No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The Relationship Between Daily Physical Activity and Pain in Individuals with Knee Osteoarthritis
Abstract
Objective:
Investigate the association between physical activity and pain severity in individuals with knee osteoarthritis.
Design:
Cross-sectional; systematic review with meta-analyses.
Methods:
Thirty-one participants with knee osteoarthritis underwent assessment of symptoms via self-report questionnaires and quantitative sensory testing. Following testing, physical activity and symptoms were monitored for seven days using accelerometers and logbooks. Cross-correlation analyses were performed on fluctuations in symptoms and physical activity across the week to detect the relative timing of the strongest association between pain and activity. These data were complemented by meta-analyses of studies that examined correlations between pain from knee osteoarthritis and physical activity or fitness.
Results:
Pain severity at baseline correlated with moderate to vigorous physical activity (r2 = 0.161-0.212, P < 0.05), whereby participants who were more physically active had less pain. Conversely, the peak of the cross-correlation analyses was most often positive and lagging, which indicated that pain was increased subsequent to periods of increased activity. These superficially discrepant findings were supported by the results of a meta-analysis of 13 studies and 9,363 participants, which identified significant heterogeneity for associations between physical activity and pain (I2 = 91%). Stronger inverse associations were found between fitness and pain.
Conclusions:
Associations between physical activity and pain in people with knee osteoarthritis are variable and dynamic. These results reflect the beneficial impact of an active lifestyle and accompanying higher fitness. Yet, the side effect of acute periods of physical activity to transiently exacerbate pain may influence the behavior of some people to avoid activity because of pain.
... Osteoarthritis (OA) is a degenerative joint condition associated with pain, functional limitations, and stiffness that impacts physical activity, work participation, mental health, and quality of life [1][2][3][4][5]. Evidence-based guidelines recommend treating OA using non-operative treatments such as education, exercise, and weight management as the first-line approach to managing hip and knee OA symptoms [6]. ...
... The majority of participants (77%) identified that the GLA:D program had a positive impact on their health and well-being, albeit to varying degrees. Three emergent categories illustrated the improved wellness experienced by participants: (1) pain reduction and management, (2) improved mobility, and (3) improved strength. Selected quotes are referenced in this section, with the remaining quotes presented in Table 2. "I thought that I was probably, probably in more discomfort than I was when… I started it. ...
Background
The G ood L ife with osteo A rthritis: D enmark (GLA:D™), an evidence-based education and exercise program designed for conservative management of knee and hip osteoarthritis (OA), has been shown to benefit participants by reducing pain, improving function, and quality of life. Standardized reporting in the GLA:D databases enabled the measurement of self-reported and performance-based outcomes. There is a paucity of qualitative research on the participants’ perceptions of this program, and it is important to understand whether participants’ perceptions of the benefits of the program align with reported quantitative findings.
Methods
We conducted semi-structured telephone interviews with individuals who participated in the GLA:D program from January 2017 to December 2018 in Alberta, Canada. Data were analyzed using an interpretive description approach and thematic analysis to identify emergent themes and sub-themes associated with participants perceived benefits of the GLA:D program. We analyzed the data using NVivo Pro software. Member checking and bracketing were used to ensure the rigour of the analysis.
Results
30 participants were interviewed (70% female, 57% rural, 73% knee OA). Most participants felt the program positively benefited them. Two themes emerged from the analysis: wellness and self-efficacy. Participants felt the program benefited their wellness, particularly with regard to pain relief, and improvements in mobility, strength, and overall well-being. Participants felt the program benefited them by promoting a sense of self-efficacy through improving the confidence to perform exercise and routine activities, as well as awareness, and motivation to manage their OA symptoms. Twenty percent of participants felt no benefits from the program due to experiencing increased pain and feeling their OA was too severe to participate.
Discussion
The GLA:D program was viewed as beneficial to most participants, this study also identified factors (e.g., severe OA, extreme pain) as to why some participants did not experience meaningful improvements. Early intervention with the GLA:D program prior to individuals experiencing severe OA could help increase the number of participants who experience benefits from their participation.
Conclusion
As the GLA:D program expands across jurisdictions, providers of the program may consider recruitment earlier in disease progression and targeting those with mild and moderate OA.
... [2] Anterior knee pain is not usually caused by a physical abnormality in the knee, but by overuse. [3] Another cause is a training routine that does not include adequate stretching or strengthening exercises. [4] There are two major factors that commonly contribute to anterior knee pain: (i) biomechanical factors, including the way of running and due to lack of strength or anatomical factors (ii) running overload, which is caused by running too frequently or increasing volume of running too quickly, or both. ...
... There was a positive correlation found between IPAQ and NPRS in professional players. A similar study was done by Burrows et al., in 2020, [3] a systematic review with meta-analyses study to investigate the association between physical activity and pain severity in individuals with knee osteoarthritis; there is the strongest association between pain and activity. They examined correlations between pain from knee osteoarthritis and physical activity or fitness. ...
BACKGROUND: Anterior knee pain is one of the most common musculoskeletal complaints seen in the Indian population with high prevalence among those who are active in professional sports and recreational sports. It commonly occurs in many healthy young athletes, especially girls. The aim of the study is to compare the anterior knee pain in recreational and professional athletes. METHODS: This study is done to find the correlation between physical activity and anterior knee pain in recreational and professional athletes, using the Kujala Anterior Knee Pain Scale, Numeric pain rating scale (NPRS), Victorian Institute of Sports Assessment Scale(VISA) for measurement of pain, and International Physical Activity Questionnaire (IPAQ) for measurement of physical activity. A total of 112 recreational and professional athletes participated in the study. Both online and offline mode was used in data collection. RESULTS: There was a correlation between physical activity and anterior knee pain. CONCLUSION: We found a significant negative correlation between IPAQ and Kujala Scores in recreational and professional athletes. A positive correlation between IPAQ and VISA in recreational players and IPAQ and NPRS in professional athletes was found.
... [2] Anterior knee pain is not usually caused by a physical abnormality in the knee, but by overuse. [3] Another cause is a training routine that does not include adequate stretching or strengthening exercises. [4] There are two major factors that commonly contribute to anterior knee pain: (i) biomechanical factors, including the way of running and due to lack of strength or anatomical factors (ii) running overload, which is caused by running too frequently or increasing volume of running too quickly, or both. ...
... There was a positive correlation found between IPAQ [3] a systematic review with meta-analyses study to investigate the association between physical activity and pain severity in individuals with knee osteoarthritis; there is the strongest association between pain and activity. They examined correlations between pain from knee osteoarthritis and physical activity or fitness. ...
BACKGROUND: Anterior knee pain is one of the most common musculoskeletal complaints seen in the Indian population with high prevalence among those who are active in professional sports and recreational sports. It commonly occurs in many healthy young athletes, especially girls. The aim of the study is to compare the anterior knee pain in recreational and professional athletes.
METHODS: This study is done to find the correlation between physical activity and anterior knee pain in recreational and professional athletes, using the Kujala Anterior Knee Pain Scale, Numeric pain rating scale (NPRS), Victorian Institute of Sports Assessment Scale (VISA) for measurement of pain, and International Physical Activity Questionnaire (IPAQ) for measurement of physical activity. A total of 112 recreational and professional athletes participated in the study. Both online and offline mode was used in data collection.
RESULTS: There was a correlation between physical activity and anterior knee pain.
CONCLUSION: We found a significant negative correlation between IPAQ and Kujala Scores in recreational and professional athletes. A positive correlation between IPAQ and VISA in recreational players and IPAQ and NPRS in professional athletes was found.
... The relationship between activity level and OA-related pain is complex. Burrows et al. [2] demonstrated that physical activity exerts both short-term and long-term effects on pain. In the short term, sudden increases in activity intensity can temporarily worsen pain, whereas sustained physical activity over time is linked to reduced pain, underscoring its potential benefits in OA symptom management. ...
Accurate physical activity level (PAL) classification could be beneficial for osteoarthritis (OA) management. This study examines the impact of sensor placement and deep learning models on AL classification using the Metabolic Equivalent of Task values. The results show that the addition of anankle sensor (WA) significantly improves the classification of intensity activities compared to wrist-only configuration(53% to 86.2%). The CNN-LSTM model achieves the highest accuracy (95.09%). Statistical analysis confirms multi-sensor setups outperform single-sensor configurations (p < 0.05). The WA configuration offers a balance between usability and accuracy, making it a cost-effective solution for AL monitoring, particularly in OA management.
... Another potential mediator of the effect of pain on functional status is physical activity in individuals with arthritis, as pain has been shown to predict physical activity levels 41 , which in turn have been shown to improve physical functioning 42 . While this indirect effect through physical activity has recently been examined in individuals with back pain 43,44 , this mediating effect has not been examined in individuals with arthritis. ...
Objective. Arthritis is a chronic condition affecting hundreds of millions of people worldwide, often leading to pain and functional limitations. This study aimed to investigate the direct and indirect effects of pain on functional independence in individuals with arthritis. Depressive symptoms and physical activity were examined as potential mediators of this relationship.
Methods. A total of 6972 participants with arthritis (4930 with osteoarthritis and 694 with rheumatoid arthritis) were included from the Canadian Longitudinal Study on Aging. Multiple linear regression models, generalized linear models, and bootstrapping were used to assess the relationships between baseline pain, depressive symptoms, physical activity, and functional status at follow-up.
Results. Baseline pain was positively associated with depressive symptoms (b = 0.356 [95% CI: 0.310 to 0.402]) and negatively associated with physical activity (b = -0.083 [95% CI: -0.125 to -0.042]). Functional status at follow-up was significantly predicted by baseline pain (OR = 1.834 [95% CI: 1.306 to 2.610]), depressive symptoms (OR = 1.431 [95% CI: 1.205 to 1.709]), and physical activity (OR = 0.550 [95% CI: 0.440 to 0.683]). Mediation analysis showed that 30.4% of the effect of pain on functional status was mediated by the total indirect effect, with contributions from depressive symptoms (19.8%), physical activity (8.9%), and the serial mediation pathway (1.7%).
Conclusions. Pain at baseline was associated with a higher likelihood of functional dependence in basic and instrumental activities of daily living after a mean follow-up period of 6.3 years, with depressive symptoms and lower physical activity acting as partial mediators. These findings highlight the importance of managing pain, mental health, and physical activity in patients with arthritis to maintain functional independence.
Impact. These findings support the importance for intervention to target both mental health and exercise to mitigate functional decline resulting from the long-term effects of pain in patients with arthritis.
... Pain usually occurs after activity or long periods of inactivity and usually persists throughout the day. 2,3 Knee OA is the erosion of the cartilage tissue in the knee joint. Knee OA is more common, especially after a certain age. ...
Osteoarthritis (OA) means that the slippery cartilage tissue that covers the bone surfaces in the joints and allows the joint to move easily loses its properties and wears out. Knee OA is the wear and tear of the cartilage in the knee joint. Knee OA is a disease whose incidence increases especially after a certain age. Knee OA is difficult and costly to be detected by specialists using traditional methods and may lead to misdiagnosis. In this study, computer‐aided systems were used to prevent errors in traditional methods of detecting knee OA, shorten the diagnosis time, and accelerate the treatment process. In this study, a hybrid model was developed by using Darknet53, Histogram of Directional Gradients (HOG), Local Binary Model (LBP) methods for feature extraction, and Neighborhood Component Analysis (NCA) for feature selection. Our dataset used in experiments contains 1650 knee joint images and consists of five classes: Normal, Doubtful, Mild, Moderate, and Severe. In the experimental studies performed, the performance of the proposed method was compared with eight different Convolutional Neural Networks (CNN) Models. The developed model achieved better performance metrics than the eight different models used in the study and similar studies in the literature. The accuracy value of the developed model is 83.6%.
