Original Research
The Effect of Maternity Support Belts on Postural Balance in Pregnancy Bulent Cakmak, MD, Ahmet Inanir, MD, Mehmet Can Nacar, MD, Behcet Filiz, MD Objective: The purpose of this study was to evaluate the effect of maternity support belts (MSB) on postural balance during pregnancy. Design: Prospective, observational cohort study. Setting: Outpatient visits at a university hospital, obstetrics and gynecology clinic. Participants: A total of 90 pregnant women in first, second, and third trimesters of pregnancy; 30 pregnant women for each trimester. Methods: Dynamic and postural stability by using a Biodex Stability System and comparing pregnant women with and without an MSB in each cohort group. Main Outcome Measures: Overall, anterior-posterior stability index, medial-lateral stability index, and fall risk test (FRT) scores were obtained with 1 stance at platform stability of level 8. Four measurements from the Biodex Stability System were compared between pregnant women with and without an MSB in each group. Results: The scores of anterior-posterior stability index and FRT were significantly lower in the first-trimester group with an MSB than without an MSB (P < .05). Medial-lateral stability index and FRT scores were significantly lower in the second-trimester group with an MSB than without an MSB (P < .05). In the third-trimester group, overall, medial-lateral stability index, and FRT scores were lower for participants with an MSB compared with participants without an MSB (P < .05). In all trimester groups, FRT scores were detected to be lower in pregnant women with an MSB than in those without an MSB (P < .05). Conclusions: MSB use improves impaired balance and FRT scores during all periods of pregnancy, especially in the third trimester. MSB is useful for fall prevention during pregnancy, especially during the third trimester. PM R 2014;-:1-5
INTRODUCTION Pregnant women are at higher risk for falls than women who are not pregnant. Although 27% of women fall during their pregnancy, 10% of them experience 2 or more falls [1]. A fall during pregnancy may result in maternal injuries such as bone fractures, joint sprains, muscle strains, head injury, rupture of internal organs, internal hemorrhage, abruptio placenta, rupture of the uterus and membranes, and occasionally maternal death or intrauterine fetal demise [2,3]. Pregnancy-related pelvic pain from presumed joint laxity is a common and disabling problem [4]. Many methods are used for management of pelvic joint laxity during pregnancy; 1 of these strategies is use of a maternity support belt (MSB). A supportive belt decreases joint laxity if it is fitted to apply compression at the anterior superior iliac spine [5]. MSBs are regarded as safe, low-cost, and accessible devices, and are used for the management of low back and/or pelvic pain symptoms [6,7]. The belt application has been shown to have a mechanical effect of reducing the mobility, laxity, and sagittal rotation of the sacroiliac joints in women with pregnancy-related pelvic girdle pain [5,8,9]. Numerous hormonal, anatomic, and physiological states change during the course of gestation, such as substantial weight gain, increased ligamentous laxity, increased spinal lordosis, decreased neuromuscular control and coordination, decreased abdominal muscle strength, biomechanics alteration, and an anterior shift in the location of the center of body PM&R 1934-1482/13/$36.00 Printed in U.S.A.
B.C. Obstetrics and Gynecology, Gaziosmanpasa University School of Medicine, Kelardı Mahallesi, 60100, Tokat, Turkey. Address correspondence to: B.C.; e-mail: [email protected] Disclosure: nothing to disclose A.I. Department of Physical Therapy and Rehabilitation, Gaziosmanpasa University School of Medicine, Tokat, Turkey Disclosure: nothing to disclose M.C.N. Obstetrics and Gynecology, Gaziosmanpasa University School of Medicine, Tokat, Turkey Disclosure: nothing to disclose B.F. Department of Physical Therapy and Rehabilitation, Gaziosmanpasa University School of Medicine, Tokat, Turkey Disclosure: nothing to disclose Submitted for publication August 11, 2013; accepted December 22, 2013.
ª 2014 by the American Academy of Physical Medicine and Rehabilitation Vol. -, 1-5, --- 2014 http://dx.doi.org/10.1016/j.pmrj.2013.12.012
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mass [10-13]. These anatomic, hormonal, and physiological changes may be related to increased risk of falling during gestation. The Biodex Balance System (BBS) (Biodex Medical Systems, Shirley, NY) is a valuable measurement system that evaluates postural stability with different clinical situations, for example, nonspecific low back pain in adults and rheumatoid arthritis [14,15]. Currently, there are no published studies related to the effect of an MSB on postural balance during pregnancy. We hypothesized that the use of an MSB would positively affect postural balance in pregnant women. The purpose of this study was to investigate the effect of an MSB on postural stability during pregnancy.
METHODS Pregnant women 18-40 years of age were recruited and grouped by trimester as determined by their estimated date of confinement. Groups included 30 women each. Comparisons of dynamic and postural stability with and without an MSB were made within the groups and between groups as measured by the Biodex Balance System (version 3.1). The groups were compared by age, gravidity, parity, height, weight, and body mass index. The study protocol was reviewed and approved by the medical ethics committee of our institution. All the participants gave their written informed consent to participate in the study. Exclusion criteria included the following medical conditions: multiple pregnancies, gestational diabetes mellitus, hypertension, preeclampsia, a pregnancy considered by an obstetrician to be high risk, musculoskeletal or neurologic abnormalities, severe low back pain (unable to perform regular work duties), pain due to preterm labor, and any other medical condition that would affect postural stability. The MSB is made of cotton and has a flexible elastic structure (Varitex Ortopedi Sanayii, Istanbul). The appropriate belt size, based on height and weight, is used for each participant. Small, medium, and large types of belt with a length of 70, 90, 100 cm, respectively; and with an anteriorposterior width of 15 25, 20 30, 25 35 cm, respectively, were used in this study. The belt was placed on participants at the level of the anterior superior iliac spine in lateral sides, lower lumbar region around the back, and between the pubis and the umbilicus in the front (Figure 1). A measurement of dynamic postural stability was performed by using the BBS, which consists of a movable balance platform that provides up to 20 of surface tilt in a 360 range of motion. The platform is interfaced with computer software (version 3.1; Biodex) that enables the device to serve as an objective assessment of balance. The measure of postural stability includes the overall (overall stability index [OA]), the anterior-posterior (anterior-posterior stability index [APSI]), the medial-lateral (medial-lateral stability index [MLSI]) scores, and the risk of falling (fall risk test [FRT]) scores. The range of scores is between 0 and 20 for all stability indexes. A high score in the stability indexes
Figure 1. Position of maternity support belt as used in the study.
indicates poor balance [16]. Dynamic postural balance was assessed by using measurements obtained from the BBS at level 8. The system’s difficulty levels change from 1 (most difficult) to 8 (easiest). For the RFT, the platform was set at level 8 because it is used as the stable level for all subjects, and all patients were tested at the same platform level. Measurements were obtained from mean of 3 times 20-second-interval trials. Four measurements from the BBS were compared between pregnant women with and without MSB in each group. All data were analyzed by using the Statistical Package for the Social Sciences Version 18.0 (SPSS Inc, Chicago, IL). Analysis of variance with the Dunnett post hoc test was used to analyze between-group differences. Differences between the pregnant women with or those without a belt for each group were assessed by using the Mann-Whitney U test for categorized variables, and the Student t test for continuous variables. P < .05 was considered significant.
RESULTS A comparison of the demographic characteristics of the groups included in the study is given in Table 1. Demographic data regarding age and number of births and
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Table 1. Demographic features of study participants Firsttrimester Group, Mean ± SD Age, y Gravidity Parity Height, cm Weight, kg BMI, kg/m2
26.2 2.3 1.2 162.3 70.0 26.5
4.7 1.0 0.9 6.9 11.1* 3.3*
Secondtrimester Group, Mean ± SD 26.3 2.0 1.0 161.0 72.4 27.8
5.5 1.0 0.9 6.5 12.6 3.7
Thirdtrimester Group, Mean ± SD 26.6 2.1 1.0 163.2 78.3 29.5
5.6 0.9 0.8 5.7 6.7 2.1
SD ¼ standard deviation; BMI ¼ body mass index. *Significant difference from the third-trimester group (P < .05).
pregnancies were similar among the groups. Weight and body mass index were higher in the third-trimester group compared with the other groups. This difference was statistically significant from that of the first-trimester group (P < .05) but not the second-trimester group (P > .05). The first-trimester group had the lowest scores of postural stability and falling risk when compared with the secondand third-trimester groups (P < .05). In contrast, the thirdtrimester group had the highest scores. OA, APSI, MLSI, and FRT scores were found in an increased order in the first-, second-, and third-trimester subjects, respectively (min-scores in the first and max-scores in the thirdtrimester subjects) (Table 2). There were no significant differences among the first-, second-, and third-trimester groups for OA, APSI, and MLSI (P > .05), but FRT was found to be higher in the third-trimester group compared with the other groups (P < .001). The scores of APSI and FRT were significantly lower in the first-trimester group with an MSB versus without an MSB (0.32 0.18 versus 0.38 0.11 and 0.84 0.35 versus 0.99 0.26, respectively) (P < .05). There was no statistically significant difference for OA and MLSI scores. The scores of APSI and FRT were significantly lower in the first-trimester group with an MSB than without an MSB (0.32 0.18 vs 0.38 0.11 and 0.84 0.35 versus 0.99 0.26, respectively) (P < .05). However, MLSI and FRT scores were significantly lower in the second-trimester group with MSB versus without MSB (mean SD 0.24 0.14 versus 0.36 0.20 and 0.88 0.35 versus 1.27 Table 2. Descriptive statistics (mean SD) for balance stability scores among groups First-trimester Group OA APSI MLSI FRT
0.51 0.38 0.31 0.99
0.16 0.11 0.15 0.26*
Second-trimester Group 0.61 0.45 0.36 1.27
0.35 0.29 0.20 0.52*
Third-trimester Group 0.71 0.51 0.48 1.72
0.45 0.45 0.35 1.03*
SD ¼ standard deviation; OA ¼ overall; APSI ¼ anterior-posterior stability index; MLSI ¼ medial-lateral stability index; FRT ¼ fall risk test. *Significant difference among all trimester groups (P < .05).
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0.52, respectively) (P < .05). In all trimester groups, the FRT scores were lower in pregnant women with an MSB than in those without an MSB (P < .05) (Figure 2).
DISCUSSION In this study, the scores of FRT were significantly lower in each trimester group in women with an MSB than in those without an MSB. It is well documented that the risk of falling increases during the third trimester [17]. Serious risk situations, such as placental abruption, preterm labor, maternal bone fracture, and maternal-fetal deaths, can be seen because of falling during gestation [18]. The majority of fall-related hospitalizations during pregnancy are seen in the third trimester. Schiff [17] reported that fall-related hospitalizations are seen in 48.9 of 100,000 pregnancies and that 79.3% of these falls occur in the third trimester. In our study, the dynamic postural stability was assessed by BBS, and the test scores were found to be higher in the third trimester. The FRT score was found to be higher in the thirdtrimester group compared with the other groups. Similarly, the FRT score of the second-trimester group was increased with regard to the first-trimester group (P < .001). The mean score of FRT was 0.99 0.26 in the first-trimester group, whereas the second- and the third-trimester group scores were mean SD 1.27 0.52 and 1.72 1.03, respectively (P < .001). Numerous studies have reported increased postural instability during the gestational period [19-21]. In these studies, standing postural, anterior-posterior, and radial wobbling were found to be increased in pregnant women when compared with women who were not pregnant. In addition, balance measurements were found to be different between pregnant women in labor and women who were not pregnant. According to Butler et al [19], postural equability remained comparatively stable during the first trimester; however, the second trimester, third trimester, and postpartum values were increased prominently compared with values in the control subjects. Jang et al [20] reported that pregnant women displayed increased wobbling, particularly in the anterior-posterior and radial directions, compared with women who were not pregnant. Anterior-posterior sway measures strongly correlated with perceived balance and also decreased significantly between the third trimester and postpartum period. The weakest balance was found in the third trimester. Significant changes in lumbar angle, pelvic tilt, and head position were reported during pregnancy in the first and third trimesters. In the third trimester, women stood with an increased lumbar lordosis and a greater anterior pelvic tilt [22]. These changes potentially correlate with increased low back pain and pelvic disability symptoms. Similarly, the negative impacts of these changes on balance are seen during pregnancy. Various support garments such as MSBs are commonly prescribed to normalize posture, body
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Figure 2. Descriptive statistics (mean SD) for balance stability score among groups with and without maternity support belts (MSB). The left side of the bars with same color describes the results without MSB and the right ones with MSB. Note the significant difference between 2 groups in the same trimester group. *P < 0.05, **P < 0.01.
mechanics, and movement problems by providing external support to the pelvis and abdomen. Pelvic support belts are clinically used to provide an additional outside force to stabilize pelvic joints [23]. The MSB is effective for pelvic girdle pain likely because of improved stability in the pelvic region. In our study, with the same logic (providing stability for pelvic and lumbar spine joints), the use of an MSB applied to each of the 3 pregnancy trimester groups led to a decrease in the risk of falling. In this study group, significant improvement of the APSI values was seen after use of an MSB in the first-trimester pregnant women, but an absolute value of MLSI was found to be higher for the second- and third-trimester groups. However, in general, all the FRT values that evaluated falling risks improved significantly after the application of an MSB in all trimester groups (P < .05). Ho et al [24] reported that the maternity support garments reduced fatigue, pressure, and stress and strain of the back; prevented and/or relieved back pain; and corrected or improved posture. However, the maternity support garments have a mechanical effect of reducing the mobility, laxity, and sagittal rotation of the sacroiliac joints in healthy women and in women with pregnancy-related pelvic girdle pain. The maternity support garments usually are preferred by pregnant women and health care providers because they are easy to wear, adjust, and remove, and they allow a wider range of fit for increasing abdominal girth. The MSB used in our study is a belt type of conventional MSB and caused significant diminution in FRT scores without limiting the range of motion of pregnant women. However, many types of maternity support garments, such as belts, briefs, and cradle and torso supports, are used during pregnancy [25]. Although an MSB decreases fall risk, a study reported that long-leggedetype maternity support garments increased falling due to difficulty in wearing and nonstretchability [26].
CONCLUSION This is the first study that investigated the effects of maternity support garment use on the risk of falling and on balance during pregnancy. Maternity support garment use improved impaired balance and FRT scores during all periods of pregnancy, especially in the third trimester. MSB worn during pregnancy, and especially during the third trimester, may help to prevent falls. A prospective randomized trial, following up participants through the trimesters of pregnancy, with and without the use of MSBs, and measuring balance and fall risk scores, would be an important future step.
REFERENCES 1. Dunning K, LeMasters G, Levin L, Bhattachary A, Alterman T, Lordo K. Falls in workers during pregnancy: Risk factors, job hazards, and high risk occupations. Am J Ind Med 2003;44:664-672. 2. Fildes J, Reed L, Jones N, Martin M, Barrett J. Trauma: The leading cause of maternal death. J Trauma 1992;32:643-645. 3. Mirza FG, Devine PC, Gaddipati S. Trauma in pregnancy: A systematic approach. Am J Perinatol 2010;27:579-586. 4. Wu WH, Meijer OG, Uegaki K, et al. Pregnancy related pelvic girdle pain (PPP), I: Terminology, clinical presentation, and prevalence. Eur Spine J 2004;13:575-589. 5. Mens JM, Damen L, Snijders CJ, Stam HJ. The mechanical effect of a pelvic belt in patients with pregnancy-related pelvic pain. Clin Biomech (Bristol, Avon) 2006;21:122-127. 6. Ritchie JR. Orthopedic considerations during pregnancy. Clin Obstet Gynecol 2003;46:456-466. 7. Borg-Stein J, Dugan SA, Gruber J. Musculoskeletal aspects of pregnancy. Am J Phys Med Rehabil 2005;84:180-192. 8. Vleeming A, Buyruk HM, Stoeckart R, Karamursel S, Snijders CJ. An integrated therapy for peripartum pelvic instability: A study of the biomechanical effects of pelvic belts. Am J Obstet Gynecol 1992;166: 1243-1247. 9. Damen L, Spoor CW, Snijders CJ, Stam HJ. Does a pelvic belt influence sacroiliac joint laxity? Clin Biomech (Bristol, Avon) 2002;17: 495-498.
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10. Calguneri M, Bird H, Wright V. Changes in joint laxity occurring during pregnancy. Ann Rheum Dis 1982;41:126-128. 11. Dumas G, Reid J, Wolfe L, Griffin M, McGrath M. Exercise, posture, and back pain during pregnancy. Clin Biomech (Bristol, Avon) 1995; 10:98-103. 12. McCrory J, Chambers A, Daftary A, Redfern M. Dynamic postural stability during advancing pregnancy. J Biomech 2010;43:2434-2439. 13. Gilleard W, Brown J. Structure and function of the abdominal muscles in primigravid subjects during pregnancy and the immediate postbirth period. Phys Ther 1996;76:750-762. 14. Sherafat S, Salavati M, Takamjani IE, et al. Intrasession and intersession reliability of postural control in participants with and without nonspecific low back pain using the Biodex Balance System. J Manipul Physiol Ther 2013;36:111-118. 15. Aydog E, Bal A, Aydog ST, Cakci A. Evaluation of dynamic postural balance using the Biodex Stability System in rheumatoid arthritis patients. Clin Rheumatol 2006;25:462-467. 16. Testerman C, Vander Griend R. Evaluation of ankle instability using the Biodex Stability System. Foot Ankle Int 1999;20:317-321. 17. Schiff MA. Pregnancy outcomes following hospitalization for a fall in Washington State from 1987 to 2004. Br J Obstet Gynaecol 2008;115: 1648-1654. 18. Connoly AM, Katz VL, Bash KL, McMahon MJ, Hansen WF. Trauma and pregnancy. Am J Perinatol 1997;14:331-336.
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19. Butler EE, Colon I, Druzin ML, Rose J. Postural equilibrium during pregnancy: Decreased stability with an increased reliance on visual cues. Am J Obstet Gynecol 2006;195:1104-1108. 20. Jang J, Hsiao KT, Hsiao-Wecksler ET. Balance (perceived and actual) and preferred stance width during pregnancy. Clin Biomech (Bristol, Avon) 2008;23:468-476. 21. Davies J, Fernando R, McLeod A, Verma S, Found P. Postural stability following ambulatory regional analgesia for labor. Anesthesiology 2002; 97:1576-1581. 22. Franklin ME, Conner-Kerr T. An analysis of posture and back pain in the first and third trimesters of pregnancy. J Orthop Sports Phys Ther 1998;28:133-138. 23. Depledge J, McNair PJ, Keal-Smith C, Williams M. Management of symphysis pubis dysfunction during pregnancy using exercise and pelvic support belts. Phys Ther 2005;85:1290-1300. 24. Ho SS, Yu W, Lao TT, Chow DHK, Chung JW, Li Y. Comfort evaluation of maternity support garments in a wear trial. Ergonomics 2008; 51:1376-1393. 25. Ho SS, Yu WW, Lao TT, Chow DH, Chung JW, Li Y. Effectiveness of maternity support belts in reducing low back pain during pregnancy: A review. J Clin Nurs 2009;18:1523-1532. 26. Ho SS, Yu WW, Lao TT, Chow DH, Chung JW, Li Y. Garment needs of pregnant women based on content analysis of in-depth interviews. J Clin Nurs 2009;18:2426-2435.
The Effect of Maternity Support Belts on Postural Balance in Pregnancy Bulent Cakmak, MD, Ahmet Inanir, MD, Mehmet Can Nacar, MD, Behcet Filiz, MD Objective: The purpose of this study was to evaluate the effect of maternity support belts (MSB) on postural balance during pregnancy. Design: Prospective, observational cohort study. Setting: Outpatient visits at a university hospital, obstetrics and gynecology clinic. Participants: A total of 90 pregnant women in first, second, and third trimesters of pregnancy; 30 pregnant women for each trimester. Methods: Dynamic and postural stability by using a Biodex Stability System and comparing pregnant women with and without an MSB in each cohort group. Main Outcome Measures: Overall, anterior-posterior stability index, medial-lateral stability index, and fall risk test (FRT) scores were obtained with 1 stance at platform stability of level 8. Four measurements from the Biodex Stability System were compared between pregnant women with and without an MSB in each group. Results: The scores of anterior-posterior stability index and FRT were significantly lower in the first-trimester group with an MSB than without an MSB (P < .05). Medial-lateral stability index and FRT scores were significantly lower in the second-trimester group with an MSB than without an MSB (P < .05). In the third-trimester group, overall, medial-lateral stability index, and FRT scores were lower for participants with an MSB compared with participants without an MSB (P < .05). In all trimester groups, FRT scores were detected to be lower in pregnant women with an MSB than in those without an MSB (P < .05). Conclusions: MSB use improves impaired balance and FRT scores during all periods of pregnancy, especially in the third trimester. MSB is useful for fall prevention during pregnancy, especially during the third trimester. PM R 2014;-:1-5
INTRODUCTION Pregnant women are at higher risk for falls than women who are not pregnant. Although 27% of women fall during their pregnancy, 10% of them experience 2 or more falls [1]. A fall during pregnancy may result in maternal injuries such as bone fractures, joint sprains, muscle strains, head injury, rupture of internal organs, internal hemorrhage, abruptio placenta, rupture of the uterus and membranes, and occasionally maternal death or intrauterine fetal demise [2,3]. Pregnancy-related pelvic pain from presumed joint laxity is a common and disabling problem [4]. Many methods are used for management of pelvic joint laxity during pregnancy; 1 of these strategies is use of a maternity support belt (MSB). A supportive belt decreases joint laxity if it is fitted to apply compression at the anterior superior iliac spine [5]. MSBs are regarded as safe, low-cost, and accessible devices, and are used for the management of low back and/or pelvic pain symptoms [6,7]. The belt application has been shown to have a mechanical effect of reducing the mobility, laxity, and sagittal rotation of the sacroiliac joints in women with pregnancy-related pelvic girdle pain [5,8,9]. Numerous hormonal, anatomic, and physiological states change during the course of gestation, such as substantial weight gain, increased ligamentous laxity, increased spinal lordosis, decreased neuromuscular control and coordination, decreased abdominal muscle strength, biomechanics alteration, and an anterior shift in the location of the center of body PM&R 1934-1482/13/$36.00 Printed in U.S.A.
B.C. Obstetrics and Gynecology, Gaziosmanpasa University School of Medicine, Kelardı Mahallesi, 60100, Tokat, Turkey. Address correspondence to: B.C.; e-mail: [email protected] Disclosure: nothing to disclose A.I. Department of Physical Therapy and Rehabilitation, Gaziosmanpasa University School of Medicine, Tokat, Turkey Disclosure: nothing to disclose M.C.N. Obstetrics and Gynecology, Gaziosmanpasa University School of Medicine, Tokat, Turkey Disclosure: nothing to disclose B.F. Department of Physical Therapy and Rehabilitation, Gaziosmanpasa University School of Medicine, Tokat, Turkey Disclosure: nothing to disclose Submitted for publication August 11, 2013; accepted December 22, 2013.
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mass [10-13]. These anatomic, hormonal, and physiological changes may be related to increased risk of falling during gestation. The Biodex Balance System (BBS) (Biodex Medical Systems, Shirley, NY) is a valuable measurement system that evaluates postural stability with different clinical situations, for example, nonspecific low back pain in adults and rheumatoid arthritis [14,15]. Currently, there are no published studies related to the effect of an MSB on postural balance during pregnancy. We hypothesized that the use of an MSB would positively affect postural balance in pregnant women. The purpose of this study was to investigate the effect of an MSB on postural stability during pregnancy.
METHODS Pregnant women 18-40 years of age were recruited and grouped by trimester as determined by their estimated date of confinement. Groups included 30 women each. Comparisons of dynamic and postural stability with and without an MSB were made within the groups and between groups as measured by the Biodex Balance System (version 3.1). The groups were compared by age, gravidity, parity, height, weight, and body mass index. The study protocol was reviewed and approved by the medical ethics committee of our institution. All the participants gave their written informed consent to participate in the study. Exclusion criteria included the following medical conditions: multiple pregnancies, gestational diabetes mellitus, hypertension, preeclampsia, a pregnancy considered by an obstetrician to be high risk, musculoskeletal or neurologic abnormalities, severe low back pain (unable to perform regular work duties), pain due to preterm labor, and any other medical condition that would affect postural stability. The MSB is made of cotton and has a flexible elastic structure (Varitex Ortopedi Sanayii, Istanbul). The appropriate belt size, based on height and weight, is used for each participant. Small, medium, and large types of belt with a length of 70, 90, 100 cm, respectively; and with an anteriorposterior width of 15 25, 20 30, 25 35 cm, respectively, were used in this study. The belt was placed on participants at the level of the anterior superior iliac spine in lateral sides, lower lumbar region around the back, and between the pubis and the umbilicus in the front (Figure 1). A measurement of dynamic postural stability was performed by using the BBS, which consists of a movable balance platform that provides up to 20 of surface tilt in a 360 range of motion. The platform is interfaced with computer software (version 3.1; Biodex) that enables the device to serve as an objective assessment of balance. The measure of postural stability includes the overall (overall stability index [OA]), the anterior-posterior (anterior-posterior stability index [APSI]), the medial-lateral (medial-lateral stability index [MLSI]) scores, and the risk of falling (fall risk test [FRT]) scores. The range of scores is between 0 and 20 for all stability indexes. A high score in the stability indexes
Figure 1. Position of maternity support belt as used in the study.
