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Introduction Individual participation in sports with inadequate preparation, especially during competition, results in an increased incidence of injury. Athletes commonly suffer from lower extremity musculoskeletal pain. During growth, several biomechanical factors contribute to muscular imbalance, which results in injury. The aim of the current study was to determine the correlation between lower extremity strength and balance in relation to single leg squat depth. Methods A total of 100 male football players were included in the study. Lower extremity qualitative and quantitative squat analyses were performed for both legs. Isometric strength and balance for the lower extremities were assessed via a dynamometer and the Y balance test, respectively. Results There is a moderate correlation between the visual squat performance and the strength of the hip extensor in the dominant leg and the hip abductors in the non-dominant leg. A moderate correlation of the maximum squat depth was found with the hip abductors, hip extensor, and knee flexor on the dominant side. The p value was < 0.05 and the r value was between 0.50 and 0.70, which was considered significant. Conclusions Strength and balance both influence squat performance. Balance has a stronger influence than strength in single leg squat performance.

Copyright of Turkish Journal of Sport & Exercise / Türk Spor ve Egzersiz Dergisi is the property of Turkish Journal of Sport & Exercise and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction. individual participation in sports with inadequate preparation, especially during competition, results in an increased incidence of injury. Athletes commonly suffer from lower extremity musculoskeletal pain. during growth, several biomechanical factors contribute to muscular imbalance, which results in injury. The aim of the current study was to determine the correlation between lower extremity strength and balance in relation to single leg squat depth. Methods. A total of 100 male football players were included in the study. Lower extremity qualitative and quantitative squat analyses were performed for both legs. isometric strength and balance for the lower extremities were assessed via a dynamometer and the Y balance test, respectively. Results. There is a moderate correlation between the visual squat performance and the strength of the hip extensor in the dominant leg and the hip abductors in the non-dominant leg. A moderate correlation of the maximum squat depth was found with the hip abductors, hip extensor, and knee flexor on the dominant side. The p value was < 0.05 and the r value was between 0.50 and 0.70, which was considered significant. Conclusions. Strength and balance both influence squat performance. Balance has a stronger influence than strength in single leg squat performance. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of warm-up activity on the visual response time of the dominant and non-dominant hand and foot in basketball players. A total of 13 male basketball athletes with an age of 14.38 ± .506 years, height 180.15 ± 8.07 cm, body weight 66.54 ± 13.73 and sports experience 4.69 ± 13.73 years were voluntarily included in the study. Visual response time of the dominant and non-dominant hand and foot were measured before and after the warm-up protocol. The warm-up protocol consisted of a 20-minute warm-up activity including basketball-specific movements and 5-minute stretching movements. Visual response time of the athletes were measured with the Blazepod system. There was no significant difference in the group main effect and time x group interaction of the athletes' hand visual response times after warm-up (F=2.403; p>0.05; F=0.170; p>0.05). There was a statistically significant difference in the time effect (F=22.943; p

Background and Study Aim. Understanding the relationship between repeated isoinertial lunges and jump and sprint parameters is an important factor in achieving success in sports requiring explosive strength and speed. The aim of this study was to examine the acute effects of repeated isoinertial lunges on jump and sprint parameters. Material and Methods. Volunteered 42 students from Sports Sciences Faculty were participated to the study. They were randomly divided into experimental group (EG) (n=22, age=22.8±1.1year, height=180.6±7.1cm, body weight=77.5±8.8kg) and control group (CG) (n=20, age=23.0±2.1year, height=173.1±5.6 cm, body weight=71.3±8.4 kg). As pre- and post-tests, each participant performed squat jump (SJ), countermovement jump (CMJ), and 30m sprint on a non-motorized treadmill. Isoinertial lunges were included in 8 reps with dominant leg (DL), 1 min rest, and 8 reps with non-dominant leg (NDL). As a statistical analysis, pre- and post-test differences were analyzed with independent t test between groups and paired t test within groups. The level of significance was taken as p≤0.05. Results. There were pre-test and also post-test differences between groups in SJ (p

