Morphological and Functional Asymmetry Among Competitive Female Fencing Athletes

Abstract

Maintaining body symmetry in sports characterized by high lateralization is crucial for optimizing long-term athletic performance and mitigating injury risk. This study aimed to evaluate the extent of morphological asymmetry in anthropometric features among elite professional fencers. Additionally, the presence of functional asymmetry and its associations with morphological asymmetry were assessed. Thirty-two Polish adult female fencers, aged 18–33 yrs, were examined. Data collection involved a questionnaire survey, anthropometric measurements, calculation of anthropological indices, and assessment of functional asymmetry. For the 24 bilateral anthropometric features, small differences were found in seven characteristics: foot length, subscapular skinfold thickness, upper arm circumference, minimum and maximum forearm circumference, upper limb length, and arm circumference in tension. Morphological asymmetry index did not exceed 5%. Left-sided lateralization of either the upper or lower limbs was associated with significantly high asymmetry, specifically indicating larger minimum forearm circumferences in the right limb. Continuous, individualized monitoring of morphological asymmetry and its direction in athletes is essential, demanding concurrent consideration of functional lateralization. This ongoing assessment establishes a critical baseline for evaluating training adaptations, reducing injury susceptibility, and optimizing rehabilitation strategies. Deeper investigation of symmetry within non-dominant limbs is warranted to enhance our understanding.

1. Introduction

Asymmetry among athletes across various sports disciplines is a topic extensively addressed by numerous researchers in their scientific works [1,2,3,4,5,6,7,8,9]. Assessing an athlete’s body symmetry becomes especially critical due to its implications for injury risk and, more importantly, for projected athletic outcomes [1,2,3,4,5,6,7,8,9]. It is examined from different perspectives, including morphological [10,11,12], dynamic [13,14], and functional asymmetry [15,16] perspectives. Morphological asymmetries are a consequence of the body’s adaptation to the conditions around it, reinforced by prolonged and intense activity in a chosen sports specialty, such as intensive, year-round training in one sport to the exclusion of other sports [17]. Prolonged exposure to repeated asymmetrical loading in athletes, persisting over many years, can lead to health problems such as lower back pain or issues in other body regions [18]. Long-term training, especially in sports with unilateral demands, carries potential health risks including spinal and joint deformities. Although unilateral hypertrophy (i.e., increased muscle cross-sectional area) can be a positive functional adaptation, its disproportionate nature may exacerbate these musculoskeletal issues [2]. The asymmetry that occurs, without the introduction of intervention behaviors to minimize it, can lead to unsustainable changes in the volume and condition of muscle tissue and its shortening, which affects the range of motion of joints [3]. Even if the training is aimed at increasing body symmetrization, the specificity of the physical loads imposed by the discipline can be strong enough that athletes inevitably develop a degree of functional and morphological asymmetry when adaptive changes occur on the dominant side [19]. One sport that is affected by this problem is fencing.

Fencing can be defined as the art of wielding a white weapon, the purpose of which is to hit an opponent with a cut (as in the saber) or a thrust (as in the sword or flare), without being hit yourself [20]. The art of fencing originally consisted of injuring or killing an opponent in the shortest possible time, and it was not until the 20th century that it changed to sport fighting. In modern times, fencing is based on fighting and the preparation for it by two competitors armed with a fencing outfit, a fencing mask, weapons and additional equipment that is necessary to fight according to the rules. The intention of sport fighting is to inflict as many hits as possible in a certain time (3 min) in between trying not to get hit at all or as little as possible [21].

Fencing, by its very nature, differs from many sports in that it is a distinctly asymmetrical sport. An athlete practicing this sport has an extremely lateralized posture. Competition often involves transferring body weight to one lower limb or operating only one upper limb both to score and to avoid being hit [22,23]. A heavily lateralized posture causes a variety of sports-specific conditions [24]. Symmetrization, therefore, should be one of the preventive behaviors that directly translate into injury prevention [25]. This issue is often neglected by coaches, trainers and experienced athletes [2]. With modern training and changes to the ways in which coaches conduct training, this tendency is changing.

The aim of the study was to assess the magnitude and directions of morphological asymmetries of bilateral anthropometric traits among female elite professional fencers. Furthermore, functional asymmetry of the upper and lower extremities was assessed, and the relationships between the magnitude of morphological asymmetry and functional asymmetry of the upper and lower extremities were analyzed. Our null hypothesis posited the existence of a low magnitude of morphological asymmetry in bilateral traits and a lack of association with functional asymmetry, which could be attributed to the high level of training advancement of the examined female athletes.

