Next Article in Journal
The Effect of Apilarnil Administration on Spermiation and Semen Quality in Sterlet (Acipenser ruthenus)
Previous Article in Journal
Artificial Intelligence in Prostate MRI: Redefining the Patient Journey from Imaging to Precision Care
Previous Article in Special Issue
Validity, Reliability, and Sensitivity of the Brazilian Jiu-Jitsu Cardiorespiratory Fitness Test: A Methodological Approach Based on Combat Specificity
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Applied Sciences
Volume 16
Issue 2
10.3390/app16020894
applsci-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Morphological Asymmetries and Their Relationship to Judo-Specific Performance in Youth Judokas

by
Jožef Šimenko
* and
Primož Pori
Department of Sports Medicine, Faculty of Sport, University of Ljubljana, 1000 Ljubljana, Slovenia
*
Author to whom correspondence should be addressed.
Appl. Sci. 2026, 16(2), 894; https://doi.org/10.3390/app16020894
Submission received: 20 December 2025 / Revised: 9 January 2026 / Accepted: 14 January 2026 / Published: 15 January 2026
(This article belongs to the Special Issue Athletes Performance and Analysis in Combat Sports and Martial Arts: Second Edition)
Versions Notes

Abstract

The purpose of this study was to examine morphological asymmetries in male youth judokas using an integrated assessment combining three-dimensional (3D) body scanning and bioelectrical impedance analysis (BIA), and to determine how these asymmetries relate to judo-specific performance. Twenty-seven competitive male youth judokas were evaluated for bilateral girth, segmental length, and lean mass asymmetries across upper- and lower-limb segments. The Absolute Asymmetry index, expressed as a percentage for individual body segments, and the average body symmetry across all variables were calculated, and associations with performance were assessed using the Special Judo Fitness Test (SJFT). Significant right-dominant asymmetries were found in elbow girth p < 0.001, forearm girth p < 0.001, thigh girth p = 0.028, and leg muscle mass p = 0.008. Upper-limb asymmetries were the primary contributors to total-body asymmetry, reflecting the unilateral gripping and rotational demands typical in judo. Only calf girth asymmetry was significantly associated with SJFT performance, with greater asymmetry linked to poorer outcomes, indicating a specific rather than general asymmetry–performance relationship (r = 0.405; p = 0.037). These findings underscore the importance of early detection of segment-specific asymmetries and suggest that rapid digital anthropometry is a practical tool for monitoring morphological development in youth judokas. Early targeted interventions may support balanced technical execution, enhance performance, and reduce the risk of uneven loading patterns as athletes progress to higher age categories and competition levels.

1. Introduction

Morphological asymmetries, defined as side-to-side differences in body structure or composition, are a common and often unavoidable feature of athletic development, particularly in sports that involve unilateral movements, repetitive loading, or technical motor patterns biassed to one side of the body [1]. While some degree of asymmetry may reflect functional specialization [2], pronounced or persistent asymmetries have been associated with increased injury risk [3,4] and reduced performance potential [1,5]. In elite sport, particularly at the youth developmental level, the early identification and monitoring of morphological asymmetries are crucial for preventing injuries, promoting long-term athlete development, and optimizing performance [6,7,8].
In judo, asymmetries are particularly relevant due to the sport’s inherently lateralized nature. The repeated application of throwing techniques often executed predominantly on one side, combined with asymmetric stances and grips, can create significant functional and morphological imbalances over time [9,10,11]. Studies have shown that elite and youth judokas often exhibit clear side dominance, especially in upper- and lower- limb girths and lean mass, which may manifest in asymmetrical motor performance, morphological traits and biomechanical efficiency [12,13,14].
Researchers have traditionally relied on conventional anthropometry and bioimpedance analysis (BIA) to evaluate such asymmetries from a morphological perspective [15,16]. However, with the advent of 3D body scanning technologies, morphological profiling has become more precise, efficient, and scalable. Integrating 3D body scanning with segmental BIA provides a detailed view of soft tissue distribution and structural asymmetries across the entire body [12]. These tools have shown particular promise in combat sports, where total-body symmetry contributes to balance, technique execution, and injury resilience.
In parallel, functional performance in judo has been assessed using the Special Judo Fitness Test (SJFT), a widely accepted method for evaluating judo-specific performance. The SJFT quantifies anaerobic capacity and movement efficiency through a standardized protocol that involves repeated throws and heart rate responses and has demonstrated strong reliability and ecological validity across developmental stages [17,18]. Moreover, bilateral versions of the SJFT have explored functional asymmetries in throwing performance, showing that side dominance can affect overall output and technical consistency [9,19].
Despite these advancements, a critical gap remains in the literature. Previous studies have explored segmental asymmetries in isolated body parts, such as arms or legs, and their implications for performance [20,21,22]. However, whole-body morphological asymmetries have not been comprehensively assessed or linked to judo-specific performance, particularly among male youth judokas. It has been reported that individual asymmetry measures can be useful at the local level, but it is difficult to draw conclusive statements about their global influence. Therefore, combining multiple variables may provide better methods for detecting asymmetries and their influence [23,24], like global brain asymmetry [25] and the global gait asymmetry index [26].
Therefore, this study aimed to assess morphological asymmetries and to integrate individual and full-body asymmetry scores, as well as their association with SJFT performance in youth judokas. It was hypothesized that youth judokas would exhibit measurable segmental and whole-body morphological asymmetries, and that these asymmetries would be associated with poorer judo-specific performance, as assessed by the SJFT.

2. Materials and Methods

2.1. Design

An exploratory cross-sectional research design examined SJFT performance and morphological asymmetries. Body composition measurements and 3D scanning were performed in the morning (8:00 AM–11:00 AM) in the Physiological Laboratory of the Institute of Sport in Ljubljana, Slovenia. The SJFT was conducted the following week in the study participants’ clubs.

