Immediate effect of ankle joint and rectus abdominis kinesiology taping on static and dynamic balance in rhythmic gymnasts aged 10–12 years

Abstract

Background

Balance is a critical component of athletic performance, particularly in disciplines such as rhythmic gymnastics. This study aimed to examine the immediate effects of kinesiology taping on static and dynamic balance in rhythmic gymnasts aged 10–12 years.

Methods

Thirty gymnasts were evaluated under three taping conditions: (1) no kinesiology tape (No KinT), (2) kinesiology tape applied to the ankle joints (KinT A), and (3) kinesiology tape applied to both the ankle joints and the rectus abdominis muscle (KinT AA). Balance assessments included the Static Stork Balance Test, the Dynamic Y Balance Test, and the Static and Dynamic “Bobo” Balance Board test.

Results

No significant differences were observed across conditions in the Stork Balance Test for both legs and static balance board measurements (p > 0.05). The Y Balance Test results improved when kinesiology tape was applied to both the ankle joints and the rectus abdominis muscle compared to the condition without taping for both legs (p < 0.05). In contrast, the dynamic balance board test demonstrated significantly better performance in the KinT A condition compared to both the No KinT and KinT AA conditions on the right leg (p < 0.05) and compared to the KinT AA condition on the left leg (p < 0.05). Additionally, for both legs, the No KinT condition showed superior performance relative to the KinT AA condition (p < 0.05).

Conclusions

Kinesiology taping had no immediate effect on static balance. However, dynamic balance, as assessed by the Y Balance Test, improved with tape applied to both the ankle joints and the rectus abdominis muscle. The balance board tests indicated inconsistent results, suggesting variability in their sensitivity to taping interventions.

Background

Rhythmic gymnastics is an aesthetic sport predominantly performed by female athletes, combining flexibility, strength, and athleticism with expressive and coordinated movement patterns [1]. Athletes are required to integrate artistic expression, precise apparatus handling, and the physical demands of performance within a highly complex and multifactorial framework [2]. Balance stability, defined as the ability to maintain the body’s position in both static and dynamic conditions, is a fundamental skill in rhythmic gymnastics due to the sport’s high demands for precise coordination [3]. Training programs for gymnasts should emphasize exercises that strengthen the muscles surrounding the ankle and hip joints, as these regions play a critical role in maintaining joint stability during complex balance manoeuvres [4]. Proprioception, the body’s ability to sense joint position and movement, is integral to the biomechanical precision required in gymnastics techniques. Enhanced proprioceptive function has been shown to significantly reduce the risk of injury [5].

Injury prevention is a critical component of rhythmic gymnastics, driven by the sport’s early training onset and high intensity demands [6]. Lower limb injuries are especially common, with the ankle accounting for approximately 22% of all injuries and sprains representing 35% of reported cases [7]. Effective prevention strategies should encompass both primary and secondary measures, focusing on strength and power development to mitigate mechanical stress in skeletally immature athletes [1], while also improving postural stability and dynamic balance. These elements are essential for minimizing injury risk and enhancing performance outcomes [3, 8, 9]. Furthermore, the diverse body positions required in rhythmic gymnastics place significant stress on the axial skeleton, particularly during movements involving spinal flexion and hyperextension [10, 11]. Impaired balance and insufficient postural control can adversely affect athletic performance and increase the likelihood of recurrent sprains, as well as impact daily functioning [12].

Weak core musculature or musculoskeletal imbalances can impair the transmission of energy and force, increasing the risk of injury in less resilient muscle groups [13]. Research underscores the importance of pelvic and core stability in enabling efficient and safe limb movement [14, 15]. To address these stability-related issues, kinesiology taping (KinT) has gained attention as a supportive intervention. Kinesio^® taping is designed to facilitate the body’s natural healing processes while providing support and stability to muscles and joints without limiting range of motion. The tension generated by the tape enhances proprioceptive feedback, promotes optimal posture and movement patterns, and supports muscle function, even after the tape is removed [16, 17].

