Exercise for knee osteoarthritis pain: Association or causation?

Exercise is universally recommended as a primary strategy for the management of knee osteoarthritis (OA) pain. The recommendations are based on results from more than 100 randomized controlled trials (RCTs) that compare exercise to no-attention control groups. However, due to the inherent difficulties with adequate placebo control, participant blinding and the use of patient-reported outcomes, the existing RCT evidence is imperfect. To better understand the evidence used to support a causal relationship between exercise and knee OA pain relief, we examined the existing evidence through the Bradford Hill considerations for causation. The Bradford Hill considerations, first proposed in 1965 by Sir Austin Bradford Hill, provide a framework for assessment of possible causal relationships. There are 9 considerations by which the evidence is reviewed: Strength of association, Consistency, Specificity, Temporality, Biological Gradient (Dose-Response), Plausibility, Coherence, Experiment, and Analogy. Viewing the evidence from these 9 viewpoints did neither bring forward indisputable evidence for nor against the causal relationship between exercise and improved knee OA pain. Rather, we conclude that the current evidence is not sufficient to support claims about (lack of) causality. With our review, we hope to advance the continued global conversation about how to improve the evidence-based management of patients with knee OA.

Comparative effectiveness of different placebos and comparator groups for hand osteoarthritis exploring the impact of contextual factors: A systematic review and meta-analysis of randomised trials.

OBJECTIVE: To examine the pain relief effects of comparators (placebos and untreated control groups) in hand osteoarthritis trials and the impact of contextual factors. METHODS: We systematically searched PubMed, EMBASE and CENTRAL from inception to December 26, 2021. We included randomised controlled trials of people with hand osteoarthritis with a placebo or an untreated control group. We assessed the Risk of Bias with Cochrane Risk-of-Bias tool version 2. Each comparator was contrasted with a null-arm, imputed as having a zero change from baseline with the same standard deviation as the comparator. We combined the standardised mean differences with a random effects meta-analysis. The contextual factors' effect was explored in meta-regression and stratified models with pain as the dependent variable. RESULTS: 84 trials (7262 participants) were eligible for quantitative synthesis, of which 76 (6462 participants) were eligible for the stratified analyses. Placebos were superior to their matched null-arms in relieving pain with an effect size of -0.51 (95% confidence interval -0.61 to -0.42), while untreated control groups were not. When analysing all comparators, blinded trial designs and low risk of bias were associated with higher pain relief compared to an open-label trial design and some concern or high risk of bias. CONCLUSION: The placebo response on pain for people with hand osteoarthritis was increased by appropriate blinding and a lower risk of bias assessment. Placebos were superior to a null-arm, while untreated control groups were not. Results emphasise the importance of using appropriate comparators in clinical trials. PROSPERO REGISTRATION ID: CRD42022298984.

The impact of an illness perception conversation on open-label placebo response in knee osteoarthritis: A randomised controlled trial.

OBJECTIVE: To compare the effect of an illness perception conversation (IPC), relative to a research participation conversation (RPC), on 2-week changes in knee pain in patients with knee osteoarthritis. METHOD: This was a randomised single-blind trial. Patients were randomised to two matched conversations. An IP conversation concerning the participant's knee pain-related illness perception (IP) or an RPC concerning the participant's motivation for participating in research. Both conversations were followed by an open-label intraarticular saline injection in the most symptomatic knee. The primary outcome was change in knee pain from baseline to 2 weeks follow-up on a 100 mm visual analogue scale (VAS). Key secondary outcomes included the Knee injury and Osteoarthritis Outcome Score (KOOS) subscales: Activities of daily living (ADL) and Quality of life (QoL). Main analyses were based on the intention-to-treat population using repeated measures mixed effects linear models. RESULTS: 103 patients were randomised to the IPC group (n = 52) and the RPC group (n = 51). VAS knee pain scores changed statistically significantly from baseline to end of treatment in both groups, -13.7 (standard error [SE]: 3.2) in the IPC group and -13.0 (SE: 3.1) in the RPC group with an adjusted between-group difference of -0.7 (95% CI: -8.3 to 6.9; P = 0.85). Likewise, no group differences were seen in KOOS ADL and KOOS QoL. CONCLUSION: A conversation concerning knee pain-related IP did not augment the pain-relieving effect of an open-label placebo injection when compared to a similar control conversation concerning motivations for participating in research. TRIAL REGISTRATION: NCT05225480.