2. Materials and Methods

2.1. Material

2.1.1. Study Group

The material of the study consisted of data on thirty-two adult, non-disabled women training professionally in fencing in clubs from two large cities in Poland (Warsaw: Academic Sports Association of the Józef Piłsudski University of Physical Education in Warsaw (AZS AWF Warsaw), Professional Section: Fencing, Students’ Sports Club “Syrena” Palace (UKS Pałac Młodzieży “Syrena”), Warsaw Fencing Club ‘Warszawianka’ (KSz Warszawianka), Students’ Sports Club “Szabla Ząbki” (UKS Szabla Ząbki), and Szczecin: Inter-school Sports Club “Kusy” Szczecin (MKS Kusy Szczecin)). The athletes examined were representatives of the Polish national team and had won medals at Polish Championships and international events. On physical examination, they presented no pathologies. The power analysis (G*Power Version 3.1.9.7) indicated that a sample size of 20 participants was required to detect a small effect size (Cohen’s d = 0.2) with 80% power and a significance level of α = 0.05, assuming highly correlated bilateral characteristics (e.g., r = 0.9), thus, the minimum group size was significantly exceeded. The group was ethnically homogeneous (Poles, Caucasian) with no national, linguistic, religious, or racial minorities. All the subjects practiced fencing competitively and were representatives of three types of weapons: spade, flare, and saber. The calendar age of the participants of the study was between 18 and 33 years (mean 23.36, SD = 4.80). The study was conducted in June–September 2022 by an experienced researcher using professional anthropometric instrumentation.

Inclusion criteria for the study were as follows: adulthood, at least two years of fencing training, absence of physical disability confirmed by physical examination, no declared fencing injury in the last six months, and informed consent to participate in the entire research project. The exclusion criteria were failure to meet any of the above-mentioned requirements, including, in particular, a fencing injury recorded within the last six months. Approximately 90% of invited athletes agreed to participate, which is a significantly higher percentage than in Polish population studies, where approximately 25% of invited individuals typically consent [26,27]. Complete questionnaire and anthropometric data were obtained for all participants. The basic extended characteristics of the female athletes studied are given in

Table 1. Basic characteristics and physical activity of the subjects (age, education, place of residence, marital status, having siblings, character of work performed) (n, %).

Basic Characteristics		n	%
Socio-economic characteristics
Age (mean 23.36, SD = 4.80), Sports Age Groups *	Junior (18.0–20.0 yrs)	10	31.25
	Youth U23 (20.1–23.0 yrs)	6	18.75
	Senior (23.1 yrs and above)	16	50.00
Level of education	vocational	3	9.38
	secondary	10	31.24
	incomplete higher	3	9.38
	higher	16	50.00
Level of urbanization of place of residence	urban	25	78.12
	rural	7	21.88
Marital status	single	27	84.37
	married	5	15.63
Having siblings	yes	28	87.50
	no	4	12.50
The characteristics of work performed	mental	12	37.50
	physical	10	31.24
	mental-physical (mixed)	7	21.88
	not applicable	3	9.38
Characteristics of weapon training and physical activity
The type of weapon	spade	5	15.63
	flare	2	6.25
	saber	25	78.12
Training experience	about 2–3 years	29	90.62
	more than 3 years	3	9.38
Engaging in additional physical activity	yes	25	78.12
	no	7	21.87
Total		32	100.00

Legend: n—number of participants; %—percentages; yrs—years; SD—standard deviations; *—sports age groups [28].

.

2.1.2. Ethical Consents

The study of female athletes was part of the research project Scientific School No. 5, titled: “Biomedical determinants of physical fitness and sports training in adult population” (Task 1: Determinants of biological condition and physical fitness of adult men and women in Poland; head: Monika Lopuszanska-Dawid) conducted at the Józef Piłsudski University of Physical Education in Warsaw (Poland) from 2020 to 2022.

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. All the examined women were informed orally and in writing about the aims of the projects and all testing procedures, and all gave their informed consent prior to their inclusion in the study. At any time, the subjects could withdraw without giving any reason. The research was approved by the Senate Research Ethics Committee at Józef Piłsudski University of Physical Education in Warsaw (Poland) (approval no. SKE 01-23/2020 of 20 November 2020).

2.2. Methods

2.2.1. Author’s Survey Questionnaire

In the first stage of the implementation of the research using the face-to-face diagnostic survey method, the author’s survey questionnaire was used to obtain basic socio-economic data and data on the combat sport practiced: fencing and functional asymmetry. The questionnaire was divided into three sections.

