Biomarkers associated with lower limb muscle function in individuals with sarcopenia: a systematic review.

Lower limb muscle dysfunction is a key driver for impaired physical capacity and frailty status, both characteristics of sarcopenia. Sarcopenia is the key pathway between frailty and disability. Identifying biological markers for early diagnosis, treatment, and prevention may be key to early intervention and prevention of disability particularly mobility issues. To identify biological markers associated with lower limb muscle (dys)function in adults with sarcopenia, a systematic literature search was conducted in AMED, CINAHL, Cochrane Library, EMBASE, Medline, PubMed, Scopus, SPORTDiscus, and Web of Science databases from inception to 17 November 2021. Title, abstract, and full-text screening, data extraction, and methodological quality assessment were performed by two reviewers independently and verified by a third reviewer. Depending on available data, associations are reported as either Pearson's correlations, regression R2 or partial R2 , P value, and sample size (n). Twenty eligible studies including 3306 participants were included (females: 79%, males: 15%, unreported: 6%; mean age ranged from 53 to 92 years) with 36% in a distinct sarcopenic subgroup (females: 73%, males: 19%, unreported: 8%; mean age range 55-92 years). A total of 119 biomarkers were reported, categorized into: genetic and microRNAs (n = 64), oxidative stress (n = 10), energy metabolism (n = 18), inflammation (n = 7), enzyme (n = 4), hormone (n = 7), bone (n = 3), vitamin (n = 2), and cytokine (n = 4) markers) and seven lower limb muscle measures predominately focused on strength. Seven studies reported associations between lower limb muscle measures including (e.g. power, force, and torque) and biomarkers. In individuals with sarcopenia, muscle strength was positively associated with free testosterone (r = 0.40, P = 0.01; n = 46). In analysis with combined sarcopenic and non-sarcopenic individuals, muscle strength was positively associated with combined genetic and methylation score (partial R2  = 0.122, P = 0.03; n = 48) and negatively associated with sarcopenia-driven methylation score (partial R2  = 0.401, P < 0.01; n = 48). Biomarkers related to genetics (R2  = 0.001-0.014, partial R2  = 0.013-0.122, P > 0.05; n = 48), oxidative stress (r = 0.061, P > 0.05; n ≥ 77), hormone (r = 0.01, ρ = 0.052 p > 0.05, n ≥ 46) and combined protein, oxidative stress, muscle performance, and hormones (R2  = 22.0, P > 0.05; n ≥ 82) did not report significant associations with lower limb muscle strength. Several biomarkers demonstrated associations with lower limb muscle dysfunction. The current literature remains difficult to draw clear conclusions on the relationship between biomarkers and lower limb muscle dysfunction in adults with sarcopenia. Heterogeneity of biomarkers and lower limb muscle function precluded direct comparison. Use of international classification of sarcopenia and a set of core standardized outcome measures should be adopted to aid future investigation and recommendations to be made.

Gait rehabilitation for foot and ankle impairments in early rheumatoid arthritis: a feasibility study of a new gait rehabilitation programme (GREAT Strides).

