Abstract
Background
During development, pelvic stability and mobility can vary depending on muscle endurance, spinal alignment, and clinical conditions. Because karate involves frequent weight transfer, single-leg stance, and dynamic stabilization, pelvic alignment may contribute to balance performance during such activities. This study examined the relationship between pelvic tilt and balance performance in children and adolescents practising karate.
Methods
This cross-sectional observational study included 46 karate practitioners aged 7–14 years. Static balance performance was assessed using the Flamingo Balance Test (FBT), and dynamic balance performance was assessed using the Star Excursion Balance Test (SEBT) and the Modified Bass Test (MBT). Sagittal pelvic tilt angles were measured while standing using a PALM inclinometer. The relationship between pelvic tilt and balance was analysed using Spearman’s rank correlation and multiple linear regression analyses.
Results
No significant differences were observed between right and left pelvic tilt parameters (p > 0.05). The SEBT anterior reach showed low positive correlations with right pelvic tilt range (ρ = 0.398, q = 0.025) and anterior pelvic tilt (ρ = 0.373, q = 0.044), while MBT showed a low negative correlation with right pelvic tilt (ρ = -0.431, q = 0.013). Regression analyses indicated that SEBT anterior performance was positively predicted by anterior pelvic tilt (β = 0.396, p = 0.019) and pelvic tilt range (β = 0.434, p = 0.006), with sex also significant (p < 0.05). For MBT, age was a significant positive predictor (β = 0.447, p = 0.005), while pelvic tilt showed a borderline negative association (β = -0.324, p = 0.055).
Conclusions
Pelvic tilt angles in children and adolescents practising karate may be associated with certain aspects of dynamic balance performance. Further research is needed to clarify the clinical significance of these findings.
Supplementary Information
The online version contains supplementary material available at https://doi.org/10.1186/s13102-026-01967-4.
Keywords: Pelvic tilt, Dynamic balance, Postural control, Karate, Children, Adolescents
Introduction
Karate is a martial art that requires a high level of postural control skills such as standing on one leg and rapid changes of direction [1, 2]. Karate training during childhood supports multidimensional development in physical and mental functions such as muscle strength, flexibility, balance, postural control, attention, and working memory [3–8]. Postural control is based on the integration of the musculoskeletal, vestibular, and proprioceptive systems [9]. Karate training processes support the integration of these systems and positively affect fundamental motor skills by enhancing the neuromusculoskeletal system of karate practitioners [1, 10–12]. The popularity of martial arts such as karate has been increasing, especially because of their contribution to psychomotor development during childhood [8, 13, 14].
The pelvis serves as the primary link between the trunk and the lower limbs, and changes in pelvic alignment directly affect both static and dynamic balance [15]. During development, the pelvis, along with the spine, hips, and trunk muscles, serves as a fundamental “center” for posture, balance, and walking. Spinopelvic alignment is considered a fundamental component of sagittal balance, reflecting the interaction between the spine and pelvis in postural control [16]. Current research supports the idea that pelvic tilt (PT) and alignment contribute to balance, but are not the sole or primary determinant. Biomechanical adaptations in the pelvis during childhood and adolescence can be monitored through muscle endurance, stability, and mobility. From a biomechanical perspective, pelvic position can influence performance by affecting inter-segmental coordination and stability strategies during movement. However, this relationship may vary depending on task demands [17]. The relationship between posture and balance in children and adolescents is complex. Postural parameters such as PT have been reported to show weak or inconsistent correlations [18].
Karate requires the maintenance of trunk, pelvic and hip stability due to movement characteristics such as repeated changes in stance, standing on one leg and weight transfer [9, 18]. In this context, it is essential to examine pelvic mobility in children and adolescents practising karate, as it is vital for both technical execution and postural stability. From a biomechanical perspective, pelvic alignment may influence postural control through its contribution to trunk stability, lower-extremity coordination, and force transfer during movement [17, 19]. Given that karate involves repeated weight transfer, single-leg stance, and dynamic stabilization, pelvic mobility may contribute to balance-related performance in young karate practitioners [17].