Section I dealt with questions about personal data, allowing for the basic social and economic characteristics of the female athletes to be surveyed, such as date of birth (day, month, year), level of education (possible answers to choose from: vocational/secondary/incomplete higher/higher), level of urbanization of place of residence (possible answers to choose from: urban/rural). The questions also included: marital status (possible answers: single/married), having siblings (yes, I have siblings/no, I am an only child), the characteristics of the paid work performed (mental/physical/mental/physical (mixed)/not applicable), and the name of the sports club in which the athlete under study trains.

Section II consisted of general questions characterizing the weapons trained and physical activity. The respondents were asked about the type of weapon they train with (spade/flare/saber), training experience (about 2–3 years/more than 3 years), whether they practice other forms of physical activity (yes/no), and if so, which ones.

The provided baseline characteristics aim to facilitate potential reliable matching (at least partial matching) of the comparison groups, particularly regarding variables that are not direct determinants but may, to some extent, act as confounders.

2.2.2. Unilateral and Bilateral Anthropometric Measurements

The research was conducted in a rigorous methodological manner, namely all anthropometric measurements on the female fencers were performed with rigorous technical specifications by a trained and experienced in anthropometry single researcher, using professional anthropometric instrumentation (brand product: GPM instruments GmbH, Swiss product). In order to assess intra-rater reliability, the anthropometrician took three measurements each of all body measurements on 10 subjects in two series (series I and II 10 min apart). The calculated technical error of measurement percentage indicated a maximum measurement error of 1‰.

All measurements were conducted following standardized Rudolf Martin technique procedures, which are widely applied in population-based research [29,30,31,32,33,34]. During the anthropometric measurement process, participants were measured while standing, barefoot, and wearing light clothing. All measurements were performed in the morning hours, in a well-ventilated room, and participants were assured of the confidentiality of their personal measurement data. The standard anatomical position was used as the initial body posture, meaning the head was aligned in the Frankfurt plane, gaze directed forward, back straight, scapulae retracted, upper limbs relaxed and hanging downwards, lower limbs extended, and feet positioned hip-width apart [29,30,31,32,33,34]. Measurements of all anthropometric characteristics were taken at precisely defined and described anatomical points and areas. Before initiating the measurements, the equipment was calibrated and zeroed, and all data were collected with the utmost precision attainable using the specific instruments.

Four direct unilateral measurements were taken: 1. body height, 2. body weight, 3. waist circumference, and 4. hip circumference. Body height was measured with a Martin-type four-segment anthropometer (GPM instruments GmbH) to an accuracy of 0.1 cm, with participants standing barefoot in an upright position, measured from the Basis to the vertex anthropometric point (with the required head positioning in the Frankfurt plane). Body mass was assessed using a digital scale with a precision of 0.01 kg. Waist circumference was measured using an analog measuring tape (GPM instruments GmbH, Susten, Switzerland) positioned at the midpoint between the lowest rib and the upper edge of the iliac crest. Similarly, hip circumference was determined using a tape measure, aligned over the greatest protrusion of the gluteal muscles.

Direct measurements of bilateral anthropometric features (22 measurements on the left side and 22 measurements on the right side of the body) were taken to obtain information on the morphological asymmetries present on the right side of the body relative to the left: A. measurements of body circumferences: 1. arm circumference at rest through the biceps [cm], 2. arm circumference through the biceps in tension [cm], 3. arm circumference [cm], 4. maximum forearm circumference [cm], 5. minimum forearm circumference [cm], 6. thigh circumference [cm], 7. maximum calf circumference [cm], 8. minimum calf circumference [cm]; B. width measurements: 9. elbow width [cm], 10. hand width [cm], 11. knee width [cm]; C. length measurements: 12. length of shin [cm], 13. length of foot [cm]; D. thickness of skin-fat folds: 14. over the triceps [cm], 15. over the biceps [cm], 16. under the lower angle of the scapula [cm], 17. on the abdomen [cm], 18. on the chest [cm], 19. over the hip plate [cm], 20. over the upper anterior iliac spine [cm], 21. over the knee [cm], 22. on the shin [cm]. All body circumferences were measured using an analog measuring tape with a precision of 0.1 cm. Width measurements were measured with a large bail caliper (GPM instruments GmbH) with a precision of 0.1 cm. Skinfold thickness measurements were made using a Harpenden Skinfold Caliper (Baty International, Burgess Hill, UK) with an accuracy of 0.2 mm (standardized pressure force of 10 g/mm²). The Harpenden Skinfold Caliper is CE-certified and complies with the requirements of the MDD 93/42EEC directive on medical devices.

