Effects of abdominal girdle belt on pulmonary function variables of postpartum women in Enugu, Nigeria: a quasi-experimental study

Abstract This quasi-experimental study was aimed at investigating the effects of wearing an abdominal girdle belt on pulmonary function variables of postpartum women. 40 consenting postpartum women aged between 18 and 35 years were recruited from a post-natal clinic in Enugu, Nigeria. The participants were conveniently assigned into girdle belt and control groups (20 each). Their lung function (forced expiratory volume in first second[FEV1], and %FEV1, forced vital capacity[FVC], peak expiratory flow [PEF], forced expiratory flows [25th, 75th & 25–75th percentiles]) values were measured prior to and after eight weeks of the study intervention period for each participant. Data obtained were analysed using descriptive and inferential statistics. Following the intervention period, 19 and 13 participants completed the study in the girdle belt and control groups, respectively. The main results showed that both groups were comparable at baseline for all the study variables assessed (p > 0.05). Following the intervention period, only the PEF was significantly reduced in the girdle belt group compared to control group participants (p = 0.012). Thus, wearing girdle belts for an extended period of time has no effect on the lung function values of postpartum women. IMPACT STATEMENT What is already known on the subject? Postpartum abdominal girdle belts are commonly utilised for resolution of abdominal protrusion and obesity after childbirth. Unfortunately, several adverse effects, including bleeding, compressive pain and discomfort and abnormally increased intra-abdominal pressure, have been associated with this practice. Consistent increase in intra-abdominal pressure of variable duration has been reported to affect pulmonary functions. What do the results of this study add? The study findings indicate that wearing girdle belts for eight weeks by postpartum women has no substantial effect on the pulmonary function variables. What are the implications of these findings for clinical practice and/or further research? Utilisation of abdominal girdle belts of equal or less than 8 weeks duration should not be discouraged for post-partum women due to fear of its potential negative impact on pulmonary function.


Introduction
Pregnancy produces both biomechanical and functional alterations that may impact negatively on many systems of the body (Conder et al. 2019).Major morphological modifications that may occur in the musculoskeletal system during pregnancy can be enormous especially in the abdominal area (Mota et al. 2015, Ponmathi et al. 2018, Fukano et al. 2021).These alterations can be observed either in the form of separation of the rectus abdominis muscles, weakness of the abdominal muscles, anterior tilting of the pelvis with or without lumbar lordosis, the altered length-tension relationship of the abdominal muscles and/or persistent protrusion of the abdomen after childbirth (Benjamin et al. 2014).These changes can negatively affect the aesthetic appearance of women, which is a relevant source of cosmetic concern for them (Benjamin et al. 2014, Michalska et al. 2018, Carlstedt et al. 2021).
To tackle the challenge of persistent protrusion of the abdomen after childbirth, several methods have been adopted by women including the traditional tying of clothing material around the abdominal region, use of medicinal supplements, herbs, certain medications, girdle belts and exercise training (Mota et al. 2015, Kamel and Yousif 2017, Acharry and Kutty 2015).The old practice of tying a cloth around the abdominal area has recently been replaced by the use of postpartum girdle belts or waist trainers (Mota et al. 2015).The use of these belts after delivery has been considered relevant because it is thought to reduce the size of the abdomen even to pre-pregnancy levels (Hemborg 1985, Acharry and Kutty 2015, Kamel and Yousif 2017, Ponmathi et al. 2018, Tian 2019).Beyond this, the use of these belts has gained acceptance and popularity.Moreover, they have been reported to relieve back pain, strain on muscles and ligaments, toning of abdominal muscles and also assist in maintaining proper posture during breastfeeding (Ponmathi et al. 2018, Tian 2019).
Nevertheless, despite these reported benefits, the use of postpartum abdominal girdle belts has been associated with some risks and adverse health effects (Chankhunaphas and Charoenkwan 2020).These adverse health effects may include bleeding due to excessive pressure on the uterus, itching around the body regions in contact with the belt, and an experience of tactile and compressive pressure, pain and discomfort (Mens et al. 2006).Post-caesarean section complications have also been associated with the use of these belts, especially when used prior to complete healing of sutures, thereby resulting in abdominal hernias (Tian 2019).
Additionally, the use of abdominal girdle belt is associated with an increase in intra-abdominal pressure (Ponmathi et al. 2018).This steady-state pressure concealed within the abdominal cavity typically results from the interaction between abdominal wall and viscera (Rafaela and Rita 2016).A consistent increase in intra-abdominal pressure has been earlier reported to cause a cranial-directed displacement of the chest wall elastance, thereby leading to a possible reduction functioning or impairment of the respiratory system (Pelosi et al. 2007), suggesting that there is an untoward relationship between the use of the abdominal belt and pulmonary function.However, later studies tend to indicate that abdominal belt is safe for postpartum women (Chankhunaphas andCharoenkwan 2020, Rothman et al. 2014).There is an increasing popularity and usage of these belts in among women in low-and middle-income countries despite to the conflicting reports of its potential adverse effects.This study therefore aims to determine the effects of abdominal girdle belts on the pulmonary functions of postpartum women in Enugu Nigeria.

Participants
Post-postpartum women meeting the study criteria were enrolled from the postnatal clinic of the Enugu State University Teaching Hospital, Parklane, Enugu State, Nigeria.The study inclusion criteria are as follows: (i) women within the age range of 18 to 35 years, (ii) within six and 48 weeks postpartum, and (iii) attending post-natal care services.Individuals with a confirmed or self-reported diagnosis of current pulmonary/respiratory and/or spinal musculoskeletal disorders, recent history of abdominal chest or pelvic surgery and a history of abdominal skin sensitivity were excluded from the study.
The study procedure complied with the Declaration of Helsinki and was approved by the Health Research Ethics Committee of the University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State, Nigeria (NHREC/05/01/2008B-FWA00002458-1RB00002323).This study adopted a quasiexperiment design and utilised the Transparent Reporting of Evaluations with Non-randomized Designs (TREND) checklist in reporting the study findings (Des Jarlais et al. 2004).

Intervention and procedures
Following initial screening for eligibility, 40 post-partum women were recruited to participate in the study.The participants were conveniently assigned into girdle belt and control groups (20 each).The participants in the experimental group were taught how to put on the girdle belt, after which they were all given a belt to use.In this study, the wearing of an abdominal girdle belt constituted the intervention or exposure.The belts were latex-made, soft and stretchy, long enough to span longitudinally from the mid-thoracic region to the inferior inguinal border and possessed firm adjustable slides on in the midline of their anterior components.The participants were instructed to wear their belts for at least six hours daily (at a stretch, except during sleep or while eating food) for a period of eight weeks.Compliance by the study participants was monitored via telephone daily to ensure that they were complying with the study instructions and to ensure that they had no adverse events or complaints.
The participants in the control group did not receive any intervention aside from the routine post-natal care.They were also told not to use an abdominal girdle belt or wrapper during the study intervention period (8 weeks from enrollment).
The sociodemographic data, respiratory rate, pulmonary function variables (FVC, FEV 1 , FEV 1 %, PEF, FEF 25 , FEF 75 , FEF 25-75 ) and oxygen saturation (SPO 2 ) of the participants were measured for participants in both groups prior to the start of the study and at the end of the study period (following eight weeks).
Pulmonary functions were assessed using a spirometer (Nature spirit SP-10, USA) in accordance with the protocol of the American Thoracic Society (1995).The technique of the procedure was explained to all participants carefully and practical trials were conducted prior to actual measurements.Participants only started the procedure after it was well understood.The measurement was done in high sitting.
Participants were asked to take the deepest breath possible to total lung capacity, put the mouth piece, and blow out in one continuous blast of air into the mouth piece of the spirometer as hard and as quickly as possible using the maximum effort possible until they had emptied the air in their lungs.The procedure was repeated three times for each participant and the best of the three results for parameters such as forced vital capacity (FVC), forced expiratory volume in first second (FEV 1 ), percent predicated forced expiratory volume in first second(FEV 1 %), peak expiratory flow rate (PEF), 25 th percentile forced expiratory flow (FEF 25 ), 75 th percentile forced expiratory flow (FEF 75 ), 25 th to 75 th percentile forced expiratory flow (FEF 2575 ), with <5% deviation from another was taken into consideration for analysis.

Sampling technique and sample size
In this study, we utilised a convenient sample technique and participants were selected based on their availability and willingness to participate in the study.A priori power analysis showed that a sample size of 15 participants per group will be needed for the paired sample t-test at the degree of freedom (df) ¼ 1, to achieve 80% power with a large effect size of 0.69 at an alpha level of 0.05 (Cohen 1998).To control for participant attrition, sample size of 40 participants (20 per group) was recruited for this study.However, only 32 women (girdle belt group ¼19; control group ¼ 13) successfully completed the study while 8 dropped out for personal reasons.

Statistical analysis
Descriptive statistics of mean, standard deviation and frequency were used to summarise data obtained from the study.Normality distribution was evaluated using Shapiro-Wilk test.Chi square test.Chi square test was used to compare the clinical characteristics (for categorical variables) of the participants.Furthermore, the effects of abdominal girdle belts on pulmonary function variables were tested using an independent t-test for a between-group comparison (for normally distributed continuous variables).Mann-Whitney U nonparametric tests were performed to analyse differences for variables that were not normally distributed Data were analysed using the statistical package for social sciences (SPSS) version 24 with alpha probability level significant at 0.05.

Results
A total of thirty-two postpartum women successfully participated (completed) in this study.The mean age, body mass index (BMI), and abdominal girths of the participants were 29.9 ± 4.09 years, 34.5 ± 12.51 kg/m 2 and 94.8 ± 10.34 cm, respectively (Table 1).The results of the study as presented in Table 2 indicated that participants in both groups were comparable on most of the important clinical characteristics (p > 0.05), except for alcohol consumption (p ¼ 0.007).Here, participants in the abdominal girdle group were found to report significantly higher use of alcohol (Table 2).Furthermore, no significant baseline differences were seen between both groups in the lung function parameters (p > 0.05) as presented in Table 2.
Following the study period, the findings of the study indicated that there was a significant difference in the PEF value between the abdominal girdle and control groups participants (p ¼ 0.012).Nevertheless, no significant differences between were found for all for other lung function parameters (FVC, FEV 1 , FEV 1 %, FEF 25 , FEF 75 , FEF 2575 ) between participants in the abdominal girdle and the control group (p > 0.05) difference between their mean differences (Table 3).

Discussion
This study aimed to evaluate the effects of abdominal girdle belts on the pulmonary function variables of postpartum women in Enugu Nigeria.The main findings of the study showed that the use of an abdominal girdle belt among the participants of this has no significant impact or effect on pulmonary function values.This simply implies that wearing girdle belts may not have any potential untoward effect on the pulmonary functions of postpartum mothers.Moreover, this finding is consistent with that of Ponmathi et al. (2018) who earlier suggested same.
Even though abdominal girdle belt is generally known to be associated with an increased intra-abdominal pressure  when worn, our study results nonetheless suggest that these periodic increments is insufficient to induce reductions in pulmonary functions or oxygen saturation in postpartum women overtime.From a different clinical point of view, however, it should be noted that an increase in intra-abdominal pressure could markedly affect respiratory functions among critically ill patients as reported in a previous review by Pelosi et al. (2007).This occurs following increases in the chest wall elastance, a cranial shift of the diaphragm, and consequent reduction in lung volumes and sometimes atelectasis.This clarification is necessary in view of the demographic charateristics of the participants of this study who are mainly apparently healthy young adult women.Hence, similar outcomes may not necessary be the case when other catergories of post-partum women are considered.The lack of significant difference between participants in both experimental and control group was unexpected.This is because the current evidence suggests the muscles and fascia of the anterolateral abdominal wall and lumbopelvic region play a vital role in musculoskeletal function, continence and respiration.Furthermore, the synergistic function of these structures act in such a way that is necessary for loads to be transferred effectively through the lumbopelvic region during multiple tasks of varying loads, predictability and perceived threats (Hodge and Cholewicki, 2007).Therefore, the use of girdle belts during postpartum should have aided in causing an optimal load transfer that may provide extra support to help do the work of the muscles still recovering from laxity, support the spine, improve posture and help alleviate back pain (Ponmathi et al. 2018) and consequently influencing extramusculoskeletal systems of the body such as respiration.
Nevertheless, the findings of our study also revealed a significant reduction in PEF among abdominal girdle users after 8 weeks.While this is a minority outcome, this reduction may be due a potential structural restriction of the ribcage as a result of prolonged use (Sarawgi et al. 2018).The PEF lung function parameter is a function flow of air in the airways and not volume of air in them.Hence, other extraneous variables may be implicated in the negative results seen.It is also possible that the restriction is due to increased intraabdominal pressure.Nevertheless, it is unlikely this reduction in PEF is clinically relevant because other lung function parameters remained unchanged following usage of these belts.Nonetheless Lastly, the study has a few limitations.Firstly, we did not assess reduction in the abdominal girth of the participants.This may have provided further insights and associating factors with our variables of interest.Secondly, the outcome of the study is limited by the design as thus limiting the study's ability to conclude a causal association between an intervention and an outcome (Schweizer et al. 2016).Also, a small sample size tends to exaggerate the effect size and limits the findings from being extrapolated (Faber and Fonseca 2014).Finally, we could not say for sure if participants in the control group never utilised any form of belt or wrapping cloth to prevent their abdomen from protruding.Nevertheless, our study findings add to the debate and further understanding of the clinical implication of using these belts by post-partum women.These concerns can be addressed in future studies.

Conclusion
It was concluded that wearing girdle belts has no substantial effect on the pulmonary functions of postpartum women following 8 weeks of use.Hence, we consider the use of girdle belt to be safe among postpartum women.Thus, its utilisation should not be discouraged on the grounds of its expected adverse effects on pulmonary functions, pending further elaborate studies on this subject.

Table 1 .
Age and select anthropometric characteristics of the participants.

Table 2 .
Comparison of the clinical characteristics and baseline pulmonary function variables of the study participants.