BACKGROUND: Foot impairments in early rheumatoid arthritis are common and lead to progressive deterioration of lower limb function. A gait rehabilitation programme underpinned by psychological techniques to improve adherence, may preserve gait and lower limb function. This study evaluated the feasibility of a novel gait rehabilitation intervention (GREAT Strides) and a future trial. METHODS: This was a mixed methods feasibility study with embedded qualitative components. People with early (< 2 years) rheumatoid arthritis (RA) and foot pain were eligible. Intervention acceptability was evaluated using a questionnaire. Adherence was evaluated using the Exercise Adherence Rating Scale (EARS). Safety was monitored using case report forms. Participants and therapists were interviewed to explore intervention acceptability. Deductive thematic analysis was applied using the Theoretical Framework of Acceptability. For fidelity, audio recordings of interventions sessions were assessed using the Motivational Interviewing Treatment Integrity (MITI) scale. Measurement properties of four candidate primary outcomes, rates of recruitment, attrition, and data completeness were evaluated. RESULTS: Thirty-five participants (68.6% female) with median age (inter-quartile range [IQR]) 60.1 [49.4-68.4] years and disease duration 9.1 [4.0-16.2] months), were recruited and 23 (65.7%) completed 12-week follow-up. Intervention acceptability was excellent; 21/23 were confident that it could help and would recommend it; 22/23 indicated it made sense to them. Adherence was good, with a median [IQR] EARS score of 17/24 [12.5-22.5]. One serious adverse event that was unrelated to the study was reported. Twelve participants' and 9 therapists' interviews confirmed intervention acceptability, identified perceptions of benefit, but also highlighted some barriers to completion. Mean MITI scores for relational (4.38) and technical (4.19) aspects of motivational interviewing demonstrated good fidelity. The Foot Function Index disability subscale performed best in terms of theoretical consistency and was deemed most practical. CONCLUSION: GREAT Strides was viewed as acceptable by patients and therapists, and we observed high intervention fidelity, good patient adherence, and no safety concerns. A future trial to test the additional benefit of GREAT Strides to usual care will benefit from amended eligibility criteria, refinement of the intervention and strategies to ensure higher follow-up rates. The Foot Function Index disability subscale was identified as the primary outcome for the future trial. TRIAL REGISTRATION: ISRCTN14277030.

Sex- and osteoarthritis-related differences in muscle co-activation during weight-bearing tasks.

BACKGROUND: Individuals with knee osteoarthritis (OA) demonstrate impairments in muscle function (i.e. muscle weakness, high muscle co-activation believed to have detrimental effects on joint integrity). Women with knee OA exhibit poorer health outcomes than men. Sex and muscle function are known risk factors for knee OA. It is unclear how these risk factors are associated with muscle function in knee OA and the implications for disease aetiology. RESEARCH QUESTION: How does sex and knee osteoarthritis disease status relate to muscle function, specifically strength and muscle co-activation, during walking, stair negotiation and sit-to-walk activities. METHODS: A cross-sectional study assessed muscle co-activation in 77 individuals with knee OA (mean[SD], 62.5[8.1] years; 48/29 women/men) and 18 age-matched controls (62.5[10.4] years; 9/9 women/men), during a series of walking, stair ascent and descent and sit-to-walk activities. Muscle strength of the knee extensors and flexors was assessed using maximal voluntary isometric contractions (MVIC). Electromyography was recorded from the vastus lateralis/medalis, rectus femoris, biceps femoris, semitendinosus, medial/lateral gastrocnemius normalised to MVIC. Multiple regression assessed the relationship between sex, disease status, and muscle strength on muscle co-activation. RESULTS: Individuals with knee OA were weaker than controls, had higher hamstrings-quadriceps and medial-lateral co-activation for specific phases of gait. Women were weaker than men with higher muscle co-activation across all activities. Sex and muscle weakness, but not age or disease status predicted high muscle co-activation. SIGNIFICANCE: High muscle co-activation was associated with female sex and muscle weakness regardless of disease status and age. High muscle co-activation is believed to be a compensatory mechanism for muscle weakness to maintain a certain level of function. High muscle co-activation is also thought to have detrimental effects on cartilage and joint integrity this may explain high muscle co-activation in women with muscle weakness and contribute to increased risk of incidence and progression of knee OA in women.

Muscle Co-Activation Across Activities of Daily Living in Individuals With Knee Osteoarthritis.

