ORIGINAL RESEARCH
New Approach in Fibromyalgia Exercise Program:
A Preliminary Study Regarding the Effectiveness of
Balance Training
Sibel Kibar, MD,
aHatice Ecem Yıldız, MD,
aSaime Ay, MD,
aDeniz Evcik, MD,
bEmine Su¨reyya Ergin, MD
aFrom theaDepartment of Physical Medicine and Rehabilitation, Ufuk University School of Medicine, Ankara; andbDepartment of Therapy and Rehabilitation, Ankara University Haymana Vocational School, Ankara, Turkey.
Abstract
Objectives: To determine the effectiveness of balance exercises on the functional level and quality of life (QOL) of patients with fibromyalgia syndrome (FMS) and to investigate the circumstances associated with balance disorders in FMS.
Design: Randomized controlled trial.
Setting: Physical medicine and rehabilitation clinic.
Participants: Patients (NZ57) (age range, 18e65y) with FMS were randomly assigned into 2 groups.
Interventions: Group 1 was given flexibility and balance exercises for 6 weeks, whereas group 2 received only a flexibility program as the control group.
Main Outcome Measures: Functional balance was measured by the Berg Balance Scale (BBS), and dynamic and static balance were evaluated by a kinesthetic ability trainer (KAT) device. Fall risk was assessed with the Hendrich II fall risk model. The Nottingham Health Profile, Fibromyalgia Impact Questionnaire (FIQ), and Beck Depression Inventory (BDI) were used to determine QOL and functional and depression levels, respectively. Assessments were performed at baseline and after the 6-week program.
Results: In group 1, statistically significant improvements were observed in all parameters (P<.05), but no improvement was seen in group 2 (P>.05). When comparing the 2 groups, there were significant differences in group 1 concerning the KAT static balance test (PZ.017) and FIQ measurements (PZ.005). In the correlation analysis, the BDI was correlated with the BBS (rZ.434) and Hendrich II results (rZ.357), whereas body mass index (BMI) was correlated with the KAT static balance measurements (rZ.433), BBS (rZ.285), and fall frequency (rZ.328).
Conclusions: A 6-week balance training program had a beneficial effect on the static balance and functional levels of patients with FMS. We also observed that depression deterioration was related to balance deficit and fall risk. Higher BMI was associated with balance deficit and fall frequency.
Archives of Physical Medicine and Rehabilitation 2015;96:1576-82 ª 2015 by the American Congress of Rehabilitation Medicine
Fibromyalgia syndrome (FMS) is a rheumatologic disorder with clinical features such as widespread pain, fatigue, cognitive symptoms, and nonrestorative sleep.1Up to 20% of the patients presenting at rheumatology clinics and >10% seeking general
medical care have FMS2; therefore, physicians should consider this syndrome in their usual clinical practice.
A variety of neurologic signs and symptoms (eg, dizziness, vertigo, tingling, burning) have been reported with FMS,3and it is also associated with balance problems and increased fall fre-quency.3,4Recently, it was reported that balance deficit was 1 of the 10 most debilitating symptoms of FMS, with a prevalence rate of 45%.5Additionally, compared with healthy individuals, FMS patients with a balance disorder were usually unaware of their problem.6Therefore, the daily living activities of those with FMS
Presented as a poster to the European League Against Rheumatism, June 11e14, 2014, Paris, France.
Clinical Trial Registration No.: 1506201221. Disclosures: none.
0003-9993/15/$36 - see front matterª 2015 by the American Congress of Rehabilitation Medicine
http://dx.doi.org/10.1016/j.apmr.2015.05.004
journal homepage:www.archives-pmr.org
are significantly decreased because of the balance deficit and inactivity caused by this condition.
