<LEAP> highlights the findings and application of Cochrane reviews and other evidence pertinent to the practice of physical therapy. The Cochrane Library is a respected source of reliable evidence related to health care. Cochrane systematic reviews explore the evidence for and against the effectiveness and appropriateness of interventions—medications, surgery, education, nutrition, exercise—and the evidence for and against the use of diagnostic tests for specific conditions. Cochrane reviews are designed to facilitate the decisions of clinicians, patients, and others in health care by providing a careful review and interpretation of research studies published in the scientific literature.1 Each article in this PTJ series summarizes a Cochrane review or other scientific evidence on a single topic and presents clinical scenarios based on real patients or programs to illustrate how the results of the review can be used to directly inform clinical decisions. This article focuses on the use of exercise to manage symptoms of rheumatoid arthritis. Can dynamic exercise, both aerobic and strength training, improve function and well-being in individuals with rheumatoid arthritis?
Rheumatoid arthritis (RA) is a systemic autoimmune disease with a prevalence of 0.5% to 1% of the adult population in northern Europe and North America and a slightly lower percentage of adults in other parts of the world.2,3 Rheumatoid arthritis greatly affects function.2 The predominant feature of RA is symmetrical polyarthritis, often first affecting the hands and feet. Over time, chronic synovitis can lead to joint destruction. If untreated, nearly 10% of individuals affected with RA develop joint deformities within 2 years of diagnosis. Thus, early aggressive medical therapy is recommended to prevent joint and tissue damage.4 Data indicate that people with RA are 33% to 55% weaker compared with matched controls who are healthy due to atrophy of type I and type II muscle fibers resulting from disuse.4,5 Rheumatoid arthritis–related symptoms also include joint stiffness and fatigue. The prevalence of RA-related fatigue has been reported as high as 80%.5 Muscle weakness, fatigue, and joint pain may lead to diminished aerobic capacity, functional limitations and reduced participation in social activities.
Rheumatoid arthritis–associated inflammation is a major factor affecting the risk of cardiovascular disease. People with RA are twice as likely as their age- and sex-matched peers to develop cardiovascular disease, suggesting that RA is an independent risk factor for cardiovascular events.6 Dynamic exercise programs are those of sufficient intensity, duration, and frequency to establish improvement in aerobic capacity or muscle strength, or both.7 Studies of dynamic exercise for people with RA have been a major focus in nonpharmacologic rheumatology research over the past 30 years, with respect to both determining appropriate dose of exercise and assessing safety and impact on joint integrity. A Cochrane review by Hurkmans et al7 in 2009 updated and expanded upon a Cochrane review conducted by Van den Ende et al8 in 1998, which provided evidence of the beneficial effects of dynamic exercise for people with RA with respect to aerobic capacity, muscle strength, and joint mobility.
Hurkmans et al7 provided a synthesis of randomized controlled studies on the effect of dynamic exercise therapy in patients with RA. The specific objective was to determine the effectiveness and safety of short-term (<3 months) and long-term (>3 months) supervised dynamic exercise therapy programs for people with RA, either aerobic or strengthening, performed at least twice weekly for more than 20 minutes on land or in water. To be included in the systematic review, all exercise programs must have been of at least 6 weeks' duration. Aerobic exercises had to be performed at an intensity of more than 55% of the maximum heart rate or at an intensity beginning at 40% to 50% of maximum oxygen uptake reserve and increasing to 85% during the intervention. Muscle strengthening exercises had to be performed starting at 30% to 50% of 1 repetition maximum and increasing to 80% of maximum. Outcomes were classified as either measures of effectiveness (functional ability, self-reported pain) or measures of safety (adverse events, defined as muscle injuries or substantially increased pain as a direct result of the intervention). Secondary outcomes included aerobic capacity and muscle strength of the knee extensors.
Take-Home Message
In this Cochrane review,7 Hurkmans et al compared 8 randomized controlled trials of 575 adults, predominantly female, with physician-diagnosed and physician-confirmed RA, meeting established criteria for RA.9,10 All study participants had low to moderate disease activity. Data were presented using standardized mean differences as a measure of effect size.
