Characteristics and health outcomes associated with activation for self-management in patients with non-specific low back pain: A cross-sectional study.

BACKGROUND: Research has shown that the course of non-specific low back pain (LBP) is influenced by, among other factors, patients' self-management abilities. Therefore, clinical guidelines recommend stimulation of self-management. Enhancing patients' self-management potentially can improve patients' health outcomes and reduce future healthcare costs for non-specific LBP. OBJECTIVES: Which characteristics and health outcomes are associated with activation for self-management in patients with non-specific LBP? DESIGN: Cross-sectional study. METHOD: Patients with non-specific LBP applying for primary care physiotherapy were asked to participate. Multivariable linear regression analysis was performed to analyze the multivariable relationship between activation for self-management (Patient Activation Measure, range 0-100) and a range of characteristics, e.g., age, gender, and health outcomes, e.g., self-efficacy, pain catastrophizing. RESULTS: The median activation for self-management score of the patients with non-specific LBP (N = 208) was 63.10 (IQR = 19.30) points. The multivariable linear regression analysis revealed that higher self-efficacy scores (B = 0.54), female gender (B = 3.64), and a middle educational level compared with a high educational level (B = -5.47) were associated with better activation for self-management in patients with non-specific LBP. The goodness-of-fit of the model was 17.24% (R2 = 0.17). CONCLUSIONS: Patients with better activation for self-management had better self-efficacy, had a higher educational level, and were more often female. However, given the explained variance better understanding of the factors that influence the complex construct of self-management behaviour in patients who are not doing well might be needed to identify possible barriers to engage in self-management.

The cost-effectiveness of an indicated blended care intervention in primary care compared to usual care in patients with moderate persistent somatic symptoms.

INTRODUCTION: Appropriate treatment for people with an increased risk for developing chronic Persistent Somatic Symptoms (PSS) is of great importance at an early stage to improve quality of life and prevent high costs for society. OBJECTIVE: To evaluate the cost-effectiveness of an integrated blended care intervention compared to usual care for QALYs, subjective symptom impact and physical and mental health status in patients with moderate PSS. METHODS: This economic evaluation was conducted alongside a 12-month prospective, multicenter cluster randomized controlled trial in Dutch primary care. 80 participants received the intervention and 80 participants received usual care. Seemingly unrelated regression analyzes were performed to estimate cost and effect differences. Missing data were imputed using multiple imputation. Bootstrapping techniques were used to estimate uncertainty. RESULTS: We found no significant difference in total societal costs. Intervention, primary and secondary healthcare and absenteeism costs were higher for the intervention group. The ICER for QALYs demonstrated the intervention was on average less costly and less effective compared to usual care. For the subjective symptom impact and physical health, the ICER indicated that the intervention group was on average less costly and more effective. For mental health, the intervention was on average more costly and less effective. CONCLUSION: We didn't find an integrated blended primary care intervention to be cost-effective compared to usual care. However, when looking on relevant, but specific outcome measures (subjective symptom impact and physical health) for this population, average costs are found to be lower and the effectiveness found to be higher.

Determining the optimal gait modification strategy for patients with knee osteoarthritis: Trunk lean or medial thrust?

BACKGROUND: The gait modification strategies Trunk Lean and Medial Thrust have been shown to reduce the external knee adduction moment (EKAM) in patients with knee osteoarthritis which could contribute to reduced progression of the disease. Which strategy is most optimal differs between individuals, but the underlying mechanism that causes this remains unknown. RESEARCH QUESTION: Which gait parameters determine the optimal gait modification strategy for individual patients with knee osteoarthritis? METHODS: Forty-seven participants with symptomatic medial knee osteoarthritis underwent 3-dimensional motion analysis during comfortable gait and with two gait modification strategies: Medial Thrust and Trunk Lean. Kinematic and kinetic variables were calculated. Participants were then categorized into one of the two subgroups, based on the modification strategy that reduced the EKAM the most for them. Multiple logistic regression analysis with backward elimination was used to investigate the predictive nature of dynamic parameters obtained during comfortable walking on the optimal modification gait strategy. RESULTS: For 68.1 % of the participants, Trunk Lean was the optimal strategy in reducing the EKAM. Baseline characteristics, kinematics and kinetics did not differ significantly between subgroups during comfortable walking. Changes to frontal trunk and tibia angles correlated significantly with EKAM reduction during the Trunk Lean and Medial Thrust strategies, respectively. Regression analysis showed that MT is likely optimal when the frontal tibia angle range of motion and peak knee flexion angle in early stance during comfortable walking are high (R2Nagelkerke = 0.12). SIGNIFICANCE: Our regression model based solely on kinematic parameters from comfortable walking contained characteristics of the frontal tibia angle and knee flexion angle. As the model explains only 12.3 % of variance, clinical application does not seem feasible. Direct assessment of kinetics seems to be the most optimal strategy for selecting the most optimal gait modification strategy for individual patients with knee osteoarthritis.

