Clinical efficacy of integrated 3D manual pelvic reduction, suspension training, and pelvic belt fixation for postpartum pubic symphysis diastasis

Abstract

Objective

To evaluate the clinical efficacy of integrating three-dimensional (3D) manual pelvic reduction, suspension training, and pelvic belt fixation in the treatment of postpartum pubic symphysis diastasis (PSD).

Methods

A total of 136 patients diagnosed with postpartum PSD were randomized into a control group (n = 68) receiving conventional conservative therapy and an intervention group (n = 68) undergoing additional (3D manual pelvic reduction and Redcord suspension training. The primary outcome was pelvic pain assessed by the visual analog scale (VAS). Secondary outcomes included pubic symphysis width (radiographic measurement), functional disability [Oswestry Disability Index (ODI)], quality of life [QoL; 36-Item Short-Form Health Survey (SF-36)], and sleep quality (Pittsburgh Sleep Quality Index (PSQI)].

Results

Post-intervention, the intervention group demonstrated significantly greater improvements in VAS scores, pubic symphysis narrowing, ODI reductions, SF-36 domain score, and global PSQI scores (all P < 0.001) compared to the control group.

Conclusion

The combined protocol of 3D pelvic reduction, suspension training, and pelvic belt fixation effectively alleviates pain, restores pelvic alignment, enhances functional recovery, and improves QoL in postpartum PSD patients, representing a potentially promising therapeutic strategy for clinical adoption.

Introduction

Postpartum pubic symphysis diastasis (PSD), defined as abnormal widening of the pubic symphysis during delivery or the early postpartum period, is a common yet frequently overlooked musculoskeletal injury associated with pelvic instability and functional impairment [1]. Its reported incidence rates vary widely, ranging from 1/300 to 1/30,000, with studies suggesting higher prevalence of mild cases often undiagnosed due to subtle symptoms or lack of medical consultation [2]. Clinically, PSD manifests as localized pain at the pubic symphysis, frequently accompanied by referred pain in the lumbosacral, inguinal, or perineal regions. Severe cases may present with a characteristic “waddling gait” or even immobilization, profoundly delaying maternal functional recovery and compromising quality of life (QoL) [3]. The pathogenesis of PSD is multifactorial, involving hormonal changes (e.g., elevated relaxin levels), fetal macrosomia, prolonged or precipitous labor, and operative delivery techniques, all of which contribute to ligamentous laxity, joint malalignment, or partial ligament rupture at the pubic symphysis [4].

Failure to promptly diagnose and manage postpartum PSD may result in chronic pelvic instability, pelvic floor dysfunction, and increased risks of urinary system diseases, lumbosacral disorders, and persistent pelvic pain [5]. Current therapeutic strategies for PSD predominantly rely on conservative approaches, including pelvic stabilization, functional exercises, and analgesic therapy [6]. Pelvic belts, by providing external mechanical support, remain a cornerstone intervention for reducing pain and stabilizing the pelvic ring [5]. However, their standalone use often inadequately addresses the complex biomechanical demands of pelvic realignment and neuromuscular coordination. Recent advancements in rehabilitation concepts and techniques have introduced active interventions for PSD such as three-dimensional (3D) manual pelvic reduction and suspension training. The former employs targeted manual techniques to restore anatomical alignment of the sacroiliac joints and pubic symphysis [7], while the latter utilizes the Redcord system to activate core pelvic musculature and reconstruct dynamic stability. Combining these modalities with pelvic belt fixation may synergistically enhance structural stability while promoting multidimensional improvements in pain, function, and recovery.

Nevertheless, clinical evidence supporting this integrated approach patients remains limited, particularly regarding its comprehensive efficacy in pain relief, functional restoration, QoL, and sleep quality in PSD patients. This study aims to evaluate the clinical outcomes of combining 3D manual pelvic reduction, suspension training, and pelvic belt fixation for postpartum PSD, thereby providing empirical evidence to optimize early precision rehabilitation strategies for this population.

Materials and methods

Study participants

A total of 136 parturients diagnosed with PSD after term delivery were enrolled from the Department of Obstetrics in our hospital between May 2023 and January 2025. The sample size was calculated based on the visual analog scale (VAS) [8] as the primary outcome measure, with a significance level (α) of 0.05 and statistical power of 0.80. Using a two-tailed independent-sample t-test and referencing prior effect sizes reported by Han et al., a minimum of 64 participants per group was required. To enhance statistical robustness, account for potential physiological variability, and improve external validity, the final sample size was expanded to 136 eligible participants. All subjects were randomly allocated at a 1 : 1 ratio via a computer-generated randomization table to either the control group (n = 68) or the intervention group (n = 68). The study protocol was reviewed and approved by the Ethics Committee of Shijiazhuang Maternal and Child Health Hospital (Approval No. 202006).

Inclusion criteria comprised: (1) age of 18–45 years; (2) clinical confirmation of PSD via marked tenderness over the pubic symphysis combined with positive pelvic separation or compression tests; (3) radiographic evidence of pubic symphysis widening [X-ray or magnetic resonance imaging (MRI), defined as a symphyseal gap > 10 mm]; and (4) written informed consent.

Exclusion criteria included: (1) prior history of PSD, pelvic fractures, or congenital pelvic deformities; (2) preexisting gynecological or neurological conditions affecting gait (e.g., severe cervical pathology, lumbar disc herniation); (3) severe psychiatric disorders or cognitive impairment hindering protocol adherence.

Methods

Therapeutic interventions

Control group: Participants in the control group received standard conservative therapy involving pelvic belt fixation and pelvic floor muscle training. A customized pelvic belt was applied within 24 h postpartum, adjusted to provide optimal compression for pelvic ring stabilization while preserving lower limb mobility and avoiding vascular compromise. The belt was worn for ≥ 8 h daily over 6 consecutive weeks. Concurrently, patients performed supervised Kegel exercises targeting sequential activation of the anal, vaginal, and urethral sphincter muscles with upward pelvic floor elevation. Each contraction was sustained for 5 s followed by relaxation, repeated 5 times per set (3–5 sets daily). Training emphasized isolation of pelvic floor musculature while minimizing compensatory engagement of abdominal, gluteal, or lower extremity muscles.

Intervention group: In addition to the standard protocol, the intervention group underwent integrated suspension training and manual pelvic reduction. Rehabilitation commenced with Redcord suspension system-based exercises to enhance pelvic core stability prior to manual adjustments. Participants were positioned supine with upper limbs resting on the chest, knees flexed, and lower limbs suspended via narrow straps attached 30 cm vertically above the bed at the popliteal region. An elastic wide strap provided pelvic support during 30-minute supine suspension sessions. Closed-chain weak link testing identified biomechanical deficits, followed by targeted activation of hypoactive pelvic stabilizers. Immediately post-suspension, manual pelvic realignment was performed by a certified physiotherapist. With patient maintaining a supine position, bilateral oblique-axis adjustments of the sacroiliac joints and pubic symphysis reduction were guided by pre-interventional pelvic measurements and radiographic findings. Post-reduction pelvic belt application mirrored the control protocol, maintained for 6 weeks. Pelvic X-ray imaging was used to confirm restoration of pubic symphysis width and bilateral symmetry prior to discharge. Representative suspension training procedure is illustrated in Fig. 1.

Fig. 1.

Redcord suspension training for postpartum pubic symphysis diastasis. The patient lies supine on the treatment table with both lower limbs suspended in slings. A physiotherapist adjusts the suspension ropes to provide three-dimensional support and controlled movement, aiming to stabilize the pelvis and activate core and lower limb muscles

Outcome measures

The primary outcome of this study was pain intensity was quantified using the VAS [9]. The VAS is a commonly used subjective pain assessment tool, typically consisting of a 10-cm straight line labeled at each end as “no pain” (0) and “Worst Imaginable Pain” (10). Participants marked a point along the line corresponding to their perceived pain intensity, with higher scores indicating greater pain severity.

The secondary outcomes included the following:

Therapeutic efficacy assessment [10]: Therapeutic efficacy was categorized based on clinical symptoms and radiographic findings: ① marked improvement: complete resolution of pubic symphysis pain and lumbosacral discomfort, with pubic symphysis width < 4 mm on X-ray. ② effective improvement: significant reduction in pain intensity and functional signs, accompanied by radiographic narrowing of the pubic symphysis gap to 4–8 mm. ③ no improvement: persistent symptoms and radiographic evidence of PSD (>8 mm). Overall efficacy rate was calculated as: (marked improvement + effective improvement)/total cases × 100%.

Functional disability assessment: Functional limitations were evaluated via the Oswestry Disability Index (ODI) [11]. This validated tool assesses 10 domains: pain intensity, personal care, lifting, walking, sitting, standing, sleeping, sex life, social life, and traveling. Each domain offers six graded responses (0 = no disability; 5 = maximal disability), yielding a total score ranging from 0 to 50. Higher aggregate scores correlate with severer functional impairment.

QoL assessment: Health-related QoL was measured using the 36-Item Short-Form Health Survey (SF-36) [12]. The SF-36 evaluates eight dimensions: physical functioning, bodily pain, role limitations due to physical health, general health perceptions, social functioning, vitality, role limitations due to emotional problems, and mental health. Each dimension is scored 0–100, with higher scores reflecting better QoL.

Sleep quality assessment: Sleep disturbances were assessed using the Pittsburgh Sleep Quality Index (PSQI) [13]. The PSQI comprises 19 items grouped into seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medications, and daytime dysfunction. Each component is scored 0–3, with a global score range of 0–21. Higher total scores indicate poorer sleep quality.

Serum relaxin measurement: Serum samples were collected from patients one day postpartum and analyzed using enzyme-linked immunosorbent assay (ELISA). The ELISA kit was purchased from Shanghai Enzyme-linked Biotechnology Co., Ltd. (Shanghai, China), and all procedures were performed according to the manufacturer’s instructions. Absorbance was measured with an automated microplate reader (Thermo Fisher Scientific, USA), and serum relaxin concentrations were calculated using standard curves generated with ELISA Calc software.

Statistical analysis

All statistical analyses were performed using SPSS version 26.0 (IBM Corp., Armonk, NY, USA). Normality of continuous variables was assessed using the Shapiro-Wilk test. Normally distributed data are presented as mean ± standard deviation (± s) and analyzed with independent-sample t-tests for between-group comparisons or paired t-tests for within-group comparisons. Non-normally distributed continuous variables are expressed as median (Q₂₅, Q₇₅) and compared between groups using the Mann-Whitney U test or within groups using the Wilcoxon signed-rank test. Categorical variables are summarized as n (%) and analyzed with the chi-square (x²) test.

Results

Comparison of baseline characteristics

No statistically significant differences were observed between the two groups in baseline parameters, including age (P = 0.22), educational attainment (P = 0.30), gravidity (P = 0.28), mode of delivery (P = 0.60), pre-pregnancy body mass index (BMI; P = 0.66), gestational weight gain (P = 0.33), neonatal birth weight (P = 0.70), episiotomy status (P = 0.44), or relaxin levels (P = 0.51) (all P > 0.05). These findings confirm balanced baseline comparability between the control and intervention groups (Table 1).

Table 1.

Comparison of baseline characteristics between control and intervention groups []

Characteristic		Control group (n = 68)	Intervention group (n = 68)	t/z/x2	P
Age		28.68 ± 3.22	29.38 ± 3.40	1.24	0.22
Educational attainment	High school or below	35 (51.47%)	41 (60.29%)	1.07	0.30
	College or above	33 (48.53%)	27 (39.71%)
Gravidity		2 (1, 2)	2 (1, 2)	1.09	0.28
Mode of delivery	Cesarean section	31 (45.59%)	28 (41.18%)	0.27	0.60
	Vaginal delivery	37 (54.41%)	40 (58.82%)
Pre-pregnancy BMI		21.54 ± 1.75	21.69 ± 2.09	0.44	0.66
Gestational weight gain	≥ 17.5 kg	38 (55.88%)	34 (50.00%)	0.93	0.33
	< 17.5 kg	30 (44.12%)	34 (50.00%)
Neonatal birth weight (kg)		3.28 ± 0.40	3.25 ± 0.35	0.39	0.70
Episiotomy	Yes	21 (30.88%)	25 (36.76%)	0.59	0.44
	No	47 (69.12%)	43 (63.24%)
Relaxin (ng/L)		153.24 ± 49.26	159.05 ± 54.19	0.66	0.51

Comparison of treatment efficacy between the two groups

The results showed that the efficacy rate of the intervention group was significantly higher than that of the control group (97.06% vs. 85.29%, P = 0.031). This represented an absolute increase of 11.77% in therapeutic efficacy, as shown in Table 2.

Table 2.

Comparison of treatment efficacy between the two groups [n (%)]

Indicator	Control group (n = 68)	Intervention group (n = 68)	x 2	P
Marked Effect	11 (16.18%)	24 (35.29%)
Effective	47 (69.12%)	42 (61.76%)
Ineffect	10 (14.71%)	2 (2.94%)
Efficacy Rate	58 (85.29%)	66 (97.06%)	5.85	0.031

Post-treatment pelvic pain and PSD recovery

Pre-treatment comparisons revealed no significant differences in VAS scores (P = 0.61) or pubic symphysis width (P = 0.48) between the control and intervention groups. Following treatment, both groups exhibited statistically significant improvements in VAS scores and pubic symphysis width compared to baseline (both P < 0.001). Intergroup analysis demonstrated superior outcomes in the intervention group, with significantly lower post-treatment VAS scores and reduced pubic symphysis width relative to the control group (both P < 0.001) (Table 3).

Table 3.

Post-treatment pelvic pain scores and PSD recovery [M (Q₂₅, Q₇₅)]

Group	VAS score (points)		Within-group		Pubic symphysis width (mm)		Within-group
	Pre-treatment	Post-treatment	z	P	Pre-treatment	Post-treatment	z	P
Control	7 (6, 7.75)	3 (3, 4)	7.15	< 0.001	15 (13, 16)	7 (6, 8)	7.18	< 0.001
Intervention	7 (6, 7)	2 (2, 3)	7.22	< 0.001	15 (14, 16.75)	4 (3, 5)	7.18	< 0.001
z (between-group)	0.51	7.28	-	-	0.71	6.44	-	-
P	0.61	< 0.001			0.48	< 0.001

Comparison of ODI scores

Pre-treatment analysis revealed no statistically significant difference in baseline ODI scores between the control and intervention groups (P = 0.69). Post-treatment assessments demonstrated significant reductions in ODI scores from baseline in both groups (both P < 0.001). Comparative analysis further identified superior functional recovery in the intervention group, with post-treatment ODI scores significantly lower than those of the control group (P < 0.001) (Table 4).

Table 4.

Pre- and post-treatment ODI scores []

Group	ODI score		Within-group
	Pre-treatment	Post-treatment	t	P
Control	20.40 ± 2.93	15.37 ± 2.37	10.19	< 0.001
Intervention	21.34 ± 3.05	11.13 ± 2.55	11.48	< 0.001
t (between-group)	1.83	10.04	-
P	0.69	< 0.001

Comparison of QoL

Pre-treatment analysis demonstrated no statistically significant differences in baseline scores across all eight domains of the SF-36, physical functioning, bodily pain, role limitations due to physical health, general health perceptions, social functioning, vitality, role limitations due to emotional problems, and mental health, between the two groups (all P > 0.05), indicating comparable pre-intervention QoL. Post-treatment evaluations revealed significant improvements in all SF-36 domain scores for both groups compared to baseline (all P < 0.001). Intergroup comparisons further demonstrated superior post-treatment QoL outcomes in the intervention group across all domains relative to the control group (all P < 0.001) (Table 5).

Table 5.

Pre- and post-treatment QoL scores []

Group	Physical functioning	Bodily pain	Role limitations due to physical health	General health perceptions	Social functioning	Vitality	Role limitations due to emotional problems	Mental health
Control
Pre-treatment	59.07 ± 3.14	61.46 ± 3.7	62.07 ± 3.35	67.01 ± 3.75	64.68 ± 3.75	61.24 ± 2.88	67.87 ± 3.88	68.88 ± 3.10
Post-treatment	69.91 ± 4.04	69.44 ± 4.13	71.29 ± 4.02	73.12 ± 4.08	72.72 ± 4.17	69.22 ± 3.25	75.69 ± 3.52	75.07 ± 4.12
t	16.46	12.70	14.35	9.67	12.46	16.69	10.99	9.99
P	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001
Intervention
Pre-treatment	59.29 ± 3.40	62.00 ± 4.41	61.82 ± 3.09	66.93 ± 3.28	65.79 ± 3.11	61.71 ± 2.93	66.97 ± 3.85	68.12 ± 2.62
Post-treatment	75.84 ± 4.46	73.54 ± 2.99	78.51 ± 4.26	79.69 ± 4.3	82.31 ± 3.28	78.38 ± 3.80	79.41 ± 3.71	79.49 ± 3.87
t	22.69	17.03	25.19	17.39	30.31	30.40	19.28	19.96
P	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001
t (pre-treatment between-group)	0.39	0.78	0.45	0.14	1.89	0.94	1.35	1.55
P	0.70	0.44	0.65	0.89	0.06	0.35	0.18	0.12
t (post-treatment between-group)	8.11	6.64	10.17	8.89	14.89	15.10	6.00	6.44
P	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001

Comparison of sleep quality

Pre-treatment analysis showed no statistically significant differences in baseline scores across all PSQI components, subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medications, and daytime dysfunction, between the two groups (all P > 0.05), confirming comparable baseline sleep profiles. Post-treatment assessments revealed statistically significant improvements in all PSQI components for both groups compared to baseline (all P < 0.001). Notably, the intervention group exhibited greater magnitude of improvement across all sleep metrics. Intergroup comparisons demonstrated superior post-treatment outcomes in the intervention group for all PSQI dimensions (all P < 0.001, except for sleep efficiency P = 0.001), when compared to the control group (Table 6).

Table 6.

Pre- and post-treatment sleep quality scores [M (Q₂₅, Q₇₅)]

Group	Subjective sleep quality	Sleep latency	Sleep duration	Habitual sleep efficiency	Sleep disturbances	Use of sleep medications	Daytime dysfunction
Control
Pre-treatment	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)
Post-treatment	2 (1, 2)	1.5 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)
z	2.97	5.10	5.24	4.25	3.72	4.32	4.23
P	0.003	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001
Intervention
Pre-treatment	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)	2 (1, 2)
Post-treatment	1 (1, 1)	1 (1, 1)	1 (1, 1)	1 (1, 2)	1 (1, 1)	1 (1, 1)	1 (1, 1)
t	5.69	5.25	5.85	4.42	5.20	5.86	4.88
P	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001
z (pre-treatment between-group)	0.62	0.30	0.35	0.24	0.63	0.69	0.39
P	0.53	0.77	0.73	0.81	0.53	0.49	0.70
z (post-treatment between-group)	5.24	6.23	7.00	3.43	5.11	7.37	5.34
P	< 0.001	< 0.001	< 0.001	0.001	< 0.001	< 0.001	< 0.001

Discussion

Postpartum PSD, a frequently underrecognized musculoskeletal injury during the puerperium, has historically been managed through conservative approaches such as pelvic belt fixation, analgesic interventions, and functional rehabilitation exercises [14]. However, emerging advancements in rehabilitative science have highlighted the potential of integrated structural and functional interventions to address the multifaceted pathophysiology of this condition. Building upon this paradigm, the present study investigated the clinical efficacy of a multimodal therapeutic strategy combining 3D manual pelvic reduction, suspension training, and pelvic belt fixation in postpartum PSD patients. Our findings robustly demonstrated that the intervention group exhibited superior outcomes across multiple domains, including pain alleviation, anatomical realignment, functional restoration, QoL enhancement, and sleep quality improvement, when compared to conventional treatment protocols.

The pathophysiological foundation of PSD lies in the biomechanical destabilization of the pelvic ring. During late gestation and parturition, hormonal fluctuations, particularly elevated relaxin levels, induce ligamentous laxity in the pubic symphysis and sacroiliac joints. Concurrently, mechanical stresses exerted during fetal descent exacerbate joint diastasis, compromising pelvic stability and precipitating clinical manifestations such as localized pain, gait abnormalities, and functional limitations [15, 16]. While pelvic belts provide transient symptomatic relief through external stabilization, their passive mechanical support fails to address underlying structural malalignment or restore neuromuscular coordination, which are critical determinants of sustained recovery.

The 3D manual pelvic reduction protocol employed in this study represents a targeted approach to correct the characteristic pubic symphysis and sacroiliac joint malalignment observed in PSD patients [17]. By employing manual biomechanical adjustments to restore anatomical congruity, this intervention transcends mere motion restriction to actively reestablish pelvic integrity. The integration of radiographic verification further enhances therapeutic precision, enabling objective assessment of realignment efficacy and facilitating personalized treatment optimization.

A pivotal innovation of our protocol lies in the incorporation of the Redcord suspension system, which facilitates closed-chain neuromuscular re-education through partial gravitational offloading. This system enables the identification of “weak link” muscles, hypoactive or neurologically disinhibited core stabilizers within the lumbopelvic region—and promotes their selective activation [18]. By engaging deep stabilizers such as the pelvic floor musculature, transversus abdominis, multifidus, and gluteus medius, muscle groups exhibiting postpartum deactivation associated with pelvic floor relaxation, pelvic instability, and chronic lumbosacral pain, the intervention fosters sensorimotor recalibration [19]. This process not only enhances rehabilitation safety but also cultivates dynamic stability through refined intermuscular coordination, addressing the root causes of pelvic instability. Previous literature has highlighted manual reduction as a therapeutic option for pubic symphysis diastasis, although most reports are based on case descriptions and lack standardized radiographic verification [5]. Similarly, suspension-based training such as the Redcord and analogous sling systems has demonstrated efficacy in enhancing lumbopelvic stability and neuromuscular coordination in patients with musculoskeletal dysfunctions [20, 21]. Taken together, our findings are consistent with these reports and further extend them by integrating both structural realignment and functional re-education within a single protocol, thereby achieving more comprehensive recovery outcomes in postpartum PSD.

The pronounced reduction in ODI scores observed in the intervention group underscores the functional superiority of this multimodal approach. ODI improvements reflect enhanced capacity for activities of daily living, suggesting synergistic effects between structural realignment and neuromuscular reconditioning. Such recovery likely arises from dual mechanisms: anatomical correction reduces nociceptive input by mitigating mechanical strain on periarticular tissues, while active core stabilization rebuilds motor patterns essential for weight-bearing and ambulation. This paradigm shift from passive support to active neuromuscular engagement empowers patients to regain control over pelvic kinematics, thereby improving gait symmetry, postural stability, and load tolerance.

Beyond biomechanical restoration, our intervention demonstrated profound psychosocial benefits. Postpartum PSD often engenders maternal role strain, social withdrawal, and emotional distress due to persistent pain and mobility restrictions [22]. The SF-36 outcomes revealed significant improvements across physical, social, and mental health domains in the intervention group, reflecting enhanced capacity for childcare, social reintegration, and emotional resilience. The interactive nature of suspension training further facilitated a transition from passive dependency to active self-management, reinforcing patient autonomy and therapeutic adherence through real-time biofeedback.

Notably, sleep quality improvements, quantified by PSQI reductions, represent a critical yet often overlooked dimension of postpartum recovery. Nocturnal discomfort from malaligned pelvic structures, compounded by hormonal fluctuations and infant care demands, was ameliorated through pain reduction and improved positional tolerance [23]. Additionally, exercise-induced neuroendocrine modulation, including endorphin-mediated analgesia and autonomic nervous system regulation, may synergistically normalize sleep architecture, establishing a self-reinforcing cycle that accelerates tissue repair and emotional stabilization.

Despite these promising results, several methodological considerations should be noted. The single-center design and moderate sample size may partially limit the generalizability of findings, and future multicenter studies across diverse populations are needed to strengthen external validity. The relatively brief 6-week follow-up period precludes assessment of long-term recurrence rates or chronic instability patterns. Furthermore, the technical dependency on therapist expertise underscores the need for standardized training protocols to ensure intervention fidelity in broader clinical implementation. Another limitation is the lack of blinding for patients and therapists, which may have introduced expectation bias and potentially influenced subjective outcomes. The control group received only pelvic belt fixation and Kegel training, and the absence of comparison with other active conservative interventions may exaggerate the observed treatment superiority. Moreover, although no serious adverse events were observed in this study, possible risks such as discomfort during manual reduction or fall risk during suspension training were not systematically documented, and future studies should incorporate standardized safety monitoring. Finally, this study evaluated the combined effect of 3D manual pelvic reduction and suspension training without isolating their individual contributions. While this integrated approach reflects real-world practice and emphasizes their potential synergy, it limits the ability to quantify the magnitude of effect attributable to each technique separately. Future trials with multi-arm designs are warranted to clarify the relative roles of each modality.

In conclusion, the integration of 3D manual pelvic reduction, suspension training, and pelvic belt fixation establishes a potentially promising therapeutic paradigm for postpartum PSD, harmonizing structural correction with functional neuromuscular rehabilitation. This protocol not only achieves rapid anatomical realignment but also appears to reinstate dynamic stability through sensorimotor recalibration, ultimately fostering multidimensional recovery encompassing physical, psychological, and social well-being. Future investigations with larger, multicenter cohorts and extended longitudinal follow-up are warranted to validate these preliminary outcomes, incorporating objective biomechanical assessments (e.g., instrumented gait analysis, surface electromyography) and cost-effectiveness analyses to optimize clinical adoption within postpartum care frameworks.

Authors’ contributions

Ping Li and Jing Zhang designed the study and drafted/revised the manuscript. Xiaoyu Wu and Xiaoyun Wang made contributions to the acquisition of clinical study data. Xiaoyan Su and Xiaodan Yang contributed to reviewing and revising the manuscript. All authors reviewed the manuscript.

Funding

None.

Data availability

Data will be provided by the correspondence author upon request.

Declarations

Ethics approval and consent to participate

This study was approved by Shijiazhuang Maternal and Child Health Hospital (No. 202006) and conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all patients.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.