Although research on postural control in developing gymnasts remains limited, existing studies on kinesiology taping (KinT) report several potential benefits, including enhanced joint proprioception, improved static and dynamic postural stability, reduced muscle fatigue, faster recovery, and decreased delayed-onset muscle soreness [5]. The proprioceptive input provided by KinT is particularly beneficial in reinforcing correct posture and movement patterns [16]. Additionally, kinesiology taping has been proposed as a therapeutic approach for activating abdominal muscles [18] and enhancing balance function [19]. Based on these findings, we hypothesized that kinesiology taping applied to both the ankle joint and the rectus abdominis would produce greater improvements in static and dynamic balance than ankle taping alone. Therefore, the aim of this study was to assess the immediate effects of kinesiology taping on static and dynamic balance in young rhythmic gymnasts.

Methods

Ethical considerations and study design

This study employed a quantitative experimental research design using purposive sampling. It was conducted in accordance with the ethical principles of the Declaration of Helsinki and the Good Clinical Practice guidelines, with approval obtained from the institutional bioethics committee. All participants and their legal guardians received detailed information regarding the study’s objectives, methodology, and procedures. Written informed consent was obtained from the parents or guardians of all participants who agreed to take part in the study.

All testing was conducted at the School of Rhythmic Gymnastics to ensure a controlled and consistent environment. Each participant underwent three experimental conditions across three separate sessions, with the order of conditions randomized using an online randomization tool (random.org) to ensure counterbalancing and minimize potential bias. The experimental conditions were as follows: (1) no kinesiology tape (No KinT); (2) kinesiology tape applied to the ankle joint (KinT A); and (3) kinesiology tape applied to both the ankle joint and the rectus abdominis muscle (KinT AA).

To prevent carryover effects and potential chronological testing biases, sessions were spaced 10 days apart. The study’s organizational structure is summarized in Fig. 1.

Fig. 1.

Structural organization of the study (Note: No KinT - no tape applied, KinT A - kinesiology tape applied to the ankle joints, KinT AA - kinesiology tape applied to both the ankle joint and the rectus abdominis)

Participants

Sample size calculation was conducted using G*Power 3.1 software (University of Düsseldorf, Düsseldorf, Germany). Based on an effect size of 0.4, a statistical power of 0.85, an alpha level of 0.05, and a one-way repeated measures ANOVA, the required sample size was calculated to be 27 participants. Ultimately, 30 non-elite rhythmic gymnasts, aged 10–12 years and with a minimum of two years of training experience at a rhythmic gymnastics school, were recruited for the study. Inclusion criteria were: (1) age 10–12 years, and (2) voluntary participation, with written consent provided by their legal guardians. Participants were excluded if they had a history of trauma or injury within the last six months that could affect the study outcomes. The demographic and physical characteristics of the participants are presented in Table 1.

Table 1.

Characteristics of the study participants

Characteristics	Value (mean ± SD)
Age, years	11.0 ± 0.8
Weight, kg	33.0 ± 7.1
Height, cm	144.3 ± 6.2
BMI, kg/m2	15.8 ± 3.7
Leg length, cm	75.0 ± 6.2
Dominant leg: right / left	28 / 2

Note: BMI– body mass index; SD– standard deviation

Outcome measures

Static balance was assessed using the Stork Stand Test [20]. Participants performed the test barefoot on a non-slip mat (Fig. 2). They were instructed to place their hands on their hips and position the non-supporting foot against the inner lateral side of the knee of the supporting leg. Upon command, participants raised their heel, balancing on the ball of the supporting foot, and timing began with a stopwatch. The test was terminated if any of the following occurred: (1) hands were removed from the hips, (2) the supporting foot shifted from its initial position, (3) the non-supporting foot lost contact with the knee, or (4) the heel of the supporting foot touched the floor. The test was performed on both the right and left legs, with three alternating trials conducted for each leg. A rest period of 30–50 s was allowed between trials. The best score (duration in seconds) from the three attempts was recorded.

Fig. 2.

Performance of the Stork Stand Test used to assess static balance

Dynamic balance was assessed using the Y Balance Test Kit™ (Functional Movement Systems, Inc., Chatham, VA, USA). Participants stood barefoot on the stance platform with their hands placed on their hips, aligning the big toe of the stance foot with the red line. The non-stance leg was slightly elevated and flexed, preparing for the reach movement. The participant then extended the non-stance foot to push the indicator along the tube as far as possible in three directions: anterior, posteromedial, and posterolateral, while maintaining balance (Fig. 3). The non-stance foot was required to return to the starting position under control without touching the ground or stepping outside the stance plate. If an invalid trial occurred, the data were discarded, and the participant repeated the trial. Measurements were recorded to the nearest 0.5 cm, with the maximum reach distance in each direction being recorded over three trials. The average of the three trials was used for analysis [21]. Reach distances were normalized to limb length by calculating a composite index using the formula: Composite Index = (Anterior Direction + Posteromedial Direction + Posterolateral Direction) / (3 × Limb Length) × 100% [22]. A composite index below 94% indicates an elevated risk of lower limb injuries. Limb length was measured with the participant lying supine on a firm surface, legs fully extended and aligned. The measurement was taken using a flexible tape measure, extending from the anterior superior iliac spine to the medial malleolus.