Polyacrylamide gel versus hyaluronic acid for the treatment of knee osteoarthritis: a randomised controlled study.

OBJECTIVES: To assess non-inferiority of intra-articular injectable polyacrylamide hydrogel (iPAAG) to hyaluronic acid (HA) on symptomatic benefit in individuals with knee osteoarthritis (OA). METHODS: This randomised, controlled, multi-centre trial recruited adults with symptomatic and radiographic knee OA from 3 clinical rheumatology sites in Denmark; two private clinics and one public hospital department. Participants were randomised 1:1 to receive a single intra-articular 6 mL injection of either HA or iPAAG on an outpatient basis. Primary outcome was change from baseline in WOMAC pain subscale after 26 weeks. Secondary outcomes were changes from baseline in WOMAC stiffness and physical function subscales, patients' global assessment of disease impact, EuroQoL-5D-5L, and proportion of positive OMERACT-OARSI responders after 26 and 52 weeks. RESULTS: 239 adults were randomised: 120 to HA and 119 to iPAAG. For the primary outcome, the least squares mean changes in WOMAC pain were -14.8 (95% CI: -18.0 to -11.7) for HA and -18.5 (95% CI: -21.7 to -15.4) for iPAAG; group difference: 3.7 (95% CI: -0.7 to 8.1). The lower boundary of the 95% CI respected the pre-specified non-inferiority margin of 9 WOMAC pain points. No statistically significant differences were observed for the secondary outcomes. For HA, 9 participants (7.6%) reported 13 adverse device effects (ADEs). For iPAAG, 35 participants (28.9%) reported 41 ADEs. All ADEs were mild/moderate, with no serious ADEs reported. CONCLUSIONS: iPAAG was found to be as effective and safe as HA for treatment of knee OA symptoms for at least 1 year after a single injection.

The Effect of Graded Activity and Pain Education After Lumbar Spinal Fusion on Sedentary Behavior 3 and 12 Months Postsurgery: A Randomized Controlled Trial.

OBJECTIVES: To examine the effect of an early postsurgical intervention consisting of graded activity and pain education (GAPE) in patients with chronic low back pain (CLBP) undergoing lumbar spinal fusion (LSF) on sedentary behavior, disability, pain, fear of movement, self-efficacy for exercise and health-related quality of life (HRQoL) at 3-, 6-, and 12 months follow-up. DESIGN: A parallel-group, observer-blinded randomized controlled trial. SETTING: Department of Occupational- and Physiotherapy and the Centre for Rheumatology and Spine Diseases, Rigshospitalet, Denmark. PARTICIPANTS: In total, 144 participants undergoing an LSF for CLBP were randomly assigned to an intervention or a control group. INTERVENTIONS: The intervention group received 9 sessions of GAPE, based on principles of operant conditioning. MAIN OUTCOME MEASURES: The primary outcome was reduction in time spent in sedentary behavior, measured by an accelerometer at 3 months. The secondary outcomes were reduction in time spent in sedentary behavior at 12 months and changes from baseline to 3-, 6-, and 12 months on disability, pain, fear of movement, self-efficacy for exercise, and HRQoL. RESULTS: No difference in changes in sedentary behavior between groups was found 3 months after surgery. At 12 months after surgery, there was a significant difference between groups (mean difference: -25.4 min/d (95% confidence interval -49.1 to -1.7)) in favor of the intervention group. CONCLUSIONS: Compared with usual care, GAPE had no effect on short-term changes in sedentary behavior but GAPE had a statistical, but possibly not clinical significant effect on sedentary behavior 12 months after LSF. Further, the behavioral intervention was safe to perform.

