Introduction

The optimal management of spondyloarthritis (SpA) requires a combination of non-pharmacological and pharmacological treatments. The 2010 update of the Assessment of SpondyloArthritis International Society/European League Against Rheumatism (ASAS/EULAR) recommendations for the management of ankylosing spondylitis (AS) recommends non-pharmacological therapy, the cornerstone being patient education and regular exercise . Non-pharmacologic therapy in SpA has traditionally focused on the exercise regimens whose purpose is to maintain mobility and strength, relieve symptoms, prevent or limit spinal deformity, contribute to long-term cardiopulmonary health, and improve overall function and quality of life. Axial SpA, mainly AS, has been the most-studied condition, while peripheral SpA including psoriatic arthritis (PsA) has been included in fewer reports. Although study techniques have varied widely and no standardized intervention has emerged, exercise programs such as home exercise, group exercise, inpatient programs, spa exercise, mud baths, and manual and electrotherapy have all been the subject of multiple reports that will be reviewed here. In recent years, there has been an added emphasis on maintaining cardiopulmonary function as well as addressing cardiovascular risk factors in SpA patients. In addition, there has been renewed interest in behavioral interventions that maximize disease knowledge and increase motivation for compliance, as well as healthy lifestyle choices including smoking cessation and weight management. Finally, diet and probiotics are becoming the subjects of intensive study as the interaction of the gut, the microbiome, and SpA gains widespread recognition.

Home exercise programs

Not all physical activity is automatically beneficial to AS patients. In a survey of 397 AS patients diagnosed at least 20 years previously, those with jobs requiring dynamic flexibility consisting of bending, twisting, stretching, and reaching had more functional limitations as measured by Bath Ankylosing Spondylitis Functional Index (BASFI) scores compared to patients without these physical demands . In addition, AS patients who had experienced requirements for dynamic flexibility, extent flexibility, and whole body vibration also had higher Bath Ankylosing Spondylitis Radiology Index for the spine (BASRI-s) scores indicating radiographic spinal damage.

A home exercise program (HEP) in the treatment of AS has advantages of low cost, ease of initiation, and a track record of efficacy in trials over the last 25 years. While early studies assessed more limited parameters of finger-to-floor distance and physical function , subsequent studies have included assessments of pain, mobility, disease activity, quality of life, and respiratory function . With the recognition of increased cardiovascular risk factors and mortality in patients with SpA, cardiovascular fitness has become an additional area of study , although improvement in cardiovascular risk factors has not been claimed.

The simplest comparison is of a HEP versus a control without specific intervention. The study by Sweeney et al. consisted of 200 AS patients from a registry, half of whom were assigned an exercise/intervention video, an exercise progress chart, patient education booklet, and AS exercise reminder stickers for 6 months and half were assigned to a control group without this program . While measures of function (BASFI) and disease activity (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)) showed no between-group differences, the exercise group showed a significant improvement in self-efficacy, self-reported AS mobility, and in aerobic exercise. In a second study, Lim et al. compared a HEP in 25 AS patients to 25 control patients on a waiting list . The exercises consisted of a daily 20-min program including 16 exercises targeting muscle relaxation, flexibility, strengthening, respiration, and posture. After an 8-week course, there were statistically significant improvements in joint mobility, finger-floor distance, functional capacity, pain scores, and depression scores. A third study, by Durmus et al., included an arm of 19 AS patients performing home exercise, 19 AS patients performing unsupervised global postural re-education (GPR) versus a 13-AS patient standard of care control . The 12-week exercise regimen consisted of 20 exercises, including mobilization, stretching, and respiratory exercise, while the GPR also had warm-up and posture components. The results showed a greater improvement in functional capacity (BASFI), disease activity (BASDAI), fatigue (Multidimensional Assessment of Fatigue Scale), depression (Beck Depression Inventory scores), and (QOL) Quality of Life (Short Form 36) in the pooled exercise groups.

Home exercise programs

Not all physical activity is automatically beneficial to AS patients. In a survey of 397 AS patients diagnosed at least 20 years previously, those with jobs requiring dynamic flexibility consisting of bending, twisting, stretching, and reaching had more functional limitations as measured by Bath Ankylosing Spondylitis Functional Index (BASFI) scores compared to patients without these physical demands . In addition, AS patients who had experienced requirements for dynamic flexibility, extent flexibility, and whole body vibration also had higher Bath Ankylosing Spondylitis Radiology Index for the spine (BASRI-s) scores indicating radiographic spinal damage.