Effectiveness of an intervention to reduce sedentary behaviour as a personalised secondary prevention strategy for patients with coronary artery disease: main outcomes of the SIT LESS randomised clinical trial.

BACKGROUND: A high sedentary time is associated with increased mortality risk. Previous studies indicate that replacement of sedentary time with light- and moderate-to-vigorous physical activity attenuates the risk for adverse outcomes and improves cardiovascular risk factors. Patients with cardiovascular disease are more sedentary compared to the general population, while daily time spent sedentary remains high following contemporary cardiac rehabilitation programmes. This clinical trial investigated the effectiveness of a sedentary behaviour intervention as a personalised secondary prevention strategy (SIT LESS) on changes in sedentary time among patients with coronary artery disease participating in cardiac rehabilitation. METHODS: Patients were randomised to usual care (n = 104) or SIT LESS (n = 108). Both groups received a comprehensive 12-week centre-based cardiac rehabilitation programme with face-to-face consultations and supervised exercise sessions, whereas SIT LESS participants additionally received a 12-week, nurse-delivered, hybrid behaviour change intervention in combination with a pocket-worn activity tracker connected to a smartphone application to continuously monitor sedentary time. Primary outcome was the change in device-based sedentary time between pre- to post-rehabilitation. Changes in sedentary time characteristics (prevalence of prolonged sedentary bouts and proportion of patients with sedentary time ≥ 9.5 h/day); time spent in light-intensity and moderate-to-vigorous physical activity; step count; quality of life; competencies for self-management; and cardiovascular risk score were assessed as secondary outcomes. RESULTS: Patients (77% male) were 63 ± 10 years and primarily diagnosed with myocardial infarction (78%). Sedentary time decreased in SIT LESS (- 1.6 [- 2.1 to - 1.1] hours/day) and controls (- 1.2 [ ─1.7 to - 0.8]), but between group differences did not reach statistical significance (─0.4 [─1.0 to 0.3]) hours/day). The post-rehabilitation proportion of patients with a sedentary time above the upper limit of normal (≥ 9.5 h/day) was significantly lower in SIT LESS versus controls (48% versus 72%, baseline-adjusted odds-ratio 0.4 (0.2-0.8)). No differences were observed in the other predefined secondary outcomes. CONCLUSIONS: Among patients with coronary artery disease participating in cardiac rehabilitation, SIT LESS did not induce significantly greater reductions in sedentary time compared to controls, but delivery was feasible and a reduced odds of a sedentary time ≥ 9.5 h/day was observed. TRIAL REGISTRATION: Netherlands Trial Register: NL9263. Outcomes of the SIT LESS trial: changes in device-based sedentary time from pre-to post-cardiac rehabilitation (control group) and cardiac rehabilitation + SIT LESS (intervention group). SIT LESS reduced the odds of patients having a sedentary time >9.5 hours/day (upper limit of normal), although the absolute decrease in sedentary time did not significantly differ from controls. SIT LESS appears to be feasible, acceptable and potentially beneficial, but a larger cluster randomised trial is warranted to provide a more accurate estimate of its effects on sedentary time and clinical outcomes. CR: cardiac rehabilitation.

Self-management behaviour after a physiotherapist guided blended self-management intervention in patients with chronic low back pain: A qualitative study.