OBJECTIVE: Muscle co-activation has been shown to be elevated in individuals with knee osteoarthritis (OA) during gait. Comparisons of muscle co-activation across different activities of daily living such as stair negotiation have yet to be explored. The aim of this study was to explore muscle co-activation across different activities of daily living in patients with knee OA. METHODS: Muscle co-activation was assessed in 77 symptomatic knee OA patients (mean ± SD age 62.5 ± 8.1 years, body mass index 29.4 ± 6.0 kg/m2 , and sex 48:29 female:male) using electromyography (EMG), during a series of walking, stair negotiation (ascent, descent), and sit-to-walk activities. EMG was recorded from 7 sites, mediolateral gastrocnemius, biceps femoris, semitendinosus, vastus lateralis/medialis, and rectus femoris, and normalized to maximal voluntary isometric contraction. Correlation was used to assess the consistency of co-activation across activities. Repeated-measures analysis of variance assessed the muscle combination by activity differences. RESULTS: Muscle co-activation was highest during stair ascent. When comparing muscle combinations within the same activity, we found that correlations ranged from r = 0.003 to r = 0.897, of which 80% of the combinations were significant. Between activities, muscle co-activation was significantly different (P < 0.05). Mediolateral muscle co-activation was higher than hamstrings/quadriceps across activities. CONCLUSION: Two muscle co-activation strategies were observed during activities of daily living in patients with knee OA to maintain stability. Muscle co-activation was higher during more challenging activities, particularly when the joint was accepting load. Mediolateral muscle co-activation was higher than hamstrings/quadriceps, so that mediolateral co-activation was thought to be a stabilization mechanism, while hamstrings/quadriceps co-activation responds to knee flexion moments, suggesting that different muscle combinations may have different roles in responding to joint demand.

Objective evaluation of physical functioning after tumor necrosis factor inhibitory therapy in patients with ankylosing spondylitis: a selection of 3 feasible performance-based tests.

OBJECTIVE: (1) To select a limited number of performance-based tests that are reliable, show improvement in physical functioning after tumor necrosis factor inhibitor (TNFi) therapy in patients with ankylosing spondylitis (AS), and generate information equivalent to the full set of tests, and (2) are feasible for use in daily clinical practice. METHODS: Eight performance-based tests were evaluated. To eliminate redundant testing, the tests that showed adequate reliability, the highest standardized response mean (SRM), and the largest proportion of patients with an improved performance-based physical functioning were selected. The selected tests were combined into a new criterion for improvement in physical functioning (AS Performance-based Improvement; ASPI). The number and percentage of improved patients identified with the ASPI and identified with the full set of performance tests were compared. RESULTS: Reliability for all tests was adequate to excellent (ICC 0.73-0.96). The tests for bending, putting on socks, and getting up from the floor had the highest SRM (0.52-0.74) and showed the largest proportion of improved patients after TNFi therapy. The combination of these 3 tests was feasible in daily clinical practice and showed improved physical functioning after TNFi therapy in 67% of the patients. CONCLUSION: The 3 selected tests are recommended for use in daily practice because they generate information comparable to the full set. They are reliable and feasible, and the combination of these tests showed improved physical functioning after TNFi therapy in 67% of the patients. Evaluation of physical functioning might be improved by adding these tests to other AS outcome measures.

Predictors and outcome of pain-related avoidance of activities in persons with early symptomatic knee osteoarthritis: a five-year followup study.

OBJECTIVE: It has been hypothesized that pain and low vitality lead to an increase in avoidance of activities in persons with early symptomatic knee osteoarthritis (OA), and that avoidance of activities leads to an increase in activity limitations. The present study aimed to evaluate these hypotheses. METHODS: Baseline, 2-year, and 5-year followup data of 828 participants from the Cohort Hip and Cohort Knee Study with early symptomatic knee OA were used. Autoregressive generalized estimating equations and linear regression models were used to analyze the longitudinal and cross-sectional associations between self-reported knee pain, vitality, pain-related avoidance of activities, and activity limitations. The models were adjusted for the covariates age, sex, education level, body mass index, comorbidity, radiographic severity, and hip pain. RESULTS: In longitudinal analyses, knee pain and vitality predicted a subsequent increase in avoidance of activities. Pain-related avoidance of activities predicted a subsequent increase in activity limitations; however, this relationship lost statistical significance (P = 0.089) after adjustment for covariates. Cross-sectional analyses showed strong relationships between knee pain, low vitality, pain-related avoidance of activities, and activity limitations at all time points. CONCLUSIONS: In persons with early symptomatic knee OA, knee pain and low vitality lead to a subsequent increase in avoidance of activities. Pain-related avoidance of activities is related to activity limitations at inception of symptoms, but also years later. Therefore, it can be recommended to monitor and target avoidance of activities at various stages of the disease.