A home exercise program (HEP) in the treatment of AS has advantages of low cost, ease of initiation, and a track record of efficacy in trials over the last 25 years. While early studies assessed more limited parameters of finger-to-floor distance and physical function , subsequent studies have included assessments of pain, mobility, disease activity, quality of life, and respiratory function . With the recognition of increased cardiovascular risk factors and mortality in patients with SpA, cardiovascular fitness has become an additional area of study , although improvement in cardiovascular risk factors has not been claimed.

The simplest comparison is of a HEP versus a control without specific intervention. The study by Sweeney et al. consisted of 200 AS patients from a registry, half of whom were assigned an exercise/intervention video, an exercise progress chart, patient education booklet, and AS exercise reminder stickers for 6 months and half were assigned to a control group without this program . While measures of function (BASFI) and disease activity (Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)) showed no between-group differences, the exercise group showed a significant improvement in self-efficacy, self-reported AS mobility, and in aerobic exercise. In a second study, Lim et al. compared a HEP in 25 AS patients to 25 control patients on a waiting list . The exercises consisted of a daily 20-min program including 16 exercises targeting muscle relaxation, flexibility, strengthening, respiration, and posture. After an 8-week course, there were statistically significant improvements in joint mobility, finger-floor distance, functional capacity, pain scores, and depression scores. A third study, by Durmus et al., included an arm of 19 AS patients performing home exercise, 19 AS patients performing unsupervised global postural re-education (GPR) versus a 13-AS patient standard of care control . The 12-week exercise regimen consisted of 20 exercises, including mobilization, stretching, and respiratory exercise, while the GPR also had warm-up and posture components. The results showed a greater improvement in functional capacity (BASFI), disease activity (BASDAI), fatigue (Multidimensional Assessment of Fatigue Scale), depression (Beck Depression Inventory scores), and (QOL) Quality of Life (Short Form 36) in the pooled exercise groups.

Group physical therapy compared to an HEP

Several studies have addressed whether supervised group exercise provides superior results compared to an unsupervised HEP. The first of these was a randomized study of 144 AS patients who underwent a daily 30-min HEP compared with the same HEP plus a 3-h weekly group physical therapy session consisting of exercises, sport, and hydrotherapy. While both groups achieved a benefit, there was a statistically significant further gain for the physical therapy patients in thoracolumbar flexion and extension, improved maximum load in ergometry, and patient global assessment . A second study was a prospective, double-blind study comparing 51 AS patients receiving an exercise program under the supervision of a physical therapist (50-min session, three times weekly, for 6 weeks) with an HEP carried out individually . The same exercise program was taught to both groups and included stretching, mobilization, and strengthening of the back and extremities, aerobic exercise on a stationary bicycle, and postural and respiratory exercises. The group exercise patients, but not the HEP patients, had a statistically significant improvement on measures of physical flexibility, Astrand test of physical conditioning, Beck Depression Scale, BASFI, but not pain scores. A third study compared 12 weeks of supervised twice-weekly group physical therapy plus an HEP to the unsupervised HEP alone . At 3 months after the intervention, the supervised group demonstrated improved BASFI and SF-36 scores. A fourth study compared three different conditions: group exercise 3 days a week for 3 years, 1 month annually of supervised individual exercise along with unsupervised home exercise for the remainder of 3 years, and an HEP alone for 3 years . This was the longest of the studies and no significant differences were found between groups. The most recent study was a non-randomized, 6-week study of 41 patients receiving either a group exercise program three times a week, compared to an HEP . Both groups achieved statistically significant improvement in BASDAI, Bath Ankylosing Spondylitis Metrology Index (BASMI), and several subscores of the Nottingham Health Profile, but there were no significant differences between the two groups.