Although the chronic effects of a long-term warm-up program have been widely studied, to our knowledge, the number of studies examining the acute effects of a single warm-up session on inter-limb balance asymmetries in symmetrical sports such as cycling is limited. The aim of this study was to examine the effect of warm-up on postural sway in the dominant and non-dominant leg in male bicycle athletes. Sixteen healthy young male volunteers who engage in cycling sports participated in the study. The participants' age was determined as 15.50±1.15 years, body weight as 56.06±7.79 kg, height as 169.87±4.98 cm, and sports experience as 4.31±1.25 years. The postural control performance on the dominant and non-dominant leg of the athletes was evaluated on Biodex Balance System balance device platform for 20 seconds before and after a 10-minute warm-up exercise performed at a constant pedaling frequency of 80 RPM on a bicycle ergometer. In the comparison of the pre-test to post-test dominant leg Overall Sway Index (t=3.456; p=0.004), Anterior-Posterior (Z=-3.160; p=0.002) and Medial-Lateral (Z=-2.428; p=0.015) postural control scores of the participants, a significant decrease was found in the post-test. It was determined that warm-up exercise can only improve acute postural control in the dominant leg. The effects of the study can be extended to different sports branches with symmetrical features in order to obtain comparable results.

Soccer is a complex sport, and balance appears to play a crucial role in the quality execution of technical skills, which are mostly performed while standing on one foot. Nevertheless, in younger ages, when learning still affects soccer performance, the effect of a balance-training program on the player's balance and technical skills remains unexplored. This research examined the effect of a balance-training program (BTP) on balance and technical skills of adolescent soccer players. The participating volunteers were thirty-two soccer players (12 - 13 years old with 3.84 ± 0.95 years of practice), randomly separated into two groups: an experimental (EXP, n1 = 17) and a control group (CON, n2 = 15). Both groups were evaluated in static and dynamic balance and in technical skills (dribbling, passing, juggling, and shooting with dominant and non-dominant legs) before (Pre-condition) and after the intervention (Post-condition) which was an eight-week BTP for the EXP group and a placebo-training program for the CON group. A 2 by 2 (groups x condition) mixed analysis of variance (ANOVA) with repeated measures on the condition factor was used to assess possible differences between groups. A significant groups x condition interaction effect was found in dynamic balance (p = 0.008), static (p = 0.042), and shooting (p = 0.022) with dominant leg performance. The EXP group improved (p = 0.007) its static balance by 37.82% and also significantly improved its dynamic balance and shooting accuracy with dominant leg in Post condition by 24.98% (p = 0.006) and 83.84% (p = 0.006) respectively. No significant improvement of other variables was detected in the EXP group Post condition. Dynamic and static balance, and shooting with dominant leg skills can be improved in adolescent soccer players through a specialized 8-week BTP. Balance- training program may contribute to technical skill improvement in soccer training. [ABSTRACT FROM AUTHOR]

Copyright of Turkish Journal of Sport & Exercise / Türk Spor ve Egzersiz Dergisi is the property of Turkish Journal of Sport & Exercise and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although the chronic effects of a long-term warm-up program have been widely studied, to our knowledge, the number of studies examining the acute effects of a single warm-up session on inter-limb balance asymmetries in symmetrical sports such as cycling is limited. The aim of this study was to examine the effect of warm-up on postural sway in the dominant and non-dominant leg in male bicycle athletes. Sixteen healthy young male volunteers who engage in cycling sports participated in the study. The participants' age was determined as 15.50±1.15 years, body weight as 56.06±7.79 kg, height as 169.87±4.98 cm, and sports experience as 4.31±1.25 years. The postural control performance on the dominant and non-dominant leg of the athletes was evaluated on Biodex Balance System balance device platform for 20 seconds before and after a 10-minute warm-up exercise performed at a constant pedaling frequency of 80 RPM on a bicycle ergometer. In the comparison of the pre-test to post-test dominant leg Overall Sway Index (t=3.456; p=0.004), Anterior-Posterior (Z=-3.160; p=0.002) and Medial-Lateral (Z=-2.428; p=0.015) postural control scores of the participants, a significant decrease was found in the post-test. It was determined that warm-up exercise can only improve acute postural control in the dominant leg. The effects of the study can be extended to different sports branches with symmetrical features in order to obtain comparable results. [ABSTRACT FROM AUTHOR]