2.2. Subjects

This cross-sectional study included a sample of 27 male judokas from the youth category who competed at national and international levels. Testing was performed at the beginning of the competitive season in January. Participants were 14.4 ± 1.6 years old; their body height was 170.1 ± 11.2 cm, body mass was 62.1 ± 12.3 kg, body mass index (BMI) was 21.27 ± 2.78 kg/m2, skeletal muscle mass was 30.8 ± 7.0 kg, and fat mass was 7.0 ± 3.6 kg, respectively. Hand dominance was used as an indicator of judo dominance, with participants asked which hand they use to write, draw, and throw a ball, as previously used [27]. Previous studies have shown that hand dominance is closely associated with motor lateralisation and technical side preference in judokas, particularly in youth athletes where specialization is still developing [9]. There were 24 right-hand dominant and three left-hand dominant judokas. They have been training judo for 6.7 ± 0.8 years. At the testing time, judokas had on average 3. kyu belt degree (blue belt) ± 0.75. The inclusion criteria were: they need to be training in judo for at least 3 years, training regularly at least 3 times per week; at the time of testing, participants are free from acute injuries and reported no current musculoskeletal pain; not to be engaged in rapid weight loss or to have a competition scheduled in the following weeks. The Faculty of Sport, University of Ljubljana, Ethical Board (No. 2033/2013) approved the study. During the study, the principles outlined in the Declaration of Helsinki were followed. Upon recruitment, a signed informed consent form was obtained from the parents or guardians of participants to ensure their voluntary participation in the study.

2.3. Body Composition

The InBody 720 (Biospace Co., Ltd., Seoul, Republic of Korea) body composition analyzer was used to measure body weight, lean body mass, and fat mass. Body height was measured using a GP (Swiss) anthropometer. Body composition measurements were performed in the standing position, following all necessary guidelines for accurate measurement [28,29]. The reliability of the BIA InBody 720 has been previously assessed, yielding an interclass correlation of 0.99 [30,31]. The following variables were used to conduct further analysis: body mass, skeletal muscle mass, body fat mass, and lean mass of the left and right arms and legs.

2.4. Three-Dimensional Body Scan Measurements

The 3D body scanner NX-16 was used for 3D anthropometric body measurement ([TC]2, Cary, NC, USA). This technique uses photogrammetry to project structured white-light patterns onto the body using 32 cameras. Afterwards, the body shape is digitally reconstructed from raw cloud data to produce a true-to-scale 3D body model in 8 s, enabling surface reconstruction and automatic landmark recognition. Test–retest variability of the NX-16 was reported as a coefficient of variation (CV%) and ranged from 0.2 to 3.3% [32]. Validation with the reference measure of manual anthropometry yielded r values ranging from 0.95 to 99, with an average relative error of 0.006–0.037 [33].
Participants were instructed to remove all jewellery and clothing, and to enter the 3D body scanner barefoot and in form-fitting, brightly coloured underwear, following the standard instructions [28]. Software Version 7.4.1 of the 3D Body Measurement System was used with the multi-scan option, which uses three consecutive scans to obtain the data. This option merges all three files from the three consecutive scans for final analysis. The following paired variables were taken to further analysis: upper arm girth, elbow girth, forearm girth, wrist girth, thigh girth, thigh length, knee girth, and calf girth.

2.5. Special Judo Fitness Test

The SJFT was used to assess participants’ special judo-motor abilities within their clubs. The test consisted of an ippon-seoi-nage throwing technique executed as fast as possible and as many times as possible on the judoka’s dominant side while running between two partners (6 m apart from one another—test starts in the middle, 3 m from each partner, and the starting side is chosen randomly by the participant). This is performed in three time periods. The first one lasts 15 s, the second and third last 30 s, while there are 10 s rest intervals between [18]. Three athletes of similar body mass were needed to perform the SJFT (one to perform the test-tori and 2 to be thrown-uke). The number of throws completed during each of the three periods was recorded as the primary outcome of measures, while the total number of throws (TT) was calculated by summing up the throws from those three specific periods. Heart rate was monitored using a Polar V800 heart rate (HR) monitor and a Polar H7 chest belt (Polar, Finland). HR at the end of the test and 1 min after the test was also recorded, while time was measured using a regular stopwatch. The SJFT index was calculated using the following formula: (HR at the end of the test + heart rate 1 min after the test)/total number of throws from all three series. The SJFT index is inverse, so the lower the index, the better the test result. Research has shown that the reliability of the SJFT was reported as 0.97 [9]. The testing session started with a 30 min regular judo warm-up, followed by a demonstration of the SJFT. The warm-up included walking, jogging, callisthenics, and gymnastic-type movements (forward rolls, backward rolls, handstands, handstand-to-forward roll, backward roll-to-handstand, cartwheels, round-off, headspring). That was followed by judo break falls, uchi-komi, and nage-komi.

2.6. Statistical Analysis

Data were analyzed using SPSS 31.0 (IBM Corp., Armonk, NY, USA) for Windows. For the initial presentation of data, descriptive statistics (means ± SD) and 95% confidence intervals were used. The Shapiro–Wilk test was used to determine the normality of the distribution. The Spearman correlation coefficient was used for associations between variables. Paired-variable differences were assessed using a paired-samples T-test or a Wilcoxon signed-rank test. Effect sizes (ESs) were calculated utilizing Cohen’s d or r and interpreted as follows: >0.2 small, >0.5 moderate, >0.8 large, >1.3, very large [34]. A Standardized Absolute Asymmetry (AA = (|R − L|)/(1/2(R + L)) × 100%) score in percentage was calculated, which does not account for the directionality of the asymmetry in paired variables [35]. Additionally, the average total participant asymmetry score of 10 observed variables was calculated. These 10 measures represent key upper- and lower-limb segments involved in judo and can be reliably assessed using a combination of techniques. Each variable contributed equally to the average score, thereby avoiding speculative assumptions about the relative importance of individual segments, consistent with the exploratory nature of this study. The resulting average asymmetry score, calculated as the sum of all individual AA and divided by the number of variables, is used as a global indicator of accumulated structural asymmetry.

