scholarly journals Relationship Between Isokinetic Knee Strength and Single-Leg Drop Jump Performance 9 Months After ACL Reconstruction

2022 ◽  
Vol 10 (1) ◽  
pp. 232596712110638
Author(s):  
N.M. Nuala Crotty ◽  
Katherine A.J. Daniels ◽  
Ciaran McFadden ◽  
Niall Cafferkey ◽  
Enda King
Keyword(s):  
Contact Time ◽  
Cruciate Ligament ◽  
Knee Extensor ◽  
Jump Height ◽  
Drop Jump ◽  
Linear Regression Models ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Knee Strength ◽  
The Relationship

Background: Deficits in knee strength after anterior cruciate ligament reconstruction (ACLR) surgery are common. Deficits in the single-leg drop jump (SLDJ), a test of plyometric ability, are also found. Purpose: To examine the relationship between isokinetic knee strength, SLDJ performance, and self-reported knee function 9 months after ACLR. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Knee isokinetic peak torque, SLDJ jump height, contact time, and reactive strength index (RSI), as well as International Knee Documentation Committee (IKDC) scores were assessed in 116 male, field-sport athletes at 9.2 months after ACLR. SLDJ testing took place in a 3-dimensional biomechanics laboratory. Linear regression models were used to analyze the relationship between the variables. Results: A significant relationship was found between ACLR-limb isokinetic knee extensor strength and SLDJ jump height ( P < .001, r 2 = 0.29) and RSI ( P < .001, r 2 = 0.33), and between ACLR-limb isokinetic knee flexor strength and SLDJ jump height ( P < .001, r 2 = 0.12) and RSI ( P < .001, r 2 = 0.15). A significant positive relationship was also found between knee extensor asymmetry and SLDJ jump height asymmetry ( P < .001, r 2 = 0.27) and SLDJ reactive strength asymmetry ( P < .001, r 2 = 0.18). Combined ACLR-limb jump height and contact time best predicted IKDC scores ( P < .001, r 2 = 0.12). Conclusion: Isokinetic knee extension strength explained approximately 30% of SLDJ performance, with a much weaker relationship between knee flexion strength and SLDJ performance. Isokinetic strength and SLDJ performance were weak predictors of variation in IKDC scores.

scholarly journals Healthy Pediatric Athletes Have Significant Baseline Limb Asymmetries on Common Return-to-Sport Physical Performance Tests

2021 ◽  
Vol 9 (1) ◽  
pp. 232596712098230
Author(s):  
John R. Magill ◽  
Heather S. Myers ◽  
Trevor A. Lentz ◽  
Laura S. Pietrosimone ◽  
Thomas Risoli ◽  
...  
Keyword(s):  
Physical Performance ◽  
Pediatric Population ◽  
Cruciate Ligament ◽  
Return To Sport ◽  
Cross Sectional Study ◽  
Performance Tests ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Anterior Cruciate ◽  
The Relationship

Background: Return to sport (RTS) after anterior cruciate ligament (ACL) reconstruction in children is associated with a much higher risk (∼30%) of subsequent ACL injury than in adults. Most RTS testing protocols use a limb symmetry index (LSI) ≥90% on physical performance tests (PPTs) to assess an athlete’s readiness for sport. This assumes that, in a healthy state, the physical performances across both lower extremities are and should be equal. Purpose: To determine the prevalence of limb asymmetries >10% in the uninjured pediatric population on common PPTs as well as to explore the relationship between athlete variables, limb preference, and LSI values. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This study included healthy volunteers (N = 100) evenly distributed between the ages of 6 and 18 years (mean age, 11.7 ± 3.6 years; 52% female). Participants performed 9 common PPTs. For analysis, we developed a composite score for each limb by averaging trials. We then calculated the LSI for each test. Univariable and multivariable linear regression analyses were performed to assess the relationship between athlete variables (age, sex, height, and weight) and LSI for each PPT. Results: Instances of poor baseline limb symmetry (<90% LSI) were common across all PPTs. The single-leg timed hop had the highest percentage of participants, with LSI ≥90% at 73%, while the stork on a Bosu ball had the lowest percentage at 23%. After adjusting for age, female sex showed a significant association with LSI for the stork test ( P = .010) and the quadrant hop–counterclockwise ( P = .021). Additionally, after adjusting for sex, increasing age showed a significant association with LSI for the stork test ( P < .001), single-leg squat on a Bosu ball ( P = .010), quadrant hop–clockwise ( P = .016), and quadrant hop–counterclockwise ( P = .009). Conclusion: The majority of healthy athletes 18 years and younger demonstrated significant (<90%) limb asymmetries. Limb symmetry was not consistently affected by participant age or sex, and the effect sizes of these relationships were small. These findings should encourage clinicians and coaches to exercise caution in using the LSI as an isolated measure of RTS readiness after injury in pediatric athletes.