... However, the relationship between the frequency of physical activity in daily life and the functional capacity of older adults in the community, especially those experiencing chronic pain, remains underexplored (6). Furthermore, the link between the daily volume of physical activity and the level of discomfort experienced due to knee OA is still not fully understood (7), underscoring the importance of this area of research especially in the absence of pharmaceutical interventions that can halt the progression of the disease and the associated increased risk of premature mortality (8). The variability in physical activity levels among individuals and within an individual over their lifespan (9) calls for a deeper investigation into knee pain and its risk factors, particularly in the middle-aged and older populations (10). ...
Background: Knee osteoarthritis (OA) is a leading cause of disability among older adults, significantly affecting their quality of life and mobility. The relationship between physical activity and the severity of knee OA symptoms has been a subject of extensive research, with mixed results on whether physical activity exacerbates or alleviates OA symptoms. Objective: This study aimed to investigate the association between physical activity levels and the severity of knee osteoarthritis, as well as to assess the impact of physical activity on the health-related quality of life among individuals with knee OA. Methods: A cross-sectional study was conducted among 171 patients diagnosed with knee osteoarthritis at four medical institutions. Data on demographics, physical activity levels, and OA severity were collected through standardized questionnaires, including the SF-36 Health Survey and the Knee injury and Osteoarthritis Outcome Score (KOOS). Physical activity levels were categorized as poor, moderate, and good. The severity of knee OA was classified as no OA, moderate OA, and extreme OA. Statistical analysis was performed using SPSS version 25, employing descriptive statistics, chi-square tests for categorical variables, and Pearson's correlation to assess the association between physical activity levels and OA severity. Results: The study population comprised 35.1% males and 64.9% females, with a mean age of 71.1±3.9 years. Regarding physical activity, 30.4% engaged in poor, 46.8% in moderate, and 22.8% in good physical activity. The severity of knee OA was reported as extreme in 25.1% of patients, moderate in 49.1%, and absent in 25.7%. Statistical analysis revealed a significant association between physical activity levels and knee OA severity (Pearson Chi-Square = .000), indicating that higher levels of physical activity were associated with lower severity of OA symptoms. Conclusion: This study supports the notion that engaging in physical activity is associated with a reduced severity of knee osteoarthritis symptoms and suggests that physical activity could be beneficial for managing OA symptoms and improving the quality of life among individuals with knee OA. These findings highlight the importance of promoting physical activity as a key component of knee OA management strategies.
... The relationship between exercise and arthritis has attracted considerable interest [5][6][7][8][9]. On one hand, exercise, as a non-pharmacological intervention, is widely acknowledged as a bene cial and effective treatment for arthritis [10]. ...
Background
The association between physical activities and arthritis has gained considerable attention. However, current research on the correlation between different types of physical activity and arthritis in middle-aged and elderly individuals remains relatively limited. Gaining a deeper understanding of the impact of exercise behavior on arthritis in this population holds significant importance in comprehending joint health and disease management. This study aims to investigate the relationship between various types of physical activity and arthritis in middle-aged and elderly individuals in China.
Methods
This cross-sectional study utilized the first wave data from the China Health and Retirement Longitudinal Study (CHARLS), where participants were categorized into either arthritis or non-arthritis groups. Meanwhile, based on the survey questionnaire, physical activity levels were classified into three categories of light, moderate, and vigorous. A logistic regression model was employed to evaluate the association between exercise and arthritis, with odds ratios (OR) reported to indicate the degree of correlation between the two factors.
Results
The cross-sectional analysis included a total of 5334 participants, among whom the overall prevalence of arthritis was 35.0%. After adjusting for all potential risk factors, there was an independent association between types of physical activity and arthritis (vigorous compared to light or moderate activity: OR = 1.473, 95%CI 1.276–1.701, p < 0.001; moderate compared to light activity: OR = 1.182, 95%CI 1.015–1.377, p = 0.032). In subgroup analysis, the association of types of physical activities with arthritis was also significant in participants over 55 years of age, male, BMI ≥ 24, as well as in individuals with hyperlipidemia or hypertension (p < 0.05). However, no significant associations were found in individuals with diabetes or hyperglycemia, gastrointestinal or digestive system disorders, BMI < 24, aged 45–55, or in the female population (p > 0.05).
Conclusion
Exercise intensity is an independent risk factor for arthritis in middle-aged and elderly Chinese individuals. The relationship between exercise and arthritis may be influenced by factors such as gender, age, BMI, and the presence of chronic diseases.
... The study by Nicholas Burrows and his co-authors [34] reported meta-analyses of studies that examined correlations between pain from knee osteoarthritis and physical activity or fitness. The effect sizes from the evaluated original studies were converted to standardized regression coefficients in order to be included on the forest plots and to estimate the pooled standardized coefficient. ...
The lack of consistent presentation of results in published studies on the association between a quantitative explanatory variable and a quantitative dependent variable has been a long-term issue in evaluating the reported findings. Studies are analyzed and reported in a variety of ways. The main purpose of this review is to illustrate the procedures in summarizing and synthesizing research results from multivariate models with a quantitative outcome variable. The review summarizes the application of the standardized regression coefficient as an effect size index in the context of meta-analysis and describe how it can be estimated and converted from data presented in original research articles. An example of synthesis is provided using research articles on the association between childhood body mass index and carotid intima-media thickness in adult life. Finally, the paper shares practical recommendations for meta-analysts wanting to use the standardized regression coefficient in pooling findings.
OBJECTIVE: To evaluate whether a remotely-delivered physical therapy exercise and education intervention with daily step goals increased moderate-to-vigorous intensity physical activity (MVPA) compared to a control.
DESIGN: Assessor-blinded superiority randomized controlled trial with two parallel arms.
METHODS: We included adults from the United States who met the National Institute for Health and Care Excellence osteoarthritis (OA) criteria. Participants were randomized to the intervention of five 45- to 60-minute video conferencing consultations with a physical therapist for strengthening exercises, step goals, and education over 12 weeks or a control of OA web-based resources. The primary outcome was change in MVPA over 12 weeks (measured with ActiGraph GT3X). The secondary and exploratory outcomes were changes in light intensity physical activity, steps/day, treatment beliefs, pain, function in ADL and sports and recreation, and quality of life over 12 and 24 weeks.
RESULTS: Of 103 participants who were randomized, 88 had monitor data at baseline and 67 (76% of 88) had monitor data at 12 weeks. There were no between-group differences in MVPA change over 12 weeks (between group difference -1.8 min/day 95% CI [-7.0, 3.3]), change in light intensity physical activity, or steps/day. Pain and function improved more with the intervention group compared to the control. A greater number of intervention participants (n = 44) reported non-serious adverse events than the control group (n = 10).
CONCLUSION: Incorporating daily step goals into a telehealth strength exercise and education program for people with knee OA did not increase MVPA.
Background
In addition to physical factors, psychological factors such as self-efficacy (SE) reportedly affect physical activity (PA) levels in individuals with knee osteoarthritis (OA). However, the relationship between PA and SE for walking tasks in patients with knee OA remains unclear. The present study aimed to investigate the direct and indirect pathways of SE for walking tasks and the influence of previously reported factors on PA level in individuals with knee OA.
Methods
A cross-sectional design was employed. Eighty-five individuals with knee OA were enrolled. The daily step count (Steps) was considered an objective level of PA. The SE for the walking task was assessed using a modified Gait Efficacy Scale (mGES). Data on gait speed (GS), the visual analog scale (VAS) score for knee pain, Kellgren–Lawrence (K–L) grade of radiographic severity of knee OA, age, and body mass index were collected. Path analysis was performed to investigate the direct and indirect effects of these variables on Steps.
Results
After exclusion, 70 participants were included. The alternative model, which included Steps, mGES, GS, VAS, K–L grade, and age, showed a good fit. mGES and age had a direct effect on Steps (standardized path coefficients: 0.337 and −0.542, respectively), while the other variables had indirect effects.
Conclusions
The SE for walking tasks was directly associated with Steps representative of the PA level. This finding suggests that SE for the walking task may be important in improving PA levels in individuals with knee OA.
Objective
People with osteoarthritis are likely to be physically inactive and current socio-cognitive approaches to changing physical activity in this patient population are generally ineffective. We assessed prospective associations between physical activity and the automatic processes of habit automaticity, automatic evaluations, and automatic self-schema in people with knee osteoarthritis.
Design
One-week prospective.
Method
253 adults (aged 46–82 years, 72% female, 28% male) with knee osteoarthritis self-reported their physical activity behaviour of the past week, habit automaticity for physical activity and completed two implicit association tests to assess automatic evaluations of physical activity (relative to sedentary behaviour) and automatic self-schema for physical activity. One week later, participants self-reported physical activity and pain while walking over the prior week. Linear regression models assessed associations of each automatic process with subsequent physical activity and the moderation effect of pain and each automatic process on subsequent physical activity, controlling for covariates.
Results
We did not find evidence of a statistical relationship between physical activity with automatic evaluations, automatic self-schema, or habit automaticity. The inclusion of pain while walking did not moderate the relationship between any automatic process and physical activity.
Conclusion
Although previous research on healthy, young adults suggests that automatic processes affect physical activity behaviour, we did not find evidence to confirm whether a similar relationship exists for older adults with knee osteoarthritis. Replication and extension work testing these research questions is needed to ensure the findings are not a result of measurement and design features of the study.
With the growing number of people affected by osteoarthritis, wearable technology may enable the provision of care outside a traditional clinical setting and thus transform how healthcare is delivered for this patient group. Here, we mapped the available empirical evidence on the utilization of wearable technology in a real-world setting in people with knee osteoarthritis. From an analysis of 68 studies, we found that the use of accelerometers for physical activity assessment is the most prevalent mode of use of wearable technology in this population. We identify low technical complexity and cost, ability to connect with a healthcare professional, and consistency in the analysis of the data as the most critical facilitators for the feasibility of using wearable technology in a real-world setting. To fully realize the clinical potential of wearable technology for people with knee osteoarthritis, this review highlights the need for more research employing wearables for information sharing and treatment, increased inter-study consistency through standardization and improved reporting, and increased representation of vulnerable populations.
Background:
Physical activity (PA) is important for healthy ageing. Nonetheless, recommended PA guidelines from the World Health Organization are not met by many older adults. To increase PA, influencing factors have been investigated. But it is still unknown how the onset or disappearance of pain within an individual is associated with different PA intensities in older men and women.
Method:
We used longitudinal data from the nationwide representative German Ageing Survey, waves 2014 and 2017 (analytical sample, n = 6194, 45% women). PA was assessed with questions on low, moderate, and vigorous PA per week and converted into metabolic equivalent of task (MET) values. Pain was dichotomized from a 5-point scale into no pain versus some pain. The association between the onset or disappearance of pain from 2014 to 2017 on total, vigorous, moderate, and low PA was investigated using sex stratified asymmetric fixed effects models.