3. Results

Table 1 presents descriptive statistics for the study sample, and Table 2 presents the paired t-test results for matching body parts.
Results highlight: a statistically significant asymmetry in elbow girth between body sides, t(26) = −6.18, p < 0.001, d = −1.19 (large effect size); statistically significant asymmetry in forearm girth between body sides, W = 31, p < 0.001, r = −0.84 (large effect size); significant asymmetry in thigh girth between body sides, t(26) = −2.32, p = 0.028, d = −0.45 (moderate effect size); significant asymmetry in leg muscle mass between body sides, t(26) = −2.90, p = 0.008, d = −0.56 (moderate effect size). In all significant variables, the right body side was significantly larger.
Table 3 presents absolute asymmetry of paired variables and SJFT test results that were used in the correlation analysis. The Spearman correlation analysis revealed a moderate positive association between the asymmetries of different body parts, specifically AS3 and AS6, with a correlation coefficient of r = 0.403 and a p-value of 0.037. A significant negative correlation emerged between AS2 and AS9, r = −0.452, p = 0.019, as well as between AS10 and AS1, r = −0.477, p = 0.012. Furthermore, the average asymmetry score (AVERAGE_AS) showed significant positive correlations with AS1, r = 0.430, p = 0.025, AS2, r = 0.592, p = 0.001, and AS3, r = 0.475, p = 0.012. A significant positive correlation was observed between AS9 and the SJFT index (SJFT_INDEX_D), with a correlation coefficient of r = 0.405 and a p-value of 0.037.