Fig. 3.

Performance of the Y Balance Test used to assess dynamic balance, with reach performed in three directions: A– anterior; B– posterolateral; C– posteromedial

The instrumented balance assessment was conducted using the “Bobo” Core Trainer Balance Board 2.0 (Bo&Bo, UK), an interactive smart balance board designed to improve balance, coordination, strength, and motor skills. This device functions as both a balance board and a balance disc, connecting to a smartphone or tablet via Bluetooth. Participants performed the test barefoot, standing on one foot at the center of the board, aligned with a marked triangle. Initially, participants were allowed to hold onto a support for stability; however, the test commenced upon a signal, requiring them to balance independently on the board for 20 s. Each participant completed three attempts per test, with the highest performance score, ranging from 0 to 100%, being recorded for data analysis.

• Static balance assessment: During the static balance test, participants were instructed to keep a white circle displayed on the tablet within a green target zone while minimizing board movement. If the circle moved outside the boundary, participants could adjust their position to bring it back and continue the trial (Fig. 4A).

• Dynamic balance assessment: In the dynamic balance test, participants followed a green ball moving in a figure-eight trajectory on the tablet display. They were required to synchronize their movements with the ball’s path while keeping the white circle within the green target zone. The test was terminated if participants touched the support structure, placed both feet on the board, compensated with arm movements, or lost balance (Fig. 4B).

Fig. 4.

Static (A) and dynamic (B) balance assessment using “Bobo” balance board

Taping procedures

All taping procedures were performed by the same certified physiotherapist, who had completed specialized training courses in kinesiology taping and had over 10 years of experience. To prevent bias, participants were not informed about the potential effects of kinesiology taping.

Ankle Taping Procedure. Kinesiology tape (“Compex”, 50 mm × 5 m, DJO Group, France) was used for the ankle taping (KinT A) intervention. Participants remained seated in a relaxed position during application. The tape was applied bilaterally to the ankles with approximately 30–40% stretch. Prior to application, the tape was cut to approximately 75% of the intended final length to allow for stretching between the origin and insertion points. To minimize skin irritation, the initial and final 2–3 cm of the tape were left unstretched at both ends. The KinT A application consisted of four steps, following a standardized protocol [23]: (1) Dorsiflexion application: With the ankle in slight dorsiflexion, tape was applied bilaterally from the dorsal center of the talus to the calcaneus; (2) Inversion support: With the ankle in inversion, tape was applied from 5 cm above the medial malleolus, wrapped around the lateral aspect of the calcaneus just below the subtalar joint, and directed toward the lateral dorsum of the foot; (3) Eversion support: With the ankle in eversion, tape was applied from 5 cm above the lateral malleolus, passed around the medial calcaneus below the subtalar joint, and directed toward the medial dorsum; (4) Reinforcement layer: An additional strip of tape was applied over the previously taped areas to enhance support, with the ankle maintained in slight dorsiflexion throughout.

Ankle and Rectus Abdominis Taping Procedure. In the ankle and rectus abdominis taping condition (KinT AA), the same “Compex” kinesiology tape was applied to the ankle joints using the previously described protocol. In addition, a muscle facilitation technique was implemented targeting the rectus abdominis muscle [24]. During application, participants were positioned supine. The tape was measured from the muscle’s origin at the crest of the pubis to its insertion at the xiphoid process while the trunk was in extension and the arms flexed. The base of the tape was first anchored at the pubic crest in a neutral position. It was then applied bilaterally over the rectus abdominis with approximately 10% stretch, extending upward toward the costal insertion at the ribs.