Effectiveness of an individualised occupational therapy intervention programme (ABLE) using adaptational strategies on activities of daily living among persons with chronic conditions: A randomised controlled trial (RCT).

OBJECTIVE: Compare the effectiveness of a problem-solving, individualised, home-based occupational therapy intervention (ABLE 2.0), to usual occupational therapy, on activities of daily living (ADL) ability in persons with chronic conditions. DESIGN: A single-centre, double-blinded, randomised controlled trial with 10- and 26-week follow-up. SETTING: A Danish municipality. SUBJECTS: Persons with chronic conditions experiencing problems performing ADL tasks (n = 80). INTERVENTIONS: ABLE 2.0 was compared with usual occupational therapy. MAIN MEASURES: Coprimary outcomes were self-reported ADL ability (ADL-Interview Performance) and observed ADL motor ability (Assessment of Motor and Process Skills) at Week 10. Secondary outcomes were self-reported ADL ability (ADL-Interview Performance) and observed ADL motor ability (Assessment of Motor and Process Skills) at Week 26, and perceived satisfaction with ADL ability (ADL-Interview Satisfaction) and observed ADL process ability (Assessment of Motor and Process Skills) at Weeks 10 and 26. RESULTS: In total, 78 persons were randomly assigned: 40 to usual occupational therapy and 38 to ABLE 2.0. No statistically significant nor clinically relevant difference between group mean changes in primary outcomes was identified from baseline to Week 10 (ADL-Interview Performance [-0.16; 95% CI: -0.38 to 0.06] and Assessment of Motor and Process Skills ADL motor ability [-0.1; 95% CI: -0.3 to 0.1]). At Week 26, a statistically significant and clinically relevant difference was found in Assessment of Motor and Process Skills ADL motor ability (LS mean change: -0.3; 95% CI: -0.5 to -0.1) between groups. CONCLUSION: ABLE 2.0 was effective in improving observed ADL motor ability at 26 weeks.

Quadriceps or hip exercises for patellofemoral pain? A randomised controlled equivalence trial.

OBJECTIVE: To assess effectiveness equivalence between two commonly prescribed 12-week exercise programmes targeting either the quadriceps or the hip muscles in patients with patellofemoral pain (PFP). METHODS: This randomised controlled equivalence trial included patients with a clinical diagnosis of PFP. Participants were randomly assigned to either a 12-week quadriceps-focused exercise (QE) or a hip-focused exercise (HE) programme. The primary outcome was the change in Anterior Knee Pain Scale (AKPS) (0-100) from baseline to 12-week follow-up. Prespecified equivalence margins of ±8 points on the AKPS were chosen to demonstrate comparable effectiveness. Key secondary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire pain, physical function and knee-related quality of life subscales. RESULTS: 200 participants underwent randomisation; 100 assigned to QE and 100 to HE (mean age 27.2 years (SD 6.4); 69% women). The least squares mean changes in AKPS (primary outcome) were 7.6 for QE and 7.0 for HE (difference 0.6 points, 95% CI -2.0 to 3.2; test for equivalence p<0.0001), although neither programme surpassed the minimal clinically important change threshold. None of the group differences in key secondary outcomes exceeded predefined equivalence margins. CONCLUSION: The 12-week QE and HE protocols provided equivalent improvements in symptoms and function for patients with PFP. TRIAL REGISTRATION NUMBER: NCT03069547.

Exercise and education versus saline injections for knee osteoarthritis: a randomised controlled equivalence trial.