Fatigue in patients with chronic widespread pain participating in multidisciplinary rehabilitation treatment: a prospective cohort study.

PURPOSE: To explore the associations between (improvement in) fatigue and (improvement in) clinical and cognitive factors in patients with chronic widespread pain (CWP), participating in multidisciplinary rehabilitation treatment. METHODS: Data were used from baseline, 6 and 18 months of follow-up during a prospective cohort study of 120 CWP patients who completed multidisciplinary rehabilitation treatment. Cross-sectional and longitudinal relationships were analyzed between fatigue, clinical (i.e. pain, interference of pain and depression) and pain related cognitive factors (i.e. negative emotional cognitions, active cognitive coping, and control and chronicity beliefs). RESULTS: Higher levels of pain, interference of pain, depression, negative emotional cognitions, and negative control and chronicity beliefs were associated with a higher level of fatigue. Improvement in depression was related to improvement in fatigue. CONCLUSIONS: In CWP patients, worse clinical status, and dysfunctional pain-related cognitions are associated with a higher level of fatigue. Our results suggest that improvement in depression might be a mechanism of improvement in fatigue. Furthermore, improvement in fatigue seems to be independent of improvement in pain related cognitions. Targeting fatigue in multidisciplinary pain treatment may need specific strategies. IMPLICATIONS FOR REHABILITATION: Improvement in depression may be a mechanism of change to improve the level of fatigue in CWP. Improvement in dysfunctional (pain related) cognitions seems to be independent of improvement in fatigue. Targeting fatigue in multidisciplinary treatment may need specific strategies (e.g. additional interventions focusing on reducing fatigue and specific attention to improvement of sleep).

Knee joint stabilization therapy in patients with osteoarthritis of the knee and knee instability: subgroup analyses in a randomized, controlled trial.

OBJECTIVE: To test whether knee stabilization therapy, prior to strength/functional training, may have added value in reducing activity limitations only in patients with knee osteoarthritis who have knee instability and (i) low upper leg muscle strength, (ii) impaired knee proprioception, (iii) high knee laxity, or (iv) frequent episodes of knee instability. DESIGN: Subgroup analyses in a randomized controlled trial comparing 2 exercise programmes (with/without knee stabilization therapy) (STABILITY; NTR1475). PATIENTS: Participants from the STABILITY-trial with clinical knee osteoarthritis and knee instability (n = 159). METHODS: Effect modification by upper leg muscle strength, knee proprioception, knee laxity, and patient-reported knee instability were determined using the interaction terms "treatment group subgroup factor", with the outcome measures WOMAC physical function (primary), numeric rating scale pain and the Get up and Go test (secondary). RESULTS: Effect modification by muscle strength was found for the primary outcome (p = 0.01), indicating that patients with greater muscle strength tend to benefit more from the experimental programme with additional knee stabilization training, while patients with lower muscle strength benefit more from the control programme. CONCLUSION: Knee stabilization therapy may have added value in patients with instability and strong muscles. Thus it may be beneficial if exercises target muscle strength prior to knee stabilization.

The avoidance model in knee and hip osteoarthritis: a systematic review of the evidence.

The avoidance model in patients with knee and hip osteoarthritis (OA) hypothesizes that pain and psychological distress lead to avoidance of activities, and thereby to muscle weakness and activity limitations. This paper systematically reviews the scientific evidence for the validity of this avoidance model. A qualitative data synthesis was used to identify levels of evidence. Sixty studies were included. In knee OA, strong evidence was found that avoidance of activities is associated with activity limitations via muscle weakness (mediation by muscle weakness), strong evidence was found for an association between muscle weakness and activity limitations, and weak evidence was found that pain and psychological distress are associated with muscle weakness via avoidance of activities (mediation by avoidance). In hip OA, weak evidence was found for mediation by muscle weakness; and strong evidence was found for an association between muscle weakness and activity limitations. More research is needed on the consecutive associations between pain or psychological distress, avoidance of activities and muscle weakness, and to confirm causal relationships.

Client-centred therapy in multiple sclerosis: more intensive diagnostic evaluation and less intensive treatment.