Results:
The onset of pain in older men (ß = 977.84, P = 0.041), and the disappearance of pain in older women (ß = 1531.69, P = 0.025), were associated with increased total PA. The results for men were driven by increases in vigorous (ß = 592.62, P = 0.035) PA, while the change in women was driven by low (ß = 242.16, P = 0.020) and moderate (ß = 496.48, P = 0.034) PA intensities. However, the observed differences between men and women were not statistically significant.
Conclusion:
The divergent associations between the onset and disappearance of pain and PA, driven by different PA intensities in men and women, suggest the existence of factors such as PA intensity influencing the association.
Background:
This study examined patterns of physical activity and associations with pain, function, fatigue, and sleep disturbance among individuals with knee or hip osteoarthritis.
Methods:
Participants (n = 54) were enrolled in a telephone-based physical activity coaching intervention trial; all data were collected at baseline. Self-reported measures of pain and function (WOMAC [Western Ontario and McMaster Universities Osteoarthritis Index] subscales), fatigue (10-point numeric rating scale), and PROMIS (Patient-Reported Outcomes Information System) Sleep Disturbance were collected via telephone. Accelerometers were mailed to participants and were worn for at least 3 days. Proportion of time participants spent in sedentary behavior during the morning (from wake until 12:00 PM), afternoon (12:00 PM until 5:59 PM) and evening (6:00 PM until sleep) each day was averaged across all days of wear. Pearson correlations assessed associations between activity and self-reported measures.
Results:
Participants spent a large proportion of time in sedentary behavior: 65.6% of mornings, 70.0% of afternoons, and 76.6% of evenings. Associations between proportion of time spent in sedentary behavior and reported outcomes were generally strongest in the afternoon, strongest for WOMAC function, and lowest for PROMIS Sleep Disturbance. In the evening hours, sedentary time was most strongly associated with fatigue.
Conclusions:
Overall, findings stress the importance of reducing sedentary behavior among adults with osteoarthritis and suggest behavioral interventions may be strengthened by considering patients' within-day variation in symptoms and activity.
Aim
To identify the association between hours of being barefoot/wearing footwear, physical activity (PA) and knee osteoarthritis pain flares (KOAF).
Methods
Persons with a diagnosis of knee osteoarthritis, who reported previous KOAF, were followed up in a 3 months long telephone‐based case‐crossover study. Exposures to risk factors were assessed every 10 days and whenever the participants experienced a KOAF. Conditional logistic regression examined associations of KOAF with following: hours of being barefoot/using footwear and PA performed (P < .05).
Results
There were 260 persons recruited, of whom 183 continued longitudinal follow up. Of them, 120 persons had at least one valid KOAF and control period. Participants were female (90%) with mean (SD) age and body mass index of 59.9 (7.0) years, 28.0 (5.0) kg/m² respectively. Participants were barefoot for a mean duration of 12.7 hours (SD 4.6) and used footwear for 5.1 (SD 4.7) hours daily; 99% wore heel heights <2.5 cm. Duration of being barefoot, 1 and 2 days before, demonstrated reduced multivariate odds of KOAF (odds ratio [OR] = 0.85; 95% CI 0.80‐0.90). Moderate PA performed 1, 2 days prior was associated with a significantly increased risk of KOAF (multivariate OR 4.29; 2.52‐7.30 and OR 3.36; 2.01‐5.61). Similarly, hours of using footwear 1 and 2 days before flare demonstrated increased odds of KOAF (OR 1.15; 1.07‐1.23 and 1.10; 1.03‐1.18).
Conclusions
Increased duration of being barefoot 1 to 2 days before is associated with reduced risk of KOAF. Performing moderate PA 1 to 2 days before was associated with an increased risk of KOAF.
Background:
Meniscus injury and meniscectomy both entail increased risk of knee osteoarthritis (OA). Thigh muscle weakness is a suggested mediator of OA but there is little evidence of its importance for knee OA development after meniscectomy. This study aimed to examine the association between thigh muscle strength after partial meniscectomy in middle-aged subjects with a non-traumatic meniscal tear and later radiographic knee OA changes.
Methods:
Thirty-four out of 45 participants in an exercise-trial underwent testing for isokinetic thigh muscle strength 4 years after arthroscopic partial meniscectomy and had radiographic examination 11 years later (15 years post-surgery, mean age at follow-up of 57 years (range 50-61)). Outcomes were grade of joint space narrowing and osteophyte score in the medial tibiofemoral compartment of the operated knee and the contralateral knee. We tested the association between muscle strength at baseline and the radiographic outcomes at follow-up using logistic regression analyses adjusted for sex and overweight.
Results:
At follow-up, 33/34 subjects had joint space narrowing and 27/34 subjects had osteophytes in the operated knee, in the contralateral knee joint space narrowing was found in 23 subjects. In the operated knee baseline knee extensor and flexor strength were negatively associated with grade of joint space narrowing at follow-up (OR 0.972 and 0.956, p = 0.028 and 0.026, respectively) and also with osteophyte score (OR 0.968 and 0.931, p = 0.017 and 0.011, respectively). In the contralateral knee longitudinal associations between strength and radiographic OA features were similar, OR 0.949-0.972, p < 0.05.
Conclusion:
The finding that stronger thigh muscles 4 years after meniscectomy were associated with less severe osteoarthritic changes in the medial tibiofemoral compartment of both the operated and contralateral knee 11 years later, may suggest that strong thigh muscles can help to preserve joint integrity in middle-aged subjects at risk of knee OA.
Objective:
The aim of this study was to examine the relationship of psychosocial factors, namely, pain catastrophizing, kinesiophobia, and maladaptive coping strategies, with muscle strength, pain, and physical performance in patients with knee osteoarthritis (OA)-related symptoms.
Methods:
A total of 109 women (64 with knee OA-related symptoms) with a mean age of 65.4 years (49-81 years) were recruited for this study. Psychosocial factors were quantified by the Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and Pain Coping Inventory. Clinical features were assessed using isometric and isokinetic knee muscle strength measurements, visual analog scale, Western Ontario and McMaster Universities Osteoarthritis Index, and functional tests. Associations were examined using correlation and regression analysis.
Results:
In knee OA patients, pain catastrophizing, kinesiophobia, and coping strategy explained a significant proportion of the variability in isometric knee extension and flexion strength (6.3%-9.2%), accounting for more overall variability than some demographic and medical status variables combined. Psychosocial factors were not significant independent predictors of isokinetic strength, knee pain, or physical performance.
Conclusions:
In understanding clinical features related to knee OA, such as muscle weakness, pain catastrophizing, kinesiophobia, and coping strategy might offer something additional beyond what might be explained by traditional factors, underscoring the importance of a biopsychosocial approach in knee OA management. Further research on individual patient characteristics that mediate the effects of psychosocial factors is, however, required in order to create opportunities for more targeted, personalized treatment for knee OA.
Objective
To identify predictors of pain and disability in knee osteoarthritis.
Design
A one-year prospective analysis of determinants of pain and functioning in knee osteoarthritis.
Study setting
Primary care providers in a medium-sized city.
Patients
A total of 111 patients aged from 35 to 75 with clinical symptoms and radiographic grading (Kellgren-Lawrence 2–4) of knee osteoarthritis who participated in a randomized controlled trial.
Main measures
The outcome measures were self-reported pain and function, which were recorded at 0, 3 and 12 months. Disease-specific pain and functioning were assessed using the pain and function subscales of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. Generic physical and mental functioning were assessed using the RAND-36 subscales for function, and physical and mental component summary scores. Possible baseline predictors for these outcomes were 1) demographic, socioeconomic and disease-related variables, and 2) psychological measures of resources, distress, fear of movement and catastrophizing.
Results
Multivariate linear mixed model analyses revealed that normal mood at baseline measured with the Beck Anxiety Inventory predicted significantly better results in all measures of pain (WOMAC P=0.02) and function (WOMAC P=0.002, RAND-36 P=0.002) during the one-year follow-up. Psychological resource factors (pain self-efficacy P=0.012, satisfaction with life P=0.002) predicted better function (RAND-36). Pain catastrophizing predicted higher WOMAC pain levels (P=0.013), whereas fear of movement (kinesiophobia) predicted poorer functioning (WOMAC P=0.046, RAND-36 P=0.024).
Conclusions
Multiple psychological factors in people with knee osteoarthritis pain are associated with the development of disability and longer term worse pain.
Introduction:
Recent public health objectives emphasize the importance of exercise for reducing disability among people with arthritis. Despite the documented benefits of exercise, people with arthritis are less active than those without arthritis. The purpose of this study was to examine the factors that influence exercise participation among insufficiently active individuals with arthritis and to compare these factors with those identified by nonexercisers and regular exercisers with arthritis.
Methods:
Forty-six individuals with arthritis were recruited from various community-based organizations to participate in seven focus groups segmented by exercise status and education. Trained moderators led each discussion using a standard guide. All focus group discussions were transcribed verbatim and coded.
Results:
Pain was the most commonly mentioned barrier to exercise and limited exercise participation for nonexercisers and insufficiently active individuals. Paradoxically, insufficiently active individuals also identified exercise-related reductions in pain as a potential motivation for increasing exercise. Likewise, exercise-related reductions in pain were a motivation to continue exercising for the exerciser groups. Nonexercisers expressed that a reduction in pain was a possible outcome of exercise but were skeptical of its occurrence. Receiving tailored advice from a health care provider was consistently identified as an exercise enabler across the groups.
Conclusion:
Findings from this study indicate that potential strategies for increasing exercise participation include incorporating pain management strategies and coping skills into exercise interventions and ensuring that health care providers provide specific exercise advice to their patients with arthritis.
Objective:
In healthy individuals and people with chronic pain, an inverse association between physical activity level and pain has been reported. Associations between objectively measured fitness and pain have also been found in people with chronic pain, but it is not clear whether the same relations are apparent in healthy individuals. The purpose of the present study was to examine the relation between aerobic capacity and pain in healthy individuals.
Methods:
Pressure pain threshold, ischemic pain tolerance, and pain ratings during ischemia were assessed and analyzed in relation to aerobic capacity in 35 healthy individuals. Correlation and multiple linear regression were used to analyze the data. Data from previous similar studies in healthy individuals and people with fibromyalgia were extracted and collated by literature review to support interpretation of the experimental data.
Results:
No relation was found between aerobic capacity and any measure of pain, with the exception of a moderate inverse association between aerobic capacity and lower body pressure pain threshold in males (r = -0.58, P = 0.03) when data from male and female participants were analyzed separately. The limited association between aerobic capacity and quantitative sensory testing of pain was consistent with the data synthesis from previous studies of healthy individuals but differed from studies of people with fibromyalgia.
Conclusions:
Aerobic capacity is unrelated to pain in healthy young adults. For people with chronic pain, the negative relation between aerobic capacity and pain presumably arises from the underlying pathophysiology and/or associated behaviors of the disease process.
Purpose:
Sedentariness has been proposed as an independent risk factor for poor health. However, few studies have considered associations of sedentary time (ST) with physical functional health independent of time spent in moderate-to-vigorous physical activity (MVPA).