OBJECTIVE: To compare the efficacy of an exercise and education programme with open-label placebo given as intra-articular injections of inert saline on pain and function in individuals with knee osteoarthritis (OA). METHODS: In this open-label, randomised controlled trial, we recruited adults aged ≥50 years with symptomatic and radiographically confirmed knee OA in Denmark. Participants were randomised 1:1 to undergo an 8-week exercise and education programme or four intra-articular saline injections over 8 weeks. Primary outcome was change from baseline to week 9 in the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire pain subscale (range 0 (worst)-100 (best)). Prespecified equivalence margins of ±8 KOOS pain points were chosen for the demonstration of comparable efficacy. Key secondary outcomes were the KOOS function and quality of life subscales, and patients' global assessment of disease impact. RESULTS: 206 adults were randomly assigned: 102 to exercise and education and 104 to intra-articular saline injections. For the primary outcome, the least squares mean changes in KOOS pain were 10.0 for exercise and education and 7.3 for saline injections (difference 2.7 points, 95% CI -0.6 to 6.0; test for equivalence p=0.0008). All group differences in the key secondary outcomes respected the predefined equivalence margins. Adverse events and serious adverse events were similar in the two groups. CONCLUSION: In individuals with knee OA, an 8-week exercise and education programme provided efficacy for symptomatic and functional improvements equivalent to that of four open-label intra-articular saline injections over 8 weeks. TRIAL REGISTRATION NUMBER: NCT03843931.

Writing up your clinical trial report for a scientific journal: the REPORT trial guide for effective and transparent research reporting without spin.

The REPORT guide is a 'How to' guide to help you report your clinical research in an effective and transparent way. It is intended to supplement established first choice reporting tools, such as Consolidated Standards of Reporting Trials (CONSORT), by adding tacit knowledge (ie, learnt, informal or implicit knowledge) about reporting topics that we have struggled with as authors or see others struggle with as journal reviewers or editors. We focus on the randomised controlled trial, but the guide also applies to other study designs. Topics included in the REPORT guide cover reporting checklists, trial report structure, choice of title, writing style, trial registry and reporting consistency, spin or reporting bias, transparent data presentation (figures), open access considerations, data sharing and more. Preprint (open access): https://doi.org/10.31219/osf.io/qsxdz.

Effect of aerobic exercise training on asthma in adults: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the effect of aerobic exercise training on asthma control, lung function and airway inflammation in adults with asthma. DESIGN: Systematic review and meta-analysis. METHODS: Randomised controlled trials investigating the effect of ≥8 weeks of aerobic exercise training on outcomes for asthma control, lung function and airway inflammation in adults with asthma were eligible for study. MEDLINE, Embase, CINAHL, PEDro and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up to April 3, 2019. Risk of bias was assessed using the Cochrane Risk of Bias Tool. RESULTS: We included 11 studies with a total of 543 adults with asthma. Participants' mean (range) age was 36.5 (22-54) years; 74.8% of participants were female and the mean (range) body mass index was 27.6 (23.2-38.1) kg·m-2. Interventions had a median (range) duration of 12 (8-12) weeks and included walking, jogging, spinning, treadmill running and other unspecified exercise training programmes. Exercise training improved asthma control with a standard mean difference (SMD) of -0.48 (-0.81--0.16). Lung function slightly increased with an SMD of -0.36 (-0.72-0.00) in favour of exercise training. Exercise training had no apparent effect on markers of airway inflammation (SMD -0.03 (-0.41-0.36)). CONCLUSIONS: In adults with asthma, aerobic exercise training has potential to improve asthma control and lung function, but not airway inflammation.

Perfusion in bone marrow lesions assessed on DCE-MRI and its association with pain in knee osteoarthritis: a cross-sectional study.

