***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background The effectiveness of anterior cruciate ligament reconstruction for restoring normal knee kinematics is largely unknown , particularly during sports movements generating large , rapidly applied forces . Hypothesis Under dynamic in vivo loading , significant differences in 3-dimensional kinematics exist between anterior cruciate ligament-reconstructed knees and the contralateral , uninjured knees . Study Design Prospect i ve , in vivo laboratory study . Methods Kinematics of anterior cruciate ligament-reconstructed and contralateral ( uninjured ) knees were evaluated for 6 subjects during downhill running 4 to 12 months after anterior cruciate ligament reconstruction , using a 250 frame/s stereoradiographic system .  Anatomical reference axes were determined from computed tomography scans .  Kinematic differences between the uninjured and reconstructed limbs were evaluated with a repeated- measures analysis of variance . Results Anterior tibial translation was similar for the reconstructed and uninjured limbs . However , reconstructed knees were more externally rotated on average by 3.8 ± 2.3 ° across all subjects and time points ( P = .0011 ) . Reconstructed knees were also more adducted , by an average of 2.8 ± 1.6 ° ( P = .0091 ) . Although differences were small , they were consistent in all subjects . Conclusions Anterior cruciate ligament reconstruction failed to restore normal rotational knee kinematics during dynamic loading . Clinical Relevance Although further study is required , these abnormal motions may contribute to long-term joint degeneration associated with anterior cruciate ligament injury/reconstruction Thirty-seven patients who had undergone anterior cruciate ligament reconstruction were tested in a gait analysis laboratory at 2 and 6 weeks after surgery . Between test sessions , patients were r and omly assigned to a course of either closed or open kinetic chain resistance exercises ( 3 sessions per week for 4 weeks ) . Gait analysis consisted of bilateral calculations of knee joint angle , moment , and power during level walking , stair ascent , and stair descent . An analysis of variance on the effects of training group and test session indicated that the only variable to be significantly affected by the type of exercise program was the amount of knee flexion at the beginning of step-up ( P<0.05 ) . All other measures of knee angle , moment , and power ( 16 total variables ) showed no significant difference between the exercise groups . All variables measured on the injured side showed significant improvement from test 1 to test 2 ( P<0.05 ) , but the injured leg remained functionally deficient when compared with the uninjured leg . These data suggest that there are no clinical ly significant differences in the functional improvement result ing from the choice of open or closed kinetic chain exercises in the early period after this surgery The relationships between extrinsic forces acting at the knee and knee kinematics were examined with the purpose of identifying specific phases of the walking cycle that could cause abnormal kinematics in the anterior cruciate ligament ( ACL ) deficient knee .  Intersegmental forces and moments in directions that would produce anterior-posterior ( AP ) translation , internal-external ( IE ) rotation and flexion-extension ( FE ) at the knee were compared with the respective translation and rotations of the tibia relative to the femur during four selected phases ( heel strike , weight acceptance , terminal extension and swing ) of the walking cycle . The kinematic changes associated with loss of the ACL occurred primarily during the terminal portion of swing phase of the walking cycle where , for the ACL deficient knee , the tibia had reduced external rotation and anterior translation as the knee extended prior to heel strike . The kinematic changes during swing phase were associated with a rotational offset relative to the contralateral knee in the average position of the tibia towards internal rotation . The offset was maintained through the entire gait cycle . The abnormal offsets in the rotational position were correlated with the magnitude of the flexion moment ( balanced by a net quadriceps moment ) during weight acceptance . These results suggest that adaptations to the patterns of muscle firing during walking can compensate for kinematic changes associated with the loss of the ACL . The altered rotational position would cause changes in tibiofemoral contact during walking that could cause the type of degenerative changes reported in the meniscus and the articular cartilage following ACL injury OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity Abstract The aim of this study is to analyse the changes in select gait parameters following  anterior cruciate ligament ( ACL ) reconstruction .  The study was performed on 15 subjects who underwent ACL reconstruction by the bone-patellar tendon-bone technique .  Gait analysis was performed using the Elite three-dimensional ( 3D ) optoelectronic system ( BTS ) , a Kistler force platform and the Telemg telemetric electromyograph ( BTS ) .  Kinematic data were recorded for the principal lower limb joints ( hip , knee and ankle ) . The examined muscles include vastus lateralis , rectus femoris , biceps femoris and semitendinosus . The results obtained from the operated subjects were compared with those of 10 untreated subjects and 5 subjects without ACL damage .  In the operated subjects the knee joint angular values regained a normal flexion pattern for the injured limb during the stance phase . The analysis of joint moments shows : ( a ) sagittal plane : recovery of the knee flexion moment at loading response and during preswing ; ( b ) frontal plane : recovery of the normal patterns for both hip and knee adduction-abduction moments during the entire stance phase . The examination of ground reaction forces reveals the recovery of frontal component features . The EMG traces show the normal biphasic pattern for the operated subjects as compared to the untreated subjects . The results suggest that the gait parameters shift towards normal value patterns OBJECTIVE The adduction moment at the knee during gait is the primary determinant of medial-to-lateral load distribution . If the adduction moment contributes to progression of osteoarthritis ( OA ) , then patients with advanced medial tibiofemoral OA should have higher adduction moments . The present study was undertaken to investigate the hypothesis that the adduction moment normalized for weight and height is associated with medial tibiofemoral OA disease severity after controlling for age , sex , and pain level , and to examine the correlation of serum hyaluronan ( HA ) level with disease severity and with the adduction moment in a subset of patients . METHODS Fifty-four patients with medial tibiofemoral OA underwent gait analysis and radiographic evaluation .  