BACKGROUND: Self-management support is considered an important component in the physiotherapeutic treatment of people with chronic low back pain. The stratified blended physiotherapy intervention e-Exercise Low Back Pain is an example of a self-management intervention. More insight may contribute to improving blended interventions to stimulate self-management after treatment and thus hopefully prevent chronicity and/or relapses in patients with chronic low back pain. OBJECTIVES: The aim of this study was to gain an in-depth understanding of the self-management behaviour after a physiotherapist guided blended self-management intervention in people with chronic low back pain. DESIGN: A qualitative study with semi-structured interviews nested within a randomized controlled trial on the (cost-)effectiveness of e-Exercise Low Back Pain was conducted. METHOD: Thematic analysis was used to analyse the transcriptions. A hybrid process of both deductive and inductive approaches was used. RESULTS: After 12 interviews, data saturation was reached. Analysis of the data yielded six themes related to self-management behaviour: illness beliefs, coping, cognitions, social support and resource utilization, physiotherapeutic involvement and motivation. CONCLUSIONS: In our study the majority of the participants seemed to show adequate self-management behaviour when experiencing low back pain. Most participants first try to gain control over their low back pain themselves when experiencing a relapse before contacting the physiotherapist. Participants struggle in continuing health behaviour in pain free periods between relapses of low back pain. Physiotherapists are recommended to encourage long-term behaviour change. Additionally, better facilitation by the physiotherapist or additional functionalities in the app to stimulate social support might have a useful contribution.

Sedentary Behaviour Intervention as a Personalised Secondary Prevention Strategy (SIT LESS) for patients with coronary artery disease participating in cardiac rehabilitation: rationale and design of the SIT LESS randomised clinical trial.

Patients with coronary artery disease (CAD) are more sedentary compared with the general population, but contemporary cardiac rehabilitation (CR) programmes do not specifically target sedentary behaviour (SB). We developed a 12-week, hybrid (centre-based+home-based) Sedentary behaviour IntervenTion as a personaLisEd Secondary prevention Strategy (SIT LESS). The SIT LESS programme is tailored to the needs of patients with CAD, using evidence-based behavioural change methods and an activity tracker connected to an online dashboard to enable self-monitoring and remote coaching. Following the intervention mapping principles, we first identified determinants of SB from literature to adapt theory-based methods and practical applications to target SB and then evaluated the intervention in advisory board meetings with patients and nurse specialists. This resulted in four core components of SIT LESS: (1) patient education, (2) goal setting, (3) motivational interviewing with coping planning, and (4) (tele)monitoring using a pocket-worn activity tracker connected to a smartphone application and providing vibrotactile feedback after prolonged sedentary bouts. We hypothesise that adding SIT LESS to contemporary CR will reduce SB in patients with CAD to a greater extent compared with usual care. Therefore, 212 patients with CAD will be recruited from two Dutch hospitals and randomised to CR (control) or CR+SIT LESS (intervention). Patients will be assessed prior to, immediately after and 3 months after CR. The primary comparison relates to the pre-CR versus post-CR difference in SB (objectively assessed in min/day) between the control and intervention groups. Secondary outcomes include between-group differences in SB characteristics (eg, number of sedentary bouts); change in SB 3 months after CR; changes in light-intensity and moderate-to-vigorous-intensity physical activity; quality of life; and patients' competencies for self-management. Outcomes of the SIT LESS randomised clinical trial will provide novel insight into the effectiveness of a structured, hybrid and personalised behaviour change intervention to attenuate SB in patients with CAD participating in CR. Trial registration number NL9263.

Healthcare professionals' perspectives on a blended care program in primary care; A qualitative study.

Increasingly, healthcare policies have changed focus from cure and care to behaviour and health. Prevention is becoming more important, which requires a change in the role of healthcare professionals. Healthcare professionals' role is changing from being a therapist to taking on the role of a coach. To prevent chronicity in Medically Unexplained Physical Symptoms (MUPS), an integrated blended care program was developed. To apply this new program in daily practice, it is important to gain insight into the usability. From the healthcare professionals' point of view the concept of usability consists of performance, satisfaction and acceptability. In this qualitative study participants were recruited after participating in the PARASOL program. Demographics were collected. Semi-structured interviews were conducted and analysed using thematic analysis. Ten healthcare professionals (six physical therapists and four mental health nurses) were interviewed. Four themes on usability were identified: (1) Who fits in the program, (2) preparation, (3) experience with the program and (4) interprofessional collaboration. This study gathered healthcare professionals' experiences with and attitudes towards integrating healthcare and offering blended care programs. An integrated blended care program offers the possibility to personalize treatment. Findings show attention should be given to the new responsibilities of healthcare professionals, and their role in integrated and blended care. This new approach of delivering healthcare can facilitate interprofessional collaboration. Achieving sustainable change in patients however still requires instruction and support for healthcare professionals implementing behavioural change techniques.

Quality of life in primary care patients with moderate medically unexplained physical symptoms.