Karate training supports coordination between the shoulder and trunk segments of the body and improves postural control [20–23]. Adaptations in PT movements among karate practitioners have been demonstrated by a reduction in PT, specifically a posterior PT orientation [24, 25]. Furthermore, children who undergo karate training perform pelvic movements with greater stability and less variability compared to their peers [26]. These studies help explain the importance of pelvic stability and mobility in karate performance. However, considering the current scientific literature, the relationship between postural control and balance and anterior–posterior PT movements still needs to be investigated. In this context, sagittal PT is recognized as one of the biomechanical determinants of balance performance in both static postures and dynamic activities.
The aim of this study was to examine the relationship between postural control and PT in children and adolescents training in karate. Accordingly, the main hypothesis of the study was that PT would be associated with the Flamingo Balance Test (FBT), Star Excursion Balance Test (SEBT), and Modified Bass Test (MBT), which are used to assess postural control ability. The findings obtained are expected to contribute to a better definition of the biomechanical characteristics related to postural control in karate practitioners.
Materials and methods
Study design and participants
This cross-sectional observational study was conducted on 46 children aged 7–14 years (14 boys and 32 girls) who had been receiving karate training for at least four months (mean 2.59 ± 1.96 years). The study was approved by the Non-Interventional Scientific Research Ethics Committee of Afyonkarahisar Health Sciences University (approval date: 04.10.2024; approval number: 2024/8-359). Written informed consent was obtained from the parents, and assent was obtained from all participating children prior to participation. All assessments were performed in accordance with the principles of the Declaration of Helsinki.
The inclusion criteria were determined as having at least 4 months of non-professional karate training experience (training without participation in competitions), no history of orthopaedic or physiological acute injury, a training frequency of 3–4 times per week, and no chronic disease, disability, or pain disorder. Individuals with neurological, orthopaedic, or vestibular health problems that could affect the balance test were excluded from the study.
The demographic characteristics of participants who met the eligibility criteria were recorded. Prior to data collection, all participants were given a brief explanation of the test procedures. Participants underwent assessments at designated sports clubs outside school hours (between 16:00 and 19:00). Furthermore, they were assessed prior to training sessions to ensure they were sufficiently rested. Balance tests were administered in a randomized order, and a 5-minute rest period was allowed between each test to minimize fatigue-related effects. To minimize measurement variability, all assessments were conducted following a standardized protocol. Anthropometric and PT measurements were performed by a single researcher (physiotherapist A.I.), while balance assessments were conducted by another researcher (physiotherapist S.E.). Participants also completed a brief familiarization trial before each test to ensure consistent task execution.
Anthropometric measurements
Participants’ height (cm) and body weight (kg) were measured with light clothing and without shoes using a standard measuring tape and scale. Body mass index (BMI) was calculated by dividing body weight by the square of height in meters (kg/m²). Anatomical leg length was measured as the distance between the anterior superior iliac spine (ASIS) and the medial malleolus using a measuring tape while the participant was in the supine position, and it was assessed separately for both sides. Leg length measurements were used to normalize the raw data of the SEBT. Quadriceps femoris angle measurement was performed using a standard steel goniometer (SAEHAN, SH5102). In addition, the flexibility level of the participants’ hamstring muscles was evaluated using the Sit-and-Reach Flexibility Test. The test was performed using a standard sit-and-reach test device (a fixed wooden block 30 cm in height).
Flamingo Balance Test (FBT)
The FBT is widely used in the literature as a valid and reliable method for assessing static balance in children and adolescents [27, 28]. Participants were asked to stand on one leg on the test beam while positioning the free extremity in knee flexion. Each loss of balance occurring within 1 min (falling, touching the ground with the free foot, or stepping off the beam) was recorded as an error. If more than 15 errors occurred within the first 30 s, the test was terminated and the participant was given the maximum error score of 31. The test was performed once for each participant.