Disease severity was assessed using the Kellgren-Lawrence ( K-L ) grade and medial joint space width . In a subset of 23 patients with available sera , HA was quantified by s and wich enzyme-linked immunosorbent assay . Pearson correlations , a r and om effects model , and multivariate regression models were used . RESULTS The  adduction moment  correlated with the K-L grade in the left and right knees ( r = 0.68 and r = 0.60 , respectively ) , and with joint space width in the left and right knees ( r = -0.45 and r = -0.47 , respectively ) . The relationship persisted after controlling for age , sex , and severity of pain . The partial correlation between K-L grade and adduction moment was 0.71 in the left knees and 0.61 in the right knees . For every 1.0-unit increase in adduction moment , there was a 0.63-mm decrease in joint space width . In the subset of patients in whom serum HA levels were measured , HA levels correlated with medial joint space width ( r = -0.55 ) , but not with the adduction moment . CONCLUSION There is a significant relationship between the  adduction moment and OA disease severity . Serum HA levels correlate with joint space width but not with the adduction moment . Longitudinal studies will be necessary to determine the contribution of the adduction moment , and its contribution in conjunction with metabolic markers , to progression of medial tibiofemoral OA BACKGROUND Alterations in knee joint kinematics have been suggested as a potential mechanism that influences the development of  osteoarthritis of the knee after anterior cruciate ligament reconstruction .  Whilst previous work has shown changes in internal-external tibial rotation during level walking , many patients aim to return to high impact activities following surgery . This study examined tibial rotation during single limb hop and drop l and ings in anterior cruciate ligament reconstructed knees  compared to a control group , and also evaluated the influence of graft type ( hamstring or patellar tendon ) . METHODS In 48 participants ( 17 patellar tendon graft , 18 hamstring graft and 13 controls )  internal-external rotation was measured during single limb hop and drop l and ings in a gait laboratory at mean of 10 months after surgery . FINDINGS There was no difference between the two graft types and both patient groups had less internal rotation when compared to the control group . For 60 % of patients , internal rotation values were at least 5 ° less than the control group mean . INTERPRETATION Anterior cruciate ligament reconstructed knees with both hamstring tendon and patellar tendon grafts show altered rotational kinematic patterns during high impact dynamic load activities The purpose of the present study is to evaluate the rehabilitation of different treatments of ACL ruptured knees by means of gait parameters . The gait analysis results in two surgically treated patient groups ( patellar tendon autograft reconstructions ( n = 35 ) and augmented repairs ( n = 15 ) and one non-surgically treated patient group ( n = 19 ) are evaluated by means of gait parameters of normal controls ( n = 30 ) . The technical equipment included an optoelectronic system for recording the kinematics of gait ( Primas , NL ) and two force plates for measuring the ground reaction forces ( Kistler , CH ) . The moments acting on joints can be determined experimentally with both systems . It can be shown from special gait tests that the derived quantitative evaluation parameters are independent from the gait analysis conditions . One year after surgery , both the patellar tendon autograft reconstruction group and the augmented repair group show clear deficiencies in gait parameters compared with the controls . In particular this concerns the midstance extension motion of the knee ( p < = 0.01 ) and the extension moments acting on the knee joint during the stance phase ( sagittal plane , p < = 0.01 ) . The deficiencies of both surgically treated groups are approximately the same . However , one year after occurrence of the disruption the non-surgically treated group can not be distinguished from the controls . From this and from additional pre-surgical measurements , it can be concluded , that operating has an important influence on gait parameters . The role of the gait analysis results has been discussed The objective of this study is to determine how kinematical parameters and electromyography data of selected muscles may change as a result of anterior cruciate ligament ( ACL ) deficiency and following ACL reconstruction .  The study was conducted on 25 anterior cruciate ligament deficient subjects prior to and 6 weeks , 4 months , 8 months and 12 months following ACL reconstructive surgery using the bone-patellar tendon-bone technique .  Gait analysis was performed by applying the zebris three-dimensional ultrasound-based system with surface electromyograph ( zebris ) .  Kinematic data were recorded for the lower limb . The muscles surveyed include vastus lateralis and medialis , biceps femoris and adductor longus . The results obtained from the injured subjects were compared with those of 51 individuals without any ACL damage whatsoever . Acute ACL deficient patients exhibited a quadriceps avoidance pattern prior to and 6 weeks following surgery . No quadriceps avoidance phenomenon develops in chronic ACL deficient patients . In operated individuals , tempo-spatial parameters and the knee angle regained a normal pattern for the ACL-deficient limb during gait as early as 4 months following surgery . However , the relative ACL movement parameter , which describes the tibial translation into the direction of ACL , and the EMG traces show no significant statistical difference compared with the same values of the healthy control group 
    Output:
    
Strong to moderate evidence indicated no significant difference in peak flexion angles between ACLR and control groups during walking and stair ascent .
Strong evidence was found for lower peak flexion moments in participants with ACLR compared with control groups and contralateral limb during walking and stair activities .
Strong to moderate evidence was found for lower peak adduction moment in ACLR participants for the injured compared with the contralateral limbs during walking and stair descent .
The qualitative assessment for recovery over time indicated a pattern towards restoration of peak knee flexion angle with increasing time from post-surgery .
Peak knee adduction moments were lower within the first year following surgery and higher than controls during later phases ( 5 years ) .
Conclusion Joint kinematics are restored , on average , 6 years following reconstruction , while knee external flexion moments remain lower than controls .
Knee adduction moments are lower during early phases following reconstruction , but are higher than controls , on average , 5 years post-surgery .
Findings indicate that knee function is not fully restored following reconstruction , and long-term maintenance programs may be needed