The daily functional levels of patients with FMS are also poor.6 Moreover, these patients experience a reduction in cognitive functions compared with healthy controls,7and various pathologic conditions (eg, depression, headaches, variable bowel habits) may occur concomitantly. Therefore, symptom-based treatment methods lead to polypharmacy.8Formiga et al9found that the high numbers of geriatric patients with balance deficits who experience falling also have weakened functional and cognitive statuses and use multiple medications. Similarly, polypharmacy combined with cognitive impairment may also facilitate the balance deficit and falling in patients with FMS. However, it is still not clear which of the associated risk factors are related to the balance deficit.
Because the symptoms are patient-specific, the patients should be treated on an individual basis.10The European League Against Rheumatism has recommended individually tailored exercise pro-grams that include aerobic and strength exercises,11but only a few studies have focused on balance exercises. San˜udo et al12 investi-gated the effects of whole-body vibration training and found sta-tistically significant improvements compared with traditional methods. Additionally dynamic balance with tilt vibration exercises showed positive effects on FMS.13
However, Demir-Go¨c¸men et al10 found no significant differ-ences between balance and stretching exercises in FMS. In addi-tion, because there have been previous reports stating that FMS may affect the peripheral and central mechanisms of postural control,4,14more studies are needed to determine whether balance and exercise training can improve postural stability and reduce the number of falls in patients with FMS.
In this study, we aimed to assess the effectiveness of balance training in an FMS exercise program and to investigate the cir-cumstances associated with balance disorders in FMS.
Methods
Participants
Seventy-seven patients (age range, 18e65y) with FMS were evaluated by an experienced physiatrist between 2011 and 2013. The FMS diagnosis was based on the 2010 American College of Rheumatology diagnostic criteria.1Prospective participants with vitamin B12, 25-OH vitamin D, and folate deficiencies; diabetes mellitus; neurologic diseases; rheumatoid diseases; eye and in-ternal ear pathologies; advanced cardiovascular or lung pathol-ogies; and uncontrolled hypertension or hypotension were excluded. In addition, patients who previously underwent surgery, who had injuries in their lower extremities (knees, hips, ankles, feet), and who were admitted to a physical therapy and/or exercise program for their pain within the last year were also not included.
A researcher who was unaware of the treatment procedures used a computer program to randomly assign the patients to 1 of 2 groups using their patient record numbers. The enrollment and allocation process is shown infigure 1.
Group 1 was given balance exercises along with dynamic and static balance training on the Sports Kinesthetic Ability Trainer (KAT) 4000 deviceaand flexibility exercises. Group 2 received only flexibility exercises.
Two other experienced physiatrists who were blinded to the groups performed evaluations at baseline and after the 6-week exercise program, and all participants were asked to provide no information to the examiner about their treatment protocol. Pa-tients using antidepressants or antiepileptic drugs for>3 months were allowed to continue, but they could take no new drugs other than paracetamol during the study. This research was carried out in accordance with the Declaration of Helsinki and was approved by the research committee of the Ufuk University School of Medicine. Furthermore, written consent for inclusion in the study was obtained from all of the patients.
Exercise procedures
Balance exercises
Group 1 received balance exercises as recommended by the American College of Sports Medicine.15These included postures that gradually reduced the base of support (2-legged stand, semi-tandem stand, semi-tandem stand, 1-legged stand), dynamic movements that disturbed the center of gravity (tandem walk, circle turns), exercises that stressed the postural muscle groups (heel or toe stands), and exercises that reduced sensory input (standing with eyes closed).15Training was provided by an experienced physio-therapist for 20 sessions over a 4-week period (20min for each session, 5d/wk).
KAT balance training
Group 1 also received 5 minutes of static and 5 minutes of dy-namic balance training with the KAT device 3d/wk. This device has a movable platform and a tilt sensor that is connected to a computer. The subjects maintained their balance by tilting the platform in all directions without moving their feet. They could only change their center of gravity via trunk movements. During the static balance training, the patients were asked to maintain their equilibrium while standing as motionless as possible on the platform and were told to keep the red X symbol in the center of the computer screen. In the dynamic balance training, they were asked to superimpose the X symbol onto the moving cursor while it made a 360circle on the screen.