Based on direct anthropometric measurements, the values of four indirect measurements of bilateral features (two each for the right and left sides of the body) were calculated: 1. upper limb length (acromion point height minus dactylion III point height), 2. thigh length (symphysion point height minus tibiale point height).

A total of 52 bilateral body measurements were taken. Each measurement was performed three times, and the arithmetic mean was calculated. This resulted in 156 measurements per participant (156 measurements × 32 participants = 4992 anthropometric measurements in total).

2.2.3. Anthropometric Indices

From the raw anthropometric data, the values of basic anthropological indices were calculated: body mass index (BMI), waist–hip ratio (WHR), and morphological asymmetry index (MAI).

The body mass index was calculated from the formula, body weight [kg]/(body height [m])², and then classified into underweight, normal weight-to-height ratio, overweight or obese of the first, second or third degree [35,36,37,38]. Waist–hip ratio (WHR) was calculated from the formula, waist circumference [cm]/hip circumference [cm], and the type of fat distribution was defined as gynoid (value ≤ 0.8) or android (>0.8) [39,40].

Various inter-limb asymmetry indices are reported in the scientific literature, which may provide information about right-to-left differences in strength, power, or functional performance, and can be applied depending on the research hypotheses formulated. Some asymmetry indices evaluate the magnitude of individual asymmetry types, e.g., morphological, while others combine data concerning various aspects of asymmetry in a given subject: morphological, functional, and even dynamic asymmetry [8,9]. However, a consistent methodological approach to the issue of asymmetry is still lacking, hence experts recommend caution when comparing results from different studies [8,9]. Our research hypothesis prompts the evaluation of morphological asymmetry based on the most basic mathematical formula for assessing the magnitude of right-to-left differences. The morphological asymmetry index (MAI) was calculated for each bilateral anthropometric feature as the percentage difference between the right and left side measurements, specifically: MAI = ((R − L)/L) × 100%, where R represents the right-side measurement and L represents the left-side measurement. This calculation expresses the percentage difference relative to the left side’s value, with positive MAI values indicating a larger right side and negative values indicating a larger left side. This method allows for the identification of both the magnitude and direction of asymmetry, following methodologies commonly adopted in similar anthropometric research [10,12]. The MAI, a straightforward mathematical formula readily applicable to raw datasets, seems perfectly suited to the requirements of our analysis, despite possessing certain limitations (e.g., it does not inherently capture other dimensions of asymmetry). Therefore, a second, supplementary measure of functional asymmetry, independent of morphological asymmetry, was utilized.

2.2.4. Functional Asymmetry

Functional asymmetry was assessed based on selected questions from The Edinburgh Inventory [41], which were adapted to the specifics of this study [42]. The subjects answered the questions: 1. which upper limb they fight with, i.e., which upper limb, in their opinion, is their dominant limb in fighting (right/left/ambidextrous), 2. which hand they write with (right/left/ambidextrous), 3. which upper limb they unscrew the bottle with (right/left/ambidextrous), 4. which lower limb is the dominant one (right/left/ambidextrous), 5. which one they perform the lunge with, i.e., which lower limb in their opinion is their dominant one during the fencing fight (right/left/ambidextrous), and 6. which lower limb they start climbing the stairs with (right/left/ambidextrous). Indicating a specific limb in the answers to the above questions was equivalent to subjectively determining the dominant limb in performing a specific activity.

2.2.5. Statistical Methods

Means, standard deviations (SD), minimum, maximum, and percentage frequencies were calculated. Due to the relatively small sample size of the study, a strong and sensitive Shapiro–Wilk test was used to assess the normality of the distributions of the anthropometric characteristics studied. The level of significance was set at α = 0.05. The results indicated that there were no grounds for rejecting the null hypothesis of normality of distribution. A parametric paired Student’s t-test (Student’s t-test for dependent samples) was used to assess the differences between the means of the anthropometric measurements of the right and left sides of the body. One-way analyses of variance (Fisher test) were used to assess the significance of the associations of the significant magnitude of morphological asymmetry of bilateral traits with functional asymmetry. The STATISTICA 13.3 packages were used for analyses [43].

3. Results

Table 2. Basic somatic parameters, body mass index, and waist–hip ratio classification.