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In volleyball, the approach run serves as a strategy to execute a spike from an elevated striking position. Nevertheless, the influence of the step number of the approach run on the jumping kinematics in spike jumps is unclear. Therefore, this investigation aims to clarify the impact of varying step numbers within the approach run on jumping kinematics. Seven female volleyball athletes were tasked with executing spike jumps, employing 2 and 3-step approach runs. These trials were recorded using high-speed cameras and digitized, and then the kinematics of the 2 and 3-step trials were compared. The findings of this study unveiled that, in the 3-step trial with higher horizontal velocity, the center of gravity was upheld at an elevated level, thereby curtailing the vertical displacement of the center of gravity from the last step before the takeoff to the takeoff. Within the 2-step trial, a notable deceleration of horizontal velocity in the first half of the takeoff was virtually absent. However, the 3-step trial with higher horizontal velocity entailed more flexion of the dominant knee joint to decelerate the horizontal velocity during the first half. Furthermore, the 3-step trial entails a swifter extension of the hip, knee, and ankle joints of the non-dominant leg. This accelerated extension likely contributes to an augmented vertical velocity at the foot release of the takeoff. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Elementary Education / Revija za Elementarno Izobraževanje is the property of University of Maribor, Faculty of Education and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Facta Universitatis: Series Physical Education & Sport is the property of Facta Universitatis, Series Physical Education & Sport and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: Background The present research aimed to compare landing kinematics parameters at different minutes of a simulated soccer game. Methods: In total, 15 soccer players from the youth team of Sanay Mes of Kerman with records (2 years) in the Premier League of Iran voluntarily participated in this study. Their mean±SD age and weight were 25.7±2.71 years and 77.30±7.78 kg, respectively. The players followed the Bangsbo's fatigue protocol, i.e. a simulated soccer game. Then, every 15 minutes, the studied players performed two countermovement jumps, and we compared their landing kinematics parameters accordingly. Performances were recorded with 3 cameras, 120 HTZ (Sony A7S). Information extracted from Kinova and repeated-measures analysis of variance was used for data analysis. Results: The obtained results suggested significant differences between the investigated players' knee flexion at landing at minute 0 and minute 60, and other durations (P

Purpose: The purpose of this study was to investigate of the acute effects of isoinertial resistance application on sprint, vertical and horizontal jump performance. Material: Volunteered 32 male students were divided into randomized experimental group and control group. Before and after 4-repetition maximal back squat with (for experimental group) or without isoinertial resistance application (for control group), 30 m sprint, vertical squat and countermovement jump tests with both legs, dominant leg, and non-dominant leg, standing broad jump and standing broad countermovement jump tests with both legs were assessed. Wilcoxon t test for pre- and post-test differences within the group, and Mann Whitney U test for pre- and post-test differences between the groups were used. Results: There were no significant differences within the group and between the groups for 30m both legs sprint parameters except pre-test mean stride length between the groups (Z=-2.27; p

Background: Good balance is a pre-requisite for various activities of daily life and sports. Physiotherapists thus regularly assess and train patient's balance capacities. In order to interpret the test results of unilateral balance tests, a comparison with normative data is common. In patients who had an injury or a surgery, the performance of the injured leg is often compared with performance of the non-injured leg. Nevertheless, it remains unclear if unilateral balance performance differs between the dominant and non- dominant legs. If so, this should take into consideration when interpreting test results.Research Question: This meta-analysis summarized the current evidence to determine if the balance performance of healthy adults was influenced by the leg's dominance.Methods: Articles were searched in PubMed, CINAHL, Cochrane and Embase. Data from studies meeting the pre-defined inclusion criteria were extracted in a standardized form. A meta-analysis was conducted using a random effect model.Results: Forty-six studies were included. Their data were allocated in 7 categories of balance tests. Significant differences between the dominant and the non-dominant legs were not found in any of the categories (surface stable, eyes open: -0.04, 95 % CI -0.12 to 0.05, surface stable eyes closed: -0.06, 95 % CI -0.22 to 0.11, surface unstable, eyes open: -0.15, 95 % CI -0.38 to 0.07, surface unstable, eyes closed: -0.06, 95 % CI -0.27 to 0.15, BESS (Balance Error Scoring System): 0.03, 95 % CI -1.09 to 1.14, SEBT (Star Excursion Balance Test)/YBT (Y Balance Test): 0.06, 95 % CI -0.04 to 0.16, jump: 0.04, 95 % CI -0.28 to 0.36).Significance: Results indicate that balance performance is not influenced by the leg's dominance. This means that performances of both legs can be used as reference. Evidence is strong for the one leg stance. However, future studies are needed to confirm our results for stabilization tasks after a jump landing. [ABSTRACT FROM AUTHOR]