Flexibility exercises
Active static exercises were preferred in order to enable compli-ance to exercise and its maintencompli-ance without being forced in fi-bromyalgia patients, who have fatigue and depression. Exercises were performed in 8 large muscle groups (neck, back, lower back, biceps, triceps, gluteus, iliopsoas, quadriceps femoris, hamstring, gastrosoleus) in three 60-second static stretching repetitions.16 Because in older persons holding a stretch for 30 to 60 seconds may confer greater benefit, for each muscle, to the extent that patients was capable, 30- to 60-second static stretching was car-ried out. This protocol was used in the same manner in all patients. Ten minutes of walking in place was also recommended as warm-up for the stretching exercises. Growarm-up 1 performed these flexibility
List of abbreviations:
BBS Berg Balance Scale BDI Beck Depression Inventory BMI body mass index
FIQ Fibromyalgia Impact Questionnaire FMS fibromyalgia syndrome
KAT Kinesthetic Ability Trainer QOL quality of life
exercises under the supervision of a physiotherapist throughout the entire program. Group 2 performed the flexibility exercises for only 2 sessions and were informed about the necessity of exer-cising 5d/wk. The patient’s attendance was monitored by the physiotherapist, and all of the patients received weekly telephone calls to ensure that they were achieving the needed 80% partici-pation required for a successful study.
Assessment parameters
The patients’ sociodemographic data (age, sex), education levels, and working status were recorded. After measuring their weight and height, the body mass index (BMI) [(W-kg)/H2-m2)] was calculated. Furthermore, any use of antidepressants or antiepi-leptic drugs was also noted.
Balance and fall evaluation
To establish a fall history, we conducted an interview in which the patients estimated how many times they had fallen in the preceding year. A fall was defined as unintentionally coming to rest on the ground, floor, or other lower level either with or without an injury.17 The Berg Balance Scale (BBS) was used to assess functional balance.18It consists of 14 items that measure static balance (eg, standing unsupported, single-leg stand), dynamic balance, and functional assessment during commonly performed daily activities (eg, reaching forward, standing up from a sitting position, retrieving objects from the floor).18It uses a 5-point scoring scale
with a maximum of 56 possible points. A score between 0 and 20 indicates a high fall risk, a score between 21 and 40 indicates a moderate fall risk, and a score between 41 and 56 indicates a low fall risk. The validity and reliability of the Turkish version of the BBS have been proven.19
Dynamic and static balances were evaluated using the KAT device. The patients were asked to stand barefoot on the platform, and a computer screen was positioned directly in front of them to provide concurrent biofeedback on their position. Each test lasted for 30 seconds and was repeated 3 times, with the highest score being accepted as the final score. Increased measurements indi-cated a poor balance performance.20
The Hendrich II fall risk model was used to evaluate the risk of fall, and it includes various risk factors (eg, confusion, depression, changes at discharge, vertigo, being a man, use of antiepileptics and benzodiazepines, standing up and walking test). A total score 5 indicates a fall risk.21
The validity and reliability of the Turkish version of this model have also been previously verified.22
Clinical measurements
The Fibromyalgia Impact Questionnaire (FIQ), a self-administered instrument, was used to evaluate functional status, progress, and outcomes.23It is composed of 10 items (physical functioning, daily activities, housework, work difficulty, pain, fatigue, morning tired-ness, stifftired-ness, anxiety, depression) with a maximum score of 10. Higher scores signifying greater impairment. The Turkish version of the FIQ has been previously validated.24
Enr ollm e n t Alloc at ion Anal ys is Follow -up Excluded (n=9)
Not meet inclusion criteria (n=5) Refused to parƟcipate (n=4) Baseline EvaluaƟon (n=68) RandomizaƟon AllocaƟon Group 1 (n=35) ( BalanceTraining+FlexibilityExercise) Group 2 (n=33) (Control- Flexibility Exercise)
