***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: OBJECTIVE To determine if compensatory actions take place at the pelvis and other joints of the affected lower limb in subjects who were in an early stage of hip osteoarthritis ( OA ) . DESIGN Nonr and omized , case-control study . SETTING A gait laboratory . PARTICIPANTS Seventeen patients with OA of the hip ( clinical group ) matched with 17 healthy elderly subjects ( non clinical group ) . INTERVENTIONS Video data obtained while subjects walked a 10-meter walkway twice and stepped across a forceplate . MAIN OUTCOME MEASURES Four phasic and temporal gait parameters ( walking speed , stance phase relative duration , stride length , cadence ) 10 pelvic ( pelvic tilt , obliquity , rotation at push-off maximum range of motion for all 3 ) and hip ( 3 hip angles at push-off , maximum hip flexion ) kinematic parameters , 3 hip moments , and twenty-seven 3-dimensional peak muscle powers ( labeled by joint , peak power , plane ) developed in the lower limb joints during the gait cycle . RESULTS Subjects in the clinical group were characterized by a 12.4 % slower walking speed . The pelvis was more upwardly tilted ( 2.5 times ) at push-off in the clinical group than in the non clinical group . Obliquity , measured in the frontal plane , revealed that the pelvis dropped more ( 2.4 times ) on the unsupported limb of the clinical group at push-off . In the sagittal plane , subjects in the clinical group absorbed less energy in their second hip peak power for decelerating the thigh extension and generated less hip pull ( third hip peak power ) than the non clinical group by 34 % and 29 % , respectively . In the sagittal plane , the clinical group had 57 % lower second knee peak power to straighten the joint shortly after heel strike , and 43 % less knee absorption ( third peak power ) at push-off . During the push-off phase , the clinical group developed more than twice their third peak knee power in the frontal plane and 5 times more their third peak knee power in the transversal plane than the peak knee power of the non clinical group in an attempt to control knee adduction and to facilitate body-weight transfer by an internal rotation . At the end of the swing phase , the fourth peak power in the sagittal plane showed the absorption power required to decelerate the leg ; it was reduced by 35 % in the clinical group , representing a strategy to increase walking speed by lengthening the stride length . CONCLUSIONS Even at an early stage of hip OA , joint degeneration was compensated by an increase in pelvis motion and muscle power generation or absorption modifications in other lower limb joints Osteoarthritic knee pain affects patient mobility . Relief of knee pain in osteoarthritis has been reported to increase loading of the knee during gait , but it is unknown whether such pain relief enhances knee loading during more dem and ing activities such as stair-stepping . The gait of 19 patients and stair-stepping of 14 patients with painful medial compartment osteoarthritis of the knee was assessed before and after pain-relieving intraarticular injection of the knee and compared with those of 21 healthy control subjects . There were significant increases in gait velocity , cadence , maximum external knee adduction moment ( indicating increased loading in the medial compartment of the knee ) , and maximum external hip adduction and ankle abduction moments immediately after the injection . With the exception of velocity and ankle abduction moment , these variables were returned to levels that were not statistically different from those of the control subjects . However , no significant differences were found during stair-stepping in the external adduction-abduction moments about the knee , hip , or ankle after injection . Furthermore , the postinjection magnitudes of these variables during stair-stepping were significantly less than those of the controls . Therefore , although the relief of knee pain is sufficient to enhance gait function in osteoarthritis of the knee , it is insufficient to enhance stair-stepping function Patients with st and ard total hip arthroplasties  may have reduced hip abduction and extension moments when compared with normal nonosteoarthritic hips . In comparison , patients after resurfacing total hip arthroplasty  appear to have a near-normal gait . The authors evaluated temporal-spatial parameters , hip kinematics , and kinetics in  hip resurfacing patients compared with patients with unilateral osteoarthritic hips and unilateral st and ard total hip arthroplasties . Patients with resurfacing walked faster ( average 1.26 m/s ) and were comparable with normals . There were no significant differences in hip abductor and extensor moments of patients with resurfacing compared with patients in the st and ard hip arthroplasty group . This study showed more normal hip kinematics and functionality in resurfacing hip arthroplasty , which may be due to the large femoral head OBJECTIVE To compare the effect of celecoxib vs placebo treatment on clinical and gait variables in knee osteoarthritis ( OA ) patients ; focusing on the efficiency of the locomotor mechanism . METHODS STUDY DESIGN A prospect i ve , r and omised , double-blind placebo-controlled trial . PATIENTS Eight adult patients with painful OA of the knee . OUTCOME MEASURES Clinical assessment included knee pain assessed by the visual analogue scale , range of knee motion assessed by goniometer , and locomotor function status assessed by a Knee Score Scale . Gait was assessed by means of instrumented analysis including synchronous kinematic , dynamic , electromyographic , and energetic recordings . STATISTICAL ANALYSIS The effect of treatment on the primary variable , the efficiency of the locomotor mechanism , and on secondary clinical and gait variables was assessed by the Hills and Armitage non-parametric approach . RESULTS Celecoxib treatment improved the efficiency of the locomotor mechanism significantly . Among the secondary outcome measures assessed , celecoxib treatment improved walking cadence and reduced the knee pain significantly . CONCLUSION This study shows that celecoxib is effective in improving locomotor function and pain in patients with knee OA Within the context of a double blind r and omized controlled parallel trial of 2 nonsteroidal antiinflammatory drugs , we vali date d WOMAC , a new multidimensional , self-administered health status instrument for patients with osteoarthritis of the hip or knee . The pain , stiffness and physical function subscales fulfil conventional criteria for face , content and construct validity , reliability , responsiveness and relative efficiency . WOMAC is a disease-specific purpose built high performance instrument for evaluative research in osteoarthritis clinical trials Most therapeutic tests of osteoarthritis treatments are assessed by criteria based either on fundamental data or on clinical data , which is often subjective . A quantified analysis of locomotion can be used to determine the spatiotemporal indices ( stride length and duration ) , kinematic indices ( walking speed , velocity peak ) , and symmetry criteria that are relevant to the assessment of locomotor h and icaps in patients with osteoarthritis . This study examined the progression of locomotor abilities in 11 subjects aged 49 - 69 ( mean 60.9 ) years with knee osteoarthritis before and after treatment with a non-steroidal anti-inflammatory drug . Naproxen sodium ( 1100 mg ) was given once a day for seven days . The condition before and after treatment was evaluated by quantitative analysis of locomotion , estimation of pain on a visual analogue scale , and assessment of the degree of functional disability . Significant improvement in locomotor indices ( proportional increase in walking speed 17.8 % ) and in degree of pain ( proportional decrease 27 % ) as estimated on the analogue scale was found after non-steroidal anti-inflammatory drug treatment . The lack of a significant correlation between the decrease in pain experienced by the patients and the objective improvement of their functional capabilities emphasises the need in further studies of new treatments to accompany the patients ' own assessment s of self improvement with a quantitative analysis of the way in which they walk OBJECTIVES The purpose s of this study were : ( 1 ) to identify the primary ( hip ) and secondary ( neighboring joints ) impairments during gait in subjects with a total hip arthroplasty total hip arthroplasty  , ( 2 ) to determine which impairments persist when controlling for gait speed and ( 3 ) to study the relationships between primary and secondary impairments in order to describe the locomotor strategies used by these patients . DESIGN . This cross-sectional study compared the gait patterns of women with a total hip arthroplasty to those of healthy women . BACKGROUND . Several studies have reported residual hip impairments in the sagittal plane during gait after a total hip arthroplasty . There is , however , a substantial lack of knowledge in regard to the changes at the neighboring joints and in the other planes of movement . METHODS . Subjects have been examined during a gait laboratory testing session including the simultaneous recording of three-dimensional kinematics and ground reaction forces on one side , and bilateral activation of six lower limb muscles . RESULTS . A significant decrease of 20 % in the hip extensor moment of force during the early stance phase was correlated ( R(2)=43 % ) with a significant decrease of 14 % in gait speed . Moreover , a significant decrease of 59 % in the range of hip extension at the end of the stance phase was observed together with secondary impairments such as a significant increase in the anterior pelvic