The current literature shows no consensus regarding the difference between the dominant leg (D-Leg) and the non-dominant leg (ND-Leg) in terms of postural control. This lack of consensus could stem from motor experience (i.e., symmetric or asymmetric motricity) and/or the physiological state induced by physical exercise. This study aimed to investigate the acute effects of fatiguing exercise on postural control when standing on the D-Leg and the ND-Leg, in athletes practicing symmetric (SYM) and asymmetric (ASYM) sports. Thirty healthy male participants were recruited and divided into two groups, (SYM n = 15) and (ASYM n = 15, on the basis of the motricity induced by the sport they practice. Monopedal postural control was assessed for the D-Leg and the ND-Leg before and after the fatigue period (which consisted of repeating squats until exhaustion). A force platform was used to calculate the spatio-temporal characteristics of the displacements of the center of foot pressure (COP). A significant fatigue effect was observed in both groups on the D-Leg and the ND-Leg for all the COP parameters. There was a tendency (p = 0.06) between the ASYM and SYM groups on the D-Leg, concerning the relative increase in the COP velocity in the frontal plane after the fatigue period. The fatigue condition disturbed postural control in both the SYM and ASYM groups on the D-Leg and ND-Leg. This disturbing effect related to fatigue tends to be more marked in athletes practicing asymmetric sports than in athletes practicing symmetric sports on the D-Leg.

Copyright of Facta Universitatis: Series Physical Education & Sport is the property of Facta Universitatis, Series Physical Education & Sport and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: The aim of this study was to compare the plantar pressure distribution of dominant and non-dominant legs of females who were participated in the kata and kumite national team. Methods: Twelve kumite and 8 kata female athletes of the Karate national team participated in this study. Plantar pressure was measured using emed platform during barefoot walking. After dividing the foot into 10 masks, peak pressure, pressure-time integral, maximum force and force-time integral were calculated. Wilcoxon and U-Mann-Witney tests were used to analyze parameters at a significance level of p ≤ 0.05. Results: In comparison of kata and kumite teams it was found that, kata plantar pressure parameters in Metatarsal-2 (p=0.05) and Metatarsals-3, 4, 5 (p=0.04) were significantly less than those in kumite. Also, in comparison of dominant and non-dominant leg, plantar pressure parameters of dominant leg were less in Metatarsal-2 (p=0.04) and more in Bigtoe (p=0.04) and Toes-3, 4, 5 (p=0.03) than those in the non-dominant leg. Conclusion: Results may be indicative different of natures of the two athletic fields in that Kumite has a higher impact on plantar pressure due to higher mechanical loads. Furthermore, the unequal use of the legs may affect plantar pressure because of leg dominance. Thus, further and more comprehensive studies are necessary to prevent exercise-induced adaptations in professional levels and their treatments.