4. Discussion

The study examined morphological asymmetries and their association with SJFT performance in male youth judokas using an integrated 3D anthropometric and bioelectrical impedance approach. Significant asymmetries were observed in both upper and lower body measures, favouring the right side, particularly in elbow, forearm, thigh girths, and leg muscle mass. Calf asymmetry was positively associated with the SJFT index, indicating poorer performance with greater asymmetry, whereas total body asymmetry showed no significant relationship with judo-specific performance. This suggests that the performance relevance of morphological asymmetry was localized rather than systemic. Additionally, several inter-segment associations were identified among individual asymmetries, while average body asymmetry correlated only with upper-body girth asymmetries (upper arm, elbow, and forearm). Whole-body asymmetry can be an important marker in youth athlete development, as cumulative unilateral loading may affect movement efficiency, neuromuscular coordination, and injury risk [8,36,37,38,39]. Previous research has primarily examined isolated limb asymmetries, providing a limited understanding of their whole-body interactions and performance relevance. The present findings, therefore, provide insight into early asymmetry development in youth judokas and have implications for training and long-term athlete development.
The pronounced asymmetries observed in upper-limb measures—particularly elbow and forearm girths—are consistent with prior work that reported meaningful upper-limb morphological asymmetries in youth judo athletes. For example, Fukuda et al. [10] found that upper-limb handgrip asymmetries vary across development and are influenced by training experience, with extended judo training linked to greater bilateral differences in handgrip strength. Moreover, forearm circumference has been shown to predict maximum hand grip strength in men [40], which altogether supports the findings of our study.
Šimenko et al. [12] have also demonstrated that forearm asymmetries vary by age category and are present in all age groups from U14 onward in male judokas. Together, these studies show that upper-limb morphological asymmetries are a robust and reproducible characteristic of youth judokas, especially the forearm girth asymmetry as a primary hallmark of judo-specific unilateral loading. This also demonstrates that judo is inherently lateralized due to asymmetric gripping, throwing mechanics, and tactical preferences [10,12,41,42,43].
These findings also align with evidence on neuromuscular and cerebral lateralisation in judokas [27], suggesting that both neural and mechanical factors contribute to early segment-specific asymmetries. Notably, the magnitude of upper-limb asymmetries in our sample was relatively small (approximately 2–3%), remaining well below commonly cited thresholds of concern—such as the 10% cutoff frequently used in strength and power assessments. Moreover, the fact that nearly all significant asymmetries favoured the right side aligns with the hand dominance distribution in this sample (24 of 27 athletes were right-hand dominant), which is in line with research in the judo population [44]. This might be driven by one-sided specialization in techniques and execution, unilateral gripping and pulling mechanics, and unilateral tactical choices, which are signs of too-early specialization. Comparable findings have been reported among elite judokas, in which the dominant arm and shoulder complex often exhibits greater muscular development due to repetitive technical execution [13]. The present study’s findings suggest that upper-limb asymmetry is sport-specific, largely unavoidable, and a contributor to whole-body asymmetry, yet it does not appear to be directly detrimental to performance at the youth stage. The literature reports that right-sided dominance was prevalent—particularly among younger athletes—in a large cohort of judokas, while the proportion of athletes executing throws bilaterally increased with competitive level and was highest among medalists, indicating that symmetrical training and movement versatility are key determinants of success at elite performance levels [45]. Therefore, it is recommended that youth judokas’ training be conducted bilaterally, emphasizing the non-dominant side and the development of fighting stance techniques to increase athletes’ technical-tactical repertoire, fight decision-making, and to impact symmetrical morphological development. Research from other combat sports highlights that training technical elements on the non-dominant limb can be crucial in assisting the dominant limb in increasing strength and precision of execution [46,47].
Lower-limb asymmetries were less pronounced but still evident, particularly in thigh girth and segmental leg muscle mass. Although the lower extremity plays a critical role in both tachi-waza and ne-waza actions, the magnitude of lower-limb asymmetry observed in this sample is smaller than that typically reported in senior judokas [10,12]. The moderate effect sizes found in the lower limbs suggest that asymmetry is emerging but has not yet reached levels reported in adult or elite athletes. This might also be explained by youth athletes relying more on hand-throwing than leg-throwing techniques at this developmental stage, in which greater upper-body grip fighting and constant body rotation are involved in throwing or grip breaking. The morphological data for our participants could also support this explanation, as they, on average, competed in the under-66 kg weight class, where athletes are smaller and rely more on hand-throwing techniques, which require a fast turning action and a decrease in the centre of mass, as reported in previous studies [41]. Moreover, when a correct fighting stance and proper technique are adopted during arm throws that involve upper-body rotation, the final push and drive should be generated by both lower-leg muscles. Calf girth asymmetry, interestingly, emerged as uniquely relevant to performance in our younger group, potentially reflecting early-stage neuromuscular specialization that precedes or predicts later functional asymmetry, underscoring its unique functional relevance in this age group. In our case, a positive association between calf girth asymmetry and the SJFT index (the index is inverse—lower SJFT index indicates better performance), indicating that greater asymmetry in this region corresponded with poorer performance. This aligns with previous studies, which reported that lower-limb asymmetry correlated with performance decrements in judo-specific performance [22]. When the rotation in technique performance is incomplete, most of the body weight is shifted to the right leg, and the final push and drive are performed by the right calf muscles, as indicated by our results. Moreover, from a biomechanical perspective, the triceps surae complex plays a decisive role in the final phase of throw completion, where powerful plantarflexion stabilizes the stance and contributes to vertical and rotational force transfer. Asymmetry in this region, therefore, likely reflects insufficient bilateral contribution during these phases. This interpretation is further supported by asymmetry index results, which showed that most segmental asymmetries were relatively small (<3%), whereas the Calf girth asymmetry (AS9) was substantially larger at 8.46% ± 1.91%. This value approaches the commonly referenced 10% threshold [48], often used in strength and power asymmetry research, suggesting potential clinical or developmental relevance and indicating that coaches should pay attention when calf asymmetry approaches or exceeds this threshold. The magnitude of calf girth asymmetry observed in the present study is comparable to values reported in older and elite judokas, where greater lower-limb asymmetries have been documented. Previous research has shown that lower-limb asymmetry of similar magnitude may be associated with reduced performance in judo-specific tests [22], whereas asymmetry values approaching 10% have been suggested as potentially relevant for performance and injury risk in athletic populations [42]. Moreover, evidence from youth and elite sport indicates that greater interlimb asymmetry is associated with decrements in physical performance and increased injury susceptibility [8]. In other youth sports, such as soccer [49], handball [50] and tennis [39], comparable lower-limb asymmetries have been associated with impaired performance, reduced efficiency during repeated explosive actions, and a higher injury risk. These studies suggest that asymmetries become particularly relevant during tasks requiring repeated unilateral stabilization, acceleration, and force transmission under fatigue, which closely resemble the biomechanical and physiological requirements of the SJFT. Importantly, evidence from youth team sports indicates that these asymmetries can appear before performance clearly declines, and may indicate poor movement patterns or early one-sided specialization. Therefore, bilateral techniques implementation should be encouraged as lateral preference among novice judo practitioners during randori can be modulated by the type of practice [51].
Moreover, the negative correlations observed among certain asymmetry variables might contribute to a better understanding of these developmental patterns. Elbow girth asymmetry (AS2) was negatively associated with calf girth asymmetry (AS9), r = −0.452, and upper-arm girth asymmetry (AS1) was negatively associated with leg muscle mass asymmetry (AS10), r = −0.477. These inverse relationships indicate that athletes showing greater symmetry in upper-limb segments tend to display greater asymmetry in specific lower-limb segments. This might strengthen our assumption that better upper-body symmetry—often linked to frequent use of arm-dominant throwing techniques—may coexist with diminished technical proficiency during the lower-body phases of these throws. In particular, as previous studies have highlighted that males utilize throws with greater rotation [52]. Therefore, proper technique with full body rotation should be the focus in practice for coaches to ensure techniques are not executed without complete rotation or with suboptimal coordination, as the lower limbs may be required to compensate, resulting in uneven loading patterns that contribute to the development of lower-limb morphological asymmetries. Moreover, consistent calf asymmetries in older age groups have been observed [12]. However, our results suggest that calf asymmetry may develop earlier than previously recognized and may negatively affect judo-specific performance. Calf asymmetry may reflect early specialization of the fighting stance and the associated throwing direction. This result aligns with prior research linking lower-limb asymmetry to decreased performance and heightened injury risk in youth athletes [4,7].
The present study needs to acknowledge certain limitations when interpreting its findings. The cross-sectional design prevents any inference about the developmental trajectory of morphological asymmetries or their causal relationship with performance; longitudinal monitoring would be required to determine how these asymmetries evolve with training age and increasing technical proficiency. The sample consisted exclusively of male youth judokas, which may limit generalizability to female athletes. Additionally, the sample size was relatively small, limiting statistical power for correlation analyses; therefore, some non-significant relationships may reflect limited power rather than the true absence of effects. Multiple correlations were tested without formal adjustment, which increases the risk of Type I error; therefore, these results are interpreted as exploratory and hypothesis-generating and should be confirmed in larger samples. Also, injury history was not observed, which could influence asymmetry. Another limitation is the absence of information on pubertal status, an essential factor that affects natural fluctuations in body proportions, limb girths, and overall symmetry during adolescence. Additionally, the influence of individual weight categories was not studied, which might provide deeper insight into the development of asymmetries. Muscular strength asymmetries, neuromuscular control, and kinematic analysis of throw execution were not assessed and may offer additional explanatory insight into performance outcomes. The limitations highlighted underscore the need for multidimensional, longitudinal studies that integrate morphological, functional, and biomechanical data to better understand the development of asymmetry in youth judo.