OBJECTIVE: To investigate the association between pain and perfusion in bone marrow lesions with and without cysts assessed dynamic contrast-enhanced (DCE)-MRI in patients with knee osteoarthritis. SUBJECTS AND METHODS: In a cross-sectional setting, perfusion in bone marrow lesions was assessed using 3 Tesla MRI and correlated (Spearman's rank correlation) to pain using the knee injury and osteoarthritis outcome score (KOOS). Bone marrow lesions were assessed across the whole knee with DCE-MRI using heuristic variable and non-contrast-enhanced-MRI using MRI osteoarthritis knee score. RESULTS: Data were available from 107 participants. The participants had a mean age of 60.8 years, mean BMI of 34.5 kg/m2, mean KOOS-pain of 63.7 (0-100 scale), and mean bone marrow lesion sum score of 6.5 (0-45 scale). The bivariate association between KOOS-pain and the heuristic perfusion variable time to peak in bone marrow lesions containing subchondral cysts showed a statistically significant correlation (r = 0.40; p = 0.002). The perfusion variables were not correlated with KOOS-pain in bone marrow lesions without cysts. CONCLUSION: In this cross-sectional study, the rate of perfusion (TTP) in bone marrow lesions containing subchondral cysts was associated with pain in patients with knee OA. DCE-MRI has a potential to be used for separating subtypes of OA.

Opioid-Induced Reductions in Gait Variability in Healthy Volunteers and Individuals with Knee Osteoarthritis.

OBJECTIVE: To investigate differences in gait variability induced by two different single-dose opioid formulations and an inert placebo in healthy volunteers and knee osteoarthritis patients. DESIGN: Experimental, randomized, double-blinded, crossover study of inert placebo (calcium tablets), 50 mg of tapentadol, and 100 mg of tramadol. SETTING: Laboratory setting. SUBJECTS: Healthy volunteers and knee osteoarthritis patients. METHODS: At three visits, separated by seven days, one tablet was administered per visit according to the randomization code. At each visit, a baseline measurement was done before tablet administration, after which hourly measurements were performed for six hours, yielding a total of seven measurements per visit. Gait variability was measured by three-dimensional gait analysis, recorded during six minutes of continuous treadmill walking at self-selected speed. One hundred seventy gait cycles were identified from detection of clear events of the knee joint angle trajectories. Gait variability was assessed as average standard deviations over a gait cycle of the sacrum displacements and accelerations; sagittal plane ankle, knee, and hip joint angles; step widths; and stride times. RESULTS: Twenty-four opioid-naïve and neurologically intact participants (12 healthy volunteers and 12 knee osteoarthritis patients) were included and completed the experiment. Tapentadol reduced the variability of sacrum displacements and accelerations compared with placebo and tramadol. There were no differences between experimental conditions regarding the variability in lower-extremity joint angle variability, step widths, or stride times. CONCLUSIONS: In opioid-naïve and neurologically intact individuals, tapentadol seems to reduce movement variability during treadmill walking, compared with placebo and tramadol. This can be interpreted as a loss of adaptability that might increase the risk of falling if the system is perturbed.

Exercise-induced pain changes associate with changes in muscle perfusion in knee osteoarthritis: exploratory outcome analyses of a randomised controlled trial.

BACKGROUND: Exercise therapy is recommended for knee osteoarthritis (OA), but the underlying mechanisms of pain relief are not fully understood. The purpose of this study was to explore the effects of exercise on muscle perfusion assessed by dynamic contrast enhanced MRI (DCE-MRI) and its association with changes in pain in patients with knee OA. METHODS: Exploratory outcome analyses of a randomised controlled study with per-protocol analyses ( ClinicalTrials.gov : NCT01545258) performed at an outpatient clinic at a public hospital in Denmark. We compared 12 weeks of supervised exercise therapy 3 times per week (ET) with a no attention control group (CG). Analyses of covariance (ANCOVA) were used to assess group mean differences in changes from baseline to week 12 in knee muscle perfusion quantified by DCE-MRI, patient-reported pain and function using the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, knee extensor and flexor muscle strength tests, and the six-minute walking test (6MWT). Spearman's correlation coefficients were used to determine the correlation between changes in DCE-MRI variables, KOOS, muscle strength, and 6MWT. The potential effect mediation of the DCE-MRI perfusion variables was investigated in a post-hoc mediation analysis. RESULTS: Of 60 participants randomised with knee osteoarthritis, 33 (ET, n = 16, CG, n = 17) adhered to the protocol and had complete DCE-MRI data. At follow-up, there were significant group differences in muscle perfusion changes and clinically relevant group differences in KOOS pain changes (10.7, 95% CI 3.3 to 18.1, P = 0.006) in favor of ET. There were no significant between-group differences on muscle strength and function. The changes in pain and muscle perfusion were significantly correlated (highest Spearman's rho = 0.42, P = 0.014). The mediation analyses were generally not statistically significant. CONCLUSION: The pain-reducing effects of a 12-week exercise program are associated with changes in knee muscle perfusion quantified by DCE-MRI in individuals with knee OA, but whether the effects are mediated by muscle perfusion changes remains unclear. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01545258 , first posted March 6, 2012.