Methods:
Community-based men and women (n = 8623, 48-92 yr old) in the European Prospective Investigation of Cancer-Norfolk study attended a health examination for objective measurement of physical capability, including grip strength (Smedley dynamometer (kg)), usual walking speed (UWS (cm·s)), and timed chair stand speed (TCSS (stands per minute)). Of these, 4051 participants wore an accelerometer (GT1M ActiGraph) for 7 d to estimate time spent in MVPA (MVPA, ≥1952 counts per minute) and ST (ST, <100 counts per minute). Relations between physical capability outcomes and both MVPA and ST were explored using linear regression. The mutual independence of associations was also tested, and ST-MVPA interactions were explored using fractional polynomial models to account for nonlinear associations.
Results:
Men in the highest compared with those in the lowest sex-specific quartile of MVPA were stronger (1.84 kg; 95% confidence interval (CI), 0.79-2.89), had faster UWS (11.7 cm·s; 95% CI, 8.4-15.1) and faster TCSS (2.35 stands per minute; 95% CI, 1.11-3.59) after multivariable adjustment. Similarly, women in the highest quartile of MVPA were stronger (2.47 kg; 95% CI, 1.79-3.14) and had faster UWS (15.5 cm·s; 95% CI, 12.4-18.6) and faster TCSS (3.27 stands per minute; 95% CI, 2.19-4.25). Associations persisted after further adjustment for ST. Associations between higher ST and lower physical capability were also observed, but these were attenuated after accounting for MVPA. Furthermore, no MVPA-ST interactions were observed (Pinteractions > 0.05).
Conclusions:
More time spent in MVPA was associated with higher physical capability, but there were no independent ST associations.
With no cure or effective treatments for osteoarthritis (OA), the need to identify modifiable factors to decrease pain and increase physical function is well recognized.
OBJECTIVE: To examine factors that characterize OA patients at different levels of pain, and to investigate the relationships among these factors and pain.
METHODS: Details of OA characteristics and lifestyle factors were collected from interviews with healthy adults with knee OA (n=197). The Western Ontario and McMaster Universities Osteoarthritis Index was used to assess pain. Factors were summarized across three pain score categories, and χ
2
and Kruskal-Wallis tests were used to examine differences. Multiple linear regression analysis using a stepwise selection procedure was used to examine associations between lifestyle factors and pain.
RESULTS: Multiple linear regression analysis indicated that pain was significantly higher with the use of OA medications and higher body mass index category, and significantly lower with the use of supplements and meeting physical activity guidelines (≥150 min/week). Stiffness and physical function scores, bilateral knee OA, body mass index category and OA medication use were significantly higher with increasing pain, whereas self-reported health, servings of fruit, supplement use and meeting physical activity guidelines significantly lower. No significant differences across pain categories were found for sex, age, number of diseases, duration of OA, ever smoked, alcoholic drinks/week, over-the-counter pain medication use, OA supplement use, physical therapy use, servings of vegetables or minutes walked/week.
CONCLUSIONS: Healthy weight maintenance, exercise for at least 150 min/week and appropriate use of medications and supplements represent important modifiable factors related to lower knee OA pain.
The study was conducted on two hundred patients ranging in age from 40 to 70 years with established osteoarthritis knee to examine the association of quadriceps strength with pain and disability of knee osteoarthritis. In addition the relationships between various components of health related fitness, pain, effusion and disability were also examined in the present study. Quadriceps strength seems to be an independent contributor to the severity of osteoarthritis knee; the findings illustrate the need of improving the muscle function in these patients. No association between knee pain and disability indicates that functional limitations in patients with osteoarthritis should be explored separately from the evaluation of symptoms.
Background: a major problem in evaluating and reviewing the published findings of studies on the association between a quantitative explanatory variable and a quantitative dependent variable is that the results are analysed and reported in many different ways. To achieve an effective review of different studies, a consistent presentation of the results is necessary. This paper aims to exemplify the main topics related to summarising and pooling research findings from multivariable models with a quantitative response variable. Methods: we outline the complexities involved in synthesising associations. We describe a method by which it is possible to transform the findings into a common effect size index which is based on standardised regression coefficients. To describe the approach we searched original research articles published before January 2012 for findings of the relationship between polychlorinated biphenyls (PCBs) and birth weight of new-borns. Studies with maternal PCB measurements and birth weight as a continuous variable were included. Results: the evaluation of 24 included articles reveled that there was variation in variable measurement methods, transformations, descriptive statistics and inference methods. Research syntheses were performed summarizing regression coefficients to estimate the effect of PCBs on birth weight. A birth weight decline related to increase in PCB level was found. Conclusions: the proposed method can be useful in quantitatively reviewing published studies when different exposure measurement methods are used or differential control of potential confounding factors is not an issue.
Objective We performed a systematic review, meta-analysis and assessed the evidence supporting a causal link between knee joint loading during walking and structural knee osteoarthritis (OA) progression.
Design Systematic review, meta-analysis and application of Bradford Hill's considerations on causation.
Data sources We searched MEDLINE, Scopus, AMED, CINAHL and SportsDiscus for prospective cohort studies and randomised controlled trials (RCTs) from 1950 through October 2013.
Study eligibility criteria We selected cohort studies and RCTs in which estimates of knee joint loading during walking were used to predict structural knee OA progression assessed by X-ray or MRI.
Data analyses Meta-analysis was performed to estimate the combined OR for structural disease progression with higher baseline loading. The likelihood of a causal link between knee joint loading and OA progression was assessed from cohort studies using the Bradford Hill guidelines to derive a 0–4 causation score based on four criteria and examined for confirmation in RCTs.
Results Of the 1078 potentially eligible articles, 5 prospective cohort studies were included. The studies included a total of 452 patients relating joint loading to disease progression over 12–72 months. There were very serious limitations associated with the methodological quality of the included studies. The combined OR for disease progression was 1.90 (95% CI 0.85 to 4.25; I2=77%) for each one-unit increment in baseline knee loading. The combined causation score was 0, indicating no causal association between knee loading and knee OA progression. No RCTs were found to confirm or refute the findings from the cohort studies.
Conclusions There is very limited and low-quality evidence to support for a causal link between knee joint loading during walking and structural progression of knee OA.
Trial registration number CRD42012003253
Objective
To determine the factors associated with physical activity participation in adults with hip or knee osteoarthritis.
Methods
A systematic review was conducted including searches of AMED, PsycINFO, CINAHL, MEDLINE, EMBASE, PubMed and the Cochrane Library from inception until October 2013. Studies presenting quantitative correlates of physical activity in adults with hip and/or knee osteoarthritis were included. Two independent authors conducted the searches, extracted data and completed methodological quality assessment. Correlates were analysed using the summary code approach within the socio-ecological model.
Results
A total of 170 correlates were identified from 29 publications analysing 8076 individual people with hip or knee osteoarthritis. Methodological quality was generally good. For knee osteoarthritis, factors consistently negatively associated with physical activity (reported more than four studies) were increasing age (number of participants in studies supporting association = 4558), non-white ethnicity (n = 3232), increased osteoarthritis symptoms (n = 2374) and female gender (n = 4816). Greater lower limb function (n = 1671) and faster gait speed were (n = 4098) positively associated with physical activity. Social (e.g. support from spouse (n = 141)) and environment (outdoor temperature (n = 38)) factors were identified as possible factors that influence physical activity. For hip osteoarthritis, higher body mass index (n = 99), increased comorbidities (n = 1021), lower mental health (n = 189) and unemployment (n = 65) were negatively associated with physical activity; while better social functioning (n = 1055) and health-related quality of life were positively associated with physical activity (n = 34).
Conclusion
Demographic, physical, social, psychological and environmental factors are all important correlates for physical activity for people with knee or hip osteoarthritis. Clinicians should consider these in clinical practice.
To investigate whether objectively measured time spent in light intensity physical activity is related to incident disability and to disability progression.
Prospective multisite cohort study from September 2008 to December 2012.
Baltimore, Maryland; Columbus, Ohio; Pittsburgh, Pennsylvania; and Pawtucket, Rhode Island, USA.
Disability onset cohort of 1680 community dwelling adults aged 49 years or older with knee osteoarthritis or risk factors for knee osteoarthritis; the disability progression cohort included 1814 adults.
Physical activity was measured by accelerometer monitoring. Disability was ascertained from limitations in instrumental and basic activities of daily living at baseline and two years. The primary outcome was incident disability. The secondary outcome was progression of disability defined by a more severe level (no limitations, limitations to instrumental activities only, 1-2 basic activities, or ≥3 basic activities) at two years compared with baseline.
Greater time spent in light intensity activities had a significant inverse association with incident disability. Less incident disability and less disability progression were each significantly related to increasing quartile categories of daily time spent in light intensity physical activities (hazard ratios for disability onset 1.00, 0.62, 0.47, and 0.58, P for trend=0.007; hazard ratios for progression 1.00, 0.59, 0.50, and 0.53, P for trend=0.003) with control for socioeconomic factors (age, sex, race/ethnicity, education, income) and health factors (comorbidities, depressive symptoms, obesity, smoking, lower extremity pain and function, and knee assessments: osteoarthritis severity, pain, symptoms, prior injury). This finding was independent of time spent in moderate-vigorous activities.
These prospective data showed an association between greater daily time spent in light intensity physical activities and reduced risk of onset and progression of disability in adults with osteoarthritis of the knee or risk factors for knee osteoarthritis. An increase in daily physical activity time may reduce the risk of disability, even if the intensity of that additional activity is not increased.
OBJECTIVE: To determine the correlation between performance of the knee muscles and pain, stiffness, and functionality, through the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Questionnaire applied to an elderly population with osteoarthritis of the knee (OA).
METHODS: This study uses an observational, cross-sectional approach applied to a convenience sample of 80 elderly individuals (71.2 ± 5.3 years of age) with a clinical diagnosis of OA of the knee. Muscle strength, resistance, and balance of the knee were evaluated using the Biodex System 3 Pro isokinetic dynamometer at angular speeds of 60º/s and 180º/s. The self-reported functionality, presence of pain, and stiffness were evaluated by the WOMAC questionnaire. The correlation between the variables was analyzed by Spearman's coefficient of correlation (α = 0.05).
RESULTS: A significant inverse correlation was observed between muscle strength and resistance of the quadriceps muscle (Q) and the hamstring muscle (H) at speeds of 60º/s and 180°/s, respectively, as well as in the relation between H/Q muscle balance at 180°/s and all domains of the WOMAC (p<0.05).
CONCLUSIONS: The reduction in strength, resistance, and presence of imbalance in the knee muscles are inversely correlated with all the domains of the WOMAC in elderly individuals with OA. These results indicate a need for intervention that involves strengthening, resistance, and balance of the knee extensor and flexor muscles, aimed at reducing the impact of OA in relation to pain, stiffness, and functionality in elderly individuals. Level of Evidence: Level I, diagnostic studies - investigating a diagnostic test.
To correlate muscule performance, body composition, pain and joint function in elderly people with gonarthrosis.
21 elderly patients were submitted to bioelectrical impedance analysis, dynamometry associated with electromyographic (EMG) evaluation of isometric knee extension, in addition to pain assessment by the Numeric Pain Intensity Scale and function assessment, by the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis (OA) questionnaire. Correlations were checked by the Pearson's correlation coefficient.
The sample characteristics were mean age 67.36 ± 4.21 years old, body fat percentage 40.57±6.15%, total WOMAC score 43.27 ± 16.32%, and maximum strength 19.95 ± 6.99 kgF. Pain during movement showed a statistical association with WOMAC physical activity domain (r = 0.47) and its general score (r = 0.51); pain intensity at night presented association with WOMAC stiffness domain (r = 0.55), in addition to the negative correlation with the slope values of the Medium Frequency of the EMG signal (r = - 0.57).
pain intensity is correlated to functional incapacity in elderly people with knee OA and to a greater expression of fatigue in EMG signal. Levels of Evidence III, Study of non consecutive patients.