Instructions in proper posture and exercises to improve posture have been variably included in previous exercise programs. Elyan and Khan summarized the goal of minimizing spinal deformity by: (1) keeping the spine straight while walking or sitting, (2) avoiding prolonged stooping or bending, and (3) sleeping on the back using a firm mattress and the thinnest possible pillow . The method of GPR has been described where the goal is to perform exercises that stretch and strengthen shortened muscle chains, such as eccentric work of the erector spine muscle, the posterior muscle chain in the pelvic region, and the anterior chain of the scapular girdle . In a randomized 4-month trial of 45 AS patients, one group received weekly exercises based on the GPR method, while the other had a weekly session of 20 conventional exercises used in previous clinical trials . The results showed that the GPR group achieved a greater improvement than the control group in all clinical measures of the BASMI except tragus-to-wall distance, and in the BASFI index. The same group followed up 1 year later on those patients who had continued their assigned exercise program at least three times per month and found that, compared to pre-intervention status, the GPR group had significant differences in all mobility measures of the BASMI, except for cervical rotation, and in the BASFI, in favor of the GPR group . In a more recent trial of at least 4 months, 22 patients received GPR and were compared to 16 control patients undergoing conventional segmental self-stretching and breathing exercises . All tested parameters had improved at the end of the trial in both groups, while select ones differed between the two groups. Patients in the GPR group had statistically significantly greater improvement in morning stiffness, spine mobility parameters, chest expansion, and the physical aspect component of the SF-36.

One study has specifically focused on the effects of a rehabilitation program in AS patients whose disease has already stabilized on a tumor necrosis factor (TNF) inhibitor . Sixty-two patients were randomized to rehabilitation plus an educational-behavioral program, to the educational-behavioral program alone, or to a control group. The educational-behavioral training consisted of two behavioral sessions and 10 exercise training sessions over 20 weeks, while the rehabilitation group added 12 twice-weekly exercise sessions (respiratory, stretching, mobilization, proprioceptive, and endurance). At follow-up at 2 and 6 months, patients in the rehabilitation program were able to further improve spine mobility and reduce pain, stiffness, and disability on top of their existing response to TNF-inhibitor treatment.

A large nationwide study in Spain assessed the impact of a structured education and HEP in daily practice patients with AS . A total of 756 patients with AS (72% males, mean age 45 years) participated in a 6-month prospective multicenter controlled study, 381 of whom were randomized to an education intervention (a 2-h informative session about the disease and the implementation of a non-supervised physical activity program at home) and 375 to standard care (controls). At 6 months, there was a significant difference in the education group in BASDAI and BASFI as well as in visual analog scale (VAS) for total pain, patient’s global assessment, and in AS Quality of Life (ASQoL) compared to those in standard care. Patients in the education group increased their knowledge about the disease and its treatments and practiced more regular exercise than controls .

A study attempted to develop a clinical prediction rule to identify AS patients who are likely to benefit from group-based exercise therapy . Thirty-five consecutive patients with AS underwent a standardized examination and then received eight physical therapy sessions during a 2-month period, which included an exercise program based on the GPR method. Patients were classified as having experienced a successful outcome at 1 month after discharge based on a 20% reduction on BASFI and a self-perceived global rating of change. Sixteen patients (46%) experienced a successful outcome. Regression analysis identified three predictors – physical role (from the MOS 36-Item Short Form Health Survey) >37, bodily pain (from the MOS 36-Item Short Form Health Survey) >27, and BASDAI >31. The most accurate predictor of success was if the patient exhibited two of the three variables, and the positive likelihood ratio was 11.2 (95% confidence interval, 1.7–76.0) and the posttest probability of success increased to 91%. Thus, patients with less disease severity will likely have better outcomes with group-based exercise. The clinical prediction rule requires further validation.

Overall, these studies of group exercise show improvements in multiple of the parameters that were measured compared to baseline, with the majority showing a statistically significant benefit of group exercise as compared to an HEP. As little as one weekly group physical therapy session provided a benefit . Adding a rehabilitation program to patients already controlled by TNF-inhibitor therapy added further benefit. However, the studies were small, many of short duration, and effective blinding, where attempted, was difficult with this physical intervention.

Water therapy, balneotherapy, Spa exercise, mud baths

Therapies involving bathing in water or experiencing the massage effects of flowing water are collectively referred to as water therapy or hydrotherapy. Balneotherapy indicates that these activities are carried out in mineral waters, often at a spa. Spa therapy often involves a program with multiple daily activities that may include group exercise, postural correction, hydrotherapy, balneotherapy, thermal baths, sauna treatments, and sports.