Intra-articular 2.5% polyacrylamide hydrogel for the treatment of knee osteoarthritis: an observational proof-of-concept cohort study.

OBJECTIVES: There is a drought of effective treatments of knee osteoarthritis (OA) and new therapies are needed. The present study has been conducted to establish an initial estimate of effectiveness of intra-articular (IA) injection of a proprietary 2.5% cross-linked polyacrylamide hydrogel (PAAG) for the treatment of knee OA symptoms and signs. METHODS: Patients with knee OA were invited into a prospective open-label cohort study. The patients received up to two IA injections of 3 ml of PAAG 1 month apart. The WOMAC questionnaire was used to estimate effectiveness, and was collected at baseline and after 4, 7 and 13 months. Primary outcome was change from baseline for the WOMAC pain subscale after 4 months (Normalised to 0-100 points; 100 worst). Data was analysed using a mixed-effect model without imputation of missing data. RESULTS: 84 patients (48 females) received IA PAAG. Of these WOMAC data were available from 62 after 4 months, 59 after 7 months, and 56 after 13 months. There were statistically and clinically significant reductions in WOMAC pain after 4 months (mean change -14.6 points [95% CI: -18.9 to -10.2]; p<.0001). Similar results were found in WOMAC stiffness, physical function, and WOMAC total. The improvement was sustained throughout the observation period. CONCLUSIONS: These results suggest beneficial effects of IA injection of PAAG on knee OA symptoms, even in the long term (1 year). This initial estimation of effectiveness is promising but needs to be confirmed in a randomised study with adequate measures taken to reduce risk of bias.

Weight loss for overweight and obese individuals with gout: a systematic review of longitudinal studies.

OBJECTIVES: Weight loss is commonly recommended for gout, but the magnitude of the effect has not been evaluated in a systematic review. The aim of this systematic review was to determine benefits and harms associated with weight loss in overweight and obese patients with gout. METHODS: We searched six databases for longitudinal studies, reporting the effect of weight loss in overweight/obese gout patients. Risk of bias was assessed using the tool Risk of Bias in Non-Randomised Studies of Interventions. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation. RESULTS: From 3991 potentially eligible studies, 10 were included (including one randomised trial). Interventions included diet with/without physical activity, bariatric surgery, diuretics, metformin or no intervention. Mean weight losses ranged from 3 kg to 34 kg. Clinical heterogeneity in study characteristics precluded meta-analysis. The effect on serum uric acid (sUA) ranged from -168 to 30 µmol/L, and 0%-60% patients achieving sUA target (<360 µmol/L). Six out of eight studies (75%) showed beneficial effects on gout attacks. Two studies indicated dose-response relationship for sUA, achieving sUA target and gout attacks. At short term, temporary increased sUA and gout attacks tended to occur after bariatric surgery. CONCLUSIONS: The available evidence is in favour of weight loss for overweight/obese gout patients, with low, moderate and low quality of evidence for effects on sUA, achieving sUA target and gout attacks, respectively. At short term, unfavourable effects may occur. Since the current evidence consists of a few studies (mostly observational) of low methodological quality, there is an urgent need to initiate rigorous prospective studies (preferably randomised controlled trials). SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42016037937.

Dynamic weight-bearing assessment of pain in knee osteoarthritis: construct validity, responsiveness, and interpretability in a research setting.