OBJECTIVE: Despite beneficial effects on communication and process measures, client-centred practice has been shown to result in poor functional outcomes. To examine a potential explanation for poor functional outcomes, this paper aims to assess whether in client-centred therapy more time is spent on diagnostic consultation and less time on actual treatment compared to usual care. METHOD: A multicentre cluster randomised controlled trial was performed. Thirteen hospitals and rehabilitation centres, 29 therapists and 269 outpatients with multiple sclerosis participated. Measurements included an inventory of diagnostic and treatment goals, the number of sessions, therapy duration and therapy intensity. RESULTS: In client-centred therapy, more sessions were used for diagnostic consultation (10.9% points difference, p = 0.030); the time needed to formulate the first treatment goal was longer (11.4 days difference, p = 0.041); there was a tendency towards more goals directed to diagnostic issues (0.69 goals difference, p = 0.056), spending more hours on indirect issues (1.16 h difference, p = 0.051) and towards a longer total therapy period (1.56 months difference, p = 0.058) than in usual care. CONCLUSION: Client-centred therapy resulted in more intensive diagnostic evaluation and less intensive treatment. This suggests that client-centred therapy should be adjusted towards a more proportional distribution of time devoted to diagnostic evaluation versus actual treatment.

Cognitive mechanisms of change in multidisciplinary treatment of patients with chronic widespread pain: a prospective cohort study.

OBJECTIVE: To evaluate the contribution of improvement in negative emotional cognitions, active cognitive coping, and control and chronicity beliefs to the outcome of multidisciplinary treatment in patients with chronic widespread pain. DESIGN: Prospective cohort study. PATIENTS: A total of 120 subjects diagnosed with chronic widespread pain, who completed a multidisciplinary pain programme. METHODS: Data from baseline, 6 months and 18 months follow-up measurements were analysed. Longitudinal relationships were analysed between changes in cognitions and outcome, using generalized estimated equations. Outcome domains included: pain, interference of pain in daily life, depression, and global perceived effect. Cognitive domains included: negative emotional cognitions, active cognitive coping and control and chronicity beliefs. RESULTS: Improvements in negative emotional cognitions were associated with improvements in all outcome domains, in particular with improvement in interference of pain with daily life and depression (between baseline and 6 months, and 6 and 18 months). Improvements in active cognitive coping were associated with improvements in interference of pain in daily life (between baseline and 6 months). Improvements in control and chronicity beliefs were associated with improvements in pain and depression (between 6 and 18 months). CONCLUSION: Improvement in negative emotional cognitions seems to be a key mechanism of change in multidisciplinary treatment of chronic widespread pain. Improvement in active cognitive coping and improvement in control and chronic timeline beliefs may also constitute mechanisms of change, although the evidence is less strong.

Metatarsophalangeal joint pain in psoriatic arthritis: a cross-sectional study.

OBJECTIVE: The aim of this study was to identify independent predictors of pain at the MTP joints in patients with PsA. METHODS: Thirty-four consecutive patients with PsA (mean age 45.3 years, 65% female, mean disease duration 9.9 years) and 22 control participants (mean age 37.9 years, 64% female) underwent clinical and US examination to determine the presence of pain, swelling, synovitis, erosions, effusions and submetatarsal bursae at the MTP joints. Mean barefoot peak plantar pressures were determined at each MTP joint. Levels of pain, US-determined pathology and peak pressures were compared between groups. Binary logistic regression was used to identify demographic, clinical examination-derived, US-derived and plantar pressure predictors of pain at the MTP joints in the PsA group. RESULTS: The presence of pain, deformity, synovitis, erosions (P < 0.001) and submetatarsal bursae and peak plantar pressure at MTP 3 (P < 0.05) were significantly higher in the PsA group. MTP joint pain in PsA was independently predicted by high BMI, female gender and the presence of joint subluxation, synovitis and erosion. CONCLUSION: These results suggest local inflammatory and structural factors, together with systemic factors (gender, BMI), are predominantly responsible for painful MTP joints in PsA, with no clear role for plantar pressure characteristics.

What do we miss? ASAS non-responders on anti-TNF therapy show improvement in performance-based physical function.