Direct Anthropometric Measurements
Features	Minimum	Maximum	M	SD
body height [cm]	156.1	196.0	172.0	7.3
body weight [kg]	49.5	80.3	62.9	7.0
waist circumference [cm]	64.0	91.2	72.4	5.5
hip circumference [cm]	85.1	116.5	97.9	6.2
Anthropometric Indices and Categories
Indices	Categories		n	%
BMI	underweight		1	3.12
	normal weight		30	93.76
	overweight		1	3.12
	obesity		0	0.00
WHR	<0.80		31	96.88
	≥0.80		1	3.12

Legend: M—mean; SD—standard deviations; n—number of participants; %—percentages; BMI—body mass index; WHR—waist–hip ratio.

shows the results of somatic measurements and classification of anthropological indices body mass index and waist–hip ratio among the women studied. The mean body height of the female athletes was 172.0 cm (SD = 7.3 cm), body weight was 62.9 kg (SD = 7.0 kg), waist circumference was 72.4 cm (SD = 5.5 cm), and hip circumference was 97.9 cm (SD = 6.2 cm). For the most part, the athletes’ BMI was within the normal range (93.76%) and WHR not exceeding the cutoff value of 0.8 (96.88%).

Table 3. Morphological asymmetry in circumferences, widths, lengths, skinfold thicknesses and measurements of intermediate anthropometric traits of the studied women and the morphological asymmetry index (MAI) in % (and its SD) and significance of differences right vs. left side of the body (p).

Features	Right		Left		MAI #		p
	M	SD	M	SD	M	SD
A. Circumferences [cm]
1. arm circumference at rest through the biceps	28.07	2.48	27.88	2.55	0.77	3.35	0.267
2. arm circumference through the biceps in tension	28.58	2.28	28.19	2.29	1.49	3.57	0.034 *
3. arm circumference	26.92	1.98	26.52	2.14	1.61	2.94	0.006 **
4. maximum forearm circumference	23.23	1.77	22.74	1.73	2.25	4.66	0.012 *
5. minimum forearm circumference	16.09	1.21	15.87	1.10	1.39	2.86	0.010 **
6. thigh circumference	60.30	4.33	59.74	4.38	0.99	2.89	0.077
7. maximum calf circumference	36.48	1.86	36.41	1.93	0.26	2.70	0.651
8. minimum calf circumference	22.81	1.17	23.01	1.37	−0.74	3.79	0.247
B. Width measurements [cm]
9. elbow width	6.16	0.35	6.14	0.32	0.34	3.38	0.615
10. hand width	7.68	0.47	7.66	0.45	0.28	3.27	0.677
11. knee width	8.10	0.93	8.04	0.96	0.87	3.64	0.219
C. Length measurements [cm]
12. length of shin	40.68	4.67	40.81	4.72	−0.22	4.20	0.651
13. length of foot	25.14	1.38	24.98	1.38	0.65	1.08	0.002 **
D. Thickness of skin-fat folds [cm]
14. over the triceps	1.60	0.54	1.57	0.51	3.30	22.10	0.566
15. over the biceps	1.28	0.65	1.26	0.65	3.88	14.96	0.497
16. under the lower angle of the scapula	1.55	0.44	1.55	0.43	1.11	22.07	0.949
17. on the abdomen	1.68	0.43	1.73	0.43	−2.44	8.74	0.088
18. on the chest	1.69	0.40	1.64	0.42	4.81	20.89	0.261
19. over the hip plate	1.83	0.30	1.87	0.28	−2.79	5.77	0.005 **
20. over the upper anterior iliac spine	1.40	0.43	1.43	0.42	−1.71	8.40	0.302
21. over the knee	1.53	0.49	1.48	0.48	4.94	25.07	0.503
22. on the shin	1.63	0.41	1.65	0.41	−0.90	8.93	0.470
Indirect measurements [cm]
23. upper limb length	78.85	3.63	77.75	3.73	1.47	3.18	0.019 *
24. thigh length	41.07	2.40	40.70	2.70	1.03	3.42	0.120

Legend: M—mean; SD—standard deviations; p—significance of differences; * p ≤ 0.05, ** p ≤ 0.01; MAI ^#—morphological asymmetry index—The magnitude of the difference between the right and left sides was calculated as a percentage of the left side using the formula: ((right side value − left side value)/left side value) × 100. A positive result indicates that the right side is larger than the left side by the given percentage, signifying right-sided dominance. Conversely, a negative result means the right side is smaller than the left side by that percentage, indicating left-sided dominance. A result of zero signifies that both sides are identical, reflecting symmetry or a lack of dominance.