scholarly journals Factors Influencing Creatine Kinase Response in Youth National Team Soccer Players

2021 ◽  
pp. 194173812199938
Author(s):  
Gabor Schuth ◽  
Gyorgy Szigeti ◽  
Gergely Dobreff ◽  
Peter Revisnyei ◽  
Alija Pasic ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Prediction Models ◽  
Soccer Players ◽  
Linear Regression Models ◽  
Level Of Evidence ◽  
Internal Load ◽  
Youth Soccer ◽  
National Team ◽  
Weekly Training ◽  
The Relationship

Background: Previous studies have examined the relationship between external training load and creatine kinase (CK) response after soccer matches in adults. This study aimed to build training- and match-specific CK prediction models for elite youth national team soccer players. Hypothesis: Training and match load will have different effects on the CK response of elite youth soccer players, and there will be position-specific differences in the most influential external and internal load parameters on the CK response. Study Design: Prospective cohort study. Level of Evidence: Level 4. Methods: Forty-one U16-U17 youth national team soccer players were measured over an 18-month period. Training and match load were monitored with global positioning system devices. Individual CK values were measured from whole blood every morning in training camps. The dataset consisted of 1563 data points. Clustered prediction models were used to examine the relationship between external/internal load and consecutive CK changes. Clusters were built based on the playing position and activity type. The performance of the linear regression models was described by the R2 and the root-mean-square error (RMSE, U/L for CK values). Results: The prediction models fitted similarly during games and training sessions ( R2 = 0.38-0.88 vs 0.6-0.77), but there were large differences based on playing positions. In contrast, the accuracy of the models was better during training sessions (RMSE = 81-135 vs 79-209 U/L). Position-specific differences were also found in the external and internal load parameters, which best explained the CK changes. Conclusion: The relationship between external/internal load parameters and CK changes are position specific and might depend on the type of session (training or match). Morning CK values also contributed to the next day’s CK values. Clinical Relevance: The relationship between position-specific external/internal load and CK changes can be used to individualize postmatch recovery strategies and weekly training periodization with a view to optimize match performance.

scholarly journals Biomechanical Symmetry during Drop Jump Landing and Takeoff in Adolescent Athletes Following Recent Anterior Cruciate Ligament Reconstruction

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 639
Author(s):  
Eva M. Ciccodicola ◽  
Nicole M. Mueske ◽  
Mia J. Katzel ◽  
Curtis D. VandenBerg ◽  
James Lee Pace ◽  
...  
Keyword(s):  
Power Generation ◽  
Anterior Cruciate Ligament ◽  
Anterior Cruciate Ligament Reconstruction ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Jump Height ◽  
Drop Jump ◽  
Adolescent Athletes ◽  
Cruciate Ligament Reconstruction ◽  
Anterior Cruciate

This study investigated asymmetry between lower extremities during the landing and takeoff phases of a vertical drop jump (VDJ) in adolescent athletes following anterior cruciate ligament reconstruction (ACLR) and examined if performance was affected by reducing jump height. Thirty-three athletes who underwent ACLR and were referred for 3D biomechanical assessment before returning to play (mean age 15.9, SD 1.3 years; 16/33 female; mean time since surgery 7.4, SD 1.2 months) completed the VDJ while kinematics and kinetics were collected using motion capture. Lower extremity symmetry was compared between phases using paired t-tests. Jump height was calculated to measure performance. Asymmetries in ankle inversion, ankle adduction, knee adduction, hip adduction, hip adduction moment, and hip rotation moment were observed in both phases. Asymmetry was also observed in both phases for sagittal moments and power integrals at the knee and ankle and total power integral, with the magnitude of asymmetry being smaller during takeoff for power absorption/generation. Jump height was related to power generation integrals during takeoff but not to the asymmetry of power generation. Since asymmetries are translated from landing through takeoff, rehabilitation should address both phases to decrease injury risk and maximize performance after return to play.