rotation , in knee flexion and in ankle dorsiflexion . Lastly , a significant increase in ipsilateral bending of the trunk during the single limb support on the operated limb was concomitant with a significant decrease in the hip abductor moment of force . CONCLUSIONS . The decrease in gait speed and the persistence of abnormal gait patterns one year after the total hip arthroplasty were associated respectively with a decrease in the hip extensor moment of force and with a decrease in the range of hip extension ( sagittal plane ) or in the hip abductor moment of force ( frontal plane ) . Relevance The data provided in this paper may serve as guidelines to establish rehabilitation programs design ed to restore optimal locomotor function Objective : To investigate the correlation between objective and subjective evaluation of patients with total hip replacement . Design : Prospect i ve preliminary trial comparing the Western Ontario and McMaster University question naire ( WOMAC ) and gait analysis preoperatively and three months postoperatively . Setting : A German academic orthopaedic centre specializing in total hip replacement surgery . Subjects : Seventeen patients ( median age 70 years ) with hip osteoarthritis . Intervention : All patients had had a primary unilateral total hip replacement . Main measures :  WOMAC question naire to assess self-perceived health status and gait analysis to determine objective gait parameters . Results : Performance of walking as well as subjective judgement of health status improved following surgery ( gait speed P = 0.0222 ; stride length P = 0.038 ; stance phase ratio P = 0.0466 ; WOMAC P < 0.0001 ) . However , the correlation between gait parameters and WOMAC was poor ( r = -0.27 or less ) . Correlation between changes of walking parameters and WOMAC was bad to good ( r = 0.01 to r = -0.72 ) . Conclusion : The WOMAC question naire might not reflect walking performance . The addition of gait analysis is recommended to gain objective information about the quality of gait PURPOSE OF THE STUDY This prospect i ve study was conducted to analyze the mechanisms of gait compensation in patients with painful hip and to search for correlations with preoperative clinical and radiographic findings . MATERIAL AND METHODS Optoelectronic and multicomponent force-plate data s were used to calculate joint motion , moments and intersegmental  forces  for 26 patients with unilateral hip pain and 20 normal age and sex-matched patients . Height was similar in the two groups but mean weight in the study group ( 83 kg ) was greater than in the controls ( 68 kg ) . The preoperative Harris score was 53 in the study group and 16 patients had a permanent flexion contracture of the knee ( mean 15 degrees , range 5 - 30 degrees ) . Radiographically , there were 22 cases of osteo-arthritis hip disease and 4 cases of necrosis . RESULTS Gait analysis showed a significant 0.66 + /- 0.06 m ( 12 p. 100 ) reduction in step length .  Patients who had severe hip pain walked with a decreased dynamic range of motion ( 18 + /- 5 degrees , p<0.0001 ) with a curve reversal as they extended the hip . They also reduced dynamic range of motion of the knee and ankle . Patients who presented a reversal in their dynamic hip range of motion had a greater passive flexion contracture and a greater loss in range of motion during gait than those with a smooth regular pattern ( p<0.0001 ) . Patients with hip pain walked with significantly decreased external extension , adduction , and internal and external rotation moments ( p<0.0001 ) . They also unloaded the ipsilateral knee and ankle . The decreased hip extension moment was significantly correlated with an increased level of pain ( p<0.0001 ) . There was no correlation with radiological findings . DISCUSSION Reversal of dynamic hip range of motion was interpreted as a mechanism to increase effective hip extension during stance phase through increased anterior pelvic tilt and lumbar lordosis . CONCLUSION Patients with painful hip walked with a manner that was asymmetric . These gait modifications were related to hip limitation in passive motion and pain . Patients with flexion contracture adopted a compensatory gait mechanism . This study confirms relation between hip pain and forces across the hip joint The aim of this prospect i ve follow-up study was to determine if gait measurements and /or clinical measurements could detect differences in treatment outcome between two surgical interventions in patients with knee osteoarthritis ( OA ) . The patients were followed for 5 years 
    Output:
    
Discriminant capacity showed significant reduction of gait speed , stride length and knee flexion in OA patients compared to healthy subjects .
Available data concerning validity and reliability of kinematic gait analysis are insufficient to date to consider kinematic parameters as valuable outcome measures in OA .