Paillard, T, Kadri, MA, Nouar, MB, and Noé, F. Warm-up optimizes postural control but requires some minutes of recovery. J Strength Cond Res 32(10): 2725–2729, 2018—The aim was to compare monopedal postural control between the dominant leg (D-Leg) and the nondominant leg (ND-Leg) in pre– and post–warm-up conditions. Thirty healthy male sports science students were evaluated before and after a warm-up exercise (12 minutes of pedaling with an incremental effort on a cycle ergometer with a controlled workload). Monopodal postural control was assessed for the D- and ND-Legs before and immediately, 2, 5, 10, and 15 minutes after the warm-up exercise, using a force platform and calculating the displacement velocity of the center of foot pressure on the mediolateral (COPML velocity) and anteroposterior (COPAP velocity) axes. No significant difference was observed between the D-Leg and ND-Leg for both COPML and COPAP velocity in all the periods. In comparison with pre–warm-up, COPML decreased after 15-minute and 10-minute recovery periods for the D-Leg and the ND-Leg, respectively (p < 0.05), whereas COPAP decreased after 10-minute and 15-minute recovery periods (p < 0.001; p < 0.01, respectively) for the D-Leg, and after a 10-minute recovery period for the ND-Leg (p < 0.001). The warm-up optimized monopedal postural control but did not make it possible to distinguish a difference between the D-Leg and the ND-Leg. Some minutes of recovery are required between the end of the whole-body warm-up exercise and the beginning of the postural test to optimize postural control. The optimal duration of recovery turns out to be about 10–15 minutes. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To determine the effects of kicking leg preference on the bilateral leg strength asymmetries of amateur football players. METHODS: : Thirty-four right-dominant (RD) and twenty-three left-dominant (LD) amateur football players volunteered to participate in the study. Squat and countermovement jump, standing long jump, and isokinetic knee strength (at 60, 180 and 300 ∘ /s) were tested with respect to inter-limb asymmetry index (ASI). RESULTS: There were significant differences in horizontal jump and H/Q ratio at 60 ∘ /s between DL and NDL in all football players. There were also significant differences in standing long jump, hamstring peak torque at 180 ∘ /s and H/Q ratio at 60 ∘ /s in the LD football players ( p < 0.05). Moreover, the LD group had greater percentage of subjects with ASI > 15% for standing long jump, hamstring peak torque at 180 ∘ /s. Furthermore the percentage of subjects with H/Q Ratio < 0.60 for 60 ∘ /s was greater in the LD players' DL. CONCLUSION: Bilateral leg strength asymmetries may be affected by a single leg predominantly in the mobilization workouts. Having higher inter-limb asymmetry index, LD players may be screened and trained to minimize leg strength asymmetries. [ABSTRACT FROM AUTHOR]

Kicking is one of the most important skills in soccer and the ability to achieve maximal kicking velocity with both legs leads to an advantage for the soccer player. This study examined the relationship between kicking ball velocity with both legs using anthropometric measurements and vertical jumps (a squat jump (SJ); a countermovement jump without (CMJ) and with the arm swing (CMJA) and a reactive jump (RJ)). Anthropometric measurements did not correlate with kicking ball velocity. Vertical jumps correlated significantly with kicking ball velocity using the dominant leg only (r = .47, r = .58, r = .44, r = .51, for SJ, CMJ, CMJA and RJ, respectively). Maximal kicking velocity with the dominant leg was significantly higher than with the non-dominant leg (t = 18.04, p < 0.001). Our results suggest that vertical jumps may be an optimal test to assess neuromuscular skills involved in kicking at maximal speed. Lack of the relationship between vertical jumps and kicking velocity with the non-dominant leg may reflect a difficulty to exhibit the neuromuscular skills during dominant leg kicking. [ABSTRACT FROM AUTHOR]