PURPOSE: Medically Unexplained Physical Symptoms (MUPS) have a large impact on patient's quality of life. Most studies have been limited to chronic MUPS and thus, little is known about moderate MUPS. Improved knowledge concerning determinants influencing quality of life in moderate MUPS patients can be helpful in managing MUPS. This study is aimed at describing the common characteristics seen in moderate MUPS patients and compare them with characteristics seen in chronic MUPS patients and general population. We also identified determinants of the physical and mental components of quality of life in moderate MUPS patients. METHODS: In a cross-sectional study, moderate MUPS patients (n = 160) were compared with chronic MUPS patients (n = 162) and general population (n = 1742) based on demographic characteristics and patient's quality of life. Multivariable linear regression analyses were performed to identify determinants associated with a patient's quality of life, assessed with the RAND-36. RESULTS: Moderate MUPS patients experienced a better quality of life than chronic MUPS patients, but a worse quality of life as compared to the general population. Determinants associated with the physical and mental components of quality of life explain 49.1% and 62.9% of the variance, respectively. CONCLUSION: Quality of life of patients with MUPS varies with MUPS disease stage. Based on their quality of life scores, moderate MUPS patients would be adequately distinguished from chronic MUPS patients. Half of the variance in the physical component and almost two thirds of the mental component would be explained by a number of MUPS-related symptoms and perceptions.

Identifying subgroups based on self-management skills in primary care patients with moderate medically unexplained physical symptoms.

OBJECTIVE: Medically Unexplained Physical Symptoms (MUPS) are a major burden on both patients and society and frequently develop into chronic MUPS. Self-management interventions may prevent moderate MUPS from becoming chronic. Tailoring interventions to the patient population is strongly recommended. This can be facilitated by identifying subgroups based on self-management skills. This study aimed to identify these subgroups and their clinical profiles in primary care patients with moderate MUPS. METHODS: A cross-sectional study was performed on baseline measurements from a randomized clinical trial (PARASOL-study). To identify subgroups based on self-management skills, a hierarchical cluster analysis was conducted for adults with moderate MUPS from primary health care centers. Self-management skills were measured with the Health education impact Questionnaire. Cluster variables were seven constructs of this questionnaire. Additionally, specific patient profiles were determined by comparing the identified clusters on the clinical variables pain, fatigue and physical functioning. RESULTS: Four subgroups were identified: High-Self-Management Skills (SMS) (n = 29), Medium-SMS (n = 55), Low-SMS (n = 49) and Active & Low Distress-SMS (n = 20). The latter showed a distinctly different pattern on cluster variables, while the other subgroups differed significantly on means of the cluster variables (p < .001). On clinical variables, significant differences between subgroups were mainly found on fatigue and physical functioning. CONCLUSION: This study found four specific subgroups based on self-management skills in moderate MUPS-patients. One subgroup demonstrated a distinctly different pattern on self-management skills. In other subgroups, more similar patterns on self-management skills were found that negatively correlated with pain and fatigue and positively correlated with physical functioning.

Movement behaviour in adults with haemophilia compared to healthy adults.

BACKGROUND: Limited research has been published regarding movement behaviour of adult persons with haemophilia (PWH). It is hypothesized that avoidance of activities and more sedentary behaviour cause poorer physical functioning. AIM: To determine differences in movement behaviour between PWH and healthy adults. METHODS: Movement behaviour was measured with an accelerometer distinguishing between; lying/non-wear, sitting, standing, walking, running and cycling. Time spent on activities was compared between PWH and healthy adults, using absolute time spent on activities and activities as percentage of wear time. RESULTS: One hundred and five PWH (32 mild/moderate with a mean age of 42.8 ± 15.1, severe 42.1 ± 13.6) and 98 healthy adults (mean age 41.9 ± 15.5) showed that adults with severe haemophilia sit and stand more than healthy adults (4.5 [CI 0.6-8.4] and 4.2 [CI 1.8-6.6] h/wk, respectively) and walk and run less (3.4 [CI 1.4-5.3] hours and 33.6 [CI 19.0-41.7] min/wk, respectively). Patients with mild/moderate haemophilia stand more than healthy adults (3.3 [CI 0.1-6.4] h/wk). Differences in sitting between severe haemophilia and healthy adults and differences in standing between mild/moderate haemophilia and healthy adults disappeared when using activities as percentage of wear time. CONCLUSION: Movement behaviour of adults with severe haemophilia differs from healthy adults, mainly due to less walking and less running. No differences were found in other activities and postures or the distribution of movement behaviour over the day. No significant differences were found between adults with mild/moderate haemophilia and healthy adults.