shows the mean values (and SD) of bilateral somatic traits (separately for different types of anthropometric measurements: circumference, width, length, thickness of skin-fat folds, intermediate measurements) separately for the right and left sides of the body, the morphological asymmetry index (WAI) in % (along with its SD) and the significance of the recorded differences right vs. left side of the body (p). Most of the comparisons of the values of anthropometric measurements of the right versus left side of the body showed no statistically significant differences (applicable to 17 of 24 somatic traits). Statistically significant differences for the right versus left side of the body were recorded for seven traits (ranked from most significant to least significant): foot length (p = 0.002), skinfold thickness above the hip plate (p = 0.005), arm circumference (p = 0.006), forearm circumference smallest (p = 0.010), forearm circumference largest (p = 0.012), upper limb length (p = 0.019) and arm circumference in tension through the biceps (p = 0.034) (Table 3). MAI values can be considered low, its value in all studied traits did not exceed 5%, which means that the values of the trait on the right side of the body did not differ more than 5% from the values of the identical trait on the left side of the body. The highest MAI values were recorded for the thickness of skin-fat folds above the knee (MAI = 4.94) and on the chest (MAI = 4.81). In general, the highest values and variation in MAI were recorded for skin-fat fold thickness (MAI oscillating from −0.90 to 4.94), followed by body circumference (MAI ranging from −0.74 to 2.25), and the lowest for width measurements (MAI ranging from 0.28 to 0.87) and direct (−0.22 to –0.65) and indirect (MAI ranging from 1.03 to 1.47) length measurements. A similar relationship can be seen for the standard deviation of MAI. The highest SD MAI values were recorded for skinfold thickness, followed by circumference, and then length and width measurements.

Table 4. Functional asymmetry in the upper limbs (during combat—self-assessment, holding a pen and writing, unscrewing a bottle) and lower limbs (during combat—self-assessment, performing a lunge, climbing stairs) among the women studied (n, %).

Limb	Features		n	%
upper	during combat—self-assessment	right	28	87.50
		left	4	12.50
		ambidextrous	0	0.00
	holding a pen and writing	right	28	87.50
		left	4	12.50
		ambidextrous	0	0.00
	unscrewing a bottle	right	24	75.00
		left	6	18.75
		ambidextrous	2	6.25
lower	during combat—self-assessment	right	28	87.50
		left	4	12.50
		ambidextrous	0	0.00
	performing a lunge	right	28	87.50
		left	4	12.50
		ambidextrous	0	0.00
	climbing stairs	right	24	75.00
		left	4	12.50
		ambidextrous	4	12.50
	Total		32	100.00

Legend: n—number of participants; %—percentages.

presents the results on declared responses regarding the functionally dominant upper and lower limb. More frequent use of the right upper or lower limb than the left was reported (typically 87.50% right-dominant versus 12.50% left-dominant). Only for the test of unscrewing a bottle with the upper limb and starting to climb stairs with the lower limb did 12.50% of the athletes indicate that they were indifferent.

Figure 1 presents a representative visualization of the raw anthropometric measurement distributions (minimum forearm circumference) for the right and left upper limbs in two groups of studied women, distinguished by functional lateralization of the right upper limb. As the 3D plot illustrates, the raw data distributions in this regard show slight differences.

Table 5. The strengths of the associations of the magnitude of the morphological asymmetry index (MAI) of the arm circumference through the biceps in tension, arm circumference, circumference of the largest and smallest forearm, foot length, thickness of the skin-fat fold over the hip plate and length of the upper limb with the functional lateralization of the upper and lower limbs (right versus left) (results of one-way analyses of variance ANOVA (F—Fisher test, p—level of significance)).

Features	Upper Limb		Lower Limb
	F	p	F	p
MAI arm circumference in tension	0.025	0.876	0.195	0.662
MAI arm circumference	0.215	0.646	0.001	0.974
MAI maximum forearm circumference	0.268	0.608	0.890	0.353
MAI minimum forearm circumference	20.359	0.001 ***	20.637	0.001 ***
MAI length of foot	1.212	0.280	0.492	0.488
MAI skin-fat fold over the hip plate	0.610	0.441	0.010	0.920
MAI upper limb length	1.559	0.221	2.488	0.125

Legend: F—Fisher test, p—level of significance, *** p ≤ 0.001.

presents the strengths of statistically significant associations between the magnitude of morphological asymmetries (MAI) and the declared functional lateralization of the upper and lower extremities. These asymmetries were quantified from seven bilateral anthropometric traits, with their detailed results shown in Table 3. Functional lateralization (in the upper and lower limbs separately) was used as the determining variable (independent variable), while the MAI level for the seven traits was used as the determined variable (i.e., the explained or independent variable). In terms of the MAI of the six anthropometric traits, no significant association was found with functional lateralization of the upper or lower extremities. The only statistically significant association was noted for the smallest forearm circumference with lateralization in the upper and lower extremities (p = 0.001). In female athletes with functional dominance of the left limbs (upper or lower), the smallest circumference of the right wrist was significantly greater than the smallest circumference of the left wrist. This relationship is shown in Figure 2.