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Resistance exercise effectively improves bone mineral density (BMD) and muscle quality (e.g., muscle mass and muscle strength). The present study aimed to examine the effect of a 24-week resistance exercise training (RT) program on body composition, BMD, functional fitness, and isokinetic muscle strength in obese older women. Forty obese older women were initially enrolled. Among them, 30 participants (age: 80.55 ± 4.94 years; body fat percentage: 36.25 ± 3.44%) completed the study. The participants were randomly assigned into two groups: the RT group (n = 15) and the control (CON) group (n = 15). The RT group participated in the exercise for 60 min per session and two sessions per week for 24 weeks. Pre-test and post-test body composition, BMD, functional fitness, and isokinetic muscle strength were evaluated. The RT group increased significantly in functional fitness (hand grip strength: 1.70 kg, p < 0.01, and lower body strength: 3.87 n, p < 0.001), and isokinetic muscle strength (non-dominant leg extensor peak torque %BW at 60°/s: 13.20%, p < 0.05, dominant leg (DL) flexor peak torque at 60°/s: 3.87 Nm, p < 0.05, and DL flexor peak torque %BW at 60°/s: 7.60%, p < 0.05). However, the CON group showed negative changes in body composition (fat mass: 1.15 kg, p < 0.001, body fat percentage: 1.59%, p < 0.001, and fat-free mass: -0.58 kg, p < 0.05), BMD (whole-body: -0.01 g/cm 2 , p < 0.001 and forearm: -0.01 g/cm 2 , p < 0.05), functional fitness (lower body flexibility: -3.23 cm, p < 0.01, upper body strength: -2.06 n, p < 0.01, and agility and dynamic balance: 0.54 s, p < 0.01), and isokinetic muscle strength at 60°/s and 180°/s (all peak torque % body weight variables: -7.31--1.50, p < 0.05). Our findings show that the CON group negatively affects body composition, BMD, functional fitness, and isokinetic muscle strength in obese older women for 24 weeks.

Background: Bilateral symmetry evaluation in lower limb is used for injury prevention, and is an indicator of returning to post-injury activity. The aim of present study was to investigate the effect of different angular velocities on asymmetry of the hamstring-to-quadriceps strength ratio., Method: Isokinetic concentric hamstring to quadriceps (H:Q) peak torque ratio of the 27 male and female professional basketball players was measured at seven angular velocities (60, 90, 120, 150, 180, 180, 240, 300 deg s -1 ) on both dominant and non-dominant legs with Biodex Isokinetic Dynamometer. Repeated measure analysis of variance was used to assess the effects of angular velocity and limb side on our outcomes (p≤ 0.05)., Results: The results showed that with increasing angular velocity, the ratio of hamstrings to quadriceps increases (p = 0.001). There was no difference between dominant and non-dominant limbs in the H:Q peak torque ratio (p = 0.254). In addition, velocity of measurement did not affect the bilateral asymmetry of peak torque ratio of the H:Q of both sides (p = 0.852)., Conclusions: Based on the results of this study, it can be concluded that measurement velocity does not affect the bilateral asymmetry of the H:Q peak torque ratio of the dominant and non-dominant limbs. In clinical assessments of H:Q bilateral asymmetry, we suggest that physical trainer can assess bilateral asymmetry of H:Q with arbitrary angular velocities., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Definition of strength imbalance between legs and muscles does not only play a decisive role for higher performance but also prevents sport injury. The purpose of this study was to determine bilateral differences on isokinetic and isometric strength of knee extensor and flexor muscles in male and female elite young taekwondo athletes. Ten male (age: 19.40±0.84 years) and female (age: 18.24±1.42 years) taekwondo athletes of the Turkish national team between 17-20-year of age participated in the study. Concentric peak torque of hamstring (H) and quadriceps (Q) of the dominant (D) and nondominant leg (ND) was evaluated using isokinetic machine (Cybex Humac Norm) at 60° and 180°/sec. Isometric peak torque of both legs was determined at 60°. Significant differences were found between genders ( P <0.05). Concentric and isometric knee strength was significantly greater in male than that of female ( P < 0.05). Although no significant bilateral strength difference was found in both sexes in concentric and isometric strength ( P >0.05), and isometric H strength was in favor of the dominant leg 15% for men athletes and 11% for women. H/Q ratio was similar between gender and legs. The study revealed no bilateral knee strength asymmetry in both male and female taekwondo athletes. However, male had 20%-30% higher isometric and concentric knee extensor and flexor strength than female in both legs., Competing Interests: CONFLICT OF INTEREST No potential conflict of interest relevant to this article was reported., (Copyright © 2022 Korean Society of Exercise Rehabilitation.)