A unique aspect of this updated Cochrane review is the separate reporting of data for 4 different dynamic exercise interventions: results from short-term aerobic exercises performed on land, short-term aerobic and strengthening exercises performed on land, long-term aerobic and strengthening exercises, and short-term aquatic aerobic exercises. All programs were deemed safe and did not report any adverse events (Appendix).
Analysis of data from studies of short-term, land-based aerobic exercise indicated evidence for a large, significant effect on aerobic capacity (pooled effect size=0.99, 95% confidence interval [CI]=0.29 to 1.68) immediately following the intervention and a nonsignificant trend for positive effect on functional ability (pooled effect size=0.03, 95% CI=−0.46 to 0.51) following the intervention. Data could not be pooled for muscle strength, and there were no significant effects for pain or disease activity either immediately following the intervention or at follow-up.
With respect to short-term, land-based aerobic and muscle strengthening exercises, the data could not be pooled for strength or function, nor could conclusions be drawn regarding pain and disease activity. There was a nonsignificant trend for a positive effect in functional ability (pooled effect size=−0.40, 95% CI=−0.86 to 0.06) and a significant medium effect for improved strength (pooled effect size=0.47, 95% CI=0.01 to 0.93) following the intervention.
The data from studies of short-term, water-based aerobic exercise could be pooled only for aerobic capacity and not for any other outcome measure. The results indicate a medium, nonsignificant effect for aerobic capacity (pooled effect size=0.47, 95% CI=−0.04 to 0.98).
Long-term, land-based combined aerobic and muscle strengthening exercise programs of greater than 3 months' duration could be pooled only for strength. The analysis indicates a moderate, nonsignificant effect for muscle strength (effect size=0.49, 95% CI=−0.06 to 1.04). Due to study heterogeneity, data could not be pooled for other outcomes. Based on the results of the systematic review, the authors support the use of aerobic capacity training combined with muscle strengthening exercises for people with RA and report no deleterious effects with respect to pain or increased disease activity.
Case #10: Applying Evidence to Address Muscle Weakness, Functional Impairment, and Reduced Aerobic Capacity
M.K. is a 43-year-old white woman with a 5-year history of RA. She is married and has 3 children. She began with traditional disease-modifying antirheumatic drugs (DMARDs) and was later switched to biologic therapy (bDMARDs) and was referred for physical therapy for pain management, exercise, and patient education. M.K.'s primary complaints upon presentation for physical therapy were fatigue, joint pain, and swelling in hands, feet and knees. The initial assessment included a review of her medical history, observation of functional activities, a multisystem screen, and a full musculoskeletal assessment. Her vital signs were: heart rate of 82 bpm, blood pressure (sitting) of 128/80, and respiratory rate of 15 respirations/min. Her rheumatoid disease activity score (DAS-CRP3),11 a combination of laboratory markers of disease activity and joint examination, was 3.4 (low disease activity is classified as <2.4, moderate as 2.4 to ≤3.7, and highly active RA as >3.7).12 Upon inspection, her hands and feet were swollen bilaterally. Her knees were swollen, with visible fluid present in the infrapatellar pouch. Fusiform swelling was evident in the fingers.
Performance measures included standard range of motion (ROM) and strength13 as well as core self-report outcome measures, including the Medical Outcomes Study 12-Item Short-Form Health Survey (SF-12),14,15 a measure of health status and quality of life, and the Health Assessment Questionnaire (HAQ), a disease-specific measure of disability used in people with arthritis.16 Her general physical status was poor (SF-12 score=27; the range for scores for the SF-12 is 0 [poor] to 100 [very good]). Mental health, as measured by the Mental Health Index (MHI-5),17 also was poor (MHI-5 score=45; the range of scores for the MHI-5 is 0 [poor] to 100 [very good]). Her HAQ score of 2.7 (possible range of scores=0–3, with higher scores indicating more limitations) indicated that she was severely disabled by her disease. The patient's perception of joint pain ranged from low to high, depending on time of day and activity (range=2–7 out of 10). Pain was worse in the morning than in the afternoon, and more challenging physical activities were more difficult to perform.