Measuring activities and participation in persons with haemophilia: A systematic review of commonly used instruments.

INTRODUCTION: Monitoring clinical outcome in persons with haemophilia (PWH) is essential in order to provide optimal treatment for individual patients and compare effectiveness of treatment strategies. Experience with measurement of activities and participation in haemophilia is limited and consensus on preferred tools is lacking. AIM: The aim of this study was to give a comprehensive overview of the measurement properties of a selection of commonly used tools developed to assess activities and participation in PWH. METHODS: Electronic databases were searched for articles that reported on reliability, validity or responsiveness of predetermined measurement tools (5 self-reported and 4 performance based measurement tools). Methodological quality of the studies was assessed according to the COSMIN checklist. Best evidence synthesis was used to summarize evidence on the measurement properties. RESULTS: The search resulted in 3453 unique hits. Forty-two articles were included. The self-reported Haemophilia Acitivity List (HAL), Pediatric HAL (PedHAL) and the performance based Functional Independence Score in Haemophilia (FISH) were studied most extensively. Methodological quality of the studies was limited. Measurement error, cross-cultural validity and responsiveness have been insufficiently evaluated. CONCLUSION: Albeit based on limited evidence, the measurement properties of the PedHAL, HAL and FISH are currently considered most satisfactory. Further research needs to focus on measurement error, responsiveness, interpretability and cross-cultural validity of the self-reported tools and validity of performance based tools which are able to assess limitations in sports and leisure activities.

Monitoring joint health in haemophilia: Factors associated with deterioration.

INTRODUCTION: Joint bleeds in patients with haemophilia may result in haemophilic arthropathy. Monitoring joint health is essential for identifying early signs of deterioration and allows timely adjustment of treatment. AIM: The aim was to describe changes in joint health over 5-10 years follow-up and identify factors associated with joint health deterioration in patients with haemophilia. METHODS: A post hoc analysis was performed from previous cohort studies in patients with moderate/severe haemophilia, ≥16 years. Joint health of ankles, knees and elbows was measured with the Haemophilia Joint Health Score (HJHS) from 2006-2008 (T0) to 2011-2016 (T1). Analyses were performed on patient level (ΔHJHS-total) and joint level (ΔHJHS-joint). Deterioration was defined as ΔHJHS-total ≥4 and ΔHJHS-joint ≥2. RESULTS: Sixty-two patients (median age 25, 73% severe haemophilia, median [interquartile range] 0.0 [0.0;2.0] joint bleeds between T0 to T1) were included. After median 8 years, HJHS-total deteriorated in 37% and HJHS-joint in 17%. Ankle joints (31%) showed deterioration more often than elbows (19%) and knees (3%). Deterioration of HJHS-total was only associated with severe haemophilia. Deterioration of HJHS-joint was weakly associated with a lower HJHS at baseline and more self-reported limitations in activities, and strongly with more joint bleeds between T0 and T1 and presence of synovitis. CONCLUSION: In 37% of patients with moderate/severe haemophilia and low joint bleeding rates, joint health deteriorated over 5-10 years. Ankle and elbow joints showed deterioration most frequently. Factors found in this study help to identify which joints need frequent monitoring in patients with haemophilia with access to early prophylaxis.

Lateral trunk lean and medializing the knee as gait strategies for knee osteoarthritis.

OBJECTIVE: To determine (1) if Medial Thrust or Trunk Lean reduces the knee adduction moment (EKAM) the most during gait in patients with medial knee osteoarthritis, (2) if the best overall strategy is the most effective for each patient and (3) if these strategies affect ankle and hip kinetics. DESIGN: Thirty patients with symptomatic medial knee osteoarthritis underwent 3-dimensional gait analysis. Participants received verbal instructions on two gait strategies (Trunk Lean and Medial Thrust) in randomized order after comfortable walking was recorded. The peaks and impulse of the EKAM and strategy-specific kinematic and kinetic variables were calculated for all conditions. RESULTS: Early stance EKAM peak was significantly reduced during Medial Thrust (-29%). During Trunk Lean, early and late stance EKAM peak and EKAM impulse reduced significantly (38%, 21% and -25%, respectively). In 79% of the subjects, the Trunk Lean condition was significantly more effective in reducing EKAM peak than Medial Thrust. Peak ankle dorsi and plantar flexion, knee flexion and hip extension and adduction moments were not significantly increased. CONCLUSIONS: Medial Thrust and Trunk Lean reduced the EKAM during gait in patients with knee osteoarthritis. Individual selection of the most effective gait modification strategy seems vital to optimally reduce dynamic knee loading during gait. No detrimental effects on external ankle and hip moments or knee flexion moments were found for these conditions.