Did not Complete (n=7)
Medical reasons: leg and back pain (n=2) Personal reasons (n= 1) Could not be followed (n=1) DisconƟnuaƟon up to 20% (n=3)
Did not Complete (n=4)
Personal reasons (n= 2) Could not be followed (n=2)
6 Weeks Exercise period
Group 1- Analyzed (n=28) Group 2- Analyzed (n=29) Evaluated for Eligibility (n=77)
Quality of life (QOL) was measured via the Turkish version of the Nottingham Health Profile,25which is designed to give a brief indication of perceived physical, social, and emotional health problems.26The newest version consists of 38 items in which the patients answer yes or no according to whether or not they believe the item is applicable to them.27
The Beck Depression Inventory (BDI) was used to assess the depression levels of the patients.28The BDI evaluates 21 symp-toms of depression. These sympsymp-toms deal with emotions, behav-ioral changes, and somatic symptoms. Each symptom is rated on a 4-point intensity scale. Higher scores indicate more severe depression. The validity and reliability of the Turkish version have been previously verified.29
Statistical analysis
The PASW Statistics 18.0 for Windows software programb was used for all statistical analyses. The mean values and frequencies of the parameters were assessed using descriptive statistics, and the normality of the variables was analyzed via the Kolmogorov-Smirnov test. At baseline, the differences between the groups were tested using an independent samples t test and Mann-Whitney U test. A paired sample t test was used to evaluate the intragroup comparisons. We compared the results between the 2 groups by using an independent samples t test. Pearson correlation analysis was used to determine the relation between the balance parameters and the other variables. A P value <.05 was considered to be statistically significant. Finally, a post hoc power analysis was conducted with the program G*Power 3.1.9.2c to measure the power of the present study.
Results
Overall, 57 patients completed the 6-week exercise program. Seven patients in group 1 and 4 in group 2 dropped out of the study. The follow-up period is shown infigure 1. There were no statistically significant differences between groups 1 and 2 with respect to the sociodemographic characteristics at the baseline
measurements (P>.05). The results are shown intable 1. We also compared the baseline clinical variables of the 2 groups and found significant unfavorable statistical differences in the BDI scores (PZ.02) in group 2 (table 2).
In group 1, statistically significant improvement was observed in all of the parameters (P<.05). However, there was no improvement in group 2 (P>.05) at the sixth week. When comparing the 2 groups, we also found significant differences in group 1 on the KAT 4000 static balance test (PZ.017) and FIQ measurements (PZ.005) (table 3).
Furthermore, although a negative correlation was noted be-tween the depression levels (rZ.434; P<.01), age (rZ.442; P<.01), BMI (.285; P<.05), and BBS, a positive correlation was shown between fall risk (rZ.357; P<.01) and the BBS. Age and BMI were also positively correlated with fall frequency (table 4).
To check our statistical power, we conducted a post hoc power analysis using a 2-tailed t test to determine the difference between 2 independent means. We used an alpha of .05 for 28 patients in group 1 and 29 in group 2. We also used Cohen standard and determined that the effect size (dZ.768) had a relatively large effect. After that, the statistical power was calculated as .81, which correlated with Cohen recommended level of .80.30
Table 1 Sociodemographic characteristics of the patients
Variables Group 1 (nZ28) Group 2 (nZ29) P
Age (y) 48.1113.42 (23e66) 48.1712.68 (24e65) .98
BMI 27.675.51 (16.80e38.04) 26.764.89 (19.14e38.83) .51
Sex .57 Female 27 (96.4) 27 (93.1) Male 1 (3.6) 2 (6.9) Education level .21 Primary 11 (39.3) 5 (17.2) Middle-high 10 (35.7) 14 (58.2) University 7 (25) 10 (34.5) Work status .85 Unemployed 20 (71.4) 20 (68.9) Working 8 (28.6) 9 (31.1) Drug use .86 Yes 15 (53.57) 18 (62.06) No 13 (46.43) 11 (37.94)
NOTE. Values are shown in median SD (minimumemaximum), n (%), or as otherwise indicated.