Objective:
Adults with osteoarthritis (OA) experience fatigue in daily life that is negatively related to physical activity; however, it is unclear how task demands affect fatigue and occupational performance. We examined effects of a cognitive task on subsequent symptoms and activity.
Method:
Adults with knee or hip OA completed a standardized cognitive task during a lab visit. Objective physical activity and symptoms were tracked during two home-monitoring periods (i.e., 4-day period before and 5-day period after the lab visit). Multilevel modeling was used to compare pretask with posttask fatigue, pain, and activity levels.
Results:
Fatigue increased and pain decreased for 2 days after performing the lab task. The authors found no pretask to posttask changes in activity levels. At posttask, daily fatigue and activity patterns changed relative to baseline.
Conclusion:
For adults with symptomatic OA, cognitive task demands may be an important contributor to fatigue and pain.
Purpose:
To assess correlates of physical activity, and to examine the relationship between physical activity and physical functioning, in 160 older (66 ± 6 years old), overweight/obese (mean body mass index = 33.5 ± 3.8 kg/m2), sedentary (less than 30 mins of activity, 3 days a week) individuals with knee osteoarthritis.
Methods:
Physical activity was measured with accelerometers and by self-report. Physical function was assessed by 6-min walk distance, knee strength, and the Short Physical Performance Battery. Pain and perceived function were measured by questionnaires. Pearson correlations and general linear models were used to analyze the relationships.
Results:
The mean number of steps taken per day was 6209 and the average PAEE was 237 ± 124 kcal/day. Participants engaged in 131 ± 39 minutes of light physical activity (LPA) and 10.6 ± 8.9 minutes of moderate-vigorous physical activity (MPA/VPA). Total steps/day, PAEE, and minutes of MPA/VPA were all negatively correlated with age. The 6-min walk distance and lower extremity function were better in those who had higher total steps/day, higher PAEE, higher minutes of MPA/VPA, and a higher PASE score.
Conclusions:
This study demonstrates that a population who has higher levels of spontaneous activity have better overall physical function than those who engage in less activity.
Purpose:
To examine the association between objectively measured physical activity and risk of developing incident knee osteoarthritis (OA) in a community-based cohort of middle-aged and older adults.
Methods:
We used data from the Osteoarthritis Initiative (OAI), an ongoing prospective cohort study of adults aged 45 to 83 at initial enrollment with elevated risk of symptomatic knee OA. Moderate-vigorous physical activity (MVPA) was measured by a uniaxial accelerometer for seven continuous days in two data collection cycles, and was categorized as inactive (<10 minutes/week), low activity (10-<150 minutes/week), and active (≥150 minutes/week). Incident knee OA based on radiographic and symptomatic OA and joint space narrowing were analyzed as outcomes over four years of follow-up. Participants free of the outcome of interest in both knees at study baseline were included (sample sizes ranged from 694 to 1,331 for different outcomes). We estimated hazard ratio (HR) and its 95% confidence intervals (CI).
Results:
In multivariate adjusted analyses, active MVPA participation was not significantly associated with risk of incident radiographic knee OA (HR: 1.52; 95% CI: 0.68-3.40), symptomatic knee OA (HR: 1.17; 95% CI: 0.44-3.09), or joint space narrowing (HR: 0.87; 95% CI: 0.37-2.06), when compared with inactive MVPA participation. Similar results were found for participants with low activity MVPA.
Conclusion:
MVPA was not associated with the risk of developing incident knee OA or joint space narrowing over four years of follow-up among OAI participants who are at increased risk of knee OA.
Background:
Knee pain associated with osteoarthritis is a significant contributor to decreased physical function. Recent evidence supports the inter-individual heterogeneity associated with knee pain presentation, but whether there is similar heterogeneity in physical performance among these individuals has not been previously examined. The aim of the present study was to characterize the variability in physical performance profiles and the pain evoked by their performance (i.e., movement-evoked pain).
Methods:
In a secondary analysis of the community-based study Understanding Pain and Limitations in Osteoarthritic Disease (UPLOAD), individuals (n=270) completed functional, pain, psychological, and somatosensory assessments. Hierarchical cluster analysis was used to derive physical function profiles that were subsequently compared across several clinical, psychological and experimental pain measures.
Results:
Our results support the hypothesis that among persons with knee OA pain, three different physical performance profiles exist with varying degrees of movement-evoked pain. Even as all three groups experienced moderate to severe levels of spontaneous knee pain, those individuals with the most severe movement-evoked pain and lowest physical functional performance also had the least favorable psychological characteristics along with increased mechanical pain sensitivity and temporal summation.
Conclusions:
Our findings support the need for the assessment and consideration of movement-evoked pain during physical performance tasks as these have the potential to increase the value of functional and pain assessments clinically. The identification of the mechanisms driving pain burden within homogeneous groups of individuals will ultimately allow for targeted implementation of treatments consistent with a biopsychosocial model of pain.
Normal efficiency of exercise-induced hypoalgesia (EIH) has been demonstrated in people with knee osteoarthritis (OA), while recent evidence suggests that EIH may be associated with features of pain sensitization such as abnormal conditioned pain modulation (CPM). The aim of this study was to investigate whether people with knee OA with abnormal CPM have dysfunctional EIH compared with those with normal CPM and pain-free controls.
Forty peoples with knee OA were subdivided into groups with abnormal and normal CPM, as determined by a decrease/increase in pressure pain thresholds (PPTs) following the cold pressor test. Abnormal CPM (n=19), normal CPM (n=21), and control participants (n=20) underwent PPT testing before, during, and after aerobic and isometric exercise protocols. Between-group differences were analyzed using repeated-measures analysis of variance and within-group differences were analyzed using Wilcoxon signed-rank tests.
Significant differences were demonstrated between groups for changes in PPTs postaerobic (F2,55=4.860; P=0.011) and isometric (F2,57=4.727; P=0.013) exercise, with significant decreases in PPTs demonstrated during and postexercise in the abnormal CPM group (P<0.05), and significant increases in PPTs shown during and postexercise in the normal CPM and control groups (P<0.05).
Results are suggestive of dysfunctional EIH in response to aerobic and isometric exercise in knee OA patients with abnormal CPM, and normal function of EIH in knee OA patients with an efficient CPM response. Identification of people with knee OA with inefficient endogenous pain modulation may allow for a more individualized and graded approach to exercises in these individuals.
Background:
Quadriceps muscle weakness and vitamin D deficiency are associated with knee osteoarthritis (KOA). This study aimed to investigate the relationship between quadriceps muscle strength (QMS) and vitamin D in KOA.
Methods:
Patients with KOA aged 40 years and above were studied. QMS was assessed by the dynanometry method and serum 25-hydroxyvitamin D (25-OHD) by the ELISA method. Serum 25-OHD<20 ng/mL was considered as a deficiency. The intensity of knee pain was determined by the Western Ontario and McMaster Universities Osteoarthritis Index pain scale. The Pearson test was used for correlation analysis between QMS and serum 25-OHD as well as knee pain.
Results:
A total of 92 patients (female, 80%) with a mean age of 49.6±11.7 years were studied. QMS was correlated positively with serum 25-OHD (r=0.304, r=9.24%, P=0.005) and negatively with knee pain (r=-0.232, r=5.3%, P=0.034). After adjustment for age, sex, and body mass index, the positive correlation increased to a stronger level (r=0.496, r=24.9%, P=0.01). For each 1 ng/mL increase in serum 25-OHD, the value of QMS increased by 14.2%±3.5% (P=0.014). There was no significant correlation between serum 25-OHD and knee pain (P=0.13).
Conclusions:
These findings demonstrated a significant correlation between QMS with both serum vitamin D and knee pain, indicating a confounding role for quadriceps muscle in the association between serum vitamin D and osteoarthritis knee pain. On the basis of the findings of this study, vitamin D supplementation may affect pain by strengthening quadriceps muscle in KOA.
Introduction:
Data evaluating mortality benefit from replacing sedentary time with physical activity are sparse. We explored reallocating time spent in sedentary behavior to physical activity of different intensities in relation to mortality risk.
Methods:
Women and men aged 50-85 years from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2005-2006 cycles with follow-up through December 31, 2011 were included. Sedentary time and physical activity were assessed using an ActiGraph accelerometer. Isotemporal substitution models were used to estimate the effect of replacing one activity behavior with another activity behavior for the same amount of time while holding total accelerometer wear time constant.
Results:
During a mean follow-up of 6.35 years, 697 deaths from any cause occurred. Replacing 30 minutes of sedentary time with an equal amount of light activity was associated with 14% reduced risk of mortality (multivariable-adjusted hazard ratio (HR)=0.86, 95% confidence interval (CI)=0.83-0.90). Replacement of sedentary time with moderate to vigorous activity was related to 50% mortality risk reduction (HR=0.50, 95% CI=0.31-0.80). We also noted a 42% reduced risk of mortality when light physical activity was replaced by moderate to vigorous activity (HR=0.58, 95% CI=0.36-0.93).
Conclusion:
Replacing sedentary time with an equal amount of physical activity may protect against preterm mortality. Replacement of light physical activity with moderate to vigorous activity is also associated with protection from premature mortality.
Objective:
Patients considering or engaged in exercise as treatment may expect or experience transient increases in joint pain, causing fear of exercise and influencing compliance. This study investigated the pain trajectory during an 8-week neuromuscular exercise (NEMEX) program together with acute exercise-induced pain flares in persons with knee or hip pain.
Design:
Individuals above 35 years self-reporting persistent knee or hip pain for the past 3 months were offered 8 weeks of supervised NEMEX, performed in groups twice weekly. The program consisted of 11 exercises focusing on joint stability and neuromuscular control. Participants self-reported joint pain on a 0 to 10 numerical rating scale (NRS) at baseline and 8-weeks follow-up. NRS pain ratings were also collected before and immediately after every attended exercise session.
Results:
Joint pain was reduced from baseline (NRS 3.6; 95% CI 3.2 to 4.1) to 8-weeks follow-up (2.6; 95% CI 2.1 to 3.1), (p<0.01). Pain decreased 0.04 NRS (95% CI 0.02 to 0.05, p<0.01) on average per exercise session and pre-to post-exercise pain decreased 0.04 NRS (95% CI 0.03 to 0.05, p<0.01) on average per session, approaching no acute exercise induced pain in the last weeks.
Conclusion:
This study found a clear decrease in size of acute exercise induced pain flares with increasing number of exercise sessions. In parallel, pain ratings decreased over the 8 weeks exercise period. Our findings provide helpful information for clinicians, which can be used to educate and balance patient expectation when starting supervised neuromuscular exercise.
Background:
The association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis.
Methods:
Sixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n=18), mild pain (n=27), or moderate/severe pain (n=22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified.
Findings:
The moderate/severe pain group demonstrated worse global pain (P<0.01) and physical function scores (P<0.01) compared to the no pain and the mild pain groups. The moderate/severe pain group also walked with greater knee flexion moments during the midstance phase of gait compared to the no pain group (P=0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P=0.009), which was associated with higher weight acceptance peak knee adduction moments (P=0.003) and worse global pain (P=0.003) and physical function scores (P=0.006).