Graphical depictions of the other directions of the dependency trends (without statistical significance) in Figure 3 are shown in the example of the relationship of morphological asymmetry of upper limb length (%) with the functional lateralization of these limbs. Female athletes declaring functional dominance of the right upper limb had a morphologically dominant right upper limb (morphological asymmetry index 1.62). Female athletes declaring functional dominance of the left upper limb had a morphologically dominant left upper limb (morphological asymmetry index −0.51) (Figure 3).

4. Discussion

4.1. Fencing and Asymmetry: Insights from Elite Polish Athletes

Fencing, as a combat sport, involves significant physical training loads. Due to its specific nature, often characterized by intensified work on one side of the body, differences in morphological structure, range of motion, strength, and functional dominance of one side over the other are common training challenges. Research conducted among elite Polish female fencers revealed a slight morphological asymmetry in a maximum of 30% of the examined morphological traits. Out of 24 bilateral anthropometric features analyzed, small but significant differences were found in seven features between the right and left sides of the body. Five of these seven significant asymmetries pertained to the upper limb, specifically the circumferences of the arm, flexed arm (biceps), minimum and maximum forearm, and upper limb length. The other two asymmetries involved foot length and skinfold thickness on the torso (above the iliac crest).

The observed asymmetries in Polish fencers are not substantial, reaching a maximum of approximately 5% of a given trait’s value. These findings are corroborated by other researchers who suggest that prolonged and intensive fencing training can lead to a reduction in asymmetry (i.e., greater symmetry) compared to non-athletes [44]. It is possible that the female athletes studied were subjected to specific training interventions, developed and published in scientific periodicals, aimed at reducing asymmetry in their upper and/or lower limbs [8]. Additionally, it has been shown that dynamic balance is not significantly different between the lead and trail legs in elite fencers, despite the asymmetrical nature of their sport [45]. On the other hand, some researchers indicate that the varied level of morphological asymmetry among fencers may depend on functional asymmetry and training experience [46]. However, it should be emphasized that individual differences in symmetry levels can be significantly greater, as indicated by the high standard deviation values of the morphological asymmetry index (MAI). This is particularly true for more eco-sensitive anthropometric features, namely skinfold thicknesses and circumferences.

Higher MAI values for these characteristics may, or may not, indicate an asymmetrical distribution of adipose tissue and asymmetry in the quantity and thickness of tendons or active (muscle) tissue between the right and left sides of the body. These asymmetries thus concern features that can be modified through appropriately selected training loads. Some researchers’ findings indicate an increased risk of injuries in individuals with morphological asymmetry [47,48]. Therefore, introducing training elements aimed at limb symmetrization seems to be a reasonable recommendation as a way to reduce the risk of injuries. As research indicates, symmetrizing exercises have a beneficial impact on the human body, especially for individuals exposed to unilateral overload [49,50,51]. On the other hand, some researchers indicate that minor morphological asymmetries appear to have no impact on reduced efficiency or multidirectional speed. Therefore, studies on the relationships between asymmetry and sports performance should be sport-specific and require further investigation [8,9].

The above studies, for most of the analyzed factors, did not reveal significant differentiation between the compared bilateral anthropometric features. However, the recorded asymmetries predominantly concern the upper limb, specifically the weapon-holding arm. An important aspect contributing to these results appears to be the changing trend in fencing training styles. Many researchers have obtained similar results and also believe that a small difference between body sides may be due to the introduction of symmetrizing exercises [2,52,53,54]. On the other hand, some researchers strongly emphasize that even when asymmetries appear large by conventional standards, intervention is warranted only when careful analysis demonstrates an apparent performance deficit or injury risk and when correction can occur without compromising overall athletic capability [55].

4.2. Functional Dominance in Elite Female Fencers

The vast majority of the examined female fencers displayed functional dominance on the right side of the body, for both the upper and lower limbs. This aligns with population studies indicating that up to 90% of the population exhibits right-hand dominance [56], as well as other research confirming a numerical superiority of right-footed individuals [57,58]. In this context, the studied group appears to be consistent with general population trends.

The proportion of left-handed individuals among elite fencers presents a slightly different picture, with this fraction often being higher than in the general population [46]. These results are attributed to the greater combat effectiveness of left-handed fencers when competing against the more prevalent right-handed opponents. In this particular study, however, no numerical advantage of left-handed over right-handed fencers was observed.