scholarly journals The influence of demographic factors on subjective cognitive concerns and beta-amyloid

2016 ◽  
Vol 29 (4) ◽  
pp. 645-652 ◽  
Author(s):  
Sarah L. Aghjayan ◽  
Rachel F. Buckley ◽  
Patrizia Vannini ◽  
Dorene M. Rentz ◽  
Jonathan D. Jackson ◽  
...  
Keyword(s):  
Positron Emission Tomography Imaging ◽  
Demographic Factors ◽  
Cross Sectional Study ◽  
Mediation Effect ◽  
Aging Brain ◽  
Linear Regression Models ◽  
Cross Sectional ◽  
Clinically Normal ◽  
Positron Emission ◽  
The Relationship

ABSTRACTBackground:Converging evidence suggests that subjective cognitive concerns (SCC) are associated with biomarker evidence of Alzheimer's disease (AD) prior to objective clinical impairment. However, the sensitivity of SCC reports in early AD may be biased by demographic factors. Here, we sought to investigate whether age, education, and sex influence the relationship between SCC and amyloid (Aβ) burden.Methods:In this cross-sectional study, we examined 252 clinically normal (CN) individuals (57.7% females) enrolled in the Harvard Aging Brain Study, ages 63–90 years (mean 73.7±6) with 6–20 years of education (mean 15.8±3). SCC was assessed as a composite score comprising three questionnaires. Cortical Aβ burden was assessed with Pittsburgh compound B positron emission tomography imaging. A series of linear regression models assessed the potential modifying role of demographic variables with respect to Aβ burden and SCC. A post-hoc mediation model was implemented to further understand the relationship between Aβ burden and SCC via their relationship with education.Results:Age (β = −0.84, p = 0.36) and sex (β = −0.55, p = 0.22) did not modify the relationship between SCC and Aβ burden. Fewer years of education was correlated with greater SCC (r = −0.12, p = 0.05), but the relationship between Aβ burden and SCC was stronger in those with more education (β = 1.16, p < 0.05). A partial mediation effect was found of Aβ burden on SCC via education (b = −0.12, 95% CI [−0.31, −0.02]).Conclusions:These findings suggest that the association between SCC and Aβ burden becomes stronger with greater educational attainment. Thus, SCC may be of particular importance in highly educated CN individuals harboring amyloid pathology.

scholarly journals Parkinson Disease: The Relationship Between Non-motor Symptoms and Motor Phenotype

2015 ◽  
Vol 43 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Fang Ba ◽  
Mona Obaid ◽  
Marguerite Wieler ◽  
Richard Camicioli ◽  
W.R. Wayne Martin
Keyword(s):  
Parkinson Disease ◽  
Rating Scales ◽  
Advanced Disease ◽  
Axial Component ◽  
Motor Symptoms ◽  
Linear Regression Models ◽  
Cross Sectional ◽  
The Relationship ◽  
Non Motor Symptoms ◽  
Motor Phenotype

AbstractBackground: Parkinson disease (PD) presents with motor and non-motor symptoms (NMS). The NMS often precede the onset of motor symptoms, but may progress throughout the disease course. Tremor dominant, postural instability gait difficulty (PIGD), and indeterminate phenotypes can be distinguished using Unified PD Rating scales (UPDRS-III). We hypothesized that the PIGD phenotype would be more likely to develop NMS, and that the non-dopamine–responsive axial signs would correlate with NMS severity. Methods: We conducted a retrospective cross-sectional chart review to assess the relationship between NMS and PD motor phenotypes. PD patients were administered the NMS Questionnaire, the UPDRS-III, and the Mini-Mental State Examination score. The relationship between NMS burden and PD subtypes was examined using linear regression models. The prevalence of each NMS among difference PD motor subtypes was analyzed using chi-square test. Results: PD patients with more advanced disease based on their UPDRS-III had higher NMS Questionnaire scores. The axial component of UPDRS-III correlated with higher NMS. There was no correlation between NMS and tremor scores. There was a significant correlation between PIGD score and higher NMS burden. PIGD group had higher prevalence in most NMS domains when compared with tremor dominant and indeterminate groups independent of disease duration and severity. Conclusions: NMS profile and severity vary according to motor phenotype. We conclude that in the PD population, patients with a PIGD phenotype who have more axial involvement, associated with advanced disease and poor motor response, have a higher risk for a higher NMS burden.