A recent randomized trial compared 69 patients assigned to 20 sessions of aquatic therapy over 4 weeks with patients assigned to home-based exercises demonstrated once by a physical therapist . The results showed that six scales of the SF-36 focused on pain and quality of life were statistically superior in the aquatic group compared to the home exercise group when studied at 4 and 12 weeks posttreatment. Previously, a small randomized, controlled study found that 6 weeks of outpatient hydrotherapy with home exercises was associated with significantly better short-term improvement in neck mobility and VAS for pain and stiffness compared with 6 weeks of exercise alone, but no significant differences remained 6 months later .

A small study of balneotherapy compared 28 patients receiving daily 30-min sessions for 3 weeks along with a daily 30-min HEP for 6 months with 26 patients on an HEP alone for all 6 months . At the end of the first 3 weeks, the balneotherapy group had better disease activity and quality of life measures (BASDAI, Nottingham Health Profile, pain, tiredness, and sleep score, physical activity, patient’s and physician’s global evaluation) than the HEP alone. At 6 months of follow-up, only the patient’s global evaluation and modified Schober’s test were better in the balneotherapy group but there were no significant between-group differences in physical function, pain, stiffness, or spinal mobility.

Spa therapy has been evaluated in a randomized controlled study for 40 weeks, assigning 40 patients each to two European resorts for a 3-week spa program plus 37 weeks of supervised group exercise, and a third group of 40 patients to 40 weeks of supervised group exercise alone . The spa plus exercise groups showed significant improvement in pain and Health Assessment Questionnaire for Spondyloarthropathies (HAQ-S) scores through 4 weeks, but no significant between-group differences remained by week 40. Use of spa therapy cost 3023 or 3240 euros, compared with 1754 euros for the group exercise controls .

Bathing in the waters of the Dead Sea, at times with the addition of mud-bath treatments, has been studied in three prospective trials of PsA and one of AS, as reviewed in 2012 . In PsA, the largest study had 166 patients, all of whom underwent Dead Sea water balneotherapy and phototherapy . In addition, 146 of the patients also received treatment with additional mudpacks and sulfur baths. Both groups had significant improvement in clinical parameters, with additional significant reduction in spinal pain and improved lumbar spine range of motion only in the mudpack/sulfur bath group. AS was studied in a randomized prospective 2-week trial with a blinded researcher, treating 14 patients using a freshwater pool in the Dead Sea and comparing them to 14 patients treated with mudpacks and a sulfur pool . There were significant improvements in both groups in BASDAI, the VAS for pain, and the VAS for spinal movement. Quality of life improved due to pain reduction in the mudpacks/sulfur pool group only. Uncontrolled small trials from other parts of the world have also reported benefits for peloid therapy (therapeutic mud application) and bathing in radon-containing water .

Manual therapy

Manual therapy is a physical treatment that includes kneading and manipulation of muscles, joint mobilization, and joint manipulation used to treat musculoskeletal pain and disability . The first known trial to examine manual therapy for AS was reported in 2009 . This prospective, randomized controlled study randomized 32 men, aged between 23 and 60 years, with AS to active or no treatment for 8 weeks. The patients in the treatment group were given individualized self- and manual mobilization for 1 h twice a week for 8 weeks. The physiotherapeutic intervention consisted initially of warming up the soft tissue of the back muscles (with vibrations via a vibrator) and gentle mobility exercises. This was followed by both active angular and passive mobility exercises in the physiological directions of the joints in the spinal column and in the chest wall in three directions of motion (flexion/extension, lateral flexion, and rotation) and in different starting positions (lying face down, sideways, on the back, and in a sitting position). Passive mobility exercises consisted of general, angular movements and specific, translatory movements. Stretching of tight muscles was done using the contracting–relaxing method. Soft tissue treatment (manual massage) of the neck was performed followed by relaxation exercises in a standing position and resting for some minutes lying on the treatment bench. Patients in the treatment group showed significant improvement in chest expansion, posture, spinal mobility, and the BASMI. There were no differences between the two groups with regard to vital capacity, BASDAI, Bath Ankylosing Spondylitis Global scale (BAS-G), or BASFI. At 4 months follow-up of the treatment group, cervical spine posture, lumbar flexion, and range of motion as well as BASMI remained improved.