M.K.'s ROM was within functional limitations except for grip; she was unable to make a full fist. Distal interphalangeal and proximal interphalangeal flexion was restricted to 15 degrees, and metacarpophalangeal joint extension was limited to 10 degrees bilaterally. Both wrists had an ulnar deviation of about 15 degrees. Wrist flexion was limited to 50 degrees and wrist extension was limited to 45 degrees bilaterally. M.K. had visible difficulty performing sit-to-stand transfers without use of armrests and reported difficulty with ascending and descending stairs. M.K. reported she had delegated household tasks (eg, setting the table, making beds) and avoided activities that required stairs. She also required assistance lifting dishes and pots and pans.
The patient and her therapist established the following goals for intervention: development and use of self-management techniques (application of heat or cold modalities to painful joints, modifying activities to reduce fatigue) and instruction in and appropriate use of ROM, strengthening, and aerobic exercises, depending on the condition of her joints and her disease activity. M.K. agreed to attend therapy twice weekly for a total of 60 minutes for 6 weeks.
Therapy sessions began either with modalities (initially cold packs and then, with subsiding inflammation, paraffin or hot packs) for painful days or a 10-minute warm-up on the bike. Sessions included flexibility and ROM exercises followed by low-intensity strengthening with increasing resistance as disease activity subsided. Supervised strength training began with 1-kg weights for 8 repetitions and progressed to 10 repetitions with 1- to 1.5-kg weights for the shoulder and elbow flexors and extensors. Active exercises for the wrist flexors and extensors and the forearm pronators and supinators were performed with 0.5- to 1-kg weights for 10 to 12 repetitions. To strengthen her hip and knee flexors and extensors, the patient began with 1.5- to 2-kg weights for 8 repetitions each and progressed to 10 repetitions. Resistance progressed as tolerated. Feedback was provided for proper form. Once joint inflammation subsided, exercises were performed at 60% of 1-repetition maximum contraction for 10 to 12 repetitions each. Aerobic exercises began at 30% of predicted heart rate for 10 minutes and then increased to moderate intensity (60%) for a total of 15 to 20 minutes per session. The patient performed this exercise program at home, twice a week. M.K. received information about exercise and social support programs offered through the local Arthritis Foundation chapter. Included in every session was joint protection education, information on how to modify activities to address fatigue and pain, support for good decision making, and emphasis on the importance of taking medicines as prescribed. M.K. participated in supervised therapy for 6 weeks.
At discharge, her finger ROM had improved by 10 degrees, muscle strength in the hip and knee extensors and flexors had increased by 8%, and her tolerance for aerobic cycling exercise had increased to 35 minutes at 65% of predicted heart rate. M.K. reported decreased knee pain; pain during activities ranged from 0 to 4 out of 10. She was able to rise from a chair without using armrests and could use stairs. M.K.'s disability was significantly reduced (20% decrease in HAQ score; score at 6 weeks=2.1). At this point, M.K. transitioned to community exercise and self-management programs due to the cost of co-payments and continued her home exercise program of daily active ROM exercises, integrated into routine activities of daily living (showering, before bed and upon awakening) and functional strengthening and aerobic exercises.
Can a dynamic strengthening and aerobic capacity exercise program help this patient?
The review by Hurkmans et al7 included studies of patients of similar age, disease duration, and disease activity. The review reported the outcomes of combined short-term, supervised, land-based aerobic and strengthening exercises similar to the exercise intervention provided for M.K. However, one would expect M.K.'s results to be less dramatic than those reported in the review given the differences in duration and intensity of exercise and content of therapy sessions. M.K.'s supervised exercise program lasted 6 weeks rather than 12 weeks. In clinical practice, medical care costs and insurance guidelines can influence care, so it is improbable that M.K. would receive 12 weeks of supervised therapy. Rather M.K. continued her program at home and through the support of community resources. M.K.'s program exercise began at a low intensity due to the presence of active inflammation and pain, whereas the intensity used in the clinical trials was moderate. Additionally, M.K.'s sessions included the use of modalities to reduce pain and inflammation and education regarding activity modifications to address fatigue and pain. These self-management techniques were not provided in the studies and may have led to improved self-efficacy for disease management and adherence to exercise.