How do patients and professionals differentiate between intra-articular joint bleeds and acute flare-ups of arthropathy in patients with haemophilia?

INTRODUCTION: The overlap in symptoms between joint bleeds and flare-ups of haemophilia arthropathy (HA) creates difficulties in differentiating between the two conditions. Diagnosis of haemarthrosis is currently empirically made based upon clinical presentations. However, no standard diagnostic criteria are available. To offer appropriate treatment, rapid and accurate diagnosis is essential. Additionally, adequate differentiation can decrease health costs significantly. AIM: The aim of this study was to identify signs and symptoms to differentiate between an intra-articular joint bleed and an acute flare-up of HA in patients with haemophilia and make an initial proposal of items to include in a diagnostic criteria set. METHODS: Six focus group interviews with a total of 13 patients and 15 professionals were carried out. The focus groups were structured following the Nominal Group Technique (NGT). RESULTS: The most important signs and symptoms used to differentiate between joint bleeds and HA were (i) course of the symptoms, (ii) cause of the complaints, (iii) joint history, (iv) type of pain and (v) degree of impairments in range of motion. CONCLUSION: This qualitative study provides insight into signs and symptoms that are currently used to differentiate between joint bleeds and flare-ups of HA. Results of this study can be used to develop a valid and standardized clinical diagnostic criteria set to differentiate between these two conditions. Further research is necessary to validate the signs and symptoms found in this study.

Differentiating between signs of intra-articular joint bleeding and chronic arthropathy in haemophilia: a narrative review of the literature.

INTRODUCTION: Elderly patients with haemophilia (PWH) suffer from both haemarthrosis and haemophilic arthropathy (HA). Diagnosis of haemarthrosis in PWH is currently based on clinical presentation. No diagnostic protocols or validated criteria are available to identify haemarthrosis or to differentiate haemarthrosis from HA. AIM: The aim of this study is to identify symptoms and signs that can be used to differentiate haemarthrosis from HA. METHODS: A narrative literature review was performed on symptoms associated with haemarthrosis and symptoms associated with HA. Additionally, literature on the diagnosis of haemarthrosis in patients without haemophilia, imaging techniques and biomarkers was searched. RESULTS: This review shows that there is no consensus about the symptoms associated with haemarthrosis and that there is limited literature about the symptoms associated with HA. Additionally, symptoms associated with haemarthrosis partly overlap with symptoms of HA, particularly those symptoms associated with flare-ups of HA. Due to the overlap in symptoms differentiating between these conditions is complex. Furthermore, differentiating based on imaging techniques or biomarkers causes practical difficulties. CONCLUSION: Despite the overlap in symptoms, differentiating between joint bleeds and flare-ups of HA based on clinical presentation still seems the most convenient and practical solution. Further research is necessary to identify specific symptoms that can be used to differentiate between the two conditions.

The influence of long-term exposure and timing of physical activity on new joint pain and stiffness in mid-age women.

OBJECTIVE: To examine the influence of long-term exposure and timing of physical activity (PA) on new joint pain/stiffness in mid-age women. METHODS: Data were from 5105 participants (born 1946-51) in the Australian Longitudinal Study on Women's Health (ALSWH) who completed survey items on PA (1998, 2001 and 2004) and joint pain/stiffness (2007 and 2010). PA was categorized in five levels at each survey and summed into a cumulative PA score (CPA, range 0-12). Associations were analysed using logistic regression, with separate models for the cumulative model (using CPA), the sensitive periods model (i.e., PA measured at each survey in one regression model) and the critical periods model (i.e., separate regression models for PA at each survey). RESULTS: 951 (18.6%) participants reported new-onset joint pain/stiffness. In the cumulative model, CPA was associated joint pain/stiffness when included as a continuous variable (adjusted odds ratio [OR] = 0.97, 95% confidence interval [CI] = 0.95-0.99), but not when included as a categorical variable. In both the sensitive periods and critical periods models, low to high levels of PA in 2001 and 2004 had stronger inverse associations with joint pain/stiffness than PA levels in 1998. The model fit was better for the sensitive periods than the cumulative or critical periods models. CONCLUSIONS: In mid-age women, PA between the ages 47 and 58 was associated with a lower risk of joint pain/stiffness 9 years later. Associations were stronger for PA in the last 6 years than for earlier PA.