Interpretation:
Greater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait.
Objective:
Pain is not always correlated with radiographic osteoarthritis (OA) severity possibly because people modify activities to manage symptoms. Measures of symptoms that consider pain in the context of activity level may therefore provide greater discrimination than pain alone. Our objective was to compare discrimination of a measure of pain alone with combined measures of pain relative to physical activity across radiographic OA levels.
Methods:
This is a cross-sectional study of the Osteoarthritis Initiative accelerometer substudy, including those with and without knee OA. Two composite pain and activity knee symptom (PAKS) scores were calculated as Western Ontario and McMaster (WOMAC) Universities Osteoarthritis Pain Scale plus one divided by physical activity measures (step and activity counts). Symptom score discrimination across Kellgren and Lawrence (KL) grades were evaluated using histograms and quantile regression.
Results:
1806 participants, mean age 65.1 (9.1) years, mean BMI 28.4 (4.8) kg/m(2) , and 55.6% female, were included. WOMAC, but not PAKS scores, exhibited a floor effect. Adjusted median WOMAC by KL grades 0 - 4 were 0, 0, 1, 1, and 3 respectively. Median PAKS1 and PAKS2 were 24.9, 26.0, 32.4, 46.1, 97.9, and 7.2, 7.2, 9.2, 12.9, 23.8, respectively. PAKS scores had more statistically significant comparisons between KL grades compared with WOMAC.
Conclusions:
Symptom assessments incorporating pain and physical activity did not exhibit a floor effect and were better able to discriminate radiographic severity than pain alone, particularly in milder disease. Pain in the context of physical activity level should be used to assess knee OA symptoms. This article is protected by copyright. All rights reserved.
OBJECTIVE: Severe pain in patients with knee osteoarthritis hampers the ability to exercise. A protocol for the standardized optimization of analgesics in combination with exercise therapy was developed. The purpose of this protocol was to reduce pain, thereby allowing the patient to participate in exercise therapy. The objective of the present study was to evaluate the feasibility and outcome of the protocol.
METHODS: Forty-nine patients with knee osteoarthritis and severe knee pain (NRS-pain≥7) were included. Analgesics were prescribed following an incremental protocol. After 6 weeks a 12-week exercise therapy program was added. Information about analgesic use and exercise therapy content was recorded. Knee pain and activity limitations were assessed at baseline, after six weeks and after 18 weeks.
RESULTS: Statistically significant improvements in pain and activity limitations were found in intention-to-treat analysis after six weeks of analgesic use and after the complete intervention. Mean improvements from baseline were 30% (p<0.001) for pain and 17% (p<0.001) for activity limitations after the complete intervention. Seventy-eight percent of the patients were able to exercise according to the protocol. In these patients exercise therapy following on six weeks of analgesic use resulted in a further improvement of activity limitations of 10% (p=0.004).
CONCLUSION: The combined intervention of standardized analgesic prescription and exercise therapy allows most patients with knee osteoarthritis and severe pain to participate in exercise therapy, leading to reduction of pain and activity limitations. These promising results need to be confirmed in a randomized controlled trial.
We examined the relationships between lower extremity muscle strength, power and perceived disease severity in participants with knee osteoarthritis (OA). We hypothesized that dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA.
We used baseline data from a randomized controlled trial in 190 participants with knee OA (age: 60.2 ± 10.4 yrs; BMI: 32.7 ± 7.2 kg/m(2) ). Knee pain was measured using the Western Ontario and McMaster Osteoarthritis Index and health-related quality of life using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM.
In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P < 0.02). It was also significantly and positively associated with SF-36 physical component scores (PCS) (r = 0.16, P < 0.05). After adjusting for multiple covariates, muscle power was a significant independent predictor of pain (P ≤ 0.05) and PCS (P ≤ 0.04). However, strength was not an independent determinant of pain or quality of life (P ≥ 0.06).
Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted. This article is protected by copyright. All rights reserved.
© 2015, American College of Rheumatology.
To investigate the clinical importance of hip abductor (HA) strength in people with knee osteoarthritis (OA), the purposes of this study were to 1) compare the association of HA strength and physical function to that of knee extensor (KE) strength and physical function, and 2) determine the reliability of the assessment of HA strength using a hand-held dynamometer.
Thirty-five individuals [58 years standard deviation 10 years old] with knee osteoarthritis participated. Physical function was assessed with performance-based [Get-Up and Go (GUG), stair climb and descent (SC), and five times chair rise (CR)] and self-reported (WOMAC function) measures. The relationship between strength and function was assessed using bivariate correlation and hierarchical multiple regression models. Reliability across sessions was assessed in 25 subjects.
In the bivariate models, both KE and HA strength were both significantly associated with performance-based measures of function, but not WOMAC function. After controlling for anthropometric factors and KE strength in the hierarchical models, HA made significant independent contributions to the prediction of GUG and SC, but not CR or WOMAC function. The reliability of HA strength was excellent (ICC2, 3=0.94; 95% CI=0.86-0.97), while the minimum detectable change (MDC95) was 0.29Nm/kg (95% CI=0.23-0.41).
HA strength can be reliably measured and is closely associated with functional performance in people with knee OA.
These results provide preliminary evidence suggesting that HA strength may be an important rehabilitation target for the conservative management of knee OA.
Copyright © 2015 Elsevier B.V. All rights reserved.
Although physical exercise is the commonly recommended for osteoarthritis (OA) patients, the working mechanism behind the positive effects of physical exercise on pain and function is a black box phenomenon. In the present study we aimed to identify possible mediators in the relation between physical exercise and improvements of pain and function in OA patients.
A systematic search for all studies evaluating the effects of physical exercise in OA patients and select those that additionally reported the change in any physiological factor from pre-to post-exercise.
In total, 94 studies evaluating 112 intervention groups were included. Most included studies evaluated subjects with solely knee OA (96 out of 112 groups). Based on the measured physiological factors within the included studies, 12 categories of possible mediators were formed. Muscle strength and ROM/flexibility were the most measured categories of possible mediators with 61 and 21 intervention groups measuring one or more physiological factors within these categories, respectively. 60% (31 out of 52) of the studies showed a significant increase in knee extensor muscle strength and 71% (22 out of 31) in knee flexor muscle strength over the intervention period. All 5 studies evaluating extension impairments and 10 out of 12 studies (83%) measuring proprioception found a significant change from pre-to post-intervention.
An increase of upper leg strength, a decrease of extension impairments and improvement in proprioception were identified as possible mediators in the positive association between physical exercise and OA symptoms.
Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
To study the cross-sectional association between physical activity measured with an accelerometer, structural knee abnormalities and cartilage T2-values assessed with 3T MRI.
We included 274 subjects from the Osteoarthritis Initiative cohort without definite radiographic osteoarthritis (KL 0 and1) and at most mild pain, stiffness and functional limitation in the study knee (WOMAC 0-1), which had not limited their activity due to knee pain. Physical activity was measured over seven days with an ActiGraph GT1M accelerometer. Subjects were categorized by quartile of physical activity based on the average daily minutes of moderate/vigorous activity (mv-PA). MR images of the right knee (at 48-months visit) were assessed for structural abnormalities using a modified WORMS score and for T2-relaxation times derived from segmented cartilage of 4 femorotibial regions and the patella. WORMS-grades and T2-measurements were compared between activity quartiles using a linear regression model. Covariates included age, sex, BMI, knee injury, family history of knee replacement, knee symptoms, hip and ankle pain and daily wear time of the accelerometer.
Higher mv-PA was associated with increased severity (p=0.0087) and number of lesions of the medial meniscus (p=0.0089) and severity of bone marrow edema lesions (p=0.0053). No association between cartilage lesions and mv-PA was found. T2-values of cartilage (loss, damage, abnormalities) tended to be greater in the higher quartiles of mv-PA, but the differences were non-significant.
In knees without radiographic osteoarthritis in subjects with no or mild knee pain, higher physical activity levels were associated with increases in meniscal and BMEP lesions. This article is protected by copyright. All rights reserved.
© 2015 American College of Rheumatology.
To examine: (1) the relationships between habitual approach to activity engagement and specific aspects of physical functioning in chronic pain, and (2) whether or not these relationships differ according to pain duration.
Outpatients (N=169) with generalised chronic pain completed a set of written questionnaires. Categories of "approach to activity engagement" were created using the confronting and avoidance subscales of the Pain and Activity Relations Questionnaire (PARQ). An interaction term between "approach to activity engagement" categories and pain duration was entered into analysis with age, gender, pain intensity, the categorical "approach to activity engagement" variable, and pain duration, in nine ordinal regression models investigating functioning in a variety of daily activities.
The "approach to activity engagement" category predicted the personal care, lifting, sleeping, social life, and travelling aspects of physical functioning but, interestingly, not the performance skills used during these activities, i.e., walking, sitting and standing. The interaction term was significant in two models; however, the effect of pain duration on associations was the inverse of that theorised, with the relationship between variables becoming less pronounced with increasing duration of pain.
The results of this study do not support the commonly held notion that avoidance and/or overactivity behaviour leads to deconditioning and reduced physical capacity over time. Findings do, however, suggest that a relationship exists between avoidance and/or overactivity behaviour and reduced participation in activities. Implications for the clinical management of chronic pain and directions for further research are discussed.
Background:
Knee osteoarthritis (OA) is a major public health issue because it causes chronic pain, reduces physical function and diminishes quality of life. Ageing of the population and increased global prevalence of obesity are anticipated to dramatically increase the prevalence of knee OA and its associated impairments. No cure for knee OA is known, but exercise therapy is among the dominant non-pharmacological interventions recommended by international guidelines.
Objectives:
To determine whether land-based therapeutic exercise is beneficial for people with knee OA in terms of reduced joint pain or improved physical function and quality of life.
Search methods:
Five electronic databases were searched, up until May 2013.
Selection criteria:
All randomised controlled trials (RCTs) randomly assigning individuals and comparing groups treated with some form of land-based therapeutic exercise (as opposed to exercise conducted in the water) with a non-exercise group or a non-treatment control group.
Data collection and analysis:
Three teams of two review authors independently extracted data, assessed risk of bias for each study and assessed the quality of the body of evidence for each outcome using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. We conducted analyses on continuous outcomes (pain, physical function and quality of life) immediately after treatment and on dichotomous outcomes (proportion of study withdrawals) at the end of the study; we also conducted analyses on the sustained effects of exercise on pain and function (two to six months, and longer than six months).