5. Conclusions

Overall, this study demonstrates that youth judokas exhibit identifiable morphological asymmetries, particularly in the upper limbs, and that lower-limb calf girth asymmetry is associated with reduced judo-specific performance. The overall average asymmetry score was low. These imbalances may result from arm-throwing techniques with incomplete trunk rotation or limited hip and leg engagement, placing disproportionate mechanical demands on the supporting limb—most often the right leg in right-handed athletes. Therefore, proper technique, with an emphasis on full-body rotation, may be helpful in practice to ensure bilateral loading and force development, in addition to bilateral technique and fighting stance practice. Upper-limb asymmetries were also the primary contributors to whole-body asymmetry, reflecting the unilateral gripping and rotational patterns typical in judo. Conversely, the negative correlations among selected upper- and lower-limb asymmetries highlight the complex interactions among segments during the development of throwing skills. These findings highlight the importance of early monitoring of segment-specific asymmetries in applied sports settings and of implementing targeted interventions within long-term athlete development programmes to optimize performance and prevent disproportionate loading patterns as judokas progress to higher age categories and competition levels.

Author Contributions

Conceptualization, J.Š. and P.P.; methodology, J.Š.; formal analysis, J.Š.; investigation, J.Š.; resources, J.Š. and P.P.; data curation, J.Š.; writing—original draft preparation, J.Š. and P.P.; writing—review and editing, J.Š. and P.P.; visualization, J.Š. and P.P.; supervision, J.Š.; project administration, J.Š.; funding acquisition, J.Š. and P.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki, and approved by the Faculty of Sport, University of Ljubljana, Ethical Board (No. 2033/2013; 17 September 2013).

