Is increased joint loading detrimental to obese patients with knee osteoarthritis? A secondary data analysis from a randomized trial. Occupational physical loading tasks and knee osteoarthritis: a review of the evidence. Intermittent treatment of knee osteoarthritis with oral chondroitin sulfate: a one-year, randomized, double-blind, multicenter study versus placebo. Effects of specialized footwear on joint loads in osteoarthritis of the knee. OARSI recommended performance-based tests to assess physical function in people diagnosed with hip or knee osteoarthritis. Effects of a modified shoe on knee load in people with and those without knee osteoarthritis. Medial arch supports do not significantly alter the knee adduction moment in people with knee osteoarthritis. The effect of instruction in analgesic use compared with neuromuscular exercise on knee-joint load in patients with knee osteoarthritis: a randomized, single-blind, controlled trial. The effects of hip muscle strengthening on knee load, pain, and function in people with knee osteoarthritis: a protocol for a randomised, single-blind controlled trial Higher dynamic medial knee load predicts greater cartilage loss over 12 months in medial knee osteoarthritis
OBJECTIVE To investigate whether increased knee joint loading due to improved ambulatory function and walking speed following weight loss achieved over 16 weeks accelerates symptomatic and structural disease progression over a subsequent 1 year weight maintenance period in an obese population with knee osteoarthritis ( OA ) . METHODS Data from a prospect i ve study of weight loss in obese patients with knee OA ( the CARtilage in obese knee OsteoarThritis ( CAROT ) study ) were used to determine changes in knee joint compressive loadings ( model estimated ) during walking after a successful 16 week weight loss intervention . The participants were divided into ' Unloaders ' ( participants that reduced joint loads ) and ' Loaders ' ( participants that increased joint loads ) . The primary symptomatic outcome was changes in knee symptoms , measured with the Knee injury and Osteoarthritis Outcome Score ( KOOS ) question naire , during a subsequent 52 weeks weight maintenance period . The primary structural outcome was changes in tibiofemoral cartilage loss assessed semi-quantitatively ( Boston Leeds Knee Osteoarthritis Score ( BLOKS ) from MRI after the 52 weight maintenance period . RESULTS 157 participants ( 82 % of the CAROT cohort ) with medial and /or lateral knee OA were classified as Unloaders ( n = 100 ) or Loaders ( n = 57 ) . The groups showed similar significant changes in symptoms ( group difference : -2.4 KOOS points [ 95 % CI -6.8:1.9 ] ) and cartilage loss ( group difference : -0.06 BLOKS points [ 95 % CI -0.22:0.11 ) after 1 year , with no statistically significant differences between Loaders and Unloaders . CONCLUSION For obese patients undergoing a significant weight loss , increased knee joint loading for 1 year was not associated with accelerated symptomatic and structural disease progression compared to a similar weight loss group that had reduced ambulatory compressive knee joint loads . CLINICAL TRIALSGOV NCT00655941 UNLABELLED Purpose : To perform a systematic review with best evidence synthesis examining the literature on the relationship between occupational loading tasks and  knee osteoarthritis ( OA ) . METHODS Two data bases were search ed to identify articles published between 1946 and April , 2011 . Eligible studies were those that ( 1 ) included adults reporting on their employment history ; ( 2 ) measured individuals ' exposure to work-related activities with heavy loading in the knee joint ; and ( 3 ) identified presence of knee OA ( determined by X-ray ) , cartilage defects associated with knee OA ( identified by magnetic resonance imaging ) , or joint replacement surgery . RESULTS A total of 32 articles from 31 studies met the inclusion criteria . We found moderate evidence that combined heavy lifting and kneeling is a risk factor for knee OA , with odds ratios ( OR ) varying from 1.8 to 7.9 , and limited evidence for heavy lifting ( OR=1.4 - 7.3 ) , kneeling ( OR=1.5 - 6.9 ) , stair climbing ( OR=1.6 - 5.1 ) , and occupational groups ( OR=1.4 - 4.7 ) as risk factors . When examined by sex , moderate level evidence of knee OA was found in men ; however , the evidence in women was limited . CONCLUSIONS Further high- quality prospect i ve studies are warranted to provide further evidence on the role of occupational loading tasks in knee OA , particularly in women OBJECTIVE To investigate the efficacy and tolerability