Individual selection of gait retraining strategies is essential to optimally reduce medial knee load during gait.

BACKGROUND: The progression of medial knee osteoarthritis seems closely related to a high external knee adduction moment, which could be reduced through gait retraining. We aimed to determine the retraining strategy that reduces this knee moment most effective during gait, and to determine if the same strategy is the most effective for everyone. METHODS: Thirty-seven healthy participants underwent 3D gait analysis. After normal walking was recorded, participants received verbal instructions on four gait strategies (Trunk Lean, Medial Thrust, Reduced Vertical Acceleration, Toe Out). Knee adduction moment and strategy-specific kinematics were calculated for all conditions. FINDINGS: The overall knee adduction moment peak was reduced by Medial Thrust (-0.08Nm/Bw·Ht) and Trunk Lean (-0.07Nm/Bw·Ht), while impulse was reduced by 0.03Nms/Bw·Ht in both conditions. Toeing out reduced late stance peak and impulse significantly but overall peak was not affected. Reducing vertical acceleration at initial contact did not reduce the overall peak. Strategy-specific kinematics (trunk lean angle, knee adduction angle, first peak of the vertical ground reaction force, foot progression angle) showed that multiple parameters were affected by all conditions. Medial Thrust was the most effective strategy in 43% of the participants, while Trunk Lean reduced external knee adduction moment most in 49%. With similar kinematics, the reduction of the knee adduction moment peak and impulse was significantly different between these groups. INTERPRETATION: Although Trunk Lean and Medial Thrust reduced the external knee adduction moment overall, individual selection of gait retraining strategy seems vital to optimally reduce dynamic knee load during gait.

Avoidance of activity and limitations in activities in patients with osteoarthritis of the hip or knee: a 5 year follow-up study on the mediating role of reduced muscle strength.

OBJECTIVE: To evaluate the mediating role of reduced muscle strength in the relationship between avoidance of activity and limitations in activities in patients with knee or hip osteoarthritis (OA). METHODS: A longitudinal cohort study with 5 years follow-up was conducted. Patients with knee or hip OA (n = 288) were recruited at rehabilitation centers and hospitals. Self-reported and performance based limitations in activities, avoidance of activity and muscle strength were assessed at baseline, 1, 2, 3 and 5 years follow-up. Generalized Estimating Equations (GEE) analyses were used to evaluate mediation. RESULTS: In patients with knee OA, reduced knee extensor muscle strength mediated the relationship between avoidance of activity and limitations in activities. In patients with hip OA reduced hip abductor muscle strength mediates the relationship between avoidance of activity and limitations in activities. CONCLUSION: The results of this longitudinal study support the theory that avoidance of activity leads to deterioration of muscle strength and consequently to more limitations in activities in patients with knee and hip OA.

Measurement properties of patient-specific instruments measuring physical function.

OBJECTIVE: To identify patient-specific self-assessment instruments, which measure physical function in patients with musculoskeletal disorders and to evaluate the descriptive properties and the psychometric qualities of these instruments. STUDY DESIGN AND SETTING: After a systematic search, included instruments were evaluated psychometrically by the checklist "quality criteria for measurement properties of health status instruments." RESULTS: Twenty-three studies were included, referring to 12 instruments. Nine different versions of the Patient-Specific Functional Scale (PSFS) were identified. The practical elaboration of the different versions of the PSFS varied widely. None of the instruments were tested on all psychometric quality criteria of the checklist. The PSFS described by Cleland et al. was most extensively investigated and obtained exclusively positive scores. Overall, construct validity, reliability, and responsiveness were evaluated most frequently. CONCLUSION: The descriptive properties and psychometric quality of patient-specific instruments measuring physical function are only partly investigated. The PSFS was the most investigated instrument: nine different versions have been evaluated psychometrically. The version of Cleland et al. was most extensively investigated, obtained exclusively positive scores following the quality criteria by Terwee et al., and could be recommended for clinical use therefore. Future research will be necessary to confirm the psychometric quality of patient-specific instruments measuring physical function in patients with musculoskeletal disorders.