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

The data supporting this study’s findings are available from the corresponding author upon reasonable request.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Maloney, S.J. The Relationship Between Asymmetry and Athletic Performance: A Critical Review. J. Strength Cond. Res. 2019, 33, 2579–2593. [Google Scholar] [CrossRef]
  2. Sanchis-Moysi, J.; Idoate, F.; Dorado, C.; Alayón, S.; Calbet, J.A.L. Large Asymmetric Hypertrophy of Rectus Abdominis Muscle in Professional Tennis Players. PLoS ONE 2010, 5, e15858. [Google Scholar] [CrossRef]
  3. Błach, W.; Rydzik, Ł.; Stanula, A.; Cynarski, W.J.; Ambroży, T. Injury Symmetry in Judo. Symmetry 2022, 15, 13. [Google Scholar] [CrossRef]
  4. Helme, M.; Tee, J.; Emmonds, S.; Low, C. Does Lower-Limb Asymmetry Increase Injury Risk in Sport? A Systematic Review. Phys. Ther. Sport 2021, 49, 204–213. [Google Scholar] [CrossRef]
  5. Maly, T.; Zahalka, F.; Mala, L.; Unilateral, L. Unilateral and Ipsilateral Strength Asymmetries in Elite Youth Soccer Players With Respect to Muscle Group and Limb Dominance. Int. J. Morphol. 2016, 34, 1339–1344. [Google Scholar] [CrossRef]
  6. Kannus, P.; Haapasalo, H.; Sankelo, M.; Sievanen, H.; Pasanen, M.; Heinonen, A.; Oja, P.; Vuori, I. Effect of Starting Age of Physical Activity on Bone Mass in the Dominant Arm of Tennis and Squash Players. Ann. Intern. Med. 1995, 123, 27–31. [Google Scholar] [CrossRef] [PubMed]
  7. Fort-Vanmeerhaeghe, A.; Milà-Villarroel, R.; Pujol-Marzo, M.; Arboix-Alió, J.; Bishop, C. Higher Vertical Jumping Asymmetries and Lower Physical Performance Are Indicators of Increased Injury Incidence in Youth Team-Sport Athletes. J. Strength Cond. Res. 2022, 36, 2204–2211. [Google Scholar] [CrossRef] [PubMed]
  8. Fort-Vanmeerhaeghe, A.; Bishop, C.; Buscà, B.; Aguilera-Castells, J.; Vicens-Bordas, J.; Gonzalo-Skok, O. Inter-Limb Asymmetries Are Associated with Decrements in Physical Performance in Youth Elite Team Sports Athletes. PLoS ONE 2020, 15, e0229440. [Google Scholar] [CrossRef]
  9. Šimenko, J.; Hadžić, V. Bilateral Throw Execution in Young Judokas for a Maximum All Year Round Result. Int. J. Sports Physiol. Perform. 2022, 17, 720–725. [Google Scholar] [CrossRef] [PubMed]
  10. Fukuda, D.H.; Beyer, K.S.; Boone, C.H.; Wang, R.; La Monica, M.B.; Wells, A.J.; Hoffman, J.R.; Stout, J.R. Developmental Associations with Muscle Morphology, Physical Performance, and Asymmetry in Youth Judo Athletes. Sport Sci. Health 2018, 14, 555–562. [Google Scholar] [CrossRef]
  11. Socha, M.; Witkowski, K.; Jonak, W.; Sobiech, K.A. Body Composition and Selected Anthropometric Traits of Elite Polish Female Judokas in Relation to the Performance of Right-Dominant, Left-Dominant, or Symmetrical Judo Techniques in Vertical Posture (Tachi Waza). Arch. Budo 2016, 12, 257–265. [Google Scholar]
  12. Šimenko, J.; Sertić, H.; Segedi, I.; Čuk, I. Rapid Assessment of Morphological Asymmetries Using 3D Body Scanner and Bioelectrical Impedance Technologies in Sports: A Case of Comparative Analysis Among Age Groups in Judo. Symmetry 2024, 16, 1387. [Google Scholar] [CrossRef]
  13. Mala, L.; Maly, T.; Cabell, L.; Cech, P.; Hank, M.; Coufalova, K.; Zahalka, F. Body Composition and Morphological Limbs Asymmetry in Competitors in Six Martial Arts. Int. J. Morphol. 2019, 37, 568–575. [Google Scholar] [CrossRef]
  14. Šimenko, J. Status of Body Symmetries of Youth Judokas in -73kg Category. Rev. Artes Marciales Asiáticas 2016, 11, 58. [Google Scholar] [CrossRef]
  15. Mala, L.; Maly, T.; Cabell, L.; Hank, M.; Bujnovsky, D.; Zahalka, F. Anthropometric, Body Composition, and Morphological Lower Limb Asymmetries in Elite Soccer Players: A Prospective Cohort Study. Int. J. Environ. Res. Public Health 2020, 17, 1140. [Google Scholar] [CrossRef]
  16. Yáñez-Sepúlveda, R.; Herrera-Amante, C.A.; Clemente-Suárez, V.J.; Vasquez-Bonilla, A.; Alacid, F.; Tuesta, M.; Báez-San Martín, E.; Giakoni-Ramírez, F.; Cristi-Montero, C. Anthropometry, Body Composition, Somatotype and Asymmetry of Canoe Sprint World Champion: A Case Study. Nutr. Health 2025, 31, 31–37. [Google Scholar] [CrossRef] [PubMed]
  17. Franchini, E.; Sterkowicz, S.; Szmatlan-Gabrys, U.; Gabrys, T.; Garnys, M. Energy System Contributions to the Special Judo Fitness Test. Int. J. Sports Physiol. Perform. 2011, 6, 334–343. [Google Scholar] [CrossRef]
  18. Ceylan, B.; Šimenko, J.; Balcı, Ş.S. Which Performance Tests Best Define the Special Judo Fitness Test Classification in Elite Judo Athletes? J. Funct. Morphol. Kinesiol. 2022, 7, 101. [Google Scholar] [CrossRef]
  19. Sogabe, A.; Sterkowicz-Przybycień, K.; Maehara, K.; Sasaki, T.; Sterkowicz, S. Effect of Preferred Body Stance Side on the Performance of Special Judo Fitness Test in Japanese Judo Athletes. Arch. Budo 2015, 11, 1–6. [Google Scholar]
  20. Kons, R.L.; Pupo, J.D.; Gheller, R.G.; Costa, F.E.; Rodrigues, M.M.; Bishop, C.; Detanico, D. Effects of Successive Judo Matches on Interlimb Asymmetry and Bilateral Deficit. Phys. Ther. Sport 2021, 47, 15–22. [Google Scholar] [CrossRef]
  21. Escobar-Molina, R.; Cuevas-Laguna, M.; Chirosa-Ríos, I.J.; Merino-Fernández, M.; Chirosa-Ríos, L.J.; Franchini, E. Analysis of Grip Specificity on Force Production in Grapplers and Its Effect on Bilateral Deficit Grip Specificity and Bilateral Deficit in Force Production among Grapplers. Front. Sports Act. Living 2023, 5, 1190369. [Google Scholar] [CrossRef] [PubMed]