Main results:
In total, we extracted data from 54 studies. Overall, 19 (20%) studies reported adequate random sequence generation and allocation concealment and adequately accounted for incomplete outcome data; we considered these studies to have an overall low risk of bias. Studies were largely free from selection bias, but research results may be vulnerable to performance and detection bias, as only four of the RCTs reported blinding of participants to treatment allocation, and, although most RCTs reported blinded outcome assessment, pain, physical function and quality of life were participant self-reported.High-quality evidence from 44 trials (3537 participants) indicates that exercise reduced pain (standardised mean difference (SMD) -0.49, 95% confidence interval (CI) -0.39 to -0.59) immediately after treatment. Pain was estimated at 44 points on a 0 to 100-point scale (0 indicated no pain) in the control group; exercise reduced pain by an equivalent of 12 points (95% CI 10 to 15 points). Moderate-quality evidence from 44 trials (3913 participants) showed that exercise improved physical function (SMD -0.52, 95% CI -0.39 to -0.64) immediately after treatment. Physical function was estimated at 38 points on a 0 to 100-point scale (0 indicated no loss of physical function) in the control group; exercise improved physical function by an equivalent of 10 points (95% CI 8 to 13 points). High-quality evidence from 13 studies (1073 participants) revealed that exercise improved quality of life (SMD 0.28, 95% CI 0.15 to 0.40) immediately after treatment. Quality of life was estimated at 43 points on a 0 to 100-point scale (100 indicated best quality of life) in the control group; exercise improved quality of life by an equivalent of 4 points (95% CI 2 to 5 points).High-quality evidence from 45 studies (4607 participants) showed a comparable likelihood of withdrawal from exercise allocation (event rate 14%) compared with the control group (event rate 15%), and this difference was not significant: odds ratio (OR) 0.93 (95% CI 0.75 to 1.15). Eight studies reported adverse events, all of which were related to increased knee or low back pain attributed to the exercise intervention provided. No study reported a serious adverse event.In addition, 12 included studies provided two to six-month post-treatment sustainability data on 1468 participants for knee pain and on 1279 (10 studies) participants for physical function. These studies indicated sustainability of treatment effect for pain (SMD -0.24, 95% CI -0.35 to -0.14), with an equivalent reduction of 6 (3 to 9) points on 0 to 100-point scale, and of physical function (SMD -0.15 95% CI -0.26 to -0.04), with an equivalent improvement of 3 (1 to 5) points on 0 to 100-point scale.Marked variability was noted across included studies among participants recruited, symptom duration, exercise interventions assessed and important aspects of study methodology. Individually delivered programmes tended to result in greater reductions in pain and improvements in physical function, compared to class-based exercise programmes or home-based programmes; however between-study heterogeneity was marked within the individually provided treatment delivery subgroup.
Authors' conclusions:
High-quality evidence indicates that land-based therapeutic exercise provides short-term benefit that is sustained for at least two to six months after cessation of formal treatment in terms of reduced knee pain, and moderate-quality evidence shows improvement in physical function among people with knee OA. The magnitude of the treatment effect would be considered moderate (immediate) to small (two to six months) but comparable with estimates reported for non-steroidal anti-inflammatory drugs. Confidence intervals around demonstrated pooled results for pain reduction and improvement in physical function do not exclude a minimal clinically important treatment effect. Since the participants in most trials were aware of their treatment, this may have contributed to their improvement. Despite the lack of blinding we did not downgrade the quality of evidence for risk of performance or detection bias. This reflects our belief that further research in this area is unlikely to change the findings of our review.
This is the first book to introduce the new statistics—effect sizes, confidence intervals, and meta-analysis-in an accessible way. It is chock full of practical examples and tips on how to analyze and report research results using these techniques. The book is invaluable to readers interested in meeting the new APA Publication Manual guidelines by adopting the new statistics—which are more informative than null hypothesis significance testing, and becoming widely used in many disciplines. This highly accessible book is intended as the core text for any course that emphasizes the new statistics, or as a supplementary text for graduate and/or advanced undergraduate courses in statistics and research methods in departments of psychology, education, human development, nursing, and natural, social, and life sciences. Researchers and practitioners interested in understanding the new statistics, and future published research, will also appreciate this book. A basic familiarity with introductory statistics
IntroductionIndividual studiesThe summary effectHeterogeneity of effect sizesSummary points
Objective
Investigate the relationship between sedentary behavior and physical function in adults with knee osteoarthritis (OA), controlling for moderate-vigorous physical activity (MVPA) levels.Methods
Sedentary behavior was objectively measured by accelerometer on 1,168 participants ages 49-83 years in the Osteoarthritis Initiative with radiographic knee OA at the 48-month clinic visit. Physical function was assessed using 20-meter walk and chair stand testing. Sedentary behavior was identified by accelerometer activity counts/minute <100. The cross-sectional association between sedentary quartiles and physical function was examined by multiple linear regression, adjusting for demographic factors (age, sex, race/ethnicity, education level), health factors (comorbidity, body mass index, knee pain, knee OA severity, presence of knee symptoms), and average daily MVPA minutes.ResultsAdults with knee OA spent two-thirds of their daily time in sedentary behavior. The average gait speed among the most sedentary quartile was 3.88 feet/second, which was significantly slower than the speed of the less sedentary groups (4.23, 4.33, and 4.33 feet/second, respectively). The average chair stand rate among the most sedentary group was significantly lower (25.9 stands/minute) than the rates of the less sedentary behavior groups (28.9, 29.1, and 31.1 stands/minute, respectively). These trends remained significant in multivariable analyses adjusted for demographic factors, health factors, and average daily MVPA minutes.Conclusion
Being less sedentary was related to better physical function in adults with knee OA independent of MVPA time. These findings support guidelines to encourage adults with knee OA to decrease time spent in sedentary behavior in order to improve physical function.
The use of accelerometers in physical activity (PA) research has increased exponentially over the past 20 years. The first commercially available accelerometer for assessing PA, the Caltrac, was worn on the waist and estimated PA energy expenditure (PAEE) in kilocalories. Around 1995, the emphasis shifted to measuring minutes of moderate-to-vigorous PA (MVPA), especially for bouts of 10 min or longer. Recent studies, however, show that light-intensity PA and intermittent (non-bout) MVPA also have important health benefits. The total volume of PA performed is an important variable, since it takes the frequency, intensity, and duration of activity bouts, and condenses them down to a single metric. The total volume of PA is appropriate for many research applications, and can enhance comparisons between studies. In the future, machine learning algorithms will provide improved accuracy for activity type recognition and estimation of PAEE. However, in the current landscape of objectively measured PA, total activity counts per day (TAC/d) is a proxy for the total volume of PA. TAC/d percentiles for age and gender-specific groups have been developed from NHANES ActiGraph data (2003-06), providing a novel way to assess PA. The use of TAC/d, or standardized units of acceleration, could harmonize PA across studies. TAC/d should be viewed as an additional metric, not intended to replace other metrics (e.g., sedentary time, light-intensity PA, moderate PA, and vigorous PA) that may also be related to health. As future refinements to wearable monitors occur, researchers should continue to consider metrics that reflect the total volume of PA, in addition to existing PA metrics.
Objective:
Adherence to physical activity at ≥150 minutes/week has proven to offer disease management and health-promoting benefits among adults with arthritis. While highly active people seem undaunted by arthritis pain and are differentiated from the moderately active by adherence-related psychological factors, knowledge about inactive individuals is lacking. This knowledge may identify what to change in order to help inactive people begin and maintain physical activity. The present study examined the planned, self-regulated activity of high, moderate, and inactive individuals to determine if differences existed in negative psychological factors.
Methods:
Adults with a medical diagnosis of arthritis completed online measures of physical activity, perceived pain intensity, pain anxiety, and negative disease-related outcome expectations from being active. High active (n = 94), moderately active (n = 77), and inactive (n = 104) groups were identified.
Results:
A significant multivariate analysis of covariance revealed group differences (P < 0.001). Followup analyses indicated that inactive participants had the most negative psychological profile. Inactive participants reported that negative disease-related outcomes expectancies were more distressing and likely to occur than either group of active participants and expressed greater pain intensity and pain anxiety than the highly active participants (P < 0.05 for all).
Conclusion:
Identifying differences in negative psychological factors aids in the understanding of differential adherence between activity groups and highlights possible factors to change in future intervention and research.
Objective:
Few strategies to improve pain outcome in knee osteoarthritis (OA) exist in part because how best to evaluate pain over the long term is unclear. Our objectives were to determine the frequency of a good pain experience outcome based on previously formulated OA pain stages and test the hypothesis that less depression and pain catastrophizing and greater self-efficacy and social support are each associated with greater likelihood of a good outcome.
Methods:
Study participants, all with knee OA, reported pain stage at baseline and 2 years. Baseline assessments utilized the Geriatric Depression Scale, Pain Catastrophizing Scale, Arthritis Self-Efficacy Scale, and Medical Outcomes Study social support survey. Using pain experience stages, good outcome was defined as persistence in or movement to no pain or stage 1 (predictable pain, known trigger) at 2 years. A multivariable logistic regression model was developed to identify independent predictors of a good outcome.
Results:
Of 212 participants, 136 (64%) had a good pain outcome and 76 (36%) a poor pain outcome. In multivariable analysis, higher self-efficacy was associated with a significantly higher likelihood of good outcome (adjusted odds ratio [OR] 1.14 [95% confidence interval (95% CI) 1.04-1.24]); higher pain catastrophizing was associated with a significantly lower likelihood of good outcome (adjusted OR 0.88 [95% CI 0.83-0.94]).
Conclusion:
This stage-based measure provides a meaningful and interpretable means to assess pain outcome in knee OA. The odds of a good 2-year outcome in knee OA were lower in persons with greater pain catastrophizing and higher in persons with greater self-efficacy. Targeting these factors may help to improve pain outcome in knee OA.
Objective:
To determine the relationship between fatigue and the American College of Rheumatology (ACR) core set outcomes in patients with inflammatory arthritis (IA).
Methods:
This prospective longitudinal study evaluated fatigue in patients with active IA commencing tumor necrosis factor (TNF) inhibitor therapy. Fatigue was assessed using the multidimensional assessment of fatigue scale and the ACR core set (swollen and tender joint counts, pain, global health score, Health Assessment Questionnaire [HAQ] disability index [DI], and C-reactive protein level) was used for standard assessment of disease activity.
Results:
Assessments at baseline, 3 months, and 6 months were completed by 125, 92, and 82 patients, respectively. Fatigue and disease activity improved significantly within the first 3 months, with fatigue improving by 29% (F[2, 118] = 17.14, P < 0.001; repeated-measures analysis of variance). Using multiple regression, the amount of fatigue explained by the core outcomes differed at each time point: 28% at baseline (P < 0.001; significant predictors were the HAQ DI, global health, and C-reactive protein level), 37% at 3 months (P < 0.001; significant predictors were pain and tender joint count), and 46% at 6 months (P < 0.001; significant predictor was global health). Regression modelling using the fatigue change score at 3 months explained 17% of fatigue change (P < 0.012; significant predictors were HAQ DI and global health).
Conclusion:
Fatigue, which improved following treatment with TNF inhibitors, was poorly and inconsistently explained through the core set outcomes. Further, fatigue was least accounted for when the disease was most active, highlighting the need for further research into alternate explanations. These findings suggest further exploration of contributing variables and mechanisms in order to develop targeted symptom management of fatigue in IA.
Background It has been hypothesized (i) that pain and low vitality lead to an increase in avoidance of activities in persons with early symptomatic knee osteoarthritis (OA), and (ii) that avoidance of activities leads to an increase in activity limitations.
Objectives The present study aimed to evaluate these hypotheses in a cross-sectional and longitudinal design.
Methods Baseline, 2-year and 5-year follow-up data of 828 participants from the Cohort Hip and Cohort Knee (CHECK) study with early symptomatic knee OA were used. Knee pain, vitality, avoidance of activities and activity limitations were measured with reliable and validated instruments. Regression and autoregressive generalized estimating equations (GEE) models analyzed the cross-sectional and longitudinal associations between pain, vitality, avoidance of activities and activity limitations. The models were adjusted for age, gender, education level, body-mass index, comorbidity, and radiographic severity.