Overnight call is associated with poor resting heart rate and heart rate variability in orthopaedic surgeons

2019 ◽  
Vol 4 (3) ◽  
pp. 123-126
Author(s):  
Kyle R Sochacki ◽  
David Dong ◽  
Leif Peterson ◽  
Patrick C McCulloch ◽  
Kevin Lisman ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Orthopaedic Surgery ◽  
Resting Heart Rate ◽  
Linear Regression Models ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Hours Worked ◽  
Significance Level ◽  
Orthopaedic Surgeons

ObjectivesThe purpose of this study was to determine orthopaedic surgery residents’ and attending surgeons’ resting heart rate (RHR) and heart rate variability (HRV) and if there is a correlation between subject-specific variables (age, attending surgeon, resident, postgraduate year (PGY) level, gender, number of calls, total hours worked, and total hours of sleep) and surgeon RHR and HRV.MethodsOrthopaedic surgery residents and attending surgeons at a single institution were prospectively enrolled and provided a validated wearable device to determine hours of sleep, RHR and HRV. Demographic information, hours worked and overnight calls were recorded. Bivariate correlations were determined using the Spearman rank correlation. Multiple linear regression models were constructed to determine the effect of relevant variables. All p values were reported, and a significance level of α=0.05 was used (p<0.05).ResultsTwenty-one of 26 enrolled subjects completed the 4-week study. The average RHR and HRV for orthopaedic surgeons was 61.8+10.0 bpm and 42.96+21.2ms, respectively. Residents had a significantly higher RHR (66.4+8.4 vs 55.6+8.9, p=0.011) compared with attending surgeons. Overnight calls had the strongest association with decreased HRV (r=−0.447; p=0.038), moderate positive correlation with RHR (r=0.593; p=0.005) and weak negative correlation with HRV (r=−0.469; p=0.032). There was no significant correlation between PGY level, gender, total hours worked and total hours of sleep with RHR or HRV.ConclusionOrthopaedic surgeons have poor RHR and HRV. Additionally, the number of overnight calls had the strongest correlation with worse RHR and HRV.Level of evidenceLevel II; diagnostic, individual cross-sectional study with a consistently applied reference standard.

scholarly journals Reporting Skill: The Missing Ingredient in Concussion Reporting Intention Assessment

2019 ◽  
Vol 11 (5) ◽  
pp. 416-424 ◽  
Author(s):  
Dee Warmath ◽  
Andrew P. Winterstein
Keyword(s):  
Structural Equation ◽  
Age Groups ◽  
Cross Sectional Study ◽  
Equation Modeling ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Confirmatory Factor Analyses ◽  
Concussion Knowledge ◽  
The Relationship ◽  
Reporting Intentions

Background: Extant literature suggests that a substantial portion of athletes may not report a possible concussion and that concussion knowledge is insufficient to predict concussion reporting behavior. One area that has not been explored is reporting skill; that is, mastery of the actions required to report a concussion. This study evaluated the relationship between reporting skill and reporting intention, introducing a measure of the reporting skill construct. Hypotheses: Reporting intentions will be more closely associated with reporting skill than with concussion/symptom knowledge. The relationship between concussion (or symptom) knowledge and reporting intentions will differ by level of reporting skill. Study Design: Repeated cross-sectional study. Level of Evidence: Level 2. Methods: A set of items was administered to young adults aged 18 to 24 years from the Survey Sampling International panel. Exploratory/confirmatory factor analyses were conducted on 2 waves of data to develop the scale (n = 899). Hypotheses were tested using structural equation modeling on the responses from the third wave of participants (n = 406). Results: Knowing the actions to take in reporting was more important than having knowledge of concussions or concussion symptoms. Reporting skill, not concussion or concussion symptom knowledge, was associated with higher intentions to report symptoms. Among those with higher levels of reporting skill, concussion symptom knowledge (but not general concussion knowledge) was associated with higher intentions to report symptoms. Conclusion: Reporting skill is an important and, until now, missing ingredient in the concussion literature and practice. Clinical Relevance: Incorporating reporting skill development in concussion education and team activities to teach athletes how to report is likely to improve actual reporting intentions. While further study is needed with particular sports and additional age groups, reporting skill holds promise as a new avenue for increased concussion reporting.