Statistical analysis

All statistical analyses were performed using IBM SPSS Statistics (version 26.0; IBM Corp., Armonk, NY, USA). Data are presented as means ± standard deviations. A repeated measures analysis of variance (ANOVA) was conducted to assess differences in static and dynamic balance across three conditions: (1) no kinesiology taping (KinT), (2) KinT applied to the ankle joint, and (3) KinT applied to both the ankle joint and the rectus abdominis. The within-subjects factor was the taping condition. The dependent variables included: Stork Balance Test (right and left leg), Y Balance Test (right and left leg), “Bobo” Static Balance Test (right, left, and both legs), and “Bobo” Dynamic Balance Test (right, left, and both legs). Where significant main effects were observed, Bonferroni-adjusted post hoc tests were performed to identify pairwise differences between conditions. Statistical significance was set at P < 0.05. Partial eta squared is reported as effect size (ηp2).

Results

The results of static and dynamic balance assessment under three different conditions are summarized in Table 2. A repeated measures ANOVA revealed no significant differences in static balance performance across conditions for the Stork Balance Test. Specifically, no significant differences were found for either right leg (F(2.58) = 0.02, p = 0.98, ƞ2p = 0.00) or left leg (F(2.58) = 0.07, p = 0.93, ƞ2p = 0.00).

Table 2.

Results of static and dynamic balance assessments across taping conditions

Outcome measures	No KinT Mean ± SD	KinT A Mean ± SD	KinT AA Mean ± SD	P value between conditions
Stork balance, right leg, sec.	3.13 ± 1.51	3.10 ± 1.54	3.15 ± 1.64	0.98
Stork balance, left leg, sec.	3.20 ± 1.69	3.30 ± 1.56	3.21 ± 1.40	0.93
Y-Balance Test, right leg, score	101.44 ± 6.97	102.76 ± 4.97	104.22 ± 5.43*	0.02
Y-Balance Test, left leg, score	99.67 ± 7.61	101.62 ± 5.38	102.86 ± 6.07*	0.01

Note: * - different from No KinT

For the Y Balance Test, a repeated measures ANOVA revealed a significant main effect of condition for both the right leg (F(2.58) = 4.23, p = 0.02, ηp2 = 0.13) and the left leg (F(2.58) = 6.56, p = 0.01, ηp2 = 0.18). Post hoc pairwise comparisons with Bonferroni correction revealed that dynamic balance performance was significantly better in the KinT AA condition compared to the No KinT condition for both legs (p = 0.02 for the right leg, p = 0.01 for the left leg). No significant differences were observed between the KinT A and KinT AA conditions or between the No KinT and KinT A conditions for either leg (p > 0.05).

Table 3 presents the results of the “Bobo” static balance assessments. For the “Bobo” Static Balance Test, a repeated measures ANOVA revealed no significant main effects of condition for any stance: right leg (F(2.58) = 0.29, p = 0.75, ηp2 = 0.01), left leg (F(2.58) = 0.39, p = 0.68, ηp2 = 0.01), or both legs (F(2.58) = 1.12, p = 0.33, ηp2 = 0.04). These results indicate that static balance performance did not significantly differ across the No KinT, KinT A, and KinT AA conditions.

Table 3.

Static balance results assessed using the “Bobo” balance board

Outcome measures	No KinT Mean ± SD	KinT A Mean ± SD	KinT AA Mean ± SD	P value between conditions
Static balance, right leg, %	82.90 ± 22.44	86.00 ± 14.83	84.73 ± 20.16	0.75
Static balance, left leg, %	86.30 ± 15.16	85.30 ± 15.33	87.50 ± 13.40	0.68
Static balance, both legs, %	80.50 ± 14.38	79.27 ± 19.83	83.90 ± 12.93	0.33

Figure 5 shows the results of the “Bobo” Dynamic Balance Test. A repeated measures ANOVA revealed a significant main effect of condition for the right leg (F(2.58) = 4.69, p = 0.01, ηp2 = 0.14), left leg (F(2.58) = 6.54, p = 0.01, ηp2 = 0.18), and both legs (F(2.58) = 4.51, p = 0.02, ηp2 = 0.14). For the right leg, post hoc pairwise comparisons with Bonferroni correction indicated significantly better balance in the KinT A condition compared to the No KinT (p = 0.02) and KinT AA (p = 0.03) conditions. For the left leg, dynamic balance performance was significantly better in the KinT A condition compared to the KinT AA condition (p = 0.03). For both legs, significantly better balance was found in the No KinT condition compared to the KinT AA condition (p = 0.02).