Star Excursion Balance Test (SEBT)
The anterior, posteromedial, and posterolateral directions of the SEBT were used to assess dynamic balance. The test has been reported to have moderate-to-high test–retest reliability and good validity for evaluating dynamic balance in children and adolescents [29–32]. Participants were encouraged to reach as far as possible in the specified directions with the free foot while maintaining balance on the dominant extremity. The dominant limb was used for testing in accordance with standard protocols to ensure consistency in dynamic balance assessment. The trial was considered invalid and repeated if balance was lost, the stance foot lifted off the ground, or weight was transferred onto the reaching foot. Three trials were performed for each direction, and the maximum reach distance was normalized to lower extremity length and calculated as a percentage (%). In addition, a composite score was obtained by averaging the values from the anterior, posteromedial, and posterolateral directions. Composite Score (%) = [(Anterior + Posteromedial + Posterolateral) / (3 × Leg Length)] × 100.
Modified Bass Test (MBT)
For the test setup, a total of 11 marking tapes, each measuring 2.5 cm × 2 cm, were placed on the floor according to the original test protocol. To ensure consistency in the test procedure, all participants started the MBT with their right foot, and each participant performed the test only once. The test was initiated from the “start” line in a single-leg stance position on the right foot. Participants were asked to jump to the first marked point with their left foot and maintain balance on the forefoot for as long as possible, up to a maximum of 5 s. They then jumped to the second marked point with the right foot, proceeding alternately with each foot to the subsequent marked points. After each landing, participants were instructed to maintain balance on the forefoot for a maximum of 5 s. During landing, the foot was required to completely cover the marking tape so that it was not visible.
Scoring was based on landing accuracy and balance duration. Five points were awarded for each successful landing, and one point was given for each second of maintained balance (maximum 5 s). Thus, a maximum of 10 points could be obtained for each marked point and 100 points for the entire test. Higher scores indicated better dynamic balance performance. Penalties applied in the test were classified as landing errors and balance errors. In the case of a landing error, 5 points were deducted. Landing errors included failure to stabilize after the jump, contact of any part of the support foot other than the heel or forefoot with the ground, or failure of the foot to completely cover the marking tape. After a landing error, participants were allowed to readjust their body position for the 5-second balance period. Balance errors were recorded if any body part other than the forefoot of the support foot touched the ground or if the support foot moved before completing the 5-second balance period, and a deduction of 1 point was applied for each second. If balance was completely lost, participants were instructed to return to the relevant marked point and then proceed to the next one. The test protocol and scoring system were applied according to previously described standard methods. This test has been reported to have acceptable reliability (r = 0.75) [33–38].
Pelvic tilt measurements
Standing PT measurements of the participants were performed using a PALM inclinometer with high validity and reliability [39, 40]. All measurements were performed by the same assessor using standardized procedures to minimize measurement variability. During the measurement, participants were positioned standing with hips and knees extended and feet shoulder-width apart. When the arms of the PALM device were placed on the anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS), the degree measured on the inclinometer was recorded as the resting PT angle for the right and left sides [41]. Participants were then asked to perform anterior and posterior PT sequentially to determine the maximum range of motion. These values were recorded as maximum anterior PT (APT) and maximum posterior PT (PPT) angles. In addition, the difference between APT and PPT angles was calculated to determine the total PT range of motion (PTr). Participants were not allowed to compensate with trunk movements during the assessments.
Statistical analysis
All statistical analyses were performed using IBM SPSS Statistics for Windows (Version 25.0; IBM Corp., Armonk, NY, USA). Data distribution was assessed using the Shapiro–Wilk test, indicating non-normality. Accordingly, descriptive statistics were reported as mean ± standard deviation, median (interquartile range), and minimum–maximum values. The Wilcoxon signed-rank test was used to compare right and left PT angles. Associations between PT parameters and balance performance were analysed using Spearman’s rank correlation coefficient (ρ). To control for multiple comparisons, the false discovery rate (FDR) was adjusted using the Benjamini–Hochberg procedure. Multiple linear regression analyses were performed to examine the independent associations between PT parameters and balance performance outcomes (MBT and SEBT anterior reach), adjusting for age, sex, BMI, duration of karate training, and hamstring flexibility. Correlation strength was interpreted as negligible (0.00–0.29), low (0.30–0.49), moderate (0.50–0.69), high (0.70–0.89), and very high (0.90–1.00) [42]. Statistical significance was set at p < 0.05.
An a priori power analysis was performed using G*Power 3.1 software [43, 44]. Based on a medium effect size (ρ = 0.40), 80% power (1–β = 0.80), and a two-tailed significance level of 5% (α = 0.05) for Spearman correlation analyses, the minimum required sample size was determined to be 46 participants. Therefore, the sample size in this study was considered sufficient for statistical analyses. The assumed effect size was based on conventional guidelines for correlation coefficients as described by Cohen (1988) and was considered appropriate given the absence of prior data and multiple outcome measures [45]. The SEBT anterior direction was considered the primary outcome for the sample size estimation, as it represents a key indicator of dynamic balance performance. In addition, a post hoc power analysis based on the observed correlation (ρ = 0.40) indicated a statistical power of approximately 0.80, further supporting the adequacy of the sample size.
Results
A total of 47 participants were initially assessed for eligibility. One participant declined to complete the balance assessments and was excluded, resulting in a final sample of 46 participants. The descriptive characteristics of the participants are presented in Table 1. The mean age was 10.33 ± 1.83 years, the mean height was 144.63 ± 11.42 cm, and the mean body weight was 41.16 ± 10.08 kg. The mean BMI was 19.51 ± 3.69 kg/m². The majority of participants were female (69.6%), had received kumite training (87.0%), and were right-dominant (89.1%). The mean duration of karate training was 2.59 ± 1.96 years.
Table 1.
Demographic and physical characteristics of the participants (n = 46)
| Mean ± SD | Median (Q25–Q75) | ||
|---|---|---|---|
| Age (years) | 10.33 ± 1.83 | 10.00 (9.00–12.00) | |
| Height (cm) | 144.63 ± 11.42 | 146.00 (135.75–151.25) | |
| Right leg length (cm) | 75.07 ± 7.01 | 75.00 (70.75–80.00) | |
| Left leg length (cm) | 75.09 ± 7.03 | 75.00 (70.75–80.00) | |
| Body weight (kg) | 41.16 ± 10.08 | 43.10 (32.98–49.23) | |
| Body mass index (kg/m²) | 19.51 ± 3.69 | 19.96 (16.84–21.83) | |
| Q angle (right) (°) | 12.52 ± 2.54 | 13.00 (10.00–14.00) | |
| Q angle (left) (°) | 12.43 ± 2.83 | 12.00 (10.00–15.00) | |
| Sit-and-Reach Test (cm) | 30.47 ± 7.21 | 31.25 (25.00–36.25) | |
| Duration of karate training (years) | 2.59 ± 1.96 | 2.00 (1.00–3.00) | |
| Category | n | % | |
|---|---|---|---|
| Sex | Female | 32 | 69.6 |
| Male | 14 | 30.4 | |
| Karate Events | Kumite | 40 | 87.0 |
| Kata | 6 | 13.0 | |
| Dominant extremity | Right | 41 | 89.1 |
| Left | 5 | 10.9 |
SD standard deviation, Q25–Q75 interquartile range (25th–75th percentile), Q angle quadriceps angle
The balance performance results are shown in Table 2. The mean FBT scores were 10.24 ± 7.78 (right) and 10.74 ± 7.71 (left), whilst the mean MBT score was 85.50 ± 15.43. For the SEBT, the mean normalised reach distances were 97.10 ± 15.36% (anterior), 86.27 ± 15.93% (posteromedial) and 79.36 ± 12.84% (posterolateral), respectively, with a composite score of 87.30 ± 14.07%.
Table 2.
Balance performance characteristics (n = 46)
| Variable | Mean ± SD | Median (Q25–Q75) | 95% CI (Lower–Upper) |
|---|---|---|---|
| FBT right (score) | 10.24 ± 7.78 | 9.00 (5.25–12.00) | 7.93–12.55 |
| FBT left (score) | 10.74 ± 7.71 | 9.50 (6.00–14.00) | 8.45–13.03 |
| MBT (score) | 85.50 ± 15.43 | 89.00 (81.25–95.75) | 80.92–90.08 |
| SEBT Anterior (%) | 97.10 ± 15.36 | 94.68 (88.80–111.55) | 92.53–101.66 |
| SEBT Posteromedial (%) | 86.27 ± 15.93 | 81.65 (74.47–98.24) | 81.54–91.00 |
| SEBT Posterolateral (%) | 79.36 ± 12.84 | 79.88 (70.51–88.09) | 75.54–83.17 |
| SEBT Composite (%) | 87.30 ± 14.07 | 85.51 (76.86–97.61) | 83.13–91.48 |
SD standard deviation, Q25–Q75 interquartile range (25th–75th percentile), CI confidence interval, FBT Flamingo Balance Test score, MBT Modified Bass Test, SEBT Star Excursion Balance Test
Table 3 shows that the measurements of right and left PT are symmetrical. No significant difference was found between the two sides in terms of PT, APT, PPT and PTr values (all p > 0.05). The effect sizes were small, indicating that the differences between the two sides were minor.
Table 3.
Comparison of right and left pelvic tilt measurements (n = 46)
| Variable | Right | Left | Comparison | ||||
|---|---|---|---|---|---|---|---|
| Mean ± SD | Median (Q25–Q75) |
Mean ± SD | Median (Q25–Q75) |
Z | p | Effect size (r) | |
| PT | 1.54 ± 1.05 |
2.00 (1.00–2.00) |
1.59 ± 1.34 |
1.00 (1.00–2.00) |
-0.573 | 0.567 | 0.09 |
| APT | 11.11 ± 2.69 |
11.00 (9.75–12.00) |
11.54 ± 2.99 |
11.00 (9.00–13.00) |
-1.294 | 0.196 | 0.19 |
| PPT | -3.39 ± 2.45 |
-3.00 (-5.00–2.00) |
-3.15 ± 2.17 |
-3.00 (-5.00–1.00) |
-0.915 | 0.360 | 0.14 |
| PTr | 14.54 ± 4.16 |
13.00 (12.00–17.25) |
14.70 ± 4.03 |
14.00 (12.00–17.00) |
-0.501 | 0.616 | 0.07 |
Right and left side comparisons were performed using the Wilcoxon signed-rank test
SD standard deviation, Q25–Q75 interquartile range (25th–75th percentile), PT Pelvic tilt at rest, APT Anterior pelvic tilt, PPT Posterior pelvic tilt, PTr Pelvic tilt range
A complete list of correlations between PT parameters and balance performance is presented in Supplementary Table S1 and Fig. 1. Relationships found to be significant after applying FDR correction for multiple comparisons are summarised in Table 4. Accordingly, low positive correlations were found between the anterior direction of SEBT and right PTr (ρ = 0.398) and right APT (ρ = 0.373) (q < 0.05). Furthermore, a low negative correlation was observed between MBT and right PT (ρ = -0.431) (q < 0.05). The other correlations were not statistically significant (q > 0.05).
Fig. 1.
Heatmap of Spearman correlations among balance and pelvic tilt variables. The color scale represents correlation coefficients ranging from − 1.00 to + 1.00; warm colors indicate negative correlations and cool colors indicate positive correlations, with values close to 0 shown in lighter shades
Table 4.
Correlations between pelvic tilt parameters and balance performance after FDR correction
| Variables | ρ (Spearman) | p-value | q-value (FDR) |
|---|---|---|---|
| SEBT Anterior – Right PTr | 0.398 | 0.006 | 0.025* |
| SEBT Anterior – Right APT | 0.373 | 0.011 | 0.044* |
| MBT – Right PT | -0.431 | 0.003 | 0.013* |
| SEBT Composite – Right PTr | 0.309 | 0.037 | 0.139NS |
| SEBT Anterior – Left PTr | 0.300 | 0.042 | 0.152NS |
P-values were adjusted for multiple comparisons using the Benjamini–Hochberg false discovery rate (FDR) procedure across all correlation analyses (n = 105). Correlations with q < 0.05 were considered statistically significant (*). NS indicates non-significant results
MBT Modified Bass Test, SEBT Star Excursion Balance Test, PT pelvic tilt, APT anterior pelvic tilt, PTr pelvic tilt range.
According to the analysis results presented in Table 5, in the multiple linear regression analysis where the right APT variable was included in the model for the SEBT anterior direction, the model was found to be statistically significant (F (6,39) = 2.744, p = 0.025) and explains 29.7% of the variance (R² = 0.297). Right APT is a significant and positive predictor of performance (β = 0.396, p = 0.019) and the sex variable is also significant (p = 0.034). The contributions of the other variables are not significant (p > 0.05). In the multiple linear regression analysis for the SEBT anterior direction, where the right PTr variable was included in the model, the model was found to be statistically significant (F (6,39) = 3.287, p = 0.010) and explains 33.6% of the variance (R² = 0.336). The right PTr is a significant and positive predictor of performance (β = 0.434, p = 0.006). Furthermore, the sex variable is also significant (p = 0.007). The other variables are not significant (p > 0.05). In the multiple linear regression analysis conducted for MBT, the model was found to be statistically significant (F (6,39) = 4.455, p = 0.002) and explains 40.7% of the variance (R² = 0.407). The age variable is a significant and positive predictor of performance (β = 0.447, p = 0.005), whilst right PT shows a marginally significant and negative relationship (β = -0.324, p = 0.055). The contributions of the other variables are not significant (p > 0.05).
Table 5.
Multiple linear regression analyses for balance performance outcomes
| Variables | B | SE | β | t | p | 95% CI |
|---|---|---|---|---|---|---|
| Dependent Variable: SEBT Anterior (APT model) | ||||||
| Constant | 100.588 | 22.730 | — | 4.425 | < 0.001 | (54.61–146.57) |
| Right APT | 2.257 | 0.923 | 0.396 | 2.445 | 0.019* | (0.39–4.12) |
| Hamstring flexibility | -0.174 | 0.324 | -0.082 | -0.538 | 0.594 | (-0.83–0.48) |
| Age | -0.483 | 1.404 | -0.057 | -0.344 | 0.733 | (-3.32–2.36) |
| BMI | -0.625 | 0.581 | -0.150 | -1.075 | 0.289 | (-1.80–0.55) |
| Duration of karate training | 0.449 | 1.457 | 0.057 | 0.308 | 0.760 | (-2.50–3.40) |
| Sex (female) | -10.410 | 4.741 | — | -2.196 | 0.034* | (-20.00–-0.82) |
| Model statistics: F = 2.744,p = 0.025, R² = 0.297, Adjusted R² = 0.189, Durbin–Watson = 1.665 | ||||||
| Dependent Variable: SEBT Anterior (PTr model) | ||||||
| Constant | 102.891 | 21.130 | — | 4.869 | < 0.001 | (60.15–145.63) |
| Right PTr | 1.603 | 0.546 | 0.434 | 2.937 | 0.006** | (0.50–2.71) |
| Hamstring flexibility | -0.100 | 0.308 | -0.047 | -0.324 | 0.748 | (-0.72–0.52) |
| Age | -0.780 | 1.335 | -0.093 | -0.584 | 0.562 | (-3.48–1.92) |
| BMI | -0.507 | 0.566 | -0.122 | -0.896 | 0.376 | (-1.65–0.64) |
| Duration of karate training | 0.359 | 1.395 | 0.046 | 0.257 | 0.798 | (-2.46–3.18) |
| Sex (female) | -13.007 | 4.530 | — | -2.871 | 0.007** | (-22.17–-3.85) |
| Model statistics: F = 3.287,p = 0.010, R² = 0.336, Adjusted R² = 0.234, Durbin–Watson = 1.676 | ||||||
| Dependent Variable: MBT (Right PT model) | ||||||
| Constant | 33.653 | 18.689 | — | 1.801 | 0.079 | (-4.15–71.46) |
| Right PT | -4.771 | 2.417 | -0.324 | -1.974 | 0.055 | (-9.66–0.12) |
| Hamstring flexibility | 0.034 | 0.298 | 0.016 | 0.115 | 0.909 | (-0.57–0.64) |
| Age | 3.778 | 1.262 | 0.447 | 2.993 | 0.005** | (1.23–6.33) |
| BMI | 1.072 | 0.564 | 0.256 | 1.901 | 0.065 | (-0.07–2.21) |
| Duration of karate training | 0.207 | 1.251 | 0.026 | 0.165 | 0.869 | (-2.32–2.74) |
| Sex (female) | -3.319 | 4.997 | — | -0.664 | 0.510 | (-13.43–6.79) |
| Model statistics: F = 4.455,p = 0.002, R² = 0.407, Adjusted R² = 0.315, Durbin–Watson = 2.332 | ||||||
Sex was coded as 0 = male and 1 = female
SEBT Star Excursion Balance Test, APT Anterior Pelvic Tilt, PT Pelvic Tilt, PTr Pelvic Tilt Range, BMI Body Mass Index, B Unstandardized coefficient, SE Standard error, β Standardized coefficient, CI Confidence interval (95%)
Significance: **p < 0.01, *p < 0.05
Discussion
This study examined the relationship between PT and balance performance in 46 children and adolescents undergoing karate training. Overall, the findings revealed a limited association between PT parameters and dynamic balance performance. This suggests that, in addition to pelvic alignment, other factors also influence the balance of karate practitioners. Pelvic mobility was associated with forward reach performance under dynamic conditions, with low but statistically significant associations observed for APT and PTr. However, balance performance is influenced by multiple factors, including age, sex, and neuromuscular development. Furthermore, as a test overlapping with key karate elements such as jumping, landing, stabilisation and coordination, the MBT findings suggest that age may play a more pronounced role in balance conditions, whilst PT provides only a limited contribution. These findings suggest that PT contributes to balance performance as one component of a multifactorial system, thereby partially supporting the study hypothesis.
Recent research has shown that balance performance is the result of numerous interacting factors, such as neuromuscular control, muscle strength and endurance, flexibility, sensory integration, coordination, and age-related maturation [46–48]. Therefore, pelvic-focused assessments and interventions should be considered as part of a broader, multifactorial approach to balance.
Our findings regarding the relationship between balance and PT are partly consistent with previous studies reporting that karate training is associated with adaptations in pelvic alignment, particularly a tendency towards greater posterior tilt [24–26]. It is also known that karate training enhances pelvic stability and postural control abilities [4–7, 20, 22, 23]. However, it is thought that the motor development process in young karate practitioners may also play a significant role in this relationship. In particular, at younger ages such as around 8–9 years, it is known that athletes frequently adopt a guard with the non-dominant leg forward and execute attacks with the dominant limb; whereas in later years, the right and left sides are used more evenly [49–50]. This developmental progression may influence pelvic control and load distribution, thereby affecting balance performance. Indeed, the identification of age as the strongest predictor of MBT performance in this study supports the notion that balance performance is closely related not only to pelvic biomechanical characteristics but also to neuromuscular development.
Sex also emerged as a significant predictor of SEBT anterior performance in the present study. Previous studies have reported sex-related differences in balance performance during childhood and adolescence; however, these findings have not been consistent across studies. Such differences may be related to variations in motor and neuromuscular development as well as differences in the balance tasks used across studies [51, 52]. Therefore, the reasons underlying the observed sex effect remain unclear. Nevertheless, the associations between APT, PTr, and SEBT anterior performance remained significant after adjustment for sex, suggesting that these relationships were not solely explained by sex-related differences.
In addition, no significant differences were observed between right and left pelvic tilt measurements. This finding suggests a relatively symmetrical pelvic alignment in the studied karate athletes. Such symmetry may be related to the technical demands of karate, which require coordinated, balanced, and repetitive use of both lower extremities during training and competition [23, 53]. Consequently, the relatively symmetrical loading patterns associated with karate practice may contribute to the maintenance of pelvic alignment during growth and development. However, this interpretation should be considered with caution and requires confirmation in future studies.