Table 2 Comparison of baseline assesments between the 2 groups
Variables Group 1 (nZ28) Group 2 (nZ29) P
KAT static 162.7558.06 170.1743.21 .39 KAT dynamic 1994.71492.97 1881.37409.90 .41 BBS 44.787.41 48.685.57 .06 Hendrich II 4.641.06 3.931.36 .37 Fall frequency 0.640.73 0.550.78 .52 FIQ 65.7814.73 65.8918.05 .94 NHP 0.420.18 0.560.19 .30 BDI 19.469.33 13.897.89 .02
NOTE. Values are mean SD or as otherwise indicated. Abbreviation: NHP, Nottingham Health Profile.
Discussion
In this 6-week study, we found that balance exercises, KAT balance training, and flexibility exercises provided significant improvement in static balance and functional levels in patients with FMS. However, no significant improvement was noted regarding func-tional balance, dynamic balance, depression levels, QOL, or fall risk. We also determined that the functional balance evaluation was correlated with lower depression levels, increased age, and higher BMIs, whereas fall frequency was only related to age and BMI. Moreover, fall risk was related to age and depression levels.
To our knowledge, there is only 1 previous study that has evaluated the effectiveness of balance exercises on FMS. Demir-Go¨c¸men10compared a 12-week balance exercise program with a stretching exercise program in 50 patients, and the baseline evaluations indicated that the stretching group had significantly higher BBS scores. Ultimately, they determined that there was significant improvement in the balance parameters in both exercise groups, and an intergroup comparison showed that the improved BBS scores were higher in the stretching group. However, this might have been caused by a better baseline evaluation of balance in the stretching group.10
In our study, the baseline evaluations revealed that the depression scores in group 1 were significantly lower than those in group 2. Various studies have reported that depression can cause a decrease in the ability to adapt to exercise.31,32In addition, the balance disorder can increase according to the levels of depres-sion.33This study showed an improvement in static balance, but there was no change in dynamic balance. Furthermore, despite the risk of falling in group 1 at the end of 6 weeks, there were no significant differences between the groups. However, baseline depression scores might have affected this outcome.
Despite the well-known negative effects of depression, sig-nificant improvement was observed in all parameters (balance, functional level, depression level) in group 1. Moreover, there was also a marked improvement in the FIQ scores in group 1 compared with group 2. The improvement was only significant in the functional participation in life. Despite the lack of significant improvement in functional balance, the changes in the patients’ functional levels in this study may have been associated with the improved static balance and the effectiveness of the flexibility exercises. In recent years, there have been several studies that have evaluated whether exercises involving high flexibility (eg, Tai Chi) were efficacious34 when combined with strengthening, aerobic, and stretching exercises.11,35,36 However, to our knowledge, no study has focused on the effectiveness of flexibility exercises alone. In an evaluation of 2596 patients with FMS by Bennett et al,5the patients stated that stretching exercises were better for coping with their symptoms in contrast with our results.
We found no significant changes in either balance or any other parameters in group 2. According to Dobkin et al,3150% of pa-tients with FMS adapt poorly to exercise. Although we monitored the patients via weekly telephone calls to make sure they were exercising regularly, it was somewhat difficult to estimate the real ratio of their exercise participation. Group 1 performed regular balance exercises 5d/wk. Previous studies have reported that pa-tients with FMS who exercise regularly are more functional,37 which might explain why the functional levels of our patients who exercised routinely improved so much. We also believe that improvement in static balance might have contributed to the pa-tients’ higher functional levels.
To our knowledge, no other study has investigated patients’ QOL as it relates to the effect of balance exercises on FMS. Muscle strengthening has been reported to have a favorable ef-fect on QOL and postural balance in these patients.38 In our study, despite the amelioration in the functional level, balance exercises did not result in significant improvement in the pa-tients’ QOL.