of a 3-month duration , twice a-year , intermittent treatment with oral chondroitin sulfate ( CS ) in knee osteoarthritis ( OA ) patients . DESIGN A total of 120 patients with symptomatic knee OA were r and omized into two groups receiving either 800 mg CS or placebo ( PBO ) per day for two periods of 3 months during 1 year . Primary efficacy outcome was Lequesne 's algo-functional index ( AFI ) ; secondary outcome parameters included VAS , walking time , global judgment , and paracetamol consumption . Radiological progression was assessed by automatic measurement of medial femoro-tibial joint space width on weight-bearing X-rays of both knees . Clinical and biological tolerability was assessed . RESULTS One hundred and ten of 120 patients were included in the ITT analysis .  AFI decreased significantly by 36 % in the CS group after 1 year as compared to 23 % in the PBO group . Similar results were found for the secondary outcomes parameters . Radiological progression at month 12 showed significantly decreased joint space width in the PBO group with no change in the CS group . Tolerability was good with only minor adverse events identically observed in both groups . CONCLUSION This study provides evidence s that oral CS decreased pain and improved knee function . The 3-month intermittent administration of 800mg/day of oral CS twice a year does support the prolonged effect known with symptom-modifying agents for OA . The inhibitory effect of CS on the radiological progression of the medial femoro-tibial joint space narrowing could suggest further evidence of its structure-modifying properties in knee OA OBJECTIVE Elevated dynamic joint loads have been associated with the severity and progression of osteoarthritis ( OA ) of the knee . This study compared the effects of a specialized shoe ( the mobility shoe ) design ed to lower dynamic loads at the knee with self-chosen conventional walking shoes and with a commercially available walking shoe as a control . METHODS Subjects with knee OA were evaluated in 2 groups . Group A ( n = 28 ) underwent gait analyses with both their self-chosen walking shoes and the mobility shoes .  Group B ( n = 20 ) underwent gait analyses with a control shoe and the mobility shoe .  Frontal plane knee loads were compared between the different footwear conditions . RESULTS Group A demonstrated an 8 % reduction in the peak external knee adduction moment with the mobility shoe compared with self-chosen walking shoes ( mean + /- SD 49 + /- 0.80 versus 2.71 + /- 0.84 % BW x H ; P < 0.05 ) . Group B demonstrated a 12 % reduction in the peak external knee adduction moment with the mobility shoe compared with the control shoe ( mean + /- SD 2.66 + /- 0.69 versus 3.07 + /- 0.75 % BW x H ; P < 0.05 ) . CONCLUSION Specialized footwear can effectively reduce joint loads in subjects with knee OA , compared with self-chosen shoes and control walking shoes . Footwear may represent a therapeutic target for the treatment of knee OA . The types of shoes worn by subjects with knee OA should be evaluated more closely in terms of their effects on the disease OBJECTIVES To recommend a consensus-derived set of performance-based tests of physical function for use in people diagnosed with hip or knee osteoarthritis ( OA ) or following joint replacement . METHODS An international , multidisciplinary expert advisory group was established to guide the study . Potential tests for consideration in the recommended set were identified via a survey of selected experts and through a systematic review of the measurement properties for performance-based tests . A multi-phase , consensus-based approach was used to prioritize and select performance-based tests by applying decision analysis methodology ( 1000Minds software ) via online decision surveys . The recommended tests were chosen based on available measurement-property evidence , feasibility of the tests , scoring methods and expert consensus . RESULTS Consensus incorporated the opinions of 138 experienced clinicians and research ers from 16 countries . The five tests recommended by the advisory group and endorsed by Osteoarthritis Research Society International ( OARSI ) were the  30-s chair-st and test , 40 m fast-paced walk test , a stair-climb test , timed up- and -go test and 6-min walk test . The first three were recommended as the minimal core set of performance-based tests for hip or knee OA . CONCLUSION The OARSI recommended set of performance-based tests of physical function represents the tests of typical activities relevant to individuals diagnosed with hip or knee OA and following joint replacements . These tests are complementary to patient-reported measures and are recommended as prospect i ve outcome measures in future OA research and to assist decision-making in clinical practice . Further research should be directed to exp and ing the measurement-property evidence of the recommended tests OBJECTIVE To evaluate the effects of a modified shoe that incorporates both lateral wedging and a variable-stiffness sole on knee joint loading in 3 population s : individuals with symptomatic and radiographic knee osteoarthritis ( OA ) , asymptomatic overweight individuals , and asymptomatic healthy weight individuals . METHODS Ninety participants ( 30 per group ) underwent a 3-dimensional gait analysis  across 3 test conditions : modified shoes , st and ard control shoes , and barefoot . For each condition , the first peak knee adduction moment ( KAM ) and knee flexion moment ( KFM ) ( both expressed as Nm/[body weight × height]% ) as well as the KAM impulse ( expressed as Nm.s/[body weight × height]% ) were determined . RESULTS The modified shoes significantly reduced the peak KAM as compared to the control shoes in both the OA ( P = 0.002 ) and the overweight ( P = 0.03 ) groups . In the OA group , there was no significant difference in peak KAM when walking in the modified shoe as compared to walking barefoot . In the overweight and the healthy weight groups , the peak KAM when walking in the modified shoe was significantly higher than that when walking barefoot ( P < 0.001 ) . Irrespective of group , the KAM impulse was significantly reduced when walking in the modified shoe as compared to the control shoe ( P < 0.001 ) and was significantly higher during both shoe conditions as compared to walking barefoot ( P < 0.001 ) . There was no change in the KFM between walking conditions for any group . CONCLUSION The findings illustrate that a shoe incorporating both a lateral wedge and a variable-stiffness sole can significantly reduce medial knee joint load . Further research examining the effects of these shoes on pain , function , and structural changes in the joint is warranted OBJECTIVE This study aim ed to evaluate the immediate effects of medial arch supports on indices of medial knee joint load ( the peak external knee adduction moment ( KAM ) and knee adduction angular ( KAA ) impulse ) and knee pain during walking in people with medial knee osteoarthritis ( OA ) . DESIGN Twenty-one people with medial compartment OA underwent gait analysis in st and ardised athletic shoes wearing ( 1 ) no medial arch supports and ( 2 ) prefabricated medial arch supports  , in r and om order . Outcomes were the first and second peaks in the external KAM , the KAA impulse and severity of knee pain during testing . Outcomes were compared across conditions using paired t tests ( gait data ) and Wilcoxon Signed Ranks test ( pain data ) . RESULTS There were no significant changes in either first or second peak KAM , or in the KAA impulse , with the addition of medial arch supports ( all P > 0.05 ) . Considerable individual variation in response to the arch supports was observed across participants . There was no immediate change in knee pain during walking when medial arch supports were worn ( P = 0.56 ) . CONCLUSIONS This study showed no mean change in any of the measured indices of medial knee load with medial arch supports . No immediate changes in knee pain were evident OBJECTIVE To investigate the effect of a neuro-muscular exercise ( NEMEX ) therapy program compared with instructions in optimized analgesics and anti-inflammatory drug use ( PHARMA ) , on measures of knee-joint load in people with mild to moderate knee osteoarthritis ( OA ) . We hypothesized that knee joint loading during walking would be reduced by NEMEX and potentially increased by PHARMA . DESIGN Single-blind , r and omized controlled trial ( RCT ) comparing NEMEX therapy twice a week with PHARMA . Participants with mild-to-moderate medial tibiofemoral knee OA were r and omly allocated ( 1:1 ) to one of two 8-week treatments . Primary outcome was change in knee load during walking ( Knee Index , a composite score from all three planes based on 3D movement analysis ) after 8 weeks of intervention . Secondary outcomes were frontal plane peak knee adduction moment ( KAM ) , Knee Injury and Osteoarthritis Outcome Scores ( KOOS ) and functional performance tests . RESULTS Ninety three participants ( 57 % women , 58 ± 8 years with a body mass index [ BMI ] of 27 ± 4 kg/m2 ( mean ± st and ard deviation [ SD ] ) ) were r and omized to NEMEX group ( n = 47 ) or PHARMA ( n = 46 ) ; data from 44 ( 94 % ) and 41 ( 89 % ) participants respectively , were available at follow-up . 