OBJECTIVE: A prospective study was conducted in order to establish whether AS patients, who are defined as non-responders after 3 months of anti-TNF therapy, show improvement on performance-based tests of physical functioning. METHODS: At baseline and 3 months after the start of anti-TNF therapy, AS patients completed seven performance-based tests of physical functioning, questionnaires on self-reported physical functioning (BASFI) and disease activity (BASDAI), and a pain and a global patient assessment. The concordance between ≥ 20% intra-individual improvement on the performance-based test of physical functioning and (i) response to anti-TNF therapy [Assessment of SpondyloArthritis International Society 20% (ASAS20) response] and (ii) ≥ 20% intra-individual improvement on self-reported physical functioning (BASFI) was assessed. RESULTS: One hundred AS patients were included, of which 82 patients completed all tests at both time points. After 3 months of anti-TNF therapy, 27 (32.9%) patients were categorized as non-responders according to the ASAS20 response criteria. Improvement in performance-based physical functioning was seen in 13 of the 27 non-responders (48.1%) (i.e. n = 13/82 = 15.9% of the total group). Furthermore, 30 (36.6%) patients showed no improvement on self-reported physical functioning (BASFI). However, 17 of the 30 (56.7%) patients did improve on the performance-based tests of physical functioning (i.e. n = 17/82 = 20.7% of the total group). CONCLUSION: After 3 months of anti-TNF therapy, performance-based tests of physical functioning showed improvement in 48.1% of the ASAS20 non-responders. With these performance-based tests, new information on outcome after anti-TNF therapy can be generated. Using performance-based tests alongside the BASFI could have additional value in the evaluation of outcomes for patients receiving anti-TNF therapy.

Dose-response effects of customised foot orthoses on lower limb kinematics and kinetics in pronated foot type.

Despite the widespread use of customised foot orthoses (FOs) for the pronated foot type there is a lack of reliable information on the dose-response effect on lower limb mechanics. This study investigated these effects in subjects with normal and pronated foot types. Customised FOs were administered to 12 participants with symptomatic pronated foot type and 12 age and gender matched controls. A computer-aided design (CAD) software was used to design nine FOs per participant with dose incrementally changed by varying only the rearfoot post angle. This was done in 2° increments from 6° lateral to 10° medial posting. A 3D printing method was used to manufacture the FOs. Quantification of the dose-response effect was performed using three-dimensional gait analyses for selected rearfoot and knee kinematics and kinetics. Under these experimental conditions, significant and linear effects of posting were seen for the peak (p<0.001) and mean (p<0.001) rearfoot eversions, peak (p=0.003) and mean (p<0.001) ankle eversion moments and peak (p=0.017) and mean (p=0.005) knee adduction moment variables. Group effects were observed for the peak (p=0.007) and mean (p=0.007) forefoot abduction and for the peak (p=0.007) knee adduction moment. A significant interaction between posting and group was seen for internal tibial rotation (p=0.004). These data indicate that a dose-response effect, with a linear trend for both the rearfoot and knee, exists for customised FOs used to treat pronated foot type.

A cluster randomised controlled trial on the efficacy of client-centred occupational therapy in multiple sclerosis: good process, poor outcome.

PURPOSE: To assess the efficacy of client-centred occupational therapy (OT) according to a client-centred process framework, as compared to usual care OT, in patients with multiple sclerosis (MS). METHOD: A multicentre cluster randomised controlled trial with the institution (i.e. hospital or rehabilitation centre) as the unit of randomisation was performed. A total of 269 outpatients with MS, 13 hospitals and rehabilitation centres and 29 occupational therapists participated. Primary outcomes included measures of disability, participation and autonomy. Secondary outcomes included fatigue, generic health-related quality of life, quality and evaluation of therapy, therapy compliance and therapy frequency. Measurements were taken at baseline, four months and at eight months follow-up. RESULTS: Primary outcome measures did not show significant differences between the two interventions. Secondary outcomes revealed significant differences in favour of the usual care OT on fatigue (physical scale and total scale) and health-related quality of life (bodily pain and vitality) at four months. After eight months only significant differences on mental health were found. Process outcomes (i.e. the information scale of therapy quality and the client-centredness of the organisation) were in favour of the client-centred intervention. CONCLUSION: Because the client-centred intervention resulted in no effects on the primary outcomes and small but negative effects on the secondary functional outcomes, we should seriously reconsider the application of client-centred practice. IMPLICATIONS FOR REHABILITATION: An increasing number of interventions claim to incorporate client-centred practice. Client-centred practice is associated with improved satisfaction but the effects on functional health-related outcomes have not been fully evaluated. The findings of this study show that the process outcomes of therapy were in favour of the client-centred intervention, but no effects were found on the primary outcomes and negative effects on the secondary functional health outcomes. It is suggested that the implementation of client-centred practice should be adjusted in order to achieve optimal health outcomes.