Jones et al4 investigated the potential factors that affected balance in patients with FMS and identified depression, anxiety, and fatigue as possible risks. They concluded that clinicians should prescribe more exercises to ensure postural stability. In addition, they found a correlation between depression levels and the risk of falling and balance just as we did. However, we also determined that advanced age and BMI might be associated with balance as well. In contrast, Rutledge et al39found that age and BMI had no effect on fall risk in FMS.
Table 3 Comparison of groups 1 and 2 at baseline and week 6
Variables
Group 1 (nZ28) Group 2 (nZ29)
Comparison at Week 6
Baseline Week 6 P Baseline Week 6 P P
KAT static 162.7558.1 141.1849.2 <.001 170.1743.21 171.5143.88 .61 .017 KAT dynamic 1994.7492.9 183049.15 <.001 1881.3409.9 1906.5450.2 .21 .55 BBS 44.787.41 49.966.57 <.001 48.685.57 48.965.26 .18 .53 Hendrich II 4.641.06 4.500.96 .043 3.931.36 3.931.36 .44 .07 FIQ 65.7814.73 52.8515.24 <.001 65.8918.05 65.5517.70 .88 .005 NHP 0.420.18 0.510.17 <.001 0.560.19 0.550.16 .29 .43 BDI 19.469.33 17.679.37 <.001 13.897.89 13.797.18 .80 .08
NOTE. Values are mean SD or as otherwise indicated. Abbreviation: NHP, Nottingham Health Profile.
Table 4 Correlations between BDI score, age, and BMI with balance measures
Variables BDI Age BMI
KAT static .186 .221 .433* KAT dynamic .081 .245 .122 BBS .434* .442* .285y Hendrich II .357* .281y .254 Fall frequency .079 .450* .328y * Correlation P<.001. y Correlation P<.05.
Study limitations
The major limitations of this study were the small sample size and lack of intra- and interrater reliability for the evaluation pro-cedures. In addition, our follow-up period was too short.
We included patients with FMS who were referred to the physical medicine and rehabilitation outpatient clinic, which meant that the study population had disturbing pain. This selection bias might have influenced our evaluation process.
One of the instruments used to evaluate balance was the KAT measurements. Group 1 was trained with the KAT device during the treatment period; hence, this might help explain the improved balance measurements in that group.
Two patients in group 1 dropped out of the study as a result of leg and back pain. The KAT device’s moveable platform could have put extra strain on the lower extremities during the exercises. These dropouts might have had a negative effect on statistical power of this study.
Conclusions
In this study, the 6-week balance training program had a beneficial effect on static balance and functional levels of patients with FMS. In addition, we determined that deterioration of depression and higher BMI were related to the balance deficit and fall risk. Our findings indicate that a balance assessment should be performed during the first evaluation of these patients and balance training should be included in the treatment protocols of FMS patients with balance disorders. Our study only presents preliminary re-sults regarding the effectiveness of balance exercises on FMS. Therefore, we recommend that further studies be conducted to determine whether balance training can improve postural stability and reduce falls in FMS. We hope that our findings provide the impetus for a definitive randomized trial in the future.
Suppliers
a. Sports Kinesthetic Ability Trainer 4000 device; SportKAT. b. PASW Statistics 18.0; SPSS, Chicago, IL.
c. G*Power 3.1.9.2. Available at: http://www.gpower.hhu.de/en. html.
Keywords
Exercise; Exercise therapy; Fibromyalgia; Postural balance; Rehabilitation
Corresponding author
Sibel Kibar, MD, Department of Physical Medicine and Rehabilitation, Ufuk University, School of Medicine, Mevlana Bulvarı No 88 Balgat, 06530, C¸ ankaya, Ankara, Turkey. E-mail address:sibelkbr@gmail.com.
Acknowledgments
We thank Aslihan Alhan, PhD, (statistician) for her statistical recommendations and _Ibrahim Yılmazer and Timur Ekiz, MD, for their technical and English editing recommendations.
References
1.Wolfe F, Clauw DJ, Fitzcharles MA, et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis Care Res (Hoboken) 2010;62:600-10.
2.Wolfe F. Fibromyalgia. Rheum Dis Clin North Am 1990;16:681-98. 3.Watson NF, Buchwald D, Goldberg J, Noonan C, Ellenbogen RG.
Neurologic signs and symptoms in fibromyalgia. Arthritis Rheum 2009;60:2839-44.
4.Jones KD, Horak FB, Winters-Stone K, Irvine JM, Bennett RM. Fi-bromyalgia is associated with impaired balance and falls. J Clin Rheumatol 2009;15:16-21.
5.Bennett RM, Jones J, Turk DC, Russell IJ, Matallana L. An internet survey of 2,596 people with fibromyalgia. BMC Musculoskelet Disord 2007;8:27.
6.Jones J, Rutledge DN, Jones KD, Matallana L, Rooks DS. Self-assessed physical function levels of women with fibromyalgia: a na-tional survey. Womens Health Issues 2008;18:406-12.
7.Grace GM, Nielson WR, Hopkins M, Berg MA. Concentration and memory deficits in patients with fibromyalgia syndrome. J Clin Exp Neuropsychol 1999;21:477-87.
8.McCarberg BH. Clinical overview of fibromyalgia. Am J Ther 2012; 19:357-68.
9.Formiga F, Navarro M, Duaso E, et al. Factors associated with hip fracture-related falls among patients with a history of recurrent falling. Bone 2008;43:941-4.
10.Demir-Go¨c¸men D, Altan L, Korkmaz N, Arabacı R. Effect of super-vised exercise program including balance exercises on the balance status and clinical signs in patients with fibromyalgia. Rheumatol Int 2013;33:743-50.
11.Busch AJ, Webber SC, Richards RS, et al. Resistance exercise training for fibromyalgia. Cochrane Database Syst Rev 2013;12: CD010884.
12.San˜udo B, Carrasco L, de Hoyo M, Oliva-Pascual-Vaca A´ , Rodrı´guez-Blanco C. Changes in body balance and functional performance following whole-body vibration training in patients with fibromyalgia syndrome: a randomized controlled trial. J Rehabil Med 2013;45: 678-84.
13.Gusi N, Parraca JA, Olivares PR, Leal A, Adsuar JC. Tilt vibratory exercise and the dynamic balance in fibromyalgia: a randomized controlled trial. Arthritis Care Res (Hoboken) 2010;62:1072-8. 14.Jones KD, King LA, Mist SD, Bennett RM, Horak FB. Postural
control deficits in people with fibromyalgia: a pilot study. Arthritis Res Ther 2011;13:R127.
15.American College of Sports Medicine, Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA, Minson CT, Nigg CR, Salem GJ, Skinner JS. American College of Sports Medicine position stand. Exercise and physical activity for older adults. Med Sci Sports Exerc 2009;41:1510-30.
16.Garber CE, Blissmer B, Deschenes MR, et al. American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for pre-scribing exercise. Med Sci Sports Exerc 2011;43:1334-59.
17.Buchner DM, Cress ME, de Lateur BJ, et al. The effect of strength and endurance training on gait, balance, fall risk, and health services use in community-living older adults. J Gerontol A Biol Sci Med Sci 1997; 52:M218-24.
18.Berg KO, Wood-Dauphinee SL, Williams JI, Maki B. Measuring balance in the elderly: validation of an instrument. Can J Public Health 1992;83(Suppl 2):S7-11.
19.Sahin F, Yilmaz F, Ozmaden A, Kotevolu N, Sahin T, Kuran B. Reliability and validity of the Turkish version of the Berg Balance Scale. J Geriatr Phys Ther 2008;31:32-7.
20. Hansen MS, Dieckmann B, Jensen K, Jakobsen BW. The reliability of balance tests performed on the kinesthetic ability trainer (KAT 2000). Knee Surg Sports Traumatol Arthrosc 2000;8:180-5.
21. Hendrich AL, Bender PS, Nyhuis A. Validation of the Hendrich II Fall Risk Model: a large concurrent case/control study of hospitalized patients. Appl Nurs Res 2003;16:9-21.
22. Atay S, Tu¨rgay SA, Aycan O¨ . [The Validity and Reliability Study of Hendrich II Fall Risk Model] [Turkish]. In: Alter Publishing. 12th National Nursing Congress Abstract Book; 2009 Sep 20-24; Ankara, Turkey; 2009. p 218.
23. A Burckhardt CS, Clark SR, Bennett RM. The fibromyalgia impact questionnaire: development and validation. J Rheumatol 1991; 18:728-33.
24. Sarmer S, Ergin S, Yavuzer G. The validity and reliability of the Turkish version of the Fibromyalgia Impact Questionnaire. Rheumatol Int 2000;20:9-12.
25. Ku¨cu¨kdeveci AA, McKenna SP, Kutlay S, Gu¨rsel Y, Whalley D, Arasil T. The development and psychometric assessment of the Turkish version of the Nottingham Health Profile. Int J Rehabil Res 2000;23:31-8.
26. Hunt SM, McEwen J, McKenna SP. Measuring health status: a new tool for clinicians and epidemiologists. J R Coll Gen Pract 1985;35: 185-8.
27. McDowell I. Nottingham Health Profile. In: McDowell I, editor. Measuring health: a guide to rating scales and questionnaires. 3rd ed. Oxford: Oxford Univ Pr; 2006. p 639-46.
28. Beck AT, Steer RA, Garbin MG. Psychometric properties of the Beck Depression Inventory: twenty-five years of evaluation. Clin Psychol Rev 1988;8:77-100.
29. Hisli N. [The Validity and Reliability of the Beck Depression Inventory in University Students] [Turkish]. Psikoloji Dergisi 1989;6:3-13.
30. Cohen J. Statistical power analysis for the behavioral sciences. Hillsdale: Lawrence Erlbaum Associates; 1988.
31. Dobkin PL, Da Costa D, Abrahamowicz M, et al. Adherence during an individualized home based 12-week exercise program in women with fibromyalgia. J Rheumatol 2006;33:333-41.
32. Dobkin PL, Abrahamowicz M, Fitzcharles MA, Dritsa M, da Costa D. Maintenance of exercise in women with fibromyalgia. Arthritis Rheum 2005;53:724-31.
33. Fraix M. Role of the musculoskeletal system and the prevention of falls. J Am Osteopath Assoc 2012;112:17-21.
34. Wang C, Schmid CH, Rones R, et al. A randomized trial of tai chi for fibromyalgia. N Engl J Med 2010;363:743-54.
35. Valkeinen H, Ale´n M, Ha¨kkinen A, Hannonen P, Kukkonen-Harjula K, Ha¨kkinen K. Effects of concurrent strength and endurance training on physical fitness and symptoms in postmenopausal women with fibro-myalgia: a randomized controlled trial. Arch Phys Med Rehabil 2008; 89:1660-6.
36. San˜udo B, Galiano D, Carrasco L, Blagojevic M, de Hoyo M, Saxton J. Aerobic exercise versus combined exercise therapy in women with fibromyalgia syndrome: a randomized controlled trial. Arch Phys Med Rehabil 2010;91:1838-43.
37. Rutledge DN, Jones K, Jones CJ. Predicting high physical function in people with fibromyalgia. J Nurs Scholarsh 2007;39:319-24. 38. Tomas-Carus P, Gusi N, Ha¨kkinen A, Ha¨kkinen K, Raimundo A,
Ortega-Alonso A. Improvements of muscle strength predicted benefits in HRQOL and postural balance in women with fibromyalgia: an 8-month randomized controlled trial. Rheumatology (Oxford) 2009;48:1147-51. 39. Rutledge DN, Cherry BJ, Rose DJ, Rakovski C, Jones CJ. Do fall
predictors in middle aged and older adults predict fall status in persons 50þ with fibromyalgia? An exploratory study. Res Nurs Health 2010; 33:192-206.