How well do the outcomes of intervention provided to M.K. match those suggested by the systematic review?
M.K. received twelve 60-minute therapist-supervised exercise and educational sessions over a 6-week period. She demonstrated modest improvements in ROM, likely due to the use of ROM exercises in her therapy sessions. Her self-reported disability (HAQ score) improved by 20%, a clinically important change. However, the exact change in disability is difficult to discern clinically, given that M.K. implemented strategies to adapt to her limitations (eg, encouraging her children to assist with chores) and ended supervised physical therapy sessions after 6 weeks. She reported decreased pain and improved endurance, although formal aerobic capacity testing was not implemented. M.K. did not experience any adverse events such as joint injury or increased disease activity with the intervention. In this case, manual muscle testing was used rather than a dynamometer, and scores for manual muscle testing improved up to one full grade for the upper and lower extremities. These changes are consistent with the data reported in the systematic review.7
Can you apply the results of the systematic review to your own patients?
The prevalence of female patients in the studies mirrors the epidemiology of RA (4:1 female to male ratio). The clinical trials were conducted in an outpatient setting with supervised instruction similar to the setting of therapy for most patients with RA. However, some differences that may affect patient outcomes should be noted. First, in clinical practice, 12 weeks of supervised physical therapy, twice a week, is less likely to be accepted under current models of health care plans. Thus, results of less impact may be expected in clinical practice, where the duration of supervised intervention may be limited to less than 12 weeks. Second, most study participants had less active rheumatoid disease, so results from the review7 should be generalized to patients with the same level of disease activity. Third, because some studies in the review preceded the use of biologic therapy, the presentation of patients in clinical settings may differ from that study participants with respect to joint erosions and functional ability, as biologic therapies are potent disease modifiers and recommended in practice guidelines.19 Thus, therapists may be able to use more intensive exercise and garner better results.
The Cochrane review7 has some limitations. The review excluded studies that combined exercise and patient education. This is a common and accepted practice in rheumatologic physical therapy, as patient self-management is paramount to managing RA and promoting exercise adherence. Additionally, due to data heterogeneity, effect sizes for specified outcomes could not be determined. Although the studies were conducted predominantly in outpatient settings, it is less common to provide short-term (12-week), supervised exercise, so generalizability may be a concern. However, most studies fulfilled 8 out of 10 methodological criteria, providing greater confidence in the reported results of the pooled data.
What can be advised based on the results of the systematic review?
Patients with RA who have moderate disease activity and limited joint erosions may benefit from short-term exercise including aerobic capacity and dynamic strength training. Short-term, land-based aerobic exercise is likely to improve aerobic capacity immediately following the intervention but may not affect muscle strength or functional ability. Short-term and long-term, land-based aerobic and strength training may improve aerobic capacity and muscle strength. Exercise also does not appear to produce any negative effects with respect to increased pain or disease activity.
Appendix.
Dynamic Strengthening and Aerobic Exercises to Reduce Pain and Improve Functional Outcomes and Strength in People With Established Rheumatoid Arthritis (RA): Cochrane Review7,a
a NSAIDs=nonsteroidal anti-inflammatory drugs, DMARDs=disease-modifying antirheumatic drugs, bDMARDs=disease-modifying antirheumatic drugs used in biologic therapy, ROM=range of motion, PST=progressive strengthening exercise, HAQ=Health Assessment Questionnaire, MCID=minimal clinically important difference, SMD=standardized mean difference, ESR=erythrocyte sedimentation rate, ES=effect size, CI=confidence interval, VAS=visual analog scale.
- Received November 30, 2011.
- Accepted June 20, 2012.
- © 2012 American Physical Therapy Association
References
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