Predictors of multidisciplinary treatment outcome in fibromyalgia:a systematic review.

PURPOSE: To identify outcome predictors for multidisciplinary treatment in patients with chronic widespread pain (CWP) or fibromyalgia (FM). METHODS: A systematic literature search in PubMed, PsycINFO, CINAHL, Cochrane Library, EMBASE and Pedro. Selection criteria included: age over 18; diagnosis CWP or FM; multidisciplinary treatment; longitudinal study design; original research report. Outcome domains: pain, physical functioning, emotional functioning, global treatment effect and 'others'. Methodological quality of the selected articles was assessed and a qualitative data synthesis was performed to identify the level of evidence. RESULTS: Fourteen studies (all with FM patients) fulfilled the selection criteria. Six were of high quality. Poorer outcome (pain, moderate evidence; physical functioning and quality of life, weak evidence) was predicted by depression. Similarly, poorer outcome was predicted by the disturbance and pain profile of the Minnesota Multiphasic Personality Inventory (MMPI), strong beliefs in fate and high disability (weak evidence). A better outcome was predicted by a worse baseline status, the dysfunctional and the adaptive copers profile of the Multidimensional Pain Inventory (MPI), and high levels of pain (weak evidence). Some predictors were related to specific multidisciplinary treatment (weak evidence). Inconclusive evidence was found for other demographic and clinical factors, cognitive and emotional factors, symptoms and physical functioning as predictors of outcome. DISCUSSION: It was found that a higher level of depression was a predictor of poor outcome in FM (moderate evidence). In addition, it was found that the baseline status, specific patient profiles, belief in fate, disability, and pain were predictors of the outcome of multidisciplinary treatment. Our results highlight the lack of high quality studies for evaluating predictors of the outcome of multidisciplinary treatment in FM. Further research on predictors of multidisciplinary treatment outcome is needed.

Ambulatory measurement of the knee adduction moment in patients with osteoarthritis of the knee.

High knee joint-loading increases the risk and progression of knee osteoarthritis (OA). Mechanical loading on the knee is reflected in the external knee adduction moment (KAdM) that can be measured during gait with laboratory-based measurement systems. However, clinical application of these systems is limited. Ambulatory movement analysis systems, including instrumented force shoes (IFS) and an inertial and magnetic measurement system (IMMS), could potentially be used to determine the KAdM in a laboratory-free setting. Promising results have been reported concerning the use of the IFS in KAdM measurements; however its application in combination with IMMS has not been studied. The objective of this study was to compare the KAdM measured with an ambulatory movement analysis system with a laboratory-based system in patients with knee OA. Gait analyses of 14 knee OA patients were performed in a gait laboratory. The KAdM was concurrently determined with two the systems: (i) Ambulatory: IFS and IMMS in combination with a linked-segment model (to obtain joint positions); (ii) Laboratory: force plate and optoelectronic marker system. Mean differences in KAdM between the ambulatory and laboratory system were not significant (maximal difference 0.20%BW*H in late stance, i.e. 5.6% of KAdM range, P>0.05) and below clinical relevant and hypothesized differences, showing no systematic differences at group level. Absolute differences were on average 24% of KAdM range, i.e. 0.83%BW*H, particularly in early and late stance. To achieve greater accuracy for clinical use, estimation of joint position via a more advanced calibrated linked-segment model should be investigated.