Electrotherapy

Electrotherapy has a well-established role within physiotherapy practice . The modalities may be classified into thermal, electrical, electromagnetic, and sonic. However, few studies have formally investigated the use of electrotherapy in SpA. A pilot study investigated the effect of a new modality for whole-body hyperthermia, named infrared (IR) sauna, in rheumatoid arthritis (RA) and AS . Seventeen AS and 17 RA patients were studied. Pain and stiffness decreased clinically, and improvements were statistically significant during an IR session. Fatigue also decreased. However, no statistically significant improvement in pain, stiffness, and fatigue could be demonstrated at the end of 4-week treatment period. No relevant changes in disease activity scores were found. Interestingly, whole-body cryotherapy has also been investigated. In a prospective study, 12 patients with AS and 48 with RA underwent treatment with whole-body cryotherapy twice a day . In patients with AS, statistically significant reduction in BASDAI was demonstrated. Reduction in pain over 2 months was demonstrated in these patients. The authors opined that the relief of pain could allow an intensification of physiotherapy. Transcutaneous electrical nerve stimulation (TENS) can reduce pain in many musculoskeletal disorders. No recent reports have emerged on the use of this modality in AS, although previous trials suggest that TENS may provide relief of pain and stiffness .

Inpatient rehabilitation

An inpatient rehabilitation program gives the opportunity for intensive therapy sessions multiple times a day, use of multiple modalities, as well as education and reinforcement of techniques.

A small, randomized controlled study included 15 AS patients assigned to an inpatient rehabilitation arm consisting of five weekly group exercise sessions and three weekly hydrotherapy sessions for 3 weeks and compared them to 14 patients assigned to performing 6 weeks of home exercises alone . All patients were then encouraged to continue home exercises long term. The inpatient regimen provided only short-term improvement in pain and stiffness compared to the home exercise patients, with no between-group differences remaining at 6 months. A second randomized trial consisted of 39 AS patients undergoing 3 weeks of inpatient physical therapy but added passive hip joint stretching in 27 of them . The results showed improvement in hip range of motion, except flexion, in those undergoing hip joint stretching, with reassessment of seven patients 6 months later suggesting that benefits were sustained in those who continued the exercises on their own.

There are also negative studies of inpatient rehabilitation programs. A 3-week twice-daily HEP was compared with 3 weeks (15 sessions) of inpatient rehabilitation for 60 AS patients . The inpatient program included physical therapy, occupational therapy, and therapeutic exercise, while the home program was of postural, respiratory, and stretching exercises, walking endurance, and mobilization. Assessment was of BASDAI every 3 months and BASFI at 15 months, and showed no significant between-group differences. Similar negative findings were part of EULAR 2003 presentation that was not published as a full study . Multimodal Programs with Aerobic and Pulmonary Exercises, and Incentive Spirometry .

The investigation of measures that include cardiopulmonary fitness is attractive in the setting of AS, an inflammatory disease with elevated cardiovascular morbidity and mortality as well as mechanical restriction of the chest bellows function due to bone deposition and fusion.

A small, randomized controlled study of a multimodal exercise program was performed in a convenience sample of 30 AS patients . The 3-month study compared a supervised exercise program with 50 min of aerobic exercise, stretching, and pulmonary exercises three times weekly to medical treatment alone. The exercise group showed significantly better chest expansion, chin to chest distance, modified Schober’s test, occiput to wall distance, and spinal mobility. In addition, the cardiopulmonary parameters of physical work capacity and vital capacity improved in the exercise group but declined in the controls. A more recent multimodal HEP consisted of breathing, postural, and stretching exercises (based on the Pilates, Heckscher, and McKenzie methods) . The results showed significantly improved disease activity, physical function, spinal mobility, and vital capacity compared to an exercise program that combined step aerobics and stretching.

Karapolat et al. have performed a randomized, controlled study in 45 AS patients to investigate the effects of adding aerobic exercise (swimming or walking three times per week for 6 weeks) to an HEP of stretching and mobility . While all groups showed improvement in FEV1, FVC, and VC, the two groups adding aerobic exercise to the HEP showed an improvement in the 6-min walk test and in maximal oxygen uptake. A recent report of a randomized study in 106 AS patients found that adding cardiovascular training in the form of supervised Nordic walking 30 min/day, 2 days/week for 6 weeks resulted in greater cardiovascular fitness on a bicycle test but did not alter risk factors such as cholesterol or triglycerides, disease activity, quality of life, or spinal mobility . Finally, adding incentive spirometry for 30 min daily for 16 weeks to an HEP did not result in improved measures of disease activity, pulmonary function tests, or 6-min walk testing .