  22. Kons, R.L.; Diefenthaeler, F.; Orssatto, L.B.R.; Sakugawa, R.L.; da Silva Junior, J.N.; Detanico, D. Relationship between Lower Limb Asymmetry and Judo-Specific Test Performance. Sport Sci. Health 2020, 16, 305–312. [Google Scholar] [CrossRef]
  23. Leung, B.; Forbes, M.R.; Houle, D. Fluctuating Asymmetry as a Bioindicator of Stress: Comparing Efficacy of Analyses Involving Multiple Traits. Am. Nat. 2000, 155, 101–115. [Google Scholar] [CrossRef]
  24. Rhodes, G.; Simmons, L.W.; Peters, M. Attractiveness and Sexual Behavior: Does Attractiveness Enhance Mating Success? Evol. Hum. Behav. 2005, 26, 186–201. [Google Scholar] [CrossRef]
  25. Pu, Y.; Francks, C.; Kong, X.-Z. Global Brain Asymmetry. Trends Cogn. Sci. 2025, 29, 114–117. [Google Scholar] [CrossRef] [PubMed]
  26. Cabral, S.; Resende, R.A.; Clansey, A.C.; Deluzio, K.J.; Selbie, W.S.; Veloso, A.P. A Global Gait Asymmetry Index. J. Appl. Biomech. 2016, 32, 171–177. [Google Scholar] [CrossRef]
  27. Mikheev, M.; Mohr, C.; Afanasiev, S.; Landis, T.; Thut, G. Motor Control and Cerebral Hemispheric Specialization in Highly Qualified Judo Wrestlers. Neuropsychologia 2002, 40, 1209–1219. [Google Scholar] [CrossRef]
  28. Rauter, S.; Simenko, J. Morphological Asymmetries Profile and the Difference between Low-and High-Performing Road Cyclists Using 3d Scanning. Biology 2021, 10, 1199. [Google Scholar] [CrossRef]
  29. Dopsaj, M.; Todorov, I.; Vuković, M.; Radovanović, D. Various Morphological Indicators in Elite Judo Athletes Defined By Multi-Frequency Bioelectrical Impedance Analysis. Serbian J. Sports Sci. 2013, 7, 129–141. [Google Scholar]
  30. Gibson, A.L.; Holmes, J.C.; Desautels, R.L.; Edmonds, L.B.; Nuudi, L. Ability of New Octapolar Bioimpedance Spectroscopy Analyzers to Predict 4-Component-Model Percentage Body Fat in Hispanic, Black, and White Adults. Am. J. Clin. Nutr. 2008, 87, 332–338. [Google Scholar] [CrossRef]
  31. McLester, C.N.; Nickerson, B.S.; Kliszczewicz, B.M.; McLester, J.R. Reliability and Agreement of Various InBody Body Composition Analyzers as Compared to Dual-Energy X-Ray Absorptiometry in Healthy Men and Women. J. Clin. Densitom. 2020, 23, 443–450. [Google Scholar] [CrossRef]
  32. Gleadall-Siddall, D.O.; Turpin, R.L.; Douglas, C.C.; Ingle, L.; Garrett, A.T. Test–Retest Repeatability of the NX-16: A Three-Dimensional (3D) Body Scanner in a Male Cohort. Sport Sci. Health 2020, 16, 337–346. [Google Scholar] [CrossRef]
  33. Simenko, J.; Cuk, I. Reliability and Validity of NX-16 3D Body Scanner. Int. J. Morphol. 2016, 34, 1506–1514. [Google Scholar] [CrossRef]
  34. Sullivan, G.M.; Feinn, R. Using Effect Size—Or Why the P Value Is Not Enough. J. Grad. Med. Educ. 2012, 4, 279–282. [Google Scholar] [CrossRef]
  35. Lijewski, M.; Burdukiewicz, A.; Pietraszewska, J.; Andrzejewska, J.; Stachoń, A. Asymmetry of Muscle Mass Distribution and Grip Strength in Professional Handball Players. Int. J. Environ. Res. Public Health 2021, 18, 1913. [Google Scholar] [CrossRef]
  36. Ascenzi, G.; Filetti, C.; Di Salvo, V.; Nuñez, F.J.; Suarez-Arrones, L.; Ruscello, B.; Francioni, F.M.; Villanueva, A.M. Inter-Limb Asymmetry in Youth Elite Soccer Players: Effect of Loading Conditions. PLoS ONE 2022, 17, e0269695. [Google Scholar] [CrossRef]
  37. Guan, Y.; Bredin, S.; Taunton, J.; Jiang, Q.; Wu, N.; Warburton, D. Association between Inter-Limb Asymmetries in Lower-Limb Functional Performance and Sport Injury: A Systematic Review of Prospective Cohort Studies. J. Clin. Med. 2022, 11, 360. [Google Scholar] [CrossRef]
  38. Madruga-Parera, M.; Romero-Rodríguez, D.; Bishop, C.; Beltran-Valls, M.R.; Latinjak, A.T.; Beato, M.; Fort-Vanmeerhaeghe, A. Effects of Maturation on Lower Limb Neuromuscular Asymmetries in Elite Youth Tennis Players. Sports 2019, 7, 106. [Google Scholar] [CrossRef]
  39. Madruga-Parera, M.; Bishop, C.; Fort-Vanmeerhaeghe, A.; Beltran-Valls, M.R.; Skok, O.G.; Romero-Rodríguez, D. Interlimb Asymmetries in Youth Tennis Players: Relationships With Performance. J. Strength Cond. Res. 2020, 34, 2815–2823. [Google Scholar] [CrossRef]
  40. Anakwe, R.E.; Huntley, J.S.; Mceachan, J.E. Grip Strength and Forearm Circumference in a Healthy Population. J. Hand Surg. (Eur. Vol.) 2007, 32, 203–209. [Google Scholar] [CrossRef]
  41. Šimenko, J.; Ipavec, M.; Vodičar, J.; Rauter, S. Body Symmetry/Asymmetry in Youth Judokas in the under 73 kg Category. Ido Mov. Culture J. Martial Arts Anthropol. 2017, 17, 51–55. [Google Scholar] [CrossRef]
  42. Šimenko, J.; Karpljuk, D.; Vodičar, J. Body Symmetries of Youth U-14 Judokas in under 50kg Categories. Homo. Sport. 2017, 19, 13–16. [Google Scholar]
  43. Kambič, T.; Sraka Vuković, R.; Vuković, L.; Šimenko, J. Impact of One Year Judo Training on Body Symmetries in Youth Judokas. Arch. Budo Sci. Martial Arts Extrem. Sports 2017, 13, 9–16. [Google Scholar]
  44. Dopico, X.; Iglesias-Soler, E.; Carballeira, E.; Mayo, X.; Ardá, A.; González-Freire, M. The Relationship between Motoric Dominance and Functional Dominance While Executing Judo Techniques: A Study on Laterality. Arch. Budo 2014, 10, 307–314. [Google Scholar]
  45. Starosta, W. Importance of Movement Symmetry in Technical and Tactical Preparation of High Advanced Judokas Different Level of Mastership. J. Combat. Sports Martial Arts 2017, 8, 25–29. [Google Scholar] [CrossRef]
  46. Bany, W.; Nyrć, M.; Lopuszanska-Dawid, M. Morphological and Functional Asymmetry Among Competitive Female Fencing Athletes. Appl. Sci. 2025, 15, 8020. [Google Scholar] [CrossRef]
  47. Akpinar, S.; Sainburg, R.L.; Kirazci, S.; Przybyla, A. Motor Asymmetry in Elite Fencers. J. Mot. Behav. 2015, 47, 302–311. [Google Scholar] [CrossRef]
  48. Bishop, C.; Read, P.; Lake, J.; Chavda, S.; Turner, A. Interlimb Asymmetries: Understanding How to Calculate Differences From Bilateral and Unilateral Tests. Strength Cond. J. 2018, 40, 1–6. [Google Scholar] [CrossRef]
  49. Bishop, C.; Read, P.; McCubbine, J.; Turner, A. Vertical and Horizontal Asymmetries Are Related to Slower Sprinting and Jump Performance in Elite Youth Female Soccer Players. J. Strength Cond. Res. 2021, 35, 56–63. [Google Scholar] [CrossRef]
  50. Madruga-Parera, M.; Bishop, C.; Beato, M.; Fort-Vanmeerhaeghe, A.; Gonzalo-Skok, O.; Romero-Rodríguez, D. Relationship Between Interlimb Asymmetries and Speed and Change of Direction Speed in Youth Handball Players. J. Strength Cond. Res. 2021, 35, 3482–3490. [Google Scholar] [CrossRef] [PubMed]
  51. Iglesias-Soler, E.; Mayo, X.; Dopico, X.; Fernández-Del-Olmo, M.; Carballeira, E.; Fariñas, J.; Fernández-Uribe, S. Effects of Bilateral and Non-Dominant Practices on the Lateral Preference in Judo Matches. J. Sports Sci. 2018, 36, 111–115. [Google Scholar] [CrossRef] [PubMed]
  52. Martins, F.P.; de Souza, L.S.D.P.; de Campos, R.P.; Bromley, S.J.; Takito, M.Y.; Franchini, E. Techniques Utilised at 2017 Judo World Championship and Their Classification: Comparisons between Sexes, Weight Categories, Winners and Non-Winners. Ido Mov. Cult. 2019, 19, 58–65. [Google Scholar] [CrossRef]
Table 1. Descriptive statistics of the sample with standard deviation and 95% confidence intervals.
Table 1. Descriptive statistics of the sample with standard deviation and 95% confidence intervals.
VariableMSD95% CI [Lower, Upper]
Age (years)14.401.55[13.78, 15.01]
Height (cm)170.1311.21[165.70, 174.57]
Body mass (kg)62.1312.31[57.26, 67.00]
Skeletal muscle mass (kg)30.836.99[28.06, 33.59]
Fat mass (kg)7.043.60[5.62, 8.47]
Fat mass (%)11.355.13[9.32, 13.38]
CI = confidence interval; M = mean valie; SD = standard deviation.
Table 2. Descriptive statistics of body-paired variables with paired t-test and Wilcoxon signed-rank test to detect significant differences between body sides.
Table 2. Descriptive statistics of body-paired variables with paired t-test and Wilcoxon signed-rank test to detect significant differences between body sides.
VariablesLeft SideRight Side95% CIdft/WpEffect Size (r)
MeanSDMeanSDLowerUpper
Upper-arm girth (cm)28.973.9129.013.79−0.360.2926−0.210.834−0.04
Elbow girth (cm)24.792.3325.552.25−1.02−0.5126−6.18<0.001 *−1.19
Forearm girth (cm) ˇ25.382.3425.942.37−0.70−0.032631<0.001 *−0.84
Wrist girth (cm)16.971.2517.061.12−0.370.1926−0.650.521−0.13
Arm muscle mass (kg)3.050.923.060.91−0.050.0226−0.710.484−0.14
Thigh girth (cm)54.036.3554.406.32−0.71−0.0426−2.320.028 *−0.45
Thigh length (cm)31.673.7131.693.88−0.150.1126−0.290.775−0.06
Knee girth (cm)36.812.4136.932.58−0.300.0626−1.350.187−0.26
Calf girth (cm)34.642.5434.842.78−0.420.0226−1.880.071−0.36
Leg muscle mass (kg)8.461.918.521.96−0.11−0.0226−2.900.008 *−0.56
ˇ = due to non-normal data distribution, the Wilcoxon signed-rank test statistic W is used, and r for effect size; * statistically significant data p < 0.05; CI = confidence interval.
Table 3. Descriptive statistics of Absolute Asymmetry percentage, total body Asymmetry and SJFT data.
Table 3. Descriptive statistics of Absolute Asymmetry percentage, total body Asymmetry and SJFT data.
VariableMSD95% CI [Lower, Upper]
AS1—Upper-arm girth %2.181.70[1.51, 2.85]
AS2—Elbow girth %3.362.37[2.42, 4.30]
AS3—Forearm girth %2.502.13[1.66, 3.34]
AS4—Wrist girth %3.222.65[2.17, 4.27]
AS5—Arm muscle mass %2.071.72[1.38, 2.75]
AS6—Thigh girth %1.301.06[0.88, 1.72]
AS7—Thigh length %0.740.78[0.44, 1.05]
AS8—Knee girth %0.950.79[0.64, 1.26]
AS9—Calf girth %8.461.91[7.70, 9.21]
AS10—Leg muscle mass %1.151.03[0.75, 1.56]
Average body Asymmetry %1.880.60[1.64, 2.11]
SJFT_15s_15.260.71[4.98, 5.54]
SJFT_30s_29.331.30[8.82, 9.85]
SJFT_30s_38.670.88[8.32, 9.01]
TT23.262.60[22.23, 24.29]
HR_final191.226.48[188.66, 193.78]
HR_1min160.7412.20[155.92, 165.57]
SJFT INDEX15.342.11[14.51, 16.18]
AS—asymmetry index; SJFT—special judo fitness test; TT—total throws; HR—heart rate.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Šimenko, J.; Pori, P. Morphological Asymmetries and Their Relationship to Judo-Specific Performance in Youth Judokas. Appl. Sci. 2026, 16, 894. https://doi.org/10.3390/app16020894

AMA Style

Šimenko J, Pori P. Morphological Asymmetries and Their Relationship to Judo-Specific Performance in Youth Judokas. Applied Sciences. 2026; 16(2):894. https://doi.org/10.3390/app16020894

Chicago/Turabian Style

Šimenko, Jožef, and Primož Pori. 2026. "Morphological Asymmetries and Their Relationship to Judo-Specific Performance in Youth Judokas" Applied Sciences 16, no. 2: 894. https://doi.org/10.3390/app16020894

APA Style

Šimenko, J., & Pori, P. (2026). Morphological Asymmetries and Their Relationship to Judo-Specific Performance in Youth Judokas. Applied Sciences, 16(2), 894. https://doi.org/10.3390/app16020894

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Article metric data becomes available approximately 24 hours after publication online.
Back to TopTop