Fig. 5.

Dynamic Bobo Balance Board Results for the Right, Left, and Both Legs

Note: * ‒ significantly better in the KinT A condition compared to KinT AA in right leg;

# - significantly better in KinT A condition compared to No KinT in left leg;

## - significantly better in the KinT A condition compared to KinT AA in left leg;

** 1 - significantly better in the No KinT condition compared to KinT AA in both legs.

Discussion

The main objective of this study was to evaluate the effect of kinesiology taping on balance control parameters, specifically static and dynamic balance. The existing scientific literature suggests that kinesiology taping may enhance joint stabilization by increasing afferent sensory stimulation (i.e., sensory information transmitted from the body to the central nervous system). This heightened stimulation can improve spatial awareness, body movement, and sensorimotor responses, thereby enhancing postural control compared to other ankle joint stabilization techniques [25]. Based on these findings, it was hypothesized that applying kinesiology tape to both the ankle joint and rectus abdominis muscles would result in greater improvements in static and dynamic balance than applying kinesiology tape solely to the ankle joint [23, 26, 27].

The results of this study did not support the initial hypothesis, as the application of kinesiology tape to both the ankle joints and the rectus abdominis muscles did not produce superior effects compared to ankle taping alone.

For the Stork Balance Test and the static Bobo Balance Board Test, no significant differences were found between the taping conditions. These findings suggest that kinesiology tape, regardless of the application (ankle or both ankle and rectus abdominis), does not influence static balance performance in healthy individuals. This lack of effect may be attributed to the brief duration of tape application, which might not be sufficient to elicit significant proprioceptive changes. Additionally, the static nature of the Stork Balance Test, which requires individuals to maintain a stationary posture, may not be sensitive enough to detect the subtle benefits provided by kinesiology tape. These findings are consistent with those reported in a meta-analysis by Jalaludin et al. [28], which suggested that the effectiveness of kinesiology tape in enhancing balance function becomes more evident when applied over extended durations, such as 24, 48, or 72 h, across various age groups. The potential physiological effects of kinesiology taping over prolonged periods (48–72 h or more) may promote neuromuscular adaptations and enhance proprioceptive responses. Continuous stimulation of cutaneous receptors over time facilitates adaptations that improve proprioceptive feedback, contributing to better balance performance [19, 26]. It is plausible that a longer application period is needed to provide sufficient proprioceptive stimulation and allow for adaptation, ultimately enhancing static balance. Future research should consider longer durations of tape application to fully assess its potential for improving balance control.

Interestingly, some research suggests that the duration of kinesiology tape application may be less important, particularly in individuals with soft tissue injuries. These studies report that KinT is effective regardless of wear time [29, 30]. However, such findings typically involve symptomatic populations, which contrasts with the healthy rhythmic gymnasts evaluated in this study. Methodological differences, including the use of varied assessment tools, may also explain inconsistencies in outcomes [31].

The Y Balance Test, a dynamic balance assessment, showed significant improvements in performance when kinesiology tape was applied to both the ankle joint and rectus abdominis, but not when applied to the ankle joint alone, despite scientific findings suggesting that ankle taping effectively enhances dynamic balance [25]. A potential reason for the observed results could be that kinesiology tape, when applied to both the ankle joint and rectus abdominis muscles, may enhance proprioception and stabilize the body during dynamic movements, leading to significant improvement in balance [32] in individuals with or without ankle joint instability [28]. The tape might have a synergistic effect when applied to both regions, contributing to a more stable base of support and better coordination between the trunk and lower limbs. On the other hand, the lack of significant differences between the two taping methods could be due to a methodological factor. The assessment tool (Y Balance Test) might not be sensitive enough to detect subtle differences between the two taping techniques.

In contrast, the dynamic balance component of the “Bobo” balance test showed greater improvement when kinesiology tape was applied to the ankle joints compared to both the ankle and rectus abdominis, suggesting that ankle taping alone may be more beneficial for dynamic balance on the “Bobo” balance board. Interestingly, for both legs, the No KinT condition outperformed the KinT AA condition, which could suggest that the combination of ankle and rectus abdominis taping might interfere with the body’s natural movement patterns or balance performance in “Bobo” dynamic tasks.

