis Outcome Score (KOOS)-ACL score, and ACL-Return to Sport Injury (RSI) scale. Only the Lysholm score, ACL-QOL, IKDC SKF, and ACL-RSI were evaluated for internal consistency, having an acceptable Cronbach's α (α>0.70). Most of the scoring systems were assessed for test-retest reliability, with four of them (Lysholm score, TAS, Cincinnati score, and IKDC SKF) having acceptable intraclass correlation coefficient (ICC) values (ICC > 0.70). Criterion validity was assessed for most measures with a good correlation with the IKDC. Effect sizes and standardized response means were large for three instruments that measured responsiveness (Lysholm score, TAS, and Cincinnati score) and moderate for one (ACL-QOL). Evidence is stronger and more robust for the Lysholm score, TAS, ACL-QOL, and IKDC SKF. However, there is variation in their psychometric properties as well as the aspect of knee-related health they are assessing. Hence, none can be universally applicable to all patients with ACL injuries. Recognizing these parameters is vital when choosing which instrument to use in reporting the outcomes of ACL injury or ACL surgery studies.