49 % of the participants in NEMEX and only 7 % in PHARMA demonstrated good compliance . We found no difference in the primary outcome as evaluated by the Knee Index -0.07 [ -0.17 ; 0.04 ] Nm/%BW HT . Secondary outcomes largely supported this finding . CONCLUSIONS We found no difference in the primary outcome ; knee joint load change during walking from a NEMEX program vs information on the recommended use of analgesics and anti-inflammatory drugs . Clinical Trials.gov Identifier : NCT01638962 ( July 3 , 2012 ) . Ethical Committee : S-20110153 Background Lower limb strengthening exercises are an important component of the treatment for knee osteoarthritis ( OA ) . Strengthening the hip abductor and adductor muscles may influence joint loading and /or OA-related symptoms , but no study has evaluated these hypotheses directly . The aim of this r and omised , single-blind controlled trial is to determine whether hip abductor and adductor muscle strengthening can reduce knee load and improve pain and physical function in people with medial compartment knee OA . Methods / Design 88 participants with painful , radiographically confirmed medial compartment knee OA and varus alignment will be recruited from the community and r and omly allocated to a hip strengthening or control group using concealed allocation stratified by disease severity . The hip strengthening group will perform 6 exercises to strengthen the hip abductor and adductor muscles at home 5 times per week for 12 weeks . They will consult with a physiotherapist on 7 occasions to be taught the exercises and progress exercise resistance . The control group will be requested to continue with their usual care . Blinded follow up assessment will be conducted at 12 weeks after r and omisation . The primary outcome measure is the change in the peak external knee adduction moment measured during walking . Question naires will assess changes in pain and physical function as well as overall perceived rating of change . An intention-to-treat analysis will be performed using linear regression modelling and adjusting for baseline outcome values and other demographic characteristics . Discussion Results from this trial will contribute to the evidence regarding the effect of hip strengthening on knee loads and symptoms in people with medial compartment knee OA . If shown to reduce the knee adduction moment , hip strengthening has the potential to slow disease progression . Trial Registration Australia New Zeal and Clinical Trials Registry Objective Mechanical factors , in particular increased medial knee joint load , are believed to be important in the structural progression of knee osteoarthritis . This study evaluated the relationship of medial knee load during walking to indices of structural disease progression , measured on MRI , in people with medial knee osteoarthritis . Methods A longitudinal cohort design utilising a subset of participants ( n=144 , 72 % ) enrolled in a r and omised controlled trial of lateral wedge insoles was employed .  Medial knee load parameters including the peak knee adduction moment ( KAM ) and the KAM impulse  were measured at baseline using three-dimensional gait analysis during walking . MRI at baseline and at 12 months was used to assess structural indices . Multiple regression with adjustment for covariates assessed the relationship between medial knee load parameters and the annual change in medial tibial cartilage volume . Binary logistic regression was used for the dichotomous variables of progression of medial tibiofemoral cartilage defects and bone marrow lesions ( BML ) . Results A higher KAM impulse , but not peak KAM , at baseline was independently associated with greater loss of medial tibial cartilage volume over 12 months ( β=29.9 , 95 % CI 6.3 to 53.5 , p=0.01 ) . No significant relationships were seen between medial knee load parameters and the progression of medial tibiofemoral cartilage defects or BML . Conclusion This study suggests knee loading , in particular the KAM impulse , may be a risk factor for loss of medial tibial cartilage volume . As knee load is modifiable , load-modifying treatments may potentially slow disease progression
There is very limited and low- quality evidence to support for a causal link between knee joint loading during walking and structural progression of knee OA .
OBJECTIVE We performed a systematic review , meta- analysis and assessed the evidence supporting a causal link between knee joint loading during walking and structural knee osteoarthritis ( OA ) progression .