The current literature shows no consensus regarding the difference between the dominant leg (D-Leg) and the non-dominant leg (ND-Leg) in terms of postural control. This lack of consensus could stem from motor experience (i.e., symmetric or asymmetric motricity) and/or the physiological state induced by physical exercise. This study aimed to investigate the acute effects of fatiguing exercise on postural control when standing on the D-Leg and the ND-Leg, in athletes practicing symmetric (SYM) and asymmetric (ASYM) sports. Thirty healthy male participants were recruited and divided into two groups, (SYM n = 15) and (ASYM n = 15, on the basis of the motricity induced by the sport they practice. Monopedal postural control was assessed for the D-Leg and the ND-Leg before and after the fatigue period (which consisted of repeating squats until exhaustion). A force platform was used to calculate the spatio-temporal characteristics of the displacements of the center of foot pressure (COP). A significant fatigue effect was observed in both groups on the D-Leg and the ND-Leg for all the COP parameters. There was a tendency (p = 0.06) between the ASYM and SYM groups on the D-Leg, concerning the relative increase in the COP velocity in the frontal plane after the fatigue period. The fatigue condition disturbed postural control in both the SYM and ASYM groups on the D-Leg and ND-Leg. This disturbing effect related to fatigue tends to be more marked in athletes practicing asymmetric sports than in athletes practicing symmetric sports on the D-Leg. [ABSTRACT FROM AUTHOR]

The interlimb postural comparison i.e., between the dominant leg and the non-dominant leg has been studied by numerous authors but their results are contradictory and do not lead to a consensus. Some studies showed no difference of postural balance between the dominant and the non-dominant leg whereas other studies concluded that the dominant and non-dominant leg exhibit different postural balance in healthy subjects and athletes. The aim was to analyse all these studies in order to identify the different factors that could facilitate or prevent the appearance of a postural difference between the dominant and non-dominant leg by means of a narrative review. Environmental and experimental conditions (e.g., difficulty and specificity of postural tasks; physiological state, expertise level and moment of season/period over career of subjects/athletes evaluated and nature of sport/physical activity practiced; techniques and methods used for measuring postural balance) in which postural balance is evaluated and intrinsic/individual factors (e.g., morphology, strength/power muscle, proprioception, hemispheric laterality) could influence the results. Thus, the influence of limb dominance on monopedal postural balance would probably be context-dependent. Mechanistic explanations are proposed to explain how each factor could act on the relationship between limb dominance and postural balance. However many mechanisms have not yet been explained and all the factors have not been identified, which suggests that further exploratory research is needed in order to understand this relationship. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze the body balance control of people walking and hurdling with or without a specific dominant leg in a monopodal position. This study involved 28 physical education students. The center of pressure (COP) was measured with a force plate under four conditions: single-leg standing (right and left) with eyes open and two upper limb positions (the arms were positioned in either a specific hurdle technique manner or alongside the body). A repeated measures analysis of variance (ANOVA) was conducted separately for five parameters of the COP in the medial-lateral (ML) and anterior-posterior (AP) directions under the four conditions. In the single-leg position, athletes without a dominant lower leg had better body balance than those with a dominant lower leg. The position of the upper limbs influenced the body position when hurdling. Accepting the correct position of the upper limbs helped to maintain balance (when overcoming hurdles). In hurdles, the position of the upper limbs should be improved to maintain postural stability and save this function for more demanding postural tasks.

Kicking is one of the most important skills in soccer and the ability to achieve ma ximal kicking velocity with both legs leads to an advantage for the soccer player. This study examined the relationship be tween kicking ball velocity with both legs using anthropometric measurements and vertical jumps (a squat jump (SJ); a countermovement jump without (CMJ) and with the arm swing (CMJA) and a reactive jump (RJ)). Anthropome tric measurements did not correlate with kicking ball velocity. Vertical jumps correlated significantly with kicking ball velocity using the dominant leg only (r = .47, r = .58, r = .44, r = .51, for SJ, CMJ, CMJA and RJ, respectively) . Maximal kicking velocity with the dominant leg was significantly higher than with the non-dominant leg (t = 18.0 4, p < 0.001). Our results suggest that vertical jumps may be an optimal test to assess neuromuscular skills involved in kicking at maximal speed. Lack of the relationship between vertical jumps and kicking velocity with the non-dominant leg may reflect a difficulty to exhibit the neuromuscