Effectiveness of a digital-based gradual exercise training program for preventing relapse in congenital clubfoot: a protocol for a randomized controlled clinical trial

Abstract

Background

Congenital clubfoot (CCF) is characterized by foot deformity. The Ponseti method achieves anatomical correction through casting and orthotics, but there is a high probability of further recurrence before skeletal maturity. It is challenging to maintain long-term correction and prevent relapse. Patients may benefit from physiotherapy interventions designed to enhance ankle function and overall mobility. This protocol proposed here aims to evaluate a digital-based gradual exercise training program for reducing relapse rates, improving joint flexibility, and enhancing quality of life among children with CCF and their family caregivers, in comparison to those who receive only the Ponseti method.

Methods

This study will be a single-blind, randomized controlled trial. A total of 100 patients will be allocated to the intervention group or the control group. The intervention group will receive a digital-based gradual exercise training program in addition to the Ponseti method, while the control group will receive only the Ponseti method. The exercise training program will include a caregiver reinforcement training session and a gradual personalized exercise training program. All exercises are managed digitally through the online management platform. Outcomes will be measured by assessors at the initial visit, 6 months after the intervention, and again when the child reaches 5 years of age. The therapist will continuously adjust the treatment plan based on the child’s functional status during each clinic follow-up visit. Children with CCF will be evaluated using the relapse rate as the primary outcome. The secondary outcome measures will include the Evertor muscle clinical activity (EMCA), Dimeglio scores, Pirani scores, ankle joint range of motion measurements, anthropometric measurements, the Short Form 36 Health Survey(SF-36) scores, Zarit Caregiver Burden Scale (ZCBS) score, Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) score, and Pirani Böhm Sinclair (PBS) score.

Discussion

This study aims to evaluate a digital-based rehabilitation approach for children with CCF to prevent relapse, improve joint flexibility, and enhance family compliance with treatment. It is expected that the intervention group may show lower relapse rates compared with the control group, indicating that the program could be effective in supporting both children with CCF and their families. If confirmed, these results may support the integration of a gradual exercise training program into standard CCF care and highlight its potential role in improving long-term outcomes.

Trial registration

ChiCTR2400087557, registered July 30, 2024, on the Chinese Clinical Trial Registry.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-025-06220-4.

Background

Congenital clubfoot (CCF) is a common congenital musculoskeletal disorder characterized by skeletal deformity, congenital neuromuscular imbalance, with a global incidence of approximately 1 in 1,000 live births [1]. This deformity of the foot involves the hindfoot equinus and varus, midfoot supination and cavus, and forefoot adductus [2, 3]. It is imperative to reconstruct the anatomy and biomechanics of the affected foot after birth among children with CCF. The Ponseti method has emerged as the preferred treatment for correcting anatomical deformities in infants with CCF shortly after birth. The Ponseti method involves a series of manipulations and serial casting, along with an Achilles tenotomy. After the casting phase, a foot abduction orthosis (FAO) is used to oppose the deforming forces at the medial ankle–foot joints until the child reaches five years old, helping to maintain deformity correction [4, 5].

Despite the effects of good initial treatment, there is a high probability of further recurrence before skeletal maturity. It has been reported that the relapse rate following treatment with the Ponseti method ranges from 26% to 37%, with repeated relapses occurring in 14% of cases [6, 7]. Patients with recurrent clubfoot may experience pain and functional limitations, manifesting as difficulties in walking long distances and squatting, which adversely affect the daily activities of patients [6, 8]. Additionally, changes in foot appearance can negatively affect social interactions and self-image, while foot deformities have emerged as a significant concern for parents [9]. A multicenter study showed that the group of patients with relapses exhibits poorer clinical outcomes and quality of life [6]. Guidelines recommended that treatment approaches for relapsed CCF include recasting and revision tenotomy [4]. However, even if the ankle and foot structure of patients is restored postoperatively, the function of the ankle and foot may still not be recovered due to stiffness and insufficient neuromuscular control. This significantly reduces the child’s participation in daily activities and increases the burden on caregivers [10].

The severity of the initial deformity, as assessed by Pirani scoring, along with inadequate activation of the ankle evertor muscles, restricted range of ankle motion, and non-compliance with bracing, have been identified as primary risk factors for recurrence [7, 11–13]. The Dimeglio scoring provides an objective way to assess the severity of CCF. It is correlated with the number of casts required for correction in the Ponseti method, and can predict treatment difficulty as well as relapse rate [14]. Besides, after the initial correction, ongoing or recurring fibrotic retraction in the tarsal ligaments and surrounding tissues exerts a pulling force on the medial ankle and foot joints. Evidence suggests that a congenital neuromuscular imbalance constitutes the deforming forces present in clubfoot [13]. Equinus deformity is reported as the most common deformity at relapse, primarily characterized by limited dorsiflexion of the foot, and over 26% of patients did not maintain this range of motion [7]. Therefore, it is challenging to maintain long-term correction and manage the risk factors for relapse in children with CCF [15].

Currently, caregiver intervention in the stretching exercises for children with CCF is recommended, with a focus on incorporating squatting exercises after the patients reach walking age [16]. Panjavi B et al. highlighted that the success rate of treatment can be significantly improved by incorporating regular stretching exercises performed by parents, alongside the use of an orthosis [17]. Children with clubfoot at risk of relapse could benefit from physiotherapy interventions designed to increase ankle range of motion, one-leg standing time, the number of sit-to-stand, and improve functional status and treatment satisfaction [18]. Motor development training should be included for children with CCF to address the limitations in lower limb mobility [19].

Increasingly, poor evertor muscle activation has been cited specifically as a potential risk factor for recurrence [20]. Improvement in muscle balance around the ankle, especially the evertor muscle, should be emphasized to parents after the casting regimen is completed and correction is achieved, to explore the advantages of evertor muscle-strengthening activities in preventing clubfoot deformity [6, 21]. Therefore, it would be interesting to design a rehabilitation program that helps prevent relapse, improves ankle range of motion, evertor muscle activation, and enhances the quality of life for their families while using the Ponseti method [22]. Nilgün B et al. reported that four weeks of intensive physical therapy effectively changes in the range of motion of dorsiflexion, Dimeglio score, and a decrease in rear foot varus angle. However, this approach requires substantial resources, including time, financial investment, and effort from specialized medical personnel [23].

The internet-based digital therapeutics (DTx) intervention represents a novel approach that has emerged in recent years [24]. It primarily offers patients scalable, accessible, evidence-based intervention programs delivered through software applications, thereby enhancing treatment efficacy. Furthermore, when combined with other methods, digital therapeutics improve treatment outcomes and satisfaction for both patients and parents, while also providing enhanced opportunities for home rehabilitation education [25, 26]. Additionally, considering the accessibility of rehabilitation in the post-pandemic era, a digital-based gradual exercise training program should address the needs of the child and their family. This approach saves caregivers time and reduces medical expenses, while also overcoming geographical limitations [24].

Currently, a high-quality randomized controlled study is needed to determine whether combining a digital-based gradual exercise training program with the Ponseti method results in significant improvements in reducing relapse rates and improving ankle joint flexibility compared to using the Ponseti method alone [6, 11]. The aim of this article is to present a study protocol that outlines the planned design and methodology in detail.This study aims to determine whether this digital-based combined program can provide additional benefits for preventing relapses in children with CCF than Ponseti correction only. We hypothesize that children with CCF who receive a combined program may demonstrate lower relapse rates, improved ankle evertor muscle activation, larger ankle range of motion, and better quality of life for caregivers and children.The significance of this study is to explore whether the integration of structured home-based rehabilitation with digital technology can help address a major limitation of the Ponseti method. If demonstrated to be effective, this combined program may serve as a scalable model for integrating digital therapeutics into pediatric orthopedic rehabilitation. Such an approach has the potential to improve motor function, support long-term outcomes, and reduce the burden on families.

Methods

Study design

This randomized controlled trial will investigate the clinical efficacy of a digital-based gradual exercise training program in preventing relapse and improving ankle joint flexibility and ankle evertor muscle activation in children with CCF. The control group will receive routine clinical treatment (Ponseti method), whereas the intervention group will receive a digital-based gradual exercise training program in addition to the Ponseti method. The clinical trial was designed in accordance with the recommendations of the Standard protocol items recommendations for interventional trials(SPIRIT) guidelines (2013) and the Consolidated standards of reporting trials(CONSORT)2010 statement extension to randomized pilot and feasibility trials [27, 28]. This study was approved by the XinHua Hospital Ethics Committee affiliated with the Shanghai Jiao Tong University School of Medicine (Approval No. XHEC-C-2024-110-4).

Before enrollment, parents will be asked by the intervention team to provide written informed consent. The study timeline is scheduled in Fig. 1.

Fig. 1.

Schedule of study enrolment, interventions, and assessments

Current trial status

Recruitment of participants started in October 2024, and as of October 2025, a total of 47 patients had been enrolled (24 in the intervention group and 23 in the control group). Of these, 10 patients had completed both baseline and 6-month follow-up assessments.

Participants

The participants will be recruited from the outpatient department of the center at which they receive treatment via the Ponseti method. Inclusion criteria will be used to determine the eligibility of the study subjects. Children diagnosed with CCF at Xinhua Hospital affiliated with Shanghai Jiao Tong University School of Medicine, will be recruited for this study.

The inclusion criteria for individuals with CCF will be as follows: (1) Children with CCF aged ≤ 12 months will be selected as the study population; (2) A diagnosis of CCF with a horseshoe-shaped deformity characterized by the inwards rotation of the forefoot, as well as the presentation of forefoot adduction, hindfoot inversion, plantar flexion, and high arch [1]; (3) Born at full term (≥ 37weeks gestation) and had not received any previous interventions for congenital clubfoot. The exclusion criteria will be as follows: 1) Postural or fetal clubfoot (Dimeglio score ≤ 5/20 [29]; 2) Clubfoot associated with conditions that may lead to delayed motor development, such as neurological disorders (e.g., cerebral palsy) and musculoskeletal disorders (e.g., developmental dysplasia of the hip); 3) Patients with teratologic or paralytic clubfoot deformities, those who underwent surgical management for residual or recurrent deformities, and those who changed their treatment protocol (e.g., starting with the Ponseti method protocol and switching to other programs).

Sample size

We have used PASS 2011 for sample size calculation; the relapse rates will serve as the primary outcome measure to calculate the effect size, referring to a study on physical therapy intervention for children with CCF [17]. The relapse rate in the intervention group was estimated to be 32%, while the control group was expected to have a recurrence rate of 62%. A chi-square test was planned to compare the two proportions. Using a two-sided test with a significance level of 0.05 and a power of 0.80, a sample size of 50 participants per group is needed to account for a 20% attrition rate in detecting differences in recurrence rates.

Study procedure

Participants will follow the study procedures outlined in Fig. 2. Once brace use begins, an exercise training program will be implemented for 6 months, and outcomes will be measured by assessors at both the initial visit and after intervention 6 months. During this phase, there is significant neuromotor development and a potential for fibrotic retraction in the tarsal ligaments, which heightens the risk of deformity relapse [13]. Furthermore, this phase facilitates the differentiation between true relapse and incomplete correction [30], thereby aiding clinicians in deciding whether to initiate repeat casting or to continue with bracing in conjunction with targeted rehabilitation. The therapist will adjust the treatment plan based on the child’s functional status at each clinic visit, which will occur every three months until age two, then every six months [4].

Fig. 2.

Participant flow through the study

Following the intervention, we will monitor the relapse rate of deformities, Dimeglio score, Pirani score, ankle joint range of motion, EMCA, and anthropometric index until the child reaches 5 years of age. The participants will be recruited from the Department of Rehabilitation, Xinhua Hospital affiliated with Shanghai Jiao Tong University School of Medicine, China. Prior to their participation, a consent form will be given to the parents of the patients. This form will include an explanation of the study’s assessments, interventions, and methodology. The patients will only be included after the caregivers have signed this consent form.

The participants will be stratified based on age and randomly assigned to either the intervention group or the control group at a 1:1 ratio. This random allocation will be achieved using a computer-generated algorithm available at www.randomizer.org [27]. The allocation sequence will be concealed in sequentially numbered, opaque, and sealed envelopes. A trained research assistant who will be unaware of the group allocation will recruit the patients and assign them to the intervention or control group. All assessments will be conducted by an assessment team that will remain blinded to the group allocation throughout the study.

Experienced physical therapists will guide and supervise the intervention, providing valuable information regarding the details of the exercises. The intervention group will not be blinded, as it will be necessary to communicate with parents and obtain their informed consent. Trained assessors will complete the assessments for all participants before and after the intervention period.

Interventions

Control group

For children with CCF who meet the inclusion criteria, demographic and disease-related data will be collected. According to the guidelines [4], the control group will receive treatment with the Ponseti method alone. The Ponseti method involves six to eight weeks of long leg plaster casts with gentle manipulation. Casts are changed once per week. In 90% of CCF cases, an Achilles tenotomy is needed to correct the remaining equinus deformity, which is considered a routine part of treatment. After the procedure, patients must wear a brace for 23h a day for three months. Once this period is complete, the child will wear the FAO at night and during naptimes until they reach the age of 5 years. Parents in the control group will not be authorized to access the digital platform and will receive only routine outpatient follow-up. At each follow-up visit, caregivers will be asked whether the child has engaged in any unsupervised home-based rehabilitation or accessed any digital training materials, and the rehabilitation plan will be adjusted if necessary according to caregivers’ needs. Considering ethical requirements, if parents in the control group explicitly request access to the digital program, they will also be permitted to participate in the same intervention as the intervention group.

Intervention group

A digital-based gradual exercise training program will consist of a caregiver reinforcement training session and a gradual personalized exercise training program. At each follow-up, the EMCA, ankle range of motion, and deformity severity of children with CCF will be assessed to optimize the home intervention plan for that session. Demographic data and disease information will be obtained directly from the medical records system as references for developing a home-based rehabilitation program. Additionally, family exercise preferences will be collected. The exercise program is delivered through an app-based intervention. Parents in the intervention group log in with their registered mobile phone number and gain access after verification. At each outpatient visit, physical therapists will formulate or adjust the rehabilitation plan according to the child’s functional status and demonstrate the prescribed exercises. Detailed descriptions of the exercise training program, along with illustrative images, will be uploaded to the Home-Based Rehabilitation Management Platform for Clubfoot for caregivers to follow at home. Caregivers are encouraged to upload photos and complete daily online questionnaires through the platform. Based on these uploads, together with findings from subsequent follow-up assessments, therapists can provide updated guidance, send revised exercise protocols, or record targeted training videos. An example of the home-based rehabilitation management platform for clubfoot is shown in Fig. 3.

Fig. 3.

Home-based rehabilitation management platform for clubfoot

Caregiver reinforcement training session

The caregivers will receive 15 min of reinforcement training during the initial consultation. They will be asked to join a management platform, where the therapist will share files related to motor development and regularly share videos about the exercise training program. Additionally, caregiver will also learn general principles on how to guide active participation or play with their child. Each month, therapists will conduct 30-minute online video supervision sessions with the caregivers to provide guidance and to ensure continuous adherence to the treatment principles. The treatment plan will be adjusted continuously based on the child’s functional abilities. The principles listed in Table 1 will be emphasized.

Table 1.

Key principles of exercise training program intervention

Key Principle	Notes
Sufficient intensity and duration	The training program’s intensity can be increased by adding repetitions and volume. Integrate therapeutic activities into daily routines. Exercise programs can be continuous or staged, based on the child’s alertness and compliance.
Personalized treatment	Tailor training to the child’s functional abilities, adjusting and increasing difficulty as new skills are acquired.
Active participation	Training should elicit motor and cognitive responses. Active participation in activities is encouraged, with motivation and rewards from caregivers.
Effective motivation and stimulation	Use verbal praise, tactile, or visual rewards. Vary toys, songs, and the environment to keep the child engaged.

A gradual personalized exercise training program

Individualized treatment will be provided based on the results of the baseline assessment and the child’s clinical history. During the initial visit, a physical therapist will provide caregivers with a one-hour session of movement instruction. The caregivers will be instructed to encourage and guide the child to engage in active movement as much as possible during daily game activities, with a particular focus on the use of the lower limbs or muscles on the affected side. These exercises ought to be integrated into the three core components of the child’s treatment regimen: personalized exercise training, promotion of physical activity, and daily posture management [31].

Individualized rehabilitation treatments will be provided to address the different motor function impairments of the child and the routines of the caregivers. Quality monitoring of rehabilitation treatments will also be implemented in the management platform. The treatment intensity will be adjusted based on the child’s breathing, crying, and fatigue levels, thus ensuring that the treatment is appropriately challenging without causing excessive strain. Caregivers will be required to perform the exercise training program 30 min per day, 5 times per week [32]. To optimize caregiver adherence, caregivers will receive reminder messages every week to ensure the consistency of training. Additionally, the caregivers will be prompted to complete an online questionnaire on a management platform daily, which will provide real-time reports on the child’s movement status and allow them to report any issues or concerns.

Part 1: individualized exercise training

Caregivers will receive outpatient rehabilitation guidance at each follow-up visit. The treatment program will be modified based on the results of the follow-up assessments and the preferences of both caregivers and the child. The home-based rehabilitation management platform will present rehabilitation exercise content for children of different age groups. The activity will include activities such as rolling over, hands-and-knees crawling, and walking on unstable surfaces, all of which will be designed as engaging games for the child. The activity can be performed in different settings, such as on the floor, in a stroller, on a bed, or outdoors on grass. The selection of game activities will be tailored to the child’s abilities and will be continuously adjusted as their motor development progresses and they acquire new skills. The personalized exercise training programs for children in different age groups are summarized in Table 2.

Table 2.

Individualized exercise training programs for children with congenital clubfoot in different age groups

Age	Exercise Training Program
0–3 months	1) Passive stretching: Perform passive stretching of the Achilles tendon in a neutral ankle position, and stretch the foot’s inner and inverter muscles. 2) Passive joint range of motion training: Perform ankle dorsiflexion, plantarflexion, inversion, and eversion, while also encouraging pedaling movements. 3) Proprioceptive stimulation: Massage and relax the plantar fascia, use a brush or gently tap the tibialis anterior and gastrocnemius muscles to stimulate dorsiflexion and eversion of the foot [33]. 4) Joint mobilization: Perform joint mobilization of the ankle and subtalar joint in a supine position [18]. 5) Promotion of motor development: Engage the child in activities/games in different positions, focusing on movements of the head, upper limbs, and trunk, such as lifting the head and supporting in a prone position. For example, the child can lie prone on the mother’s legs or on a pillow to practice head control [34].
3–6 months	1) Passive stretching: passive joint range of motion training, joint mobilization, and proprioceptive stimulation: Refer to 0–3 months. 2) Promotion of motor development: Rolling from a supine to a prone position, prone position with hands supporting, pulling up to a sitting position from a supine position, protective reactions forward. For example, if the child is sitting facing you, gently push him from the front to disrupt his balance and induce him to extend his arms forward to maintain balance. This can be trained like a game, but always be ready to protect the child if they do not extend their hands.
6–9 months	1) Passive stretching: passive joint range of motion training, joint mobilization, and proprioceptive stimulation: Refer to 0–3 months. 2) Promotion of motor development: Reaching for toys in a prone position, crawling and creeping, reaching for toys while in a sitting position. For example, you can place the baby between two pillows to encourage them to crawl in a prone position.
9–12 months	1) Passive stretching: passive joint range of motion training, joint mobilization, and proprioceptive stimulation: Refer to 0–3 months. 2) Active stretching: Assisted squatting and active stretching of the Achilles tendon. 3) Promotion of motor development: The following activities can be considered: ① Prone position for crawling: Place toys or objects of interest in front of the baby while they are lying on their stomach. This encourages them to lift their head, push up on their arms, and begin to crawl. ② Assisted standing: Provide support to the baby as they attempt to stand up. This can be done by holding their hands or providing a stable surface for them to hold onto. This helps develop leg strength and balance. ③ Side stepping: Encourage the baby to take steps to the side while holding onto a stable object or with support. This helps improve lateral movement and balance.
12–15 months	1) Active stretching: Encourage the child to perform active Achilles tendon stretching by squatting or standing on a wedge cushion. 2) Active joint range of motion exercises: Perform ankle joint dorsiflexion, plantarflexion, inversion, and eversion in various directions. 3) Promotion of motor development: The following activities can be considered: ① Walking: Encourage the child to practice walking independently. Provide support or hold their hands if needed, but gradually encourage them to take steps on their own. ② Throwing a ball: Engage the child in activities that involve throwing or rolling a ball. This helps improve hand-eye coordination, upper body strength, and coordination. ③ Sit-to-stand: Encourage the child to transition from a sitting position to standing. This can be done by placing toys or objects of interest just out of their reach, motivating them to stand up to reach for them. ④ Stepping: Encourage the child to take steps forward while holding onto a stable object or with minimal support. This helps improve balance, leg strength, and coordination. For example, playing a bubble-blowing game can be beneficial. The therapist can support the child with one hand while blowing bubbles. When the bubbles are close to the ground, encourage the child to step on them, focusing on training the affected leg.
15–18 months	1) Active stretching and active joint range of motion exercises: Refer to the age group of 12–15 months. 2) Promotion of motor development and balance training activities ① Kneeling: Encourage the child to kneel on both knees or on the affected leg to improve stability and strengthen the lower body muscles. Provide support or use cushions/pillows for comfort and stability. ② Squatting: Guide the child to perform squats, focusing on proper form and alignment. Start with partial squats and gradually progress to deeper squats as the child’s strength and flexibility improve. ③ Kicking a Ball: Engage the child in kicking a ball to improve coordination, balance, and lower body strength. Start with a stationary ball and progress to kicking a moving ball. ④ Going Up and Down Stairs: Practice going up and down stairs, focusing on proper foot placement and balance control.

Part 2: promotion of physical activity

According to recommendations from the World Health Organization (WHO), different types of physical activities and durations are recommended for children of different ages. For infants under 1 year of age, activities such as tummy time games and swimming are recommended, with a minimum of 30 min of physical activity spread throughout the day while the child is awake. Toddlers aged 1–2 years are encouraged to engage in at least 180 min of physical activity of varying intensities, including moderate to vigorous activities [35]. It’s beneficial for these activities to be spread throughout the day, with more being preferable. To monitor and encourage compliance, the caregivers will be included in the management platform where they will complete a daily online questionnaire. A “traffic light” system will be employed to provide feedback on the level of completion, with red indicating a significant deviation from the recommended time, yellow indicating proximity to the recommended time, and green indicating adherence to the recommended time. At the end of the questionnaire, feedback on the duration of physical activity will be provided. Each completed activity will earn the child a star, with a maximum of 5 stars awarded per week. The weekly completion status of all children will be ranked using gold, silver, and bronze medals, which will serve to increase caregivers’ confidence in promoting activity.Parents will have the opportunity to exchange these stars for rewards, such as training tools and or toys.

Part 3: daily posture management

Family factors are related to relapse rates during treatment with the Ponseti method, particularly in terms of compliance with wearing the FAO [16]. The proper wearing of the cast and orthosis is closely associated with the correction of the deformity. To maintain a good position for deformity correction, it is essential that the orthosis is worn correctly, ensuring a snug fit between the heel and the shoe counter. Weekly themes on posture management during daily activities or care for casts and orthosis will be shared through the management platform. These themes may include topics such as how to hold the child during cast treatment, how to promote rolling over while wearing the FAO, precautions for cast and orthosis care, proper orthosis-wearing methods, and complication management during cast and orthosis treatment [36].

Compliance assessment

The effectiveness of the treatment will be evaluated during the initial visit and at the 6 months follow-up. During the compliance assessment phase, compliance with the digital-based gradual exercise training program will be evaluated. Therapists in the intervention group will have access to compliance data. Compliance will be represented by the percentage of completed daily online questionnaires in the management platform that report the daily training time. At the end of the 4th week, the intervention group will be further stratified based on compliance (compliance < 50% group and compliance ≥ 50% group). Researchers will contact the caregivers of children in the compliance < 50% group for video conferences to determine the reasons for the decrease in compliance and to provide online counseling. If the compliance of families with good compliance (≥ 50%) decreases to less than 50% for at least 2 weeks during the 2nd to 6th month of the intervention, the caregivers will receive online video conferences for guidance.

Adverse events

All adverse events occurring during the trial will be recorded by the team members in the adverse event table through each follow-up and platform feedback. These events may include plaster cast slipping, minor skin irritation, fever, ankle sprains, accidental damage to plaster or orthosis, accidental falls, etc., that occur during the treatment period. The researchers will assess the associations between adverse events and the intervention and decide whether to stop the intervention. Additionally, targeted interventions will be provided immediately for adverse events, and follow-up will be conducted until the symptoms disappear.

Outcome measures

The following data will be collected: age, sex, affected side, family history, number of initial corrective casts, need for Achilles tendon release surgery, compliance with orthosis, and the presence of deformity recurrence in the children. In general, once a brace begins to be used, clinical assessments will be conducted before and after 6 months of intervention. Dimeglio scores, Pirani scores, ankle joint range of motion, evertor muscle clinical activity, and anthropometric measurements will be recorded. Additionally, the caregivers of the children will complete the SF-36 and the ZCBS. Relapse rate, Dimeglio score, Pirani score, ankle joint range of motion, EMCA, anthropometric measurements, OxAFQ-C, and PBS score will be collected until the child reaches 5 years of age.

Primary outcome measure

Relapse rate

Relapse was defined as the deterioration of any component of the deformity (cavus, adducts, varus, or equinus) following a satisfactory correction, with a Pirani score greater than 0.5. The relapse rate is the proportion of individuals who experience relapse out of the total number treated [13, 37].

Secondary outcome measurements

EMCA

The EMCA was assessed semi-quantitatively using foot scores. EMCA was measured as follows: 0 for normal muscle activity, 0.5 for weak activity such as toe flaring without foot eversion or subtle muscle flickering beneath the skin, and 1 for no activity. A score of zero was considered good, while scores of 0.5 and 1 were classified as poor ankle evertor activation. In infants, the EMCA was measured by stimulating the lateral border of the foot or leg plantar surface. In older children, it was assessed by measuring the ankle evertor activity against resistance.

Pirani score

The Pirani scoring system divides clubfoot into six components. The hindfoot score is based on the posterior crease, the empty heel, and the rigidity of the clubfoot. The midfoot score is based on the medial crease, the lateral border of the foot, and the position of the talus bone. Each component is scored from 0 to 3, resulting in a total score ranging from 0 to 6. Higher scores indicate more severe deformities.

Dimeglio score

The severity of the deformity will be evaluated using the Dimeglio score [14]. A normal foot will be assigned a score of 0. The maximum score is 20. Higher scores indicate more severe deformities. A score of 1–5 indicates grade I (mild deformity), scores from 5 to 10 indicate grade II (moderate deformity), scores from 10 to 15 indicate grade III (severe deformity), and scores from 15 to 20 indicate grade IV (extremely severe deformity).

Ankle joint range of motion

To assess the passive range of motion for ankle dorsiflexion, plantar flexion, inversion, and eversion, the child will be placed in a supine position with the knee fully extended. The lower leg will be stabilized and then moved to dorsiflexion and plantar flexion. Furthermore, the foot will be inverted and everted while a goniometer is used to measure the angles between specific anatomical landmarks. Three measurements will be taken for each movement, and their average values will be recorded, along with any observed limitations or discomfort.

Anthropometric measurements

Lower limb length, calf circumference, and foot length will be measured. Specifically, lower limb length will be measured using a tape measure to determine the distance between the anterior superior iliac spine and the medial malleolus. Calf circumference will be assessed by wrapping a flexible tape measure horizontally around the thickest part of the calf. Foot length will be measured by determining the distance from the calcaneus to the tip of the second toe.

ZCBS

The ZCBS is a widely used assessment tool for measuring caregiver burden [38]. It has been extensively used to assess caregiver burden in various chronic diseases, and the Chinese version has shown good reliability and validity [39].The ZCBS consists of 22 items across two dimensions: personal burden and role burden. Each item is scored on a 4-point scale, with higher scores indicating greater burden. Scores are categorized as follows: 0–20 (little or no burden), 21–40 (mild to moderate burden), 41–60 (moderate to severe burden), and 61–88 (severe burden).

SF-36

The SF-36, also known as the Medical Outcomes Study Short Form, was developed by the Boston University School of Public Health. The Chinese version of the SF-36, 2nd edition, is used to assess the quality of life of caregivers of children with health-related issues. It consists of 36 items across 9 dimensions [40]: physical functioning (PF), role-physical (RP), body pain (BP), general health (GH), vitality (VT), social functioning (SF), role-emotional (RE), mental health (MH), and health change.

OxAFQ-C

The OxAFQ-C is a crucial instrument for evaluating the quality of life in children with clubfoot. It assesses disability associated with foot and ankle issues in children aged 5 to 16 years, using a five-point scale to generate domain scores for Physical (P), School and Play (SP), Emotional (E), and Footwear (F) dimensions. Higher scores reflect better overall function, thereby quantifying the comprehensive impact on physical function, social participation, emotional status, and quality of life [41].

PBS score

The PBS Score is a clinical assessment tool for the ambulatory and recurrent clubfoot, with scores ranging from 7 (indicating no deformity) to 18 (indicating severe deformity) [42, 43].This scoring system assesses standing parameters, including hindfoot varus and fixed supination, as well as gait characteristics such as swing-phase supination and early heel rise. Additionally, it evaluates passive subtalar abduction and both active and passive ankle dorsiflexion.

Data management

Daily online questionnaires filled out by parents will be exported to Microsoft Excel. The data for outcome measures will also be entered into Microsoft Excel through a double-entry process, followed by verification for accuracy. The research assistant will de-identify all outcome measure data using participant codes. The treatment allocation will be coded and added to the spreadsheet in a way that keeps the researcher conducting the data analysis blinded to group allocation. Any adverse events will be recorded in a separate Microsoft Excel spreadsheet containing the participant ID and coded treatment allocation. All data will be stored on a password-protected server, accessible only to the research team.

Statistical analysis

Data analysis will be performed using the SPSS software package (version 25.0; IBM, Inc., Chicago, IL, USA). In accordance with the intention-to-treat(ITT) principle, all analyses will be conducted based on the original allocation to account for any residual contamination.The normality of variables will be tested via the Kolmogorov‒Smirnov test. For normally distributed continuous variables, the mean ± standard deviation (mean ± SD) will be used to describe the data, and independent sample t tests will be used for between-group comparisons. For non-normally distributed continuous variables, medians and quartiles (Q25, Q75) will be used, and between-group comparisons will be performed via Mann‒Whitney U tests. Categorical data will be presented as frequencies and percentages, and between-group comparisons will be conducted using chi-square tests. Mixed-model analysis will be used to compare outcomes between the intervention and control groups among the three assessments, The significance level will be set at α = 0.017, while the Bonferroni method will be carried out to correct multiple comparisons.Missing data will be handled using multiple imputation.

Discussion

The Ponseti method emphasizes the early correction of anatomical and biomechanical structures [44]. However, it offers no guidance for active participation from children, which is essential for continuously improving ankle joint mobility and muscle strength to maintain the correction’s effectiveness [21]. Effective management of relapse should be integrated throughout the entire treatment process. Physicians should be aware of a potential risk factor for relapse, particularly during the critical period of brace wear. Current guidelines for managing relapse in CCF primarily focus on interventions such as casting and surgical. However, they often overlook the significant role of rehabilitation therapy in preventing deformity recurrence and its potential for early intervention. In the design of this intervention program, rehabilitation is expected to improve ankle joint mobility and evertor muscle activity of children, which may help correct the anatomical deformation of the feet and lower limbs, and reduce relapse rates [45], and could lower the incidence of complications such as pain, callosity formation, skin breakdown, the inability to wear normal footwear, poor balance, and reduced mobility [4]. We anticipate that after 6 months of the personalized exercise training program, follow-up until the age of 5 may show a reduction in relapse rates compared to the control group. Improvements in ankle joint range of motion, movement patterns, caregiver burden, and quality of life may also be observed.We hope to find a more effective and convenient treatment to reduce the relapse rate in children with CCF.

This protocol emphasizes the concept of personalized rehabilitation interventions. During each follow-up visit, the intervention content is adjusted according to the child’s motor development progress. The intervention includes personalized exercise training, the promotion of physical activity, and daily posture management. Tailored rehabilitation strategies are provided based on the family’s daily living habits. Additionally, quality monitoring of parents’ involvement in the rehabilitation process should be implemented to ensure the effectiveness and scientific basis of the rehabilitation. These designs align with the goals of the protocol, as personalized rehabilitation interventions are expected to provide potential benefits to children and their families, sunch as helping to prevent relapse, and potentially improving joint mobility and ankle evertor muscle activation.

Education for caregivers is a crucial factor significantly associated with improvement [46]. In this protocol, caregiver reinforcement training and posture management are expected to enhance caregivers’ understanding of CCF, which may in turn improve adherence. During the process of orthosis correction, it is important to educate caregivers about physical therapy, which may help improve muscle balance around the ankle joint, particularly the muscles responsible for foot eversion [21]. The educational content is expected to include dorsiflexion stretching for children, guidance on squatting and standing through play, and ways to promote crawling while wearing braces.

Previous studies have shown that home-based rehabilitation methods involve high levels of participation and acceptance among children and their parents [25, 47]. A home-based rehabilitation program provides a flexible and convenient treatment option for families. This study advocates for a progressive home rehabilitation approach, incorporating regular assessments to customize subsequent sessions. Additionally, A digital-based rehabilitation has increased accessibility to treatments in the post-pandemic era [48], and digital management of exercise programs will allow for remote guidance, which may help improve intervention efficiency [49]. Regular communication and online supervision are expected to support parents in following the plan and addressing any queries. Furthermore, educational materials on physical activities will be distributed as part of the rehabilitation program.

In this trial, owing to the utilization of a comprehensive motion-based approach in contrast to solely employing the Ponseti method, it may be challenging to implement blinding for the intervention providers and families of children with CCF. However, the assessors involved in this study will remain blinded to minimize bias and are expected to help ensure precise testing results. Furthermore, as family-centered rehabilitation requires active parental involvement, reliance on parental reporting may introduce bias. To mitigate this, therapists in the intervention group will have access to real-time compliance data via the digital platform. If a decline in adherence is detected, researchers will conduct video consultations with caregivers to explore potential reasons and provide timely support.

Abbreviations

CCF

Congenital clubfoot

EMCA

Evertor muscle clinical activity

SF-36

The short form 36 health survey questionnaire

ZCBS

Zarit caregiver burden scale

PBS

Pirani Böhm Sinclair

DTx

Digital therapeutics

SPIRIT

Standard protocol items recommendations for interventional trials

CONSORT

Consolidated standards of reporting trials

FAO

Foot abduction orthosis

WHO

World Health Organization

OxAFQ-C

The Oxford ankle foot questionnaire for children

ITT

Intention-to-treat

Authors’ contributions

QD, XY, QMF, XZ, and NC designed the study and drafted the manuscript; XL and JPL reviewed and approved the final manuscript and assisted in statistical planning; XQZ and HY are physiotherapists and will perform the evaluations and interventions in the subjects included in the research; All authors read and approved the final manuscript.

Funding

This work is supported by the Children’s Rehabilitation Innovation and Transformation Research Center of Yuanshen Rehabilitation Institute, Shanghai Jiao Tong University School of Medicine (yskf3-23-1107-3), the Xinhua Hospital-Shanghai Jiaotong University coordinate project of medical robot assignment (21XJMR03), and Action Plan for Sustainable Development of Science and Technology Innovation in Chongming District, Shanghai (CKY2023-19). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Ethics approval was obtained through the Xin Hua Hospital Ethics Committee affiliated with the Shanghai Jiao Tong University School of Medicine (approval no. XHEC-C-2024-110-4). All patients’ parents/guardians will provide written informed consent prior to participation in the study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.