The lack of correlation between the results of the Y balance test and the “Bobo” dynamic balance test could be due to the different demands and mechanics of the two tests. The Y balance test primarily assesses dynamic balance by requiring participants to reach out in multiple directions while maintaining a single-leg stance [21]. It involves a combination of stability, mobility, and control, challenging the lower body’s ability to balance on one leg while engaging the core and other muscle groups for dynamic reaching movements. The “Bobo” test involves balancing on an unstable surface, which requires a different set of skills. It emphasizes stabilization and coordination while adapting to the continuous shifts in the base of support. The focus here is on maintaining balance with ongoing small adjustments, which involves both static and dynamic stability. Another reason might be the proprioceptive differences between these tests. The Y balance test demands not only balance but also the ability to dynamically shift the body’s center of gravity across various directions, which might rely more on proprioceptive feedback from the lower body, especially the ankle and hip, and the core [22]. The “Bobo” balance board test assesses dynamic balance in a more controlled manner, using a stable yet unstable surface, which demands continuous micro-adjustments and responses from the feet, ankles, and possibly the trunk. This test emphasizes proprioception under an unstable environment but may not engage the same range of muscle groups or movement patterns as the Y balance test. Additionally, in the Y balance test, the emphasis is on dynamic movement through space [21, 22], which might activate different muscle groups and strategies for balance. The test may favour more flexible individuals or those with better control over their limb positioning. The “Bobo” balance board test may require more localized adjustments and muscle engagement in the lower limbs, particularly the feet and ankles, which could explain the lack of correlation if participants perform better or worse based on different stabilization strategies.

The results from the “Bobo” balance board for static and dynamic balance assessments revealed limitations in its validity. Correlation analysis with the established Stork and Y Balance Tests showed weak relationships, suggesting that the balance board may not provide reliable data for balance evaluation. This highlights the need for further validation studies before adopting the “Bobo” board as a standard assessment tool.

Study limitations

This study has several limitations. First, the sample consisted exclusively of young, healthy, rhythmic gymnasts, which restricts the generalizability of the findings to broader populations, such as males, older individuals, or those with specific conditions. Second, the study evaluated only the immediate effects of kinesiology taping, without exploring the impact of prolonged application over 24–72 h, as suggested in previous research [19]. Third, the kinesiology taping technique applied to rectus abdominis muscles was chosen based on limited prior evidence [33, 34]. Alternative techniques or application methods may produce different outcomes. Fourth, the study design did not include a group performing tests with kinesiology tape applied solely to the rectus abdominis muscles, which limits the ability to isolate and evaluate the effects of rectus abdominis-specific taping [35].

Future studies should investigate the long-term effects of kinesiology taping, incorporating diverse populations with varied activity levels, age ranges, and specific medical conditions. Additionally, research should explore alternative taping techniques and examine their efficacy for balance and stability enhancement. The conflicting results between static and dynamic balance highlight the importance of choosing appropriate assessment tools for evaluating the effectiveness of kinesiology tape on balance performance.

Conclusions

The immediate effect of kinesiology tape, whether to the ankle joint alone or combined with the rectus abdominis muscles, does not significantly improved static balance. However, dynamic balance, as assessed by the Y Balance Test, showed enhanced performance in the KinT AA condition compared to the No KinT condition for both legs. The inconsistencies observed in individual and combined leg performance using the “Bobo” balance board suggest that while this board may be suitable for balance training and recreational use, it is not sufficiently sensitive for precise balance assessments. Further validation studies are required to confirm its reliability as a balance testing tool.

Abbreviations

No KinT

No tape applied

KinT A

Kinesiology tape applied to the ankle joints

KinT AA

Kinesiology tape applied to both the ankle joint and the abdomen

BMI

body mass index

Author contributions

V.D. and I.R. wrote the main manuscript text, and E.L. prepared Tables 1, 2 and 3; Figs. 1, 2, 3, 4 and 5. All authors reviewed the manuscript.

Funding

No funding sources or conflicts of interest were reported for this study.

Data availability

The datasets used and analyzed during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethical approval

The Bioethics Committee of Lithuanian Sports University approved the study (Approval No. MI-KIN (M)-2023-595, dated April 4, 2023). Written informed consent was obtained from the parents or legal guardians of children who agreed to participate in the study.

Consent for publication

Written informed consent was obtained from the study participant and her parents for the publication of the photographs shown in Figs. 2 and 3.

Competing interests

The authors declare no competing interests.

Clinical trial number:

Not applicable.