BACKGROUND: The Osteoarthritis Research Society International (OARSI) has suggested to asses pain after specific activities consistently in clinical trials on knee OA. The Dynamic weight-bearing Assessment of Pain (DAP) assesses pain during activity (30 s of performing repeated deep knee-bends from a standing position). The purpose of this study is to evaluate the construct validity, responsiveness, and interpretability of the DAP for knee osteoarthritis (OA). METHODS: One-hundred participants with knee OA were tested twice each with the DAP, the Knee injury and Osteoarthritis Outcome Score (KOOS), six-minute-walk-test (6MWT), and 6-min-walk-test with subsequent pain rating (6MWTpain), and once with a transition questionnaire (TRANS-Q) for the patient-reported change in pain after 12 weeks of exercise. Construct validity (baseline-scores) and responsiveness (change-scores) were estimated by Spearman Correlation Coefficients. We hypothesized that no correlations would be excellent (<0.7) (divergent validity), except for the 6MWTpain (convergent validity). The TRANS-Q was used for interpreting the DAP change-scores in terms of responsiveness and Minimal Important Change (MIC). RESULTS: Divergent validity with the KOOS subscales (r = -0.31 to-0.45) and the 6MWT (r = -0.25) was supported. Convergent validity with the 6MWTpain was not supported (r = 0.54). The DAP change-scores corresponded to patient-reported change in pain (TRANS-Q), while correlations with change-scores on the other instruments were <0.35. The MIC was 2.4 DAP points. CONCLUSIONS: The DAP possesses divergent validity compared to other instruments for knee OA, supporting the potential for this new way of assessing pain directly during activity. Importantly, the DAP change-scores correspond to patient-reported changes in pain, showing responsiveness. A change of 2.4 or more can be interpreted as clinically relevant. The DAP is a promising alternative to using 'pain on walking' as a clinical trial inclusion criterion/outcome.

Association of Physical Fitness with Depression in Women with Fibromyalgia.

OBJECTIVE: The aim of this study was to examine the association between physical fitness and depressive symptoms in women with fibromyalgia (FM). We also assessed whether different fitness components present independent relationships with depressive symptoms. DESIGN: Cross-sectional study. SETTING: University facilities and FM associations. SUBJECTS: Four hundred and forty-four patients with FM according to the 1990 American College of Rheumatology criteria. METHODS: Depressive symptoms were assessed using the Beck Depression Inventory (BDI-II). Physical fitness (aerobic fitness, muscle strength, flexibility, and motor agility) was assessed using the standardized Senior Fitness Test battery and the handgrip strength test. A standardized composite score for fitness was computed and divided into quintiles. RESULTS: Overall, the fitness tests presented inverse associations with the total BDI-II score (P < 0.05). The patients in the highest fitness quintile had 8.4% lower depressive symptoms than the patients in the lowest fitness quintile (P = 0.014). The odds of severe symptoms of depression were between 3.7% and 16.9% lower for each performance unit in the back-scratch, handgrip, arm-curl, and eight-feet up-and-go tests. When all the fitness tests were simultaneously considered, the back-scratch test was the only one independently associated with the total BDI-II score (P = 0.001; R(2) = 0.023). CONCLUSIONS: Although higher physical fitness was generally associated with lower symptoms of depression in women with FM, the observed associations were somewhat weak and inconsistent, differing from those previously observed in healthy adults. Further research to determine the clinical relevance of the association between physical fitness and depression in FM is warranted.

Physiotherapy for pain: a meta-epidemiological study of randomised trials.

OBJECTIVES: To empirically assess the clinical effects of physiotherapy on pain in adults. DESIGN: Using meta-epidemiology, we report on the effects of a 'physiotherapy' intervention on self-reported pain in adults. For each trial, the group difference in the outcome 'pain intensity' was assessed as standardised mean differences (SMD) with 95% CIs. Stratified analyses were conducted according to patient population (International Classification of Diseases-10 classes), type of physiotherapy intervention, their interaction, as well as type of comparator group and risks of bias. The quality of the body of evidence was assessed based on GRADE methodology. DATA SOURCES: Systematic searches were carried out in MEDLINE and PEDro from 1 January 2004-31 December 2013. 174 trials (224 comparisons) met the inclusion criteria for the meta-analysis. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised trials using 'no intervention' or of a sham-controlled design were selected. Only articles written in English were eligible. RESULTS: An overall moderate effect of physiotherapy on pain corresponding to 0.65 SD-units (95% CI 0.57 to 0.73) was found based on a moderate inconsistency (I(2)=51%). Stratified exploration showed that therapeutic exercise for musculoskeletal diseases tended to be more beneficial than multimodal interventions (difference 0.30 95% CI 0.03 to 0.57; p=0.03). Trials with a 'no intervention' comparator tended to have a higher overall effect size than trials with a sham comparator (difference 0.25; 95% CI 0.09 to 0.41; p=0.004). In general, our confidence in the estimates was low, mainly due to high risk of performance biases and between-study heterogeneity. CONCLUSIONS: Physiotherapy reduces pain in adults, but standardisation of interventions and focus on trial research with low risks of bias and reproducible treatment modalities are needed. TRIAL REGISTRATION NUMBER: CRD42014008754.

Local and Systemic Changes in Pain Sensitivity After 4 Weeks of Calf Muscle Stretching in a Nonpainful Population: A Randomized Trial.

BACKGROUND: Stretching is often used in clinical practice for a variety of purposes, including pain therapy. The possible mechanism behind the effect of stretching remains to be clarified. AIM: To investigate whether 4 weeks of unilateral stretching of the calf muscles would affect local and central pain sensitivity. METHOD: This study was a randomized assessor-blinded clinical study. Healthy participants (age 18 to 40) were included and randomized. Participants in the intervention group were instructed to perform 2 stretching exercises targeting the calf muscles; 3 times 30 seconds, 7 days a week for 4 weeks on the dominant leg. Participants in the control group were instructed not to do any stretching for 4 weeks. Pressure pain threshold (PPT) and temporal summation (TS) of pressure pain were measured on the stretched calf, the contra-lateral calf, and contra-lateral lower arm using a computerized cuff algometer. Analyses of variance on the per-protocol population (defined as participants that adhered to the protocol) were used to assess group differences in the changes from baseline. RESULT: Forty healthy volunteers were included, of which 34 participants adhered to the protocol (15 intervention group/19 control group). No statistically significant group differences in the changes from baseline were found regarding PPT and TS measurements for the stretched calf, the contra-lateral calf, and the arm. CONCLUSION: Four weeks of regular stretching of the calf muscles does not affect pressure pain sensitivity, suggesting that pressure pain sensitivity is unaffected by stretching in a healthy population. The mechanisms underlying any benefits of regular stretching remain to be explained.

The concept of physical limitations in knee osteoarthritis: as viewed by patients and health professionals.

OBJECTIVE: To comprehensively identify components of the physical limitation concept in knee osteoarthritis (OA) and to rate the clinical importance of these using perspectives of both patients and health professionals. DESIGN: Concept mapping, a structured group process, was used to identify and organize data in focus groups (patients) and via a global web-based survey (professionals). Ideas were elicited through a nominal group technique and then organized using multidimensional scaling, cluster analysis, participant validation, rating of clinical importance, and thematic analyses to generate a conceptual model of physical limitations in knee OA. RESULTS: Fifteen Danish patients and 200 international professionals contributed to generating the conceptual model. Five clusters emerged: 'Limitations/physical deficits'; 'Everyday hurdles'; 'You're not the person you used to be'; 'Need to adjust way of living'; and 'External limitations,' each with sub-clusters. Patients generally found their limitations more important than the professionals did. CONCLUSION: Patients and professionals agreed largely on the physical limitation concept in knee OA. Some limitations of high importance to patients were lower rated by the professionals, highlighting the importance of including patients when conceptualizing patient outcomes. These data offer new knowledge to guide selection of clinically relevant outcomes and development of outcome measures in knee OA.