Obstetric and urogynecological history are associated with lower limb strength and physical performance in middle-age and older women: a community-based cross-sectional study

Abstract

Objectives

To investigate the association of urogynecological and obstetric history with lower limb physical performance and knee flexion/extension strength in middle-aged and older women.

Study design

Observational, cross-sectional study.

Methods

A total of 581 middle-aged and older women receiving care at a primary health service were included in this study. Lower limb physical performance was assessed using the Short Physical Performance Battery (SPPB), and isometric knee flexion and extension strength was evaluated using a hand-held dynamometer. Data were collected on gynecological and obstetric history, socioeconomics, demographics, physical health, anthropometrics, and physical activity levels.

Results

Number of deliveries was inversely associated with isometric knee extension strength (β = -0.41; 95% CI = -0.60 to -0.20; p = 0.009) and SPPB scores (β = -0.08; 95% CI = -0.13 to -0.03; p = 0.002).

Conclusion

The findings suggest that a higher number of deliveries is associated with poorer physical function among middle-aged and older women. Preventive and rehabilitative strategies targeting women with a history of multiple deliveries may help address functional limitations in this population.

Introduction

The global population aged 60 years and older is increasing at an unprecedented rate. The number of older adults (1 billion in 2019) is projected to reach 1.4 billion in 2030 and 2.1 billion by 2050. Around the middle of the century, women over the age of 65 are expected to represent more than half of this demographic, highlighting the need for sex-specific perspectives in aging research and healthcare planning [1, 2].

While women generally live longer than men (average life expectancy of 79 years vs. 73 years) [3], they are more likely to experience functional limitations and a higher burden of disability in later life [4, 5]. These impairments may negatively impact independence, increase the risk of institutionalization [6], and contribute to poorer health-related quality of life [7, 8].

Within this framework, identifying factors associated with the physical decline in aging women is essential, since reproductive events may represent an important but underexplored dimension of women’s health trajectories. Therefore, life course events such as early childbearing, high parity rate, pregnancy-related musculoskeletal and hormonal changes, and pelvic floor disorders (e.g., urinary incontinence and pelvic organ prolapse) may be associated with long-term differences in physical function [1, 9–11]. These conditions have been associated with mobility, balance, and muscle strength, yet their long-term impact on objective measures of physical performance remains poorly understood. Moreover, these biological processes may interact with social and environmental conditions, potentially being associated with physical performance in later life [12, 13]. Despite growing interest in sex-based determinants of aging, few studies have addressed how obstetric and urogynecological histories relate to muscle strength and lower limb function in later life. Lower limb (LL) strength is a key predictor of physical performance in older adults [14, 15] with knee extension strength serving as an indicator of overall LL muscle strength [16]. However, most research has focused either on general risk factors for frailty or on isolated pelvic floor outcomes, without integrating physical performance assessments [17–19]. Only a few studies, such as that conducted by Bondarev et al. [20], have linked menopausal status to lower limb strength, leaving a substantial gap in understanding the broader implications of women’s reproductive history on functional aging.

Therefore, the present study investigated the association between urogynecological and obstetric history and lower limb physical performance with isometric knee flexion/extension strength in middle-aged and older women. The study may help inform the early identification of women at risk of poorer functional performance and support the development of targeted interventions. Importantly, given the cross-sectional nature of the study design, the objective was to investigate associations rather than causal relationships.

Materials and methods

Study design, location, and ethical considerations

This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines to ensure transparency and methodological rigor in reporting observational research. It was a community-based cross-sectional study conducted in the municipalities of Parnamirim and Santa Cruz, located in the state of Rio Grande do Norte, in northeastern Brazil. The study was approved by the institutional research ethics committee under protocols CAAE: 15765013.0.0000.5537 and CAAE: 1875802.

Population and sample

Participants were recruited through primary health care units and community outreach strategies conducted in collaboration with local health professionals. Women who met the eligibility criteria and expressed interest in participating were invited to attend assessment sessions at designated community locations. Because recruitment relied on voluntary participation among users of primary health care services and required attendance at these sessions, women with more severe mobility limitations may have been underrepresented in the sample.

Therefore, the study used a convenience sample of middle-aged and older women who were users of primary health care services in the municipalities of Parnamirim and Santa Cruz. A minimum sample size of 537 participants was estimated based on an expected prevalence of functional impairment of 20%, a population of 14,520 women, α = 5%, and β = 20%. To account for an anticipated 10% loss rate, additional participants were recruited. The final sample included 381 women from Parnamirim and 200 from Santa Cruz, totaling 581 participants. Eligibility criteria were to be community-dwelling women aged 40 to 80 years who could commute to the assessment sites. Exclusion criteria were neurological disorders (e.g., Parkinson’s disease, stroke, or degenerative spinal conditions), limb fractures, or ongoing conditions that would interfere with physical performance assessment (e.g., severe pain). Women who had undergone bilateral oophorectomy were also excluded, as well as those with cognitive impairment, defined as four or more errors on the Leganès Cognitive Test [21, 22].

Independent variables

Gynecological and obstetric history

Gynecological history was obtained during clinical evaluation. Participants were asked about the following variables: age of menarche (in years), early menarche (< 10 years old), number of pregnancies and deliveries, age of first and last pregnancy, early maternal age at first birth (< 18 years old), use of hormone therapy (never, in current use, previous use of hormone therapy), history of hysterectomy, urinary incontinence (UI) in the last 12 months, and pelvic organ prolapse (POP) [10, 22, 23].

The presence of hysterectomy, UI, and POP were self-reported after explaining the conditions to participants. The participants answered the questions to verify the presence or absence of UI (“Did you lose a small amount of urine in the last 12 months?”) and POP complaints (“Do you have the sensation that there is a protuberance in your vagina or that something is falling out of your vagina?”) [12].

It is important to highlight that these variables were assessed using single self-reported questions. Although this approach has been used in large epidemiological surveys, it does not provide information on symptom severity or clinical diagnosis. Therefore, the possibility of misclassification cannot be ruled out. This limitation was considered in the interpretation of results.

Dependent variables

Isometric knee flexion and extension strength

Muscle strength was measured using a portable hand-held dynamometer (MicroFet2, Hoggan^® Health Industries, UT, USA), with the force expressed in kilograms of force (Kgf), as this measure reflects the total force available for functional tasks. For the assessment of knee extension strength, participants were instructed to remain seated with their knees flexed at 90 degrees [6]. A strap was used to secure the dynamometer to the anterior region of the dominant leg above the malleolus and perpendicular to the tibial crest. The evaluator instructed the participant to perform a maximum isometric contraction of the knee extensors for five seconds [16]. Knee flexion strength was assessed with the participant standing and hands resting on the stretcher. Then, they were instructed to bear the body weight on one leg while the dynamometer was positioned on the posterior face of the distal region of the contralateral leg above the medial malleolus and attached to the wall with an inelastic strap. Three maximum isometric contractions of knee flexors were requested with hip in neutral position, with a one-minute rest interval between each attempt. The mean of these measurements was used for analysis.

Short Physical Performance Battery (SPPB)

The Brazilian version of the SPPB, validated for the Brazilian population, [21, 24] was used to assess physical and LL performance based on standing balance, gait speed, and LL strength (chair stands) [8]. The evaluator demonstrated each test. The SPPB total score (0 to 12 points) was obtained by summing scores. High scores represented better physical performance [8].

Covariates

Socioeconomic and demographic data

Self-reported data included age (in years), educational level (up to elementary school (< 7 years of study), between elementary and high school (> 7 and < 11 years of study), and high school or more (> 11 years of study) [18]; marital status as stable union (yes or no); and family income (less than three minimum wages [MW] or three or more MW).

Physical health and anthropometric variables

Hypertension, diabetes, and dyslipidemia were assessed through self-report, based on participants’ report of a previous medical diagnosis made by a health professional. BMI-based nutritional classification was calculated from weight and height measurements obtained with a digital scale (Wiso^®, model W903) and a stadiometer (Welmy^®), respectively. BMI was categorized according to World Health Organization [17] criteria: normal weight (18.5–24.9 kg/m²), overweight (25.0–29.9 kg/m²), and obesity (≥ 30.0 kg/m²).

Regular practice of physical activity

Participants were asked to report their engagement in regular physical activity (≥ 30 min, three times per week) [25].

Statistical analysis

Data analysis was performed using the Statistical Package for Social Sciences (SPSS, IBM Corp, USA) software, version 22.0. Data distribution was verified using Kolmogorov-Smirnov test and expressed as mean and standard deviation for quantitative variables, and relative and absolute frequencies for categorical variables.

Comparison of means between SPPB scores and knee flexion and extension strength, and the independent variables and covariates (stable union, educational level, family income, hypertension, diabetes, dyslipidemia, categorical BMI, regular physical activity, UI, hysterectomy, POP, early menarche, hormone therapy, and early maternal age at first birth) were analyzed using unpaired t-test and one-way analysis of variance (ANOVA) with Tukey’s post-hoc. Pearson’s correlation coefficients were calculated between dependent and independent variables and quantitative covariates. Correlation strength was interpreted as negligible (r ≤ 0.30), weak (0.31 ≤ r ≤ 0.50), moderate (0.51 ≤ r ≤ 0.70), strong (0.71 ≤ r ≤ 0.90), or very strong (r > 0.90) [26].

Multiple linear regression models were constructed to examine the associations between knee flexion and extension strength, SPPB scores, and reproductive history variables with lower-limb physical performance outcomes. Variables showing an association with the dependent variables at p < 0.20 in the bivariate analyses were considered eligible for inclusion in the multivariable models, in order to avoid premature exclusion of potential confounders. Additionally, variables considered clinically relevant based on previous literature were also tested. The final models were obtained using a backward stepwise elimination procedure, retaining variables with p < 0.05. Covariates evaluated during the modeling process included stable union, educational level, family income, hypertension, diabetes, dyslipidemia, BMI, physical performance, and number of comorbidities. Multicollinearity among independent variables was assessed using variance inflation factors (VIF), and all values were within commonly accepted thresholds, indicating adequate model stability and absence of significant multicollinearity. All analyses were conducted considering 95% confidence intervals and a significance level of p < 0.05.

Results

Characteristics of participants

The sample had a mean age of 54.8 (± 9.4) years. A substantial proportion of participants reported an educational level up to elementary school (46.7%), monthly household income below three minimum wages (71%), and being in a stable union (69%). Most participants did not report comorbidities, but 43% had hypertension, 16% had diabetes, and 29% had high cholesterol levels.

The prevalence of overweight was high, affecting 42% of the sample. Regarding gynecological and obstetric history, the majority of women did not use hormone therapy (79.2%), did not have hysterectomy (82.4%), and no complaints of pelvic organ prolapse (58.7%). However, 55% of the participants reported experiencing urinary incontinence. The mean knee flexion strength was 14 (± 5) Kgf, and the mean knee extension strength was 22 (± 7) Kgf. The mean total SPPB score was 11 points (Table 1).

Table 1.

Characteristics of participants

Variables	n* (%) or mean ± SD
Age (years)	54.8 ± 9.4
Stable union
Yes	399 (69)
Education
Up to elementary school	271 (47)
From elementary to high school	220 (38)
Completed high school or more	89 (15)
Family income
Less than three MW	412 (71)
Hypertension
Yes	241 (43)
Diabetes
Yes	88 (16)
Dyslipidemia
Yes	158 (29)
BMI
Normal weight	112 (19)
Overweight	243 (42)
Obesity	224 (39)
BMI (kg/m2)	29 ± 5
Number of comorbidities	1 ± 1
Regular physical activity
Yes	182 (31)
Age of menarche	13 ± 2
Number of pregnancies	4 ± 3
Number of deliveries	3 ± 2
Age of first pregnancy	22 ± 6
Age of last pregnancy	30 ± 6
Early menarche
≤10 years	18 (3)
Early maternal age at first birth
Yes	169 (31)
Hormone therapy
Never	457 (79)
Currently	24 (4)
Previously	96 (17)
Hysterectomy
Yes	102 (18)
Urinary incontinence
Yes	205 (55)
Pelvic organ prolapse
Yes	240 (41)
Knee flexion (Kgf)	14 ± 5
Knee extension (Kgf)	22 ± 7
SPPB total score	11 ± 1

MW minimum wage, BMI body mass index, Kg/m² kilogram per square meter, SD standard deviation, Kgf kilogram-force, SPPB Short Physical Performance Battery

*Valid cases

Comparisons between dependent and independent variables and covariates

Knee flexion strength was significantly different among educational levels (p < 0.001), family income (p = 0.001), BMI categories (p = 0.001), and physical activity (p < 0.001). Knee extension strength was also different among educational levels (p < 0.001) and those with hypertension (p = 0.02) and diabetes (p = 0.03).

Regarding overall physical performance, as measured by the total SPPB score, significant differences were found according to educational levels (p < 0.001), hypertension (p < 0.001), diabetes (p < 0.001), and POP (p < 0.001) (Table 2).

Table 2.

Comparisons of dependent variables as a function of independent variables and covariates

Variables	Knee flexion	Knee extension	SPPB score
	Mean ± SD
Stable union
No	14.6 ± 5.0	22.1 ± 7.5	11.0 ± 1.4
Yes	13.8 ± 5.3	21.3 ± 7.1	11.1 ± 1.2
p-value	0.10	0.21	0.88
Education
Up to elementary school	13.1 ± 4.7	20.5 ± 7.0	10.7 ± 1.4
From elementary to high school	15.2 ± 5.4	22.8 ± 7.6	11.3 ± 1.1
Completed high school or more	14.1 ± 5.5	21.8 ± 6.8	11.4 ± 0.9
p-value	0.001	0.001	< 0.001
Family income
Three MW or more	15.5 ± 5.9	21.8 ± 7.5	11.2 ± 1.1
Less than three MW	13.5 ± 4.8	21.4 ± 7.2	11.0 ± 1.3
p-value	0.001	0.53	0.10
Hypertension
No	14.2 ± 5.2	22.1 ± 7.2	11.2 ± 1.1
Yes	13.9 ± 5.2	20.6 ± 7.3	10.7 ± 1.4
p-value	0.45	0.02	0.001
Diabetes
No	14.1 ± 5.2	21.6 ± 7.4	11.1 ± 1.2
Yes	13.4 ± 5.2	19.8 ± 7.1	10.4 ± 1.6
p-value	0.25	0.03	0.001
Dyslipidemia
No	14.4 ± 5.7	21.3 ± 7.3	11.0 ± 1.3
Yes	13.5 ± 4.4	21.1 ± 7.4	10.8 ± 1.3
p-value	0.09	0.85	0.11
Categorical BMI
Average	12.4 ± 4.5	20.9 ± 6.3	11.1 ± 1.3
Overweight	14.1 ± 5.4	21.1 ± 7.5	11.1 ± 1.3
Obese	14.8 ± 5.1	22.4 ± 7.5	11.0 ± 1.3
p-value	0.001	0.08	0.71
Regular physical activity
No	13.6 ± 5.1	21.1 ± 7.3	11.0 ± 1.3
Yes	15.1 ± 5.3	22.4 ± 7.2	11.2 ± 1.1
p-value	0.001	0.05	0.10
Urinary incontinence
No	13.9 ± 4.7	22.4 ± 6.9	11.4 ± 0.9
Yes	13.6 ± 5.0	21.8 ± 7.1	11.3 ± 1.0
p-value	0.54	0.44	0.85
Hysterectomy
No	13.9 ± 5.1	21.3 ± 7.3	11.0 ± 1.3
Yes	14.6 ± 5.7	22.7 ± 7.0	11.2 ± 1.1
p-value	0.44	0.29	0.54
Pelvic organ prolapse
No	13.8 ± 4.7	21.8 ± 7.0	11.2 ± 1.1
Yes	14.4 ± 5.8	21.2 ± 7.7	10.8 ± 1.4
p-value	0.14	0.31	0.001
Early menarche
Up to 10 years	15.3 ± 6.8	24.1 ± 5.4	11.3 ± 0.9
11 years or more	14.0 ± 5.1	21.5 ± 7.3	11.0 ± 1.3
p-value	0.31	0.13	0.33
Hormone therapy
Never	14.1 ± 5.2	21.4 ± 7.2	11.0 ± 1.3
Currently	14.3 ± 5.3	23.6 ± 8.1	11.0 ± 1.0
Previously	13.7 ± 5.0	21.8 ± 7.6	11.0 ± 1.0
p-value	0.78	0.33	0.23
Early maternal age at first birth
No	14.2 ± 5.1	21.5 ± 7.3	11.0 ± 1.0
Yes	13.9 ± 5.2	21.6 ± 7.1	11.0 ± 1.0
p-value	0.48	0.96	0.33

MW minimum wage, BMI body mass index, SPPB Short Physical Performance Battery, SD standard deviation

Correlations between dependent and independent variables and covariates

Significant correlations were observed between the dependent variables (SPPB total score and knee flexion and extension strength) and several independent variables. Age showed a moderate negative correlation with knee flexion (r = -0.21; p < 0.001), knee extension strength (r = -0.24; p < 0.001), and SPPB score (r = -0.45; p < 0.001). The number of pregnancies was negatively correlated with knee flexion (r = -0.10; p = 0.01), knee extension strength (r = -0.16; p < 0.001), and SPPB score (r = -0.28; p < 0.001). Similarly, the number of deliveries showed negative correlations with knee flexion (r = -0.16; p < 0.001), knee extension strength (r = -0.20; p < 0.001), and SPPB score (r = -0.32; p < 0.001).

Regarding reproductive history, age at menarche was significantly correlated only with the SPPB score (r = -0.09; p = 0.02). Age at last pregnancy was also negatively correlated with SPPB score (r = -0.14; p = 0.001), although no significant correlations were found with knee strength measures. The number of comorbidities was negatively associated with knee flexion strength (r = -0.14; p = 0.009) and SPPB score (r = -0.17; p = 0.001), but not significantly associated with knee extension strength (p = 0.10). No significant correlations were found between age at first pregnancy and any of the dependent variables.

In summary, according to the predefined classification adopted in the present study (r ≤ 0.30 = negligible), the observed correlations between reproductive variables and physical performance outcomes should be interpreted as small in magnitude.

Multiple linear regressions for physical performance

Table 3 presents the results of the multivariable regression models examining the association between reproductive history variables and lower-limb physical performance indicators. A higher number of deliveries was associated with poorer physical performance outcomes, including lower knee extension strength (β = −0.41; p = 0.009) and poorer SPPB scores (β= -0.08; p = 0.002). In contrast, urinary incontinence was not significantly associated with the physical performance indicators evaluated.

Table 3.

Adjusted multiple linear regression models for physical performance variables

Outcome / Variables in the final model	B	95% CI	Standardized β	t	p
Knee flexion
Constant	23.41	20.60 to 26.20	—	17.10	< 0.001
Age (years)	-0.14	-0.18 to -0.10	-0.259	-6.10	< 0.001
Family income	-1.92	-2.60 to -0.99	-0.170	-4.06	< 0.001
Regular physical activity	1.84	0.80 to 2.60	0.166	3.90	< 0.001
Stable union	-1.30	-2.09 to -0.34	-0.119	-2.80	0.005
Knee extension
Constant	30.49	26.10 to 34.10	—	16.30	< 0.001
Age (years)	-0.15	-0.23 to -0.08	-0.195	-3.90	< 0.001
Regular physical activity	1.82	0.50 to 3.18	0.114	2.67	0.008
Number of deliveries	-0.41	-0.60 to -0.20	-0.129	-2.60	0.009
SPPB score
Constant	14.18	11.50 to 16.90	—	10.28	< 0.001
Age (years)	-0.05	-0.08 to -0.02	-0.410	-3.27	< 0.001
Regular physical activity	0.39	0.19 to 0.60	0.140	3.71	< 0.001
Number of deliveries	-0.08	-0.13 to -0.03	-0.130	-3.10	0.002

CI confidence interval, SPPB Short Physical Performance Battery

Among the covariates, younger age, regular physical activity, higher family income, and living in a stable union were associated with better physical performance outcomes after adjustment. All regression models were reviewed for internal consistency. Multicollinearity diagnostics showed acceptable values (variance inflation factor within recommended limits), indicating adequate model specification and stability of the estimates.

Discussion

The present study investigated the association between reproductive history and lower-limb physical performance in middle-aged and older women receiving primary health care in Northeast Brazil. Our findings indicate that a higher number of deliveries was associated with poorer physical performance, even after considering important sociodemographic and behavioral factors. These results reinforce the hypothesis that reproductive history may be associated with long-term functional outcomes in women. In this study, the number of deliveries was associated with both knee extensor strength and SPPB total score, in agreement with prior studies. Hurt, Ronsmans, and Thomas [9] reported that a high number of pregnancies has been associated with maternal musculoskeletal exhaustion, possibly related to changes involving bone and ligament structures, nerves, pelvis, and hip. Likewise, previous studies have shown that a higher number of deliveries was associated with worse SPPB scores and handgrip strength [19, 27]. Notably, we also observed that parity was not associated with knee flexion strength, possibly because flexor muscles may be less affected and show less variation in strength during the aging process than knee extensors [27]. In this sense, knee extension strength may represent a more sensitive marker of age-related muscle deterioration [28].

Specifically in Brazil, multiple pregnancies and higher parity are often associated with lifelong adversities (e.g., low socioeconomic status and poor diet quality) and may also be associated with lower-limb (LL) strength and poorer long-term physical performance. Previous literature indicates that women with five or more pregnancies are more likely to experience obesity, chronic diseases, cognitive decline, osteoporosis, cardiovascular complications, and frailty [3, 29–32].

Although more than half of the participants reported urinary incontinence (UI), this condition was not associated with physical performance outcomes in the present study. Moreno-Vecino et al. [33] reported an association between UI and overweight and sedentary behavior, which were also prevalent in our sample. Indeed, excess body weight was reported by more than 80% of participants (42% overweight and 38.7% obese). These findings may be partially related to hormonal changes during the climacteric period, which have been associated with central fat accumulation [34]. In addition, reduced levels of physical activity and menopausal hormonal changes may also be associated with pelvic floor muscle dysfunction, one of the most prevalent conditions related to UI in older adults [35–37].

Despite the high prevalence of UI, our findings contrast with those of Corrêa et al. [19], who reported an association between UI and lower physical performance in older women. One possible explanation for this discrepancy may be related to our broader age range and the relatively higher SPPB scores observed in our sample, suggesting that physical decline may not yet be fully manifested in many participants. Unlike our study, Vieira et al. [12] observed associations between pelvic organ prolapse (POP) symptoms and poorer physical performance in middle-aged women. However, in the present study we considered the total SPPB score, and participants were older than those included in the study by Vieira et al. [12] Early maternal age has also been reported as a factor associated with poorer physical performance [10]. However, this association was not observed in our study, possibly due to the predominance of middle-aged women in our sample.

Early maternal age has also been reported as a factor associated with poorer physical function later in life, although the mechanisms underlying this association remain unclear [10]. However, this association was not observed in the present study, which may be related to the predominance of middle-aged women in our sample and the relatively preserved physical performance observed in this group.

Regarding covariates, age, physical activity, stable union, and family income were associated with LL performance. Our results regarding age and physical activity as factors associated with physical decline are consistent with the literature [38]. Physical activity is a modifiable variable, and its regular practice can be stimulated by public policies. In Brazil, approximately 69.1% of older adults practice physical activity irregularly, similar to the present study, in which 68.6% of women did not perform regular physical activity [39].

Similar to Brazil, 61% of women in Finland do not practice regular physical activity, and inactive women report more symptoms of menopause and pelvic floor disorders than active women 20. Corrêa et al. [19] observed that general menopausal symptoms, such as psychosocial and physical symptoms, were associated with levels of physical activity. Studies also showed that the level of physical activity may be associated with physical performance: low- and moderate-intensity physical activity was associated with better physical performance in older women [40] and lower mortality from chronic diseases [41].

Sousa et al. [42] reported that living alone during adulthood is associated with a higher likelihood of poor physical performance. Family relationships have also been associated with lower levels of disability and frailty [22]. Low family income was also associated with worse physical performance. Previous studies have shown that low educational level in women is associated with poorer financial conditions [42], which is consistent with our findings, as most women in our sample had education up to elementary school and monthly income lower than three minimum wages (MW). Social and economic adversities have also been associated with differences in the menopausal experience and with lower physiological reserves among women living in less favored environments, which may be related to greater loss of muscle strength in postmenopausal years and poorer physical performance [43].

In terms of LL function, mean knee flexion and extension strength were lower than reference values [2]. Similarly, Rolland et al. [44] observed that older women had a mean knee extension strength of 16.48 Kgf, which may be related to decreased estradiol levels that occur with aging [20,45]. However, this pattern may also be associated with environmental conditions, occupation, social and economic adversities in childhood, family income [42, 43] and physical activity [20].

On the other hand, participants showed good physical performance in the SPPB [24]. Gómez et al. [46] reported that SPPB scores were inversely associated with age [47, 48]. This association was also observed in the present study and is consistent with the findings of Shaffer et al. [49], who reported mean total scores of 10.98 in younger older adults (54.8 ± 9.4 years), whereas Rolland et al. [44] observed that older women (80.50 ± 3.76 years) presented a mean SPPB total score of 8.66 points.

This study has some limitations. First, the use of a convenience sample may limit the generalizability of the findings. Because participation required attending assessment sessions at community locations, women with greater mobility or functional limitations may have been underrepresented in the sample, which may introduce potential selection bias. In addition, the cross-sectional design may be subject to survival bias, as women with poorer health or more severe functional limitations may have been less likely to participate in the study. However, similarities in key characteristics between the two participating municipalities—such as educational level, parity, hysterectomy prevalence, and maternal age at first birth—suggest some consistency within the study population [32, 50]. Second, some variables were based on self-report, which may be subject to recall bias or underreporting, particularly regarding physical activity, chronic diseases, and pelvic floor disorders. In addition, urogynecological conditions such as urinary incontinence were assessed through self-report rather than clinical evaluation or validated questionnaires, which may introduce potential misclassification bias. Instruments such as the International Consultation on Incontinence Questionnaire–Short Form (ICIQ-SF) could provide a more comprehensive assessment of urinary incontinence symptoms. However, the present study relied on previously collected data, and reassessment using a validated instrument was not possible. A third limitation relates to the fact that muscle strength was analyzed using absolute values (Kgf). Although normalization by body weight or body composition may be considered in some contexts, absolute strength values were maintained because they reflect the total force available for functional tasks such as standing, walking, and chair rise, which are directly evaluated by the SPPB. Despite these limitations, the present study offers important contributions. First, the sample included both middle-aged and older women, allowing the investigation of factors associated with functional performance across an important transitional period in women’s aging trajectory. Second, we evaluated both knee extension and flexion strength as indicators of lower-limb performance, providing a more comprehensive assessment of functional capacity.

In particular, knee extensor strength may represent an early marker of functional decline, offering opportunities for preventive strategies before substantial disability occurs. Therefore, our findings may assist health professionals in identifying factors associated with reduced physical performance and in developing targeted interventions aimed at preserving functional independence among women during the menopausal transition and later life.

Conclusion

A higher number of deliveries was associated with poorer lower-limb physical performance among middle-aged and older women receiving primary health care. Urinary incontinence, although highly prevalent, was not significantly associated with physical performance outcomes. Sociodemographic and behavioral factors, particularly age and physical inactivity, were also associated with functional performance. These findings highlight the relevance of reproductive history and modifiable lifestyle factors in the assessment of functional health in women during aging.

Authors’ contributions

B.S.A.C.N., S.G.G.F.M., R.S.S.A.G., M.A.M., S.M.A.C., M.S.M.M., and W.B.S. contributed to the conceptualization, investigation, methodology, data curation, formal analysis, visualization, and writing of the original draft. E.R.V. provided methodological guidance, validation, and critical revision of the manuscript. A.C.C.M. contributed to supervision, project administration, funding acquisition, and writing – review and editing.All authors reviewed and approved the final manuscript.

Funding

This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001, and the National Council for Scientific and Technological Development – CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Data availability

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request, subject to ethical approval and data protection regulations.

Declarations

Ethics approval and consent to participate

This study was conducted in accordance with the ethical standards of the Declaration of Helsinki. The research protocol was reviewed and approved by the Research Ethics Committee of the Universidade Federal do Rio Grande do Norte (UFRN), Brazil, under the following approval numbers: CAAE 15765013.0.0000.5537 and CAAE 1875802.

Consent for publication

Not Applicable.

Competing interests

The authors declare no competing interests.