Biomechanical factors and physical examination findings in osteoarthritis of the knee: associations with tissue abnormalities assessed by conventional radiography and high-resolution 3.0 Tesla magnetic resonance imaging.

INTRODUCTION: We aimed to explore the associations between knee osteoarthritis (OA)-related tissue abnormalities assessed by conventional radiography (CR) and by high-resolution 3.0 Tesla magnetic resonance imaging (MRI), as well as biomechanical factors and findings from physical examination in patients with knee OA. METHODS: This was an explorative cross-sectional study of 105 patients with knee OA. Index knees were imaged using CR and MRI. Multiple features from CR and MRI (cartilage, osteophytes, bone marrow lesions, effusion and synovitis) were related to biomechanical factors (quadriceps and hamstrings muscle strength, proprioceptive accuracy and varus-valgus laxity) and physical examination findings (bony tenderness, crepitus, bony enlargement and palpable warmth), using multivariable regression analyses. RESULTS: Quadriceps weakness was associated with cartilage integrity, effusion, synovitis (all detected by MRI) and CR-detected joint space narrowing. Knee joint laxity was associated with MRI-detected cartilage integrity, CR-detected joint space narrowing and osteophyte formation. Multiple tissue abnormalities including cartilage integrity, osteophytes and effusion, but only those detected by MRI, were found to be associated with physical examination findings such as crepitus. CONCLUSION: We observed clinically relevant findings, including a significant association between quadriceps weakness and both effusion and synovitis, detected by MRI. Inflammation was detected in over one-third of the participants, emphasizing the inflammatory component of OA and a possible important role for anti-inflammatory therapies in knee OA. In general, OA-related tissue abnormalities of the knee, even those detected by MRI, were found to be discordant with biomechanical and physical examination features.

Proprioception, laxity, muscle strength and activity limitations in early symptomatic knee osteoarthritis: results from the CHECK cohort.

OBJECTIVE: To establish whether proprioception and varus-valgus laxity moderate the association between muscle strength and activity limitations in patients with early symptomatic knee osteoarthritis. DESIGN: A cross-sectional study. SUBJECTS: A sample of 151 participants with early symptomatic knee osteoarthritis from the Cohort Hip and Cohort Knee study. METHODS: Regression analyses were performed to establish the associations between muscle strength, proprioception (knee joint motion detection threshold in the anterior--posterior direction), varus-valgus laxity and activity limitations (self-reported and performance-based). Interaction terms were used to establish whether proprioception and laxity moderated the association between muscle strength and activity limitations. RESULTS: Proprioception moderated the association between muscle strength and activity limitations: the negative association between muscle strength and activity limitations was stronger in participants with poor proprioception than in participants with accurate proprioception (performance-based activity limitations p = 0.02; self-reported activity limitations p = 0.08). The interaction between muscle strength and varus-valgus laxity was not significantly associated with activity limitations. CONCLUSION: The results of the present study support the theory that in the absence of adequate proprioceptive input, lower muscle strength affects a patient's level of activities to a greater degree than in the presence of adequate proprioceptive input.

Avoidance of activities in early symptomatic knee osteoarthritis: results from the CHECK cohort.

BACKGROUND: Pain-related avoidance of activities is hypothesized to lead to lower muscle strength and thereby activity limitations. Negative affect (e.g., low vitality, depression) is thought to strengthen the tendency to avoid activities. PURPOSE: The aim of this study was to assess the validity of this "avoidance model" in patients with early symptomatic knee osteoarthritis (OA). METHODS: Cross-sectional data (n=151) were used. The associations between pain, negative affect, avoidance, muscle strength, and activity limitations were modeled using structural equation modeling. RESULTS: Pain and negative affect were associated with lower muscle strength via avoidance (mediation by avoidance). Avoidance was associated with activity limitations via lower muscle strength (mediation by muscle strength). There were also direct associations between pain, negative affect, avoidance, muscle strength, and activity limitations. CONCLUSIONS: The results support the validity of the avoidance model, which explains the associations between pain, negative affect, avoidance, muscle strength, and activity limitations in patients with early symptomatic knee OA.