Introduction

Pregnancy-related low back pain (PLBP) was a prevalent discomfort during pregnancy1, affecting approximately 63% of pregnant women worldwide2. This pain not only impacted the physical health of pregnant women but also had potential long-term negative effects on their psychological state and quality of life3. Engaging in appropriate exercise and physical activity during pregnancy could prevent and control gestational diabetes and hypertension, reduce the risk of preeclampsia, control excessive weight gain, and alleviate PLBP4,5. However, some studies showed that about 68.6% of PLBP pregnant women were afraid that exercise would cause or aggravate pain and avoid exercise or physical activities, which was called kinesiophobia6,7. This avoidance could significantly negatively impact the physical and mental health of pregnant women8,9. The high prevalence and adverse effects of kinesiophobia have prompted professionals to investigate its risk factors and develop intervention strategies.

Research have demonstrated an association between a lack of pain-related knowledge and the development of kinesiophobia10,11. However, findings were not uniform, as a study had reported no significant correlation between the two12. Fall fear was another factor that affected exercise and physical activity and may exacerbate kinesiophobia13,14,15, but there were little studies on the relationship between fall fear and kinesiophobia, which need further confirmation. Exercise self-efficacy has been identified as a key psychological factor in mitigating kinesiophobia16. It was the belief in one’s ability to perform physical activities despite pain, which could be a protective factor against the development of kinesiophobia. While studies have explored the interplay among low back pain knowledge, fall fear, exercise self-efficacy, and kinesiophobia10,15,17, the conclusions have been inconsistent. This inconsistency highlights the complexity of these relationships and the need for more research. In addition, there was a gap in understanding the comprehensive influence of these factors on kinesiophobia, particularly among pregnant women. Pregnant women may experience unique challenges due to physiological changes, which could affect their pain perception, fall fear, and exercise self-efficacy. A deeper understanding of how low back pain knowledge, fall fear, and exercise self-efficacy affect individual activity behavior can provide key insights for developing effective interventions.

The Protection Motivation Theory (PMT)18 proposed that by improving individuals’ coping resources and self-efficacy, their ability to cope with health threats can be enhanced, thus promoting positive health behaviors. This study applies the Protection Motivation Theory to explore the relationship between low back pain knowledge, fall fear, exercise self-efficacy, and kinesiophobia in pregnant women, aiming to provide targeted measures for healthcare personnel to alleviate kinesiophobia and improve health behaviors during pregnancy.

Methods

Study design and setting

This was a cross-sectional study that was conducted in the prenatal clinic of a tertiary maternity hospital in Wuxi, China from August to December 2023. The project was approved by the Ethics Committee of the host hospital (Code of Ethics: IRB2023-01-0628-21). We have confirmed that all methods were performed following the Helsinki Declaration. Our research obtained informed consent from all participants.

Participants

We recruited a group of pregnant women who were examined by obstetricians and diagnosed with pregnancy-related low back pain, provided them with the necessary explanations, and asked them to take part in the project. Women who met the inclusion criteria were entered into the study.

Inclusion and exclusion criteria

The inclusion criteria of participants were as follows: (1) age ≥ 18 years, (2) the gestational age at the time of investigation ≥ 14 weeks, (3) singleton pregnancy, (4) had PLBP, (5) no serious pregnancy comorbidities or complications, (6) normal mental intelligence, informed consent, and voluntary participation. The exclusion criteria were as follows: (1) those with a history of injury or surgery to the lumbar spine, spine, or pelvic region, (2) a history of low back pain before pregnancy, (3) those who visited the clinic for low back pain after pregnancy and found organic lesions by relevant examinations.

Measures

After explaining the purpose and significance of the study to pregnant women diagnosed with PLBP, a questionnaire survey was conducted. Informed consent was obtained before the questionnaire was distributed. A standardized guide was used to help pregnant women fill in the questionnaire and provide necessary preventive measures. Checked the collected questionnaires on site, clarified any missing or unclear items, and filled them in immediately. All subjects were informed and agreed to the research content and volunteered to participate. The flow chart of the study recruitment process was shown in Fig. 1.

Fig. 1
figure 1

Flow diagram of the study recruitment process. PLBP pregnancy-related low back pain.

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Main study variables

Kinesiophobia

Tampa Scale for Kinesiophobia (TSK)19 was utilized to evaluate kinesiophobia in pregnant women. The scale comprises 17 items, with items 4, 8, 12, and 16 being reverse-scored. The scale total scores ranged from 17 to 68. Higher scores indicate increased kinesiophobia.

Low back pain knowledge

Low Back Pain Knowledge Questionnaire (LBPKQ)20 was utilized to evaluate the pain knowledge of pregnant women. The questionnaire comprised 15 questions, with six focusing on the causes and prevention of PLBP, seven on routine health care during pregnancy, and two on the effects of PLBP on maternal and child health. Each “yes” answer was given 1 point, and each “no” answer was given 0 point. Out of 15 points. A total score of < 9 was a poor knowledge level, 9 ~ 12 was a medium knowledge level, and ≥ 13 was a good knowledge level. The Cronbach alpha value was 0.756.

Fall fear

International Falls Efficacy Scale(FES-I)21 was used to examine the fall fear among pregnant women. The scale consisted of 16 items categorized into two dimensions: indoor activities and outdoor activities. Each item was rated on a 4-point scale, resulting in a total score ranging from 16 to 64. A higher score indicated a greater fear of falling.

Exercise self-efficiency

Pregnant Women’s Exercise Self-Efficacy Scale(P-ESES)22 was used to assess pregnant women’s confidence in engaging in and persisting with exercise. This scale comprised a total of 10 items, which were categorized into three dimensions: overcoming exercise barriers, overcoming emotional barriers, and overcoming support barriers. Ratings were assigned to every item on a scale of 1 to 5, leading to a total score that spans from 10 to 50. Increased scores reflected enhanced belief in physical activity and heightened self-assurance.

Demographic and obstetric-related variables

The demographic and obstetric-related variables included age, education (high school and below, junior college /undergraduate course, master’s degree or above), family economic (< 10000RMB,10000 ~ 15000RMB,15000 ~ 20000RMB,>20000RMB), pregnancy mode (natural pregnancy/resident medical insurance), gestational age (the gestational age at the time of investigation: 14 ~ 28 week, ≥ 28week ), pre-pregnancy weight(according to BMI before pregnancy:<18.5 kg/m2,18.5 kg/ m2 ≤ BMI<24.0 kg/ m2,≥24.0 kg/m2), gestational weight gain (insufficient, normal, excessive), exercise during pregnancy (yes/no), edema of lower limbs (yes/no), fall history (yes/no). The standard recommendation for weight gain during pregnancy was used to calculate gestational weight gain23: If the BMI of a woman before pregnancy was < 18.5 kg/m2, the recommended weight gain in the second and third trimesters should be between 0.37 and 0.56 kg per week. Weight gain below this range was considered inadequate while exceeding it was considered excessive. BMI (body mass index) was calculated as weight in kilograms divided by height in meters squared.

Data analysis

SPSS 26.0 (Statistical Package for the Social Sciences, Chicago, IL, USA) was utilized for conducting a statistical analysis of influencing factors on kinesiophobia. Descriptive statistics were presented as mean and standard deviation (SD) for continuous variables that followed a normal distribution or as median and interquartile range (P25, P75) for continuous variables with non-normal distribution. At the same time, count data was presented as frequency and percentage. A sample t-test or one-way analysis of variance (ANOVA) was carried out to explore the difference in means for continuous variables with normal distribution, or else a rank-sum test was applied. Pearson’s correlation analysis was used to test the correlation between two continuous variables. We incorporated kinesiophobia-related factors (P < 0.1) from univariate analysis and correlation analysis into multivariate analysis. Multivariate linear regression was employed to find the influencing factors on kinesiophobia. The dummy variable would be set when the classified data was subjected to multiple linear regression. The path relationship model was developed using AMOS 23.0 (Analysis of Moment Structure, Chicago, IL, USA). The mediation effect was tested using Bootstrap. A two-tailed P value ≤ 0.05 was recognized as statistically significant.

Results

Demographic characteristics

This study ultimately recruited 325 pregnant women with PLBP. Their average age was 29 and their average gestational age was 32 weeks. Of these women, 71.4% (n = 232) were pregnant for the first time, 71.1% (n = 231) were in the late stage of pregnancy and 9.5% (n = 31) were at an advanced age. The Kinesiophobia score of pregnant women with PLBP was 46.3 (SD = 10.3). The low Back Pain Knowledge Score was 8.2 (SD = 3.5). The fall fear score was 40.70(SD = 12.4) and the exercise self-efficacy score was 39.7 (SD = 7.7).

The effect of socio-demographic information on kinesiophobia in PLBP pregnant women was presented in Table 1. Education, gestational age, gestational weight gain, and exercise during pregnancy are statistically significant differences (all P < 0.05) in the scores of kinesiophobia among PLBP pregnant women.

Table 1 Characteristics of categorical variables and univariate analysis (n = 325).
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Correlation analysis

The correlation between age, exercise self-efficacy, low back pain knowledge, fall fear and kinesiophobia were displayed in Table 2. A positive correlation was found between fall fear and kinesiophobia (r = 0.46, P < 0.001). Exercise self-efficacy and low back pain knowledge were negatively related to kinesiophobia(r=−0.47, P < 0.001, r = 0.49, P < 0.001).

Table 2 Correlation analysis between variables (r).
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Multiple linear regression analysis

The statistically significant variables in univariate analysis and correlation analysis: education, gestational age, gestational weight gain, edema of low limbs, exercise during pregnancy, exercise self-efficacy, low back pain knowledge, and fall fear were subjected to multiple linear regression. Table 3 demonstrated the results. Exercise self-efficacy, fall fear and low back pain knowledge were influential factors in kinesiophobia among PLBP pregnant women (P < 0.05). These variables could explain 42.7% of kinesiophobia. The low back pain knowledge (β=-0.305, P < 0.001) and exercise self-efficacy (β=−0.274, P < 0.001) were negatively correlated with kinesiophobia, which means that increasing pregnant women’s low back pain knowledge and improving their exercise self-efficacy could significantly reduce their kinesiophobia. The positive correlation coefficient of falling fear (β = 0.264, P < 0.001) showed that the increase in falling fear was related to the increase in kinesiophobia.

Table 3 Multiple linear regression (n = 325).
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Path analysis

Figure 2 presented the chain-mediating model of low back pain knowledge, fall fear, and exercise self-efficacy on kinesiophobia. The structural equation model demonstrated an excellent fit: χ2/df = 1.309, GFI = 0.989, AGFI = 0.968, TLI = 0.994, NFI = 0.988, RMSEA = 0.031. The chain-mediating model revealed that low back pain knowledge in PLBP pregnant women significantly affects their kinesiophobia, with a total effect of −0.489 (P < 0.001). When fall fear and exercise self-efficacy were included in the regression equation, low back pain knowledge negatively predicted fall fear (β=−0.33, P < 0.001) and positively predicted exercise self-efficacy (β = 0.25, P < 0.001). Fall fear positively predicted kinesiophobia (β = 0.31, P < 0.001). Exercise self-efficacy negatively predicted kinesiophobia (β=−0.30, P < 0.001). After including fall fear and exercise self-efficacy, low back pain knowledge still significantly predicted kinesiophobia (β=-0.29, P < 0.001). Therefore, fall fear and exercise self-efficacy partially mediated the relationship between low back pain knowledge and kinesiophobia in PLBP pregnant women.

Fig. 2
figure 2

The chain-mediating model of low back pain knowledge, exercise self-efficacy and fall fear on kinesiophobia. ***p < 0.001 was considered statistically significant.

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Table 4 showed the influence analysis of fall fear and exercise self-efficacy between low back pain knowledge and kinesiophobia. Fall fear had a mediating effect on low back pain knowledge and kinesiophobia, with a confidence interval of (−0.168~−0.057), accounting for 21.1% of the total effect. Exercise self-efficacy also had a mediating effect on low back pain knowledge and kinesiophobia, with a confidence interval of (−0.136~−0.033), and the mediating effect accounts for 15.5% of the total effect. The confidence interval for the chain-mediating effect of fall fear and exercise self-efficacy was (−0.041~-0.009), accounting for 41.3% of the total effect.

Table 4 Effect analysis of fall fear and exercise self-efficacy between low back pain knowledge and kinesiophobia.
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Discussion

Our results indicated that low back pain knowledge, fall fear, and exercise self-efficacy could directly affect kinesiophobia. Low back pain knowledge also indirectly affects kinesiophobia through the chain intermediary of fall fear and exercise self-efficacy. This was consistent with the theory of protective motivation: low back pain knowledge as a coping resource could affect individuals’ evaluation and response to health threats, thus affecting their behavior. In our study, PLBP pregnant women had a mean kinesiophobia score of (46.3 ± 10.3), which was higher than Vlaeyen’s definition of kinesiophobia (he defines a score > 37 as kinesiophobia)24. This suggested that PLBP pregnant women included in our study presented with elevated kinesiophobia. This may be related to the experience of pain and dysfunction during pregnancy, changes in body structure, and other factors. These factors work together to cause pregnant women to have higher fear and avoidance behavior during pregnancy7,25.

Relationship between low back pain knowledge and kinesiophobia

This study demonstrated a significant negative correlation between low back pain knowledge and kinesiophobia, consistent with previous research10,11. The direct effect of low back pain knowledge on kinesiophobia in this study was − 0.29, accounting for 59.2% of the total effect, indicating that low back pain knowledge was a major influencing factor of kinesiophobia. The knowledge-attitude-practice theory suggested that when patients accumulate a certain level of knowledge about a disease, it could lead to changes in attitude and promote healthier behaviors26. A survey on the influencing factors of prenatal exercise also found that insufficient knowledge was one of the main reasons why pregnant women do not engage in prenatal exercise27. These studies, along with our findings, accurately reflected that adequate knowledge was the foundation and driving force for behavioral change. In this study, the low back pain knowledge score of pregnant women was low (8.23 ± 3.51), and over half (62.2%) of pregnant women had poor knowledge mastery, which still needs further improvement. Currently, patients’ understanding of diseases mainly comes from health education provided by healthcare professionals, which had issues such as single-source information and limited time, leading to insufficient knowledge and affecting patients’ confidence in exercise28. Therefore, healthcare professionals should employ various technological methods, such as the internet and social media, to strengthen health education for PLBP, extend the duration of patient education, and help them acquire the knowledge and skills to cope with low back pain, thereby reducing their fear of exercise.

The mediating role of exercise self-efficacy on low back pain knowledge and kinesiophobia

Our study indicates that in PLBP pregnant women, exercise self-efficacy plays a mediating role between low back pain knowledge and kinesiophobia. This was consistent with previous findings that increasing disease knowledge can enhance patients’ sense of self-efficacy29, and self-efficacy had a negative predictive effect on kinesiophobia30. This suggested that disease knowledge was not only key to improving patients’ self-efficacy but also an important factor in reducing exercise fear. Good disease knowledge helped increase patients’ understanding of the severity of the disease and the importance of exercise, leading them to actively seek social support to improve their confidence in coping with the disease and engaging in physical activity31,32. Self-efficacy was a key predictor of exercise behavior33, and was positively correlated with exercise behavior during pregnancy34. Exercise self-efficacy can be described as an individual’s ability to manage themselves in the face of exercise tasks. The self-efficacy theory posited that a high level of exercise self-efficacy can increase an individual’s confidence and belief in their ability to perform exercise tasks, and they were less likely to avoid problems due to physical or mental discomfort33. There was also evidence that individuals with high self-efficacy have a higher pain tolerance and may experience less pain-related fear35. The mediating role of exercise self-efficacy between low back pain knowledge and kinesiophobia in PLBP pregnant women emphasizes the importance of cognitive psychological factors in the management of kinesiophobia in chronic pain patients. The results of this study suggested that interventions aimed at increasing exercise self-efficacy may be beneficial in reducing kinesiophobia and improving physical activity levels in pregnant women with PLBP.

The mediating role of fall fear on low back pain knowledge and kinesiophobia

This study indicated that fall fear was a partial mediator between low back pain knowledge and kinesiophobia. This finding was consistent with previous research36,37 suggesting that fall fear was an important psychological factor affecting individuals’ exercise behavior. Pregnancy was a period of significant change, the musculoskeletal system undergoes numerous alterations, such as a change in the body’s center of gravity, edema of low limbs and pain, which may increase the risk of falls and fall fear38,39. This was particularly true for pregnant women who experience pregnancy-related low back pain40. Studies have shown that the incidence of falls during pregnancy ranges from 25–27%41. Fall fear referred to an individual’s excessive concern about the negative psychological state associated with falling. However, the relationship between fall fear and the actual incidence of falls may not be directly proportional. Some studies have indicated that the presence of fall fear does not necessarily mean that individuals have a higher risk of falling, as fall fear may interact with other psychological factors (such as anxiety and depression) to affect individuals’ behavior and functioning42,43. Disease knowledge was an individual’s understanding and comprehension of the definition, causes, and treatment of a disease. A lack of disease knowledge may lead to an inability to correctly understand or cope with the disease, resulting in anxiety and fear10. In the current study, pregnant women scored low in low back pain knowledge and high in fall fear (40.70 ± 12.40). The insufficient understanding of PLBP among pregnant women may exacerbate concerns and fears about falling, affecting individuals’ self-confidence and attitudes towards exercise, thereby influencing exercise behavior. These suggested to healthcare providers that nursing interventions should not be limited to providing educational knowledge but should also help pregnant women cope with psychological distress.

Chain-mediated effects of fall fear and exercise self-efficacy on low back pain knowledge and kinesiophobia

Our study further revealed that fall fear and exercise self-efficacy have a serial mediating effect on the relationship between low back pain knowledge and kinesiophobia in PLBP pregnant women. The lack of disease knowledge often leads to negative emotions44. This was consistent with cognitive neuroscience, which suggested that the less know about a disease, the more intense the fear becomes. This fear can trigger anxiety, depression, and other negative emotions, thereby triggering the body’s automatic defense responses, reducing individuals’ confidence in exercise, increasing vigilance for activity safety, and resulting in avoidance behavior42. This study expanded our understanding of the potential variables affecting kinesiophobia and revealed pathways to alleviate it. In addition to increasing pregnant women’s knowledge levels, reducing their fall fear and enhancing their exercise self-efficacy may be an actively effective method to reduce kinesiophobia in pregnant women. Studies have shown that a lack of knowledge about prenatal exercise, interpersonal relationship barriers, and physical discomforts such as fatigue and vomiting were significant factors leading to low exercise self-efficacy and fall fear in pregnant women32. Therefore, in future nursing intervention studies, healthcare providers should consider both physical and psychological factors of pregnant women comprehensively, and provide targeted support and guidance, to fully address the multifaceted nature of kinesiophobia in pregnant women with PLBP. Previous studies had indicated that a lack of guidance from professional healthcare providers was a significant barrier to exercise for pregnant women45. This suggested that we should strengthen guidance on prenatal exercise, and help pregnant women develop detailed exercise plans, including specific detailed plans for when, where, and how to perform specific behaviors, to ensure they can achieve behavioral goals, thereby generating a higher sense of self-efficacy46. The most reported interpersonal barrier was the lack of someone to exercise with, so promoting family-based exercise plans and encouraging spouses to exercise with pregnant women during pregnancy was crucial for enhancing exercise self-efficacy32. In addition, providing coping skills for physiological stimulation during pregnancy was very beneficial for alleviating physical discomfort, which may improve exercise self-efficacy47.

These findings provide valuable information for developing effective clinical intervention strategies. In this study, the serial mediating effect of fall fear and exercise self-efficacy was feasible, as it partially mediated the impact of low back pain knowledge on kinesiophobia. Therefore, using fall fear and exercise self-efficacy as a “third variable” can complement the impact of low back pain knowledge on kinesiophobia, guiding healthcare providers to take targeted measures to alleviate kinesiophobia.

Advantages

This is the first study to explore the interrelationships between low back pain knowledge, fall fear, exercise self-efficacy and kinesiophobia in pregnant women with PLBP. In the present study, a chain-mediated effect of fall fear and exercise self-efficacy was feasible, which partially mediated the impact of low back pain knowledge on kinesiophobia. Therefore, healthcare providers can use this as a means to reduce kinesiophobia by increasing pregnant women’s knowledge, exercising self-efficacy and reducing their fall fear.

Limitations

This study also has some shortcomings. First, this study adopts the method of convenient sampling, and only one hospital is selected for investigation, which limits the representativeness and universality of the research results. Second, this study is a cross-sectional study, so it cannot explain the causal relationship and time-varying relationship between variables. In the future, longitudinal studies should be conducted to determine the causal relationship of these variables further. Third, many factors may affect the fall fear and exercise self-efficacy, not just the low back pain knowledge. This study has not evaluated these factors, and a more comprehensive study should be conducted in the future. Finally, the effect of low back pain knowledge on kinesiophobia in PLBP pregnant women has only been initially verified and more research was needed to further determine it in the future.

Conclusion

Through a chain-mediated model, this study explored the relationship between low back pain knowledge, fall fear, exercise self-efficacy, and kinesiophobia in pregnant women with PLBP. The findings indicated that among pregnant women with PLBP, their low back pain knowledge was negatively associated with the development of kinesiophobia. Fall fear and exercise self-efficacy were identified as factors with independent mediating effects between low back pain knowledge and kinesiophobia and contributing to a chain mediating effect. These associations suggest that interventions aimed at enhancing the understanding of low back pain, bolstering exercise self-efficacy, and mitigating fall fear may hold potential for reducing kinesiophobia in pregnant women with PLBP. However, it is crucial to acknowledge that the current study’s design limits the ability to draw definitive causal inferences, and future prospective studies, including longitudinal analyses, are necessary to establish the temporal stability of these mediators and to confirm the causal relationships.

In light of these findings, we suggest that future research can integrate these associations into broader maternal health frameworks to better understand the complex interplay between physical, and psychological factors and health-related behaviors during pregnancy. Future research can be to formulate targeted educational strategies, including not only providing information about low back pain but also aiming at improving exercise self-efficacy. Additionally, psychological support interventions could be explored to address fall fear and enhance overall mental well-being. These interventions include cognitive-behavioral therapy, group support sessions, or tailored exercise programs that emphasize safety and empowerment, thereby potentially reducing kinesiophobia and improving maternal health outcomes.