Single-Leg Jump Performance Before and After Exercise in Healthy and Anterior Cruciate Ligament Reconstructed Individuals

2020 ◽  
Vol 29 (7) ◽  
pp. 879-885
Author(s):  
Haley Bookbinder ◽  
Lindsay V. Slater ◽  
Austin Simpson ◽  
Jay Hertel ◽  
Joseph M. Hart
Keyword(s):  
Anterior Cruciate Ligament ◽  
Repeated Measures ◽  
Contact Time ◽  
Cruciate Ligament ◽  
Ground Contact ◽  
Jump Height ◽  
Before And After ◽  
Healthy Control ◽  
Ground Contact Time ◽  
Anterior Cruciate

Context: Many clinicians measure lower-extremity symmetry after anterior cruciate ligament reconstruction (ACLR); however, testing is completed in a rested state rather than postexercise. Testing postexercise may better model conditions under which injury occurs. Objective: To compare changes in single-leg performance in healthy and individuals with history of ACLR before and after exercise. Design: Repeated-measures case-control. Setting: Laboratory. Patients: Fifty-two subjects (25 control and 27 ACLR). Intervention: Thirty minutes of exercise. Main Outcome Measures: Limb symmetry and involved limb performance (nondominant for healthy) for single-leg hop, ground contact time, and jump height during the 4-jump test. Cohen d effect sizes were calculated for all differences identified using a repeated-measures analysis of variance. Results: Healthy controls hopped farther than ACLR before (d = 0.65; confidence interval [CI], 0.09 to 1.20) and after exercise (d = 0.60; CI, 0.04 to 1.15). Those with ACLR had longer ground contact time on the reconstructed limb compared with the uninvolved limb after exercise (d = 0.53; CI, −0.02 to 1.09), and the reconstructed limb had greater ground contact time compared with the healthy control limb after exercise (d = 0.38; CI, −0.21 to 0.73). ACLR were less symmetrical than healthy before (d = 0.38; CI, 0.17 to 0.93) and after exercise (d = 0.84; CI, 0.28 to 1.41), and the reconstructed limb demonstrated decreased jump height compared with the healthy control limbs before (d = 0.75; CI, 0.19 to 1.31) and after exercise (d = 0.79; CI, 0.23 to 1.36). Conclusions: ACLR became more symmetric, which may be from adaptations of the reconstructed limb after exercise. Changes in performance and symmetry may provide additional information regarding adaptations to exercise after reconstruction.

Rate of Force Development Remains Reduced in the Knee Flexors 3 to 9 Months After Anterior Cruciate Ligament Reconstruction Using Medial Hamstring Autografts: A Cross-Sectional Study

2020 ◽  
Vol 48 (13) ◽  
pp. 3214-3223
Author(s):  
Jakob Lindberg Nielsen ◽  
Kamilla Arp ◽  
Mette Lysemose Villadsen ◽  
Stine Sommer Christensen ◽  
Per Aagaard
Keyword(s):  
Functional Capacity ◽  
Cruciate Ligament ◽  
Knee Extensor ◽  
Cross Sectional Study ◽  
Healthy Controls ◽  
Sectional Study ◽  
Cross Sectional ◽  
Force Development ◽  
Anterior Cruciate ◽  
Maximal Muscle Strength

Background: Anterior cruciate ligament (ACL) rupture is a serious injury with a high prevalence worldwide, and subsequent ACL reconstructions (ACLR) appear to be most commonly performed using hamstring-derived (semitendinosus tendon) autografts. Recovery of maximal muscle strength to ≥90% of the healthy contralateral limb is considered an important criterion for safe return to sports. However, the speed of developing muscular force (ie, the rate of force development [RFD]) is also important for the performance of many types of activities in sports and daily living, yet RFD of the knee extensor and flexor muscles has apparently never been examined in patients who undergo ACLR with hamstring autograft (HA). Purpose: To examine potential deficits in RFD, maximal muscle strength (ie, maximal voluntary isometric contraction [MVIC]), and functional capacity of ACLR-HA limbs in comparison with the healthy contralateral leg and matched healthy controls 3 to 9 months after surgery. Study Design: Cross-sectional study; Level of evidence: 3. Methods: A total of 23 young patients who had undergone ACLR-HA 3 to 9 months earlier were matched by age to 14 healthy controls; both groups underwent neuromuscular screening. Knee extensor and flexor MVIC and RFD, as well as functional capacity (single-leg hop for distance [SLHD] test, timed single-leg sit-to-stand [STS] test), were assessed on both limbs. Furthermore, patient-reported knee function (Knee injury and Osteoarthritis Outcome Score) was assessed. Results: Knee extensor and flexor MVIC and RFD were markedly compromised in ACLR-HA limbs compared with healthy contralateral limbs (MVIC for extensor and flexor, 13% and 26%, respectively; RFD, 14%-17% and 32%-39%) and controls (MVIC, 16% and 31%; RFD, 14%-19% and 30%-41%) ( P < .05-.001). Further, ACLR-HA limbs showed reduced functional capacity (reduced SLHD and STS performance) compared with contralateral limbs (SLHD, 11%; STS, 14%) and controls (SLHD, 20%; STS, 31%) ( P < .01-.001). Strength (MVIC) and functional (SLHD) parameters were positively related to the duration of time after surgery ( P < .05), although this relationship was not observed for RFD and STS. Conclusion: Knee extensor and flexor RFD and maximal strength, as well as functional single-leg performance, remained substantially reduced in ACLR-HA limbs compared with noninjured contralateral limbs and healthy controls 3 to 9 months after reconstructive surgery.

Effect of Subcutaneous Tissue on Changes in Thigh Circumference Following Anterior Cruciate Ligament Reconstruction

2019 ◽  
Vol 40 (08) ◽  
pp. 544-550
Author(s):  
Ryo Yoshii ◽  
Yu Konishi ◽  
Daisuke Ando ◽  
Satoshi Ochiai ◽  
Tetsuo Hagino ◽  
...  
Keyword(s):  
Subcutaneous Tissue ◽  
Cruciate Ligament ◽  
Subcutaneous Fat ◽  
Quadriceps Muscle ◽  
Thigh Circumference ◽  
Cross Sectional ◽  
Short Period ◽  
Anterior Cruciate ◽  
Muscle Cross Sectional Area ◽  
The Relationship

AbstractCircumference measurements have been used to estimate muscle cross-sectional area (CSA) in clinical settings. Measurements of thigh circumference are affected by muscle and subcutaneous fat (SF). In fact, SF could increase over a short period. Therefore, clarifying the relationship between thigh circumference and muscle and SF following ACL reconstruction is important. This study’s primary purpose was to examine pre- and post-operative changes in thigh circumference, thigh muscles and SF CSAs in both legs. Secondary, the relationship between thigh circumference and muscle and SF CSAs was examined to demonstrate that circumference measurements could be used to detect atrophy. Quadriceps, hamstrings, and SF CSAs at 15, 10, and 5 cm proximal to the patella were measured by MRI pre- and 4 weeks postoperatively to examine how reconstruction affected those tissues in the thighs. The results showed increases in SF CSA (r=0.72 at 10 cm, r=0.67 at 15 cm) greatly affected thigh circumference in females on the surgical side. In males, increases in SF CSA (r=0.83) at 15- and 5-cm and decreases in quadriceps muscle CSA (r=0.73) at 5 cm affected thigh circumference on the surgical side. Thigh circumference measurements might not reflect actual muscle CSA in ACL patients.

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