Among the examined elite female fencers, no statistically significant correlations were found between morphological asymmetry and functional asymmetry in the vast majority of analyzed relationships. However, discernible trends of dependence were observed: fencers who reported functional dominance of the right upper or lower limb generally had a morphologically dominant right upper or lower limb (positive MAI values), while those reporting functional dominance of the left limb had a morphologically dominant left limb (negative MAI values). These trends observed in the current study are supported by research on symmetry levels in athletes from various disciplines considered inherently lateralized, concerning, for example, morphological symmetry, body composition symmetry, handgrip strength, or blood vessel diameter [59,60,61].

An exception to this general lack of correlation was a highly significant relationship between the smallest forearm circumference and functional asymmetry of both the lower and upper limb. Interestingly, the direction of this relationship was counter-intuitive: functional dominance of the left side of the body was associated with significantly larger values of this feature on the right side of the body. As mentioned previously, most research findings tend to indicate the opposite direction of relationships [59,60,61], although sometimes the results are not as clear-cut [45].

In fencing, the role of the non-dominant hand can be highly specific, which may lead to unique adaptations. Particularly in foil and saber (and to some extent in épée), the non-dominant hand can play a crucial role in maintaining balance, providing support, and contributing to movement dynamics. It actively participates in maintaining correct posture and guard. During dynamic lunges, retreats, parries, and quick changes in direction, the non-dominant upper limb is often extended backward or to the side to help maintain body balance. This demands continuous, isometric work from the forearm and wrist muscles to keep the limb in a stable position and prevent loss of balance. Such constant muscular work can lead to hypertrophy and strengthening of the tendons, which in turn may increase wrist circumference. The non-dominant upper limb, along with the shoulder, acts as a counterweight, and the wrist and forearm muscles of this limb may be engaged in controlling and stabilizing these movements, also contributing to their development. Strong muscular adaptations can therefore result from the necessity to maintain proper posture, stability, and reaction speed.

As the results of some researchers seem to confirm, certain technical elements of the non-dominant limb can be crucial in assisting the dominant limb to increase strength or precision [44]. Thus, adaptations of the non-dominant side uniquely support the action of the dominant side. As stated in [44], “The non-dominant arm often performs the stabilization component that must impede the forces that are imposed on by the dominant arm on the sliced object.” Studies concerning general asymmetry in fencing, and particularly the specific role of the non-dominant arm in stabilization and balance, appear to validate the observed phenomenon [62,63].

4.3. Strengths and Future Directions of the Study

This study’s significant strength stems from its focus on a highly homogeneous group of elite female fencers competing at the highest national level. This unique participant pool, combined with the meticulous and precise application of research tools, including highly accurate and reliable anthropometric measurements conducted by an experienced researcher using gold-standard equipment in a rigorous methodological manner, underscores the robustness of our findings.

To enhance the inferential value of future research, several improvements could be made. Firstly, increasing the number of participants (including those with left-sided functional lateralization) would be beneficial. Secondly, much more detailed information should be collected on the training process, especially if training was conducted to increase the symmetry of the somatic structure of the athletes. Therefore, data on the frequency and intensity of training in general and training aimed at reducing asymmetry will be necessary for registration.

Crucially, incorporating data on past injuries would be a valuable addition. This would include injuries that either precluded participation in training or, in cases like fractures, completely immobilized a body segment, which could have influenced the final somatic measurements of those body parts. In the future, it will be necessary to record very detailed data regarding the history of injuries, their anatomical location, nature of the injury, method of treatment, and recovery history.

Finally, a valuable enhancement for future studies would be to expand the range of tools used to include body composition analysis. For athletes, this would allow for a more precise analysis of symmetry in active tissue distribution. Furthermore, incorporating an analysis of the biomechanics of movement for individual body parts, particularly non-dominant limbs, would provide richer insights.

A key prospective challenge that could significantly strengthen future research on athletic asymmetry is the adoption of standardized tools for assessing symmetry levels, consistently employed by other researchers. This approach is essential for enabling reliable comparisons across diverse groups, populations, and sports disciplines. Regrettably, a unified methodology remains elusive among researchers studying symmetry and its various components [8,9,55].

5. Conclusions

Despite the relatively low degree of morphological asymmetry in the somatic build of professional female fencers, constant monitoring of individual levels and directions of morphological asymmetry remains necessary, with essential consideration for functional lateralization. This longitudinally collected information should serve as a foundation for analyzing training progress, minimizing injury risk, and advancing potential rehabilitation. Further in-depth analysis is required for studies on asymmetry in non-dominant limbs, which significantly support dominant limbs.