Balance and postural control are direction-dependent. The ankle strategy has been shown to play a dominant role in anteroposterior disturbances, whereas the hip and pelvis contribute more substantially during tasks requiring greater movement and stability control [54, 55]. In young, healthy individuals, the ankle strategy typically dominates during low-demand static tasks [54], which may provide a theoretical explanation for the weak and inconsistent associations observed between PT and static balance performance in the present study. Conversely, it has been reported that in dynamic tasks requiring greater demands, the contribution of the hip and trunk segments increases, and that these segments are decisive for reach performance [56]. In this regard, the relationships observed particularly in dynamic balance tasks involving reaching forward and weight transfer suggest that pelvic control becomes more pronounced as task demands increase. In this context, it is considered that PT and PTr measured in the standing position may reflect the movement capacity utilised in dynamic tasks, and that the finding of an association with SEBT anterior performance in particular may be explained by this mechanism.
In martial arts such as karate, the need for movement control of the pelvis increases during balance tasks involving challenging jumps and stabilization [55, 57, 58]. In the present study, PT values were generally close to neutral, and greater PTr, particularly in the anterior direction, was associated with improved dynamic balance performance in tasks such as the SEBT. In addition, a tendency toward a more PPT orientation on the right side was observed in participants with better MBT performance. These findings suggest the importance of sagittal pelvic mobility and control in dynamic balance tasks requiring forward reach and controlled weight transfer [50, 59–61]. Functional mobility of the pelvis in the anteroposterior plane may contribute to more effective force transmission to the lower extremities by supporting trunk stability [58, 62].
Several limitations should be considered when interpreting the findings of this study. The cross-sectional nature of the design limits the ability to establish causal relationships. In addition, biological maturation was not assessed, which may have influenced both pelvic alignment and balance performance, particularly given the rapid neuromuscular and biomechanical changes occurring between 7 and 14 years of age [63]. Therefore, the observed associations should be interpreted within a developmental as well as task-specific context. The sample consisted of amateur karate practitioners with varying training experience, which may limit the generalisability of the findings. Participants’ involvement in other sports or physical activities was not recorded, which may have influenced balance performance. The use of a single trial for each balance assessment may have affected measurement reliability, as balance performance can vary across repeated attempts. Finally, the absence of assessor blinding and the unequal distribution of sex among participants may have introduced potential bias.
Conclusion
The findings of this study suggest that PT mobility may be associated with dynamic balance performance in young karate practitioners. However, given the cross-sectional design and small effect sizes, no causal inferences can be made. Future research should investigate these relationships using longitudinal designs and more comprehensive biomechanical models.
Supplementary Information
Acknowledgements
The authors thank all participants for their contribution to the study.
Abbreviations
- PT
Pelvic Tilt
- APT
Anterior Pelvic Tilt
- PPT
Posterior Pelvic Tilt
- PTr
Pelvic Tilt Range of Motion
- FBT
Flamingo Balance Test
- FDR
False Discovery Rate
- SEBT
Star Excursion Balance Test
- MBT
Modified Bass Test
- ASIS
Anterior Superior Iliac Spine
- PSIS
Posterior Superior Iliac Spine
- BMI
Body Mass Index
- PALM
Palpation Meter
Authors' contributions
AI: Conceptualization, Data curation, Investigation, Funding acquisition, Project administration, Writing—original draft. SE: Methodology, Data curation, Investigation, Writing—original draft. YEK: Conceptualization, Methodology, Writing—review & editing, Supervision. All authors read and approved the final manuscript.
Funding
This study was supported under the TÜBİTAK 2209-A University Students Research Projects Support Program.
Data availability
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Declarations
Ethics approval and consent to participate
The study was approved by the Non-Interventional Scientific Research Ethics Committee of Afyonkarahisar Health Sciences University (approval date: 04/10/2024; approval number: 2024/8-359). The study was conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent was obtained from the parents, and assent was obtained from all participating children prior to participation.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.