Results (i) In cross-sectional analyses, greater knee pain and lower vitality were associated with higher levels of avoidance of activities. In longitudinal analyses, pain and vitality predicted a subsequent increase in avoidance of activities. (ii) In cross-sectional analyses, a higher level of avoidance of activities was associated with greater activity limitations. In longitudinal analyses, this relationship was marginally significant.
Conclusions Knee pain and low vitality lead to a subsequent increase in avoidance of activities, already at an early stage of knee OA. Avoidance of activities is related to activity limitations: alternative measurement instruments and a longer follow-up may be required to establish the longitudinal relationship.
Disclosure of Interest None declared
DOI 10.1136/annrheumdis-2014-eular.1194
Objective:
Exercise has beneficial effects on pain in knee osteoarthritis (OA), yet the underlying mechanisms are unclear. The purpose of this study was to investigate the effects of exercise on pressure-pain sensitivity in patients with knee OA.
Methods:
In a randomized controlled trial, participants were assigned to 12 weeks of supervised exercise therapy (ET; 36 sessions) or a no attention control group (CG). Pressure-pain sensitivity was assessed by cuff pressure algometry on the calf of the most symptomatic leg. The coprimary outcomes were pressure-pain thresholds (PPTs) and cumulated visual analog scale pain scores during constant pressure for 6 minutes at 125% of the PPT as a measure of temporal summation (TS) of pressure-pain. Secondary outcomes included self-reported pain using the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire. Analyses were based on the "per-protocol" population (participants following the protocol).
Results:
Sixty participants were randomized (31 in ET group, 29 in CG), and the per-protocol population included 48 participants (25 in ET group, 23 in CG). At followup, mean group differences in the change from baseline were 3.1 kPa (95% confidence interval [95% CI] 0.2, 6.0; P = 0.038) for the PPT, 2,608 mm × seconds (95% CI 458, 4,758; P = 0.019) for TS, and 6.8 points (95% CI 1.2, 12.4; P = 0.018) for KOOS pain, all in favor of ET.
Conclusion:
Pressure-pain sensitivity, TS, and self-reported pain are reduced among patients completing a 12-week supervised exercise program compared to a no attention CG. These results demonstrate beneficial effects of exercise on basic pain mechanisms and further exploration may provide a basis for optimized treatment.
The technology and application of current accelerometer-based devices in physical activity (PA) research allow the capture and storage or transmission of large volumes of raw acceleration signal data. These rich data not only provide opportunities to improve PA characterisation, but also bring logistical and analytic challenges. We discuss how researchers and developers from multiple disciplines are responding to the analytic challenges and how advances in data storage, transmission and big data computing will minimise logistical challenges. These new approaches also bring the need for several paradigm shifts for PA researchers, including a shift from count-based approaches and regression calibrations for PA energy expenditure (PAEE) estimation to activity characterisation and EE estimation based on features extracted from raw acceleration signals. Furthermore, a collaborative approach towards analytic methods is proposed to facilitate PA research, which requires a shift away from multiple independent calibration studies. Finally, we make the case for a distinction between PA represented by accelerometer-based devices and PA assessed by self-report.
Patients with Total Knee Arthroplasty (TKA) demonstrate persistent functional limitations and disability. Identifying modifiable risk factors of persistent disability is warranted. Prior to surgery, patients have muscle weakness that is pervasive throughout the lower extremity. Strength of the hip abductors is often not targeted in post-operative rehabilitation and may contribute to functional limitations after surgery.
To examine reliability of hand-held dynamometry to measure hip abductor strength and to determine whether hip abductor strength would contribute physical function above and beyond the contribution of quadriceps strength.
Cross-sectional study.
210 subjects underwent quadriceps and hip abductor strength testing and measurement of physical function (performance-based and self-reported outcomes). Correlation and regression equations were built to determine the relationship between strength, pain and functional ability. A subset of 16 subjects underwent hip abductor strength testing at two sessions to measure reliability of the measure.
Measuring hip abductor strength using HHD yielded excellent relative reliability ICC2,3= 0.95 (95% CI: 0.86, 0.98) but moderate absolute reliability MDC95 of 47.6 N(95% CI: 35.5, 76.5). Hip abductor strength showed significant additional contribution to performance-based measures of physical function after accounting for anthropometric covariates and quadriceps strength. Hip abductor strength did not show bivariate correlation with patient-reported measures of physical function and did not contribute to patient-reported physical function after accounting for covariates and quadriceps strength.
The cause and effect relationship between hip abductor strength and physical function cannot be established.
In patients with unilateral TKA, testing the strength of the hip abductors using HHD is reliable. Hip abductor strength contributes to performance-based measures of physical function, but not to patient-reported measures in patients with unilateral TKA.
To determine whether a single bout of resistance exercise produces an analgesic effect in individuals with knee osteoarthritis (OA).
Eleven participants with knee OA (65.9 ± 10.4yrs), and 11 old (61.3 ± 8.2yrs) and 11 young (25 ± 4.9yrs) healthy adults performed separate bouts of upper and lower body resistance exercise. Baseline and post-exercise pressure pain thresholds were measured at eight sites across the body and pressure pain tolerance was measured at the knee.
Pressure pain thresholds increased following exercise for all three groups, indicating reduced pain sensitivity. For the young and old healthy groups this exercise-induced analgesia occurred following upper or lower body resistance exercise. In contrast, only upper body exercise significantly raised pain thresholds in the knee OA group, with variable non-significant effects following lower body exercise. Pressure pain tolerance was unchanged in all groups following either upper or lower body exercise.
An acute bout of upper or lower body exercise evoked a systemic decrease in pain sensitivity in healthy individuals irrespective of age. The decreased pain sensitivity following resistance exercise can be attributed to changes in pain thresholds, not pain tolerance. While individuals with knee OA experienced exercise-induced analgesia, a systemic decrease in pain sensitivity was only evident following upper body exercise.
Objective
Knee osteoarthritis (OA) is a leading cause of disability and joint pain. Although other risk factors of knee OA have been identified, how physical activity affects incident knee OA remains unclear. Methods
Using data from the first (1999–2004) and second (2005–2010) followup periods of the Johnston County Osteoarthritis Project study, we tested the association between meeting physical activity guidelines and incident knee outcomes among 1,522 adults ages ≥45 years. The median followup time was 6.5 years (range 4.0–10.2 years). Physical activity at baseline (moderate-equivalent physical activity minutes/week) was calculated using the Minnesota Leisure Time Physical Activity questionnaire. Incident knee radiographic OA (ROA) was defined as the development of Kellgren/Lawrence grade ≥2 in a knee at followup. Incident knee symptomatic ROA (sROA) was defined as the development of ROA and symptoms in at least 1 knee at followup. Weibull regression modeling was used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for interval-censored data. ResultsIn multivariable models, meeting the 2008 Department of Health and Human Services (HHS) physical activity guidelines (≥150 minutes/week) was not significantly associated with ROA (HR 1.20 [95% CI 0.92–1.56]) or sROA (HR 1.24 [95% CI 0.87–1.76]). Adults in the highest level (≥300 minutes/week) of physical activity had a higher risk of knee ROA and sROA compared with inactive (0 to <10 minutes/week) participants; however, these associations were not statistically significant (HR 1.62 [95% CI 0.97–2.68] and HR 1.42 [95% CI 0.76–2.65], respectively). Conclusion
Meeting the HHS physical activity guidelines was not associated with incident knee ROA or sROA in a cohort of middle-aged and older adults.
Recent findings suggest that certain individuals with musculoskeletal pain conditions have increased Sensitivity to Physical Activity (SPA) and respond to activities of stable intensity with increasingly severe pain. This study aimed to determine the degree to which individuals with knee OA show heightened SPA in response to a standardized walking task and whether SAP cross-sectionally predicts psychological factors, responses to Quantitative Sensory Testing (QST) and different OA-related outcomes. 107 adults with chronic knee osteoarthritis completed self-report measures of pain, function and psychological factors, underwent QST and performed a 6-minute walk test. Participants rated their discomfort levels throughout the walking task; an index of SPA was created by subtracting first ratings from peak ratings. Repeated measures analysis of variance revealed that levels of discomfort significantly increased throughout the walking task. A series of hierarchical regression analyses determined that after controlling for significant covariates, psychological factors and measures of mechanical pain sensitivity, individual variance in SPA predicted self-report pain and function and performance on the walking task. Analyses also revealed that both pain catastrophizing and the temporal summation of mechanical pain were significant predictors of SPA and that SPA mediated the relationship between catastrophizing and self-reported pain and physical function. The discussion addresses the potential processes contributing to SPA and the role it may play in predicting responses to different interventions for musculoskeletal pain conditions.
Objective:
To investigate associations between self-reported knee confidence and pain, self-reported knee instability, muscle strength, and dynamic varus-valgus joint motion during walking.
Methods:
We performed a cross-sectional analysis of baseline data from 100 participants with symptomatic and radiographic medial tibiofemoral compartment osteoarthritis (OA) and varus malalignment recruited for a randomized controlled trial. The extent of knee confidence, assessed using a 5-point Likert scale item from the Knee Injury and Osteoarthritis Outcome Score, was set as the dependent variable in univariable and multivariable ordinal regression, with pain during walking, self-reported knee instability, quadriceps strength, and dynamic varus-valgus joint motion during walking as independent variables.
Results:
One percent of the participants were not troubled with lack of knee confidence, 17% were mildly troubled, 50% were moderately troubled, 26% were severely troubled, and 6% were extremely troubled. Significant associations were found between worse knee confidence and higher pain intensity, worse self-reported knee instability, lower quadriceps strength, and greater dynamic varus-valgus joint motion. The multivariable model consisting of the same variables significantly accounted for 24% of the variance in knee confidence (P < 0.001).
Conclusion:
Worse knee confidence is associated with higher pain, worse self-reported knee instability, lower quadriceps muscle strength, and greater dynamic varus-valgus joint motion during walking. Since previous research has shown that worse knee confidence is predictive of functional decline in knee OA, addressing lack of knee confidence by treating these modifiable impairments could represent a new therapeutic target.
To assess exercise induced analgesia (EIA) and pain sensitivity in hip and knee osteoarthritis (OA) and to study the effects of neuromuscular exercise and surgery on these parameters.
The dataset consisted of knee (n = 66) and hip (n = 47) OA patients assigned for total joint replacement at Lund University Hospital undergoing pre-operative neuromuscular exercise and 43 matched controls. Sensitivity to pressure pain was assessed by pressure algometry at 10 sites. Subjects were then instructed to perform a standardized static knee extension. Pressure pain thresholds (PPTs) were assessed at the contracting quadriceps muscle (Q) and at the resting deltoid muscle (D) before and during contraction. The relative increase in PPTs during contraction was taken as a measure of localized (Q) or generalized (D) EIA. Patients were assessed at baseline, following on average 12 weeks of neuromuscular exercise and 3 months following surgery.
We found a normal function of EIA in OA patients at baseline. Previous studies have reported beneficial effects of physical exercise on pain modulation in healthy subjects. However, no treatment effects on EIA were seen in OA patients despite the increase in muscle strength following neuromuscular exercise and reduced pain following surgery. Compared to controls, OA patients had increased pain sensitivity and no beneficial effects on pain sensitivity were seen following treatment.
To our knowledge, this is the first study of EIA in OA patients. Despite increased pain sensitivity, OA patients had a normal function of EIA.