indicates poor balance [16]. Dynamic postural balance was assessed by using measurements obtained from the BBS at level 8. The system’s difficulty levels change from 1 (most difficult) to 8 (easiest). For the RFT, the platform was set at level 8 because it is used as the stable level for all subjects, and all patients were tested at the same platform level. Measurements were obtained from mean of 3 times 20-second-interval trials. Four measurements from the BBS were compared between pregnant women with and without MSB in each group. All data were analyzed by using the Statistical Package for the Social Sciences Version 18.0 (SPSS Inc, Chicago, IL). Analysis of variance with the Dunnett post hoc test was used to analyze between-group differences. Differences between the pregnant women with or those without a belt for each group were assessed by using the Mann-Whitney U test for categorized variables, and the Student t test for continuous variables. P < .05 was considered significant.
RESULTS A comparison of the demographic characteristics of the groups included in the study is given in Table 1. Demographic data regarding age and number of births and
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Table 1. Demographic features of study participants Firsttrimester Group, Mean ± SD Age, y Gravidity Parity Height, cm Weight, kg BMI, kg/m2
26.2 2.3 1.2 162.3 70.0 26.5
4.7 1.0 0.9 6.9 11.1* 3.3*
Secondtrimester Group, Mean ± SD 26.3 2.0 1.0 161.0 72.4 27.8
5.5 1.0 0.9 6.5 12.6 3.7
Thirdtrimester Group, Mean ± SD 26.6 2.1 1.0 163.2 78.3 29.5
5.6 0.9 0.8 5.7 6.7 2.1
SD ¼ standard deviation; BMI ¼ body mass index. *Significant difference from the third-trimester group (P < .05).
pregnancies were similar among the groups. Weight and body mass index were higher in the third-trimester group compared with the other groups. This difference was statistically significant from that of the first-trimester group (P < .05) but not the second-trimester group (P > .05). The first-trimester group had the lowest scores of postural stability and falling risk when compared with the secondand third-trimester groups (P < .05). In contrast, the thirdtrimester group had the highest scores. OA, APSI, MLSI, and FRT scores were found in an increased order in the first-, second-, and third-trimester subjects, respectively (min-scores in the first and max-scores in the thirdtrimester subjects) (Table 2). There were no significant differences among the first-, second-, and third-trimester groups for OA, APSI, and MLSI (P > .05), but FRT was found to be higher in the third-trimester group compared with the other groups (P < .001). The scores of APSI and FRT were significantly lower in the first-trimester group with an MSB versus without an MSB (0.32 0.18 versus 0.38 0.11 and 0.84 0.35 versus 0.99 0.26, respectively) (P < .05). There was no statistically significant difference for OA and MLSI scores. The scores of APSI and FRT were significantly lower in the first-trimester group with an MSB than without an MSB (0.32 0.18 vs 0.38 0.11 and 0.84 0.35 versus 0.99 0.26, respectively) (P < .05). However, MLSI and FRT scores were significantly lower in the second-trimester group with MSB versus without MSB (mean SD 0.24 0.14 versus 0.36 0.20 and 0.88 0.35 versus 1.27 Table 2. Descriptive statistics (mean SD) for balance stability scores among groups First-trimester Group OA APSI MLSI FRT
0.51 0.38 0.31 0.99
0.16 0.11 0.15 0.26*
Second-trimester Group 0.61 0.45 0.36 1.27
0.35 0.29 0.20 0.52*
Third-trimester Group 0.71 0.51 0.48 1.72
0.45 0.45 0.35 1.03*
SD ¼ standard deviation; OA ¼ overall; APSI ¼ anterior-posterior stability index; MLSI ¼ medial-lateral stability index; FRT ¼ fall risk test. *Significant difference among all trimester groups (P < .05).
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0.52, respectively) (P < .05). In all trimester groups, the FRT scores were lower in pregnant women with an MSB than in those without an MSB (P < .05) (Figure 2).
DISCUSSION In this study, the scores of FRT were significantly lower in each trimester group in women with an MSB than in those without an MSB. It is well documented that the risk of falling increases during the third trimester [17]. Serious risk situations, such as placental abruption, preterm labor, maternal bone fracture, and maternal-fetal deaths, can be seen because of falling during gestation [18]. The majority of fall-related hospitalizations during pregnancy are seen in the third trimester. Schiff [17] reported that fall-related hospitalizations are seen in 48.9 of 100,000 pregnancies and that 79.3% of these falls occur in the third trimester. In our study, the dynamic postural stability was assessed by BBS, and the test scores were found to be higher in the third trimester. The FRT score was found to be higher in the thirdtrimester group compared with the other groups. Similarly, the FRT score of the second-trimester group was increased with regard to the first-trimester group (P < .001). The mean score of FRT was 0.99 0.26 in the first-trimester group, whereas the second- and the third-trimester group scores were mean SD 1.27 0.52 and 1.72 1.03, respectively (P < .001). Numerous studies have reported increased postural instability during the gestational period [19-21]. In these studies, standing postural, anterior-posterior, and radial wobbling were found to be increased in pregnant women when compared with women who were not pregnant. In addition, balance measurements were found to be different between pregnant women in labor and women who were not pregnant. According to Butler et al [19], postural equability remained comparatively stable during the first trimester; however, the second trimester, third trimester, and postpartum values were increased prominently compared with values in the control subjects. Jang et al [20] reported that pregnant women displayed increased wobbling, particularly in the anterior-posterior and radial directions, compared with women who were not pregnant. Anterior-posterior sway measures strongly correlated with perceived balance and also decreased significantly between the third trimester and postpartum period. The weakest balance was found in the third trimester. Significant changes in lumbar angle, pelvic tilt, and head position were reported during pregnancy in the first and third trimesters. In the third trimester, women stood with an increased lumbar lordosis and a greater anterior pelvic tilt [22]. These changes potentially correlate with increased low back pain and pelvic disability symptoms. Similarly, the negative impacts of these changes on balance are seen during pregnancy. Various support garments such as MSBs are commonly prescribed to normalize posture, body
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Cakmak et al
MATERNITY SUPPORT BELTS ON POSTURAL BALANCE
Figure 2. Descriptive statistics (mean SD) for balance stability score among groups with and without maternity support belts (MSB). The left side of the bars with same color describes the results without MSB and the right ones with MSB. Note the significant difference between 2 groups in the same trimester group. *P < 0.05, **P < 0.01.
mechanics, and movement problems by providing external support to the pelvis and abdomen. Pelvic support belts are clinically used to provide an additional outside force to stabilize pelvic joints [23]. The MSB is effective for pelvic girdle pain likely because of improved stability in the pelvic region. In our study, with the same logic (providing stability for pelvic and lumbar spine joints), the use of an MSB applied to each of the 3 pregnancy trimester groups led to a decrease in the risk of falling. In this study group, significant improvement of the APSI values was seen after use of an MSB in the first-trimester pregnant women, but an absolute value of MLSI was found to be higher for the second- and third-trimester groups. However, in general, all the FRT values that evaluated falling risks improved significantly after the application of an MSB in all trimester groups (P < .05). Ho et al [24] reported that the maternity support garments reduced fatigue, pressure, and stress and strain of the back; prevented and/or relieved back pain; and corrected or improved posture. However, the maternity support garments have a mechanical effect of reducing the mobility, laxity, and sagittal rotation of the sacroiliac joints in healthy women and in women with pregnancy-related pelvic girdle pain. The maternity support garments usually are preferred by pregnant women and health care providers because they are easy to wear, adjust, and remove, and they allow a wider range of fit for increasing abdominal girth. The MSB used in our study is a belt type of conventional MSB and caused significant diminution in FRT scores without limiting the range of motion of pregnant women. However, many types of maternity support garments, such as belts, briefs, and cradle and torso supports, are used during pregnancy [25]. Although an MSB decreases fall risk, a study reported that long-leggedetype maternity support garments increased falling due to difficulty in wearing and nonstretchability [26].
CONCLUSION This is the first study that investigated the effects of maternity support garment use on the risk of falling and on balance during pregnancy. Maternity support garment use improved impaired balance and FRT scores during all periods of pregnancy, especially in the third trimester. MSB worn during pregnancy, and especially during the third trimester, may help to prevent falls. A prospective randomized trial, following up participants through the trimesters of pregnancy, with and without the use of MSBs, and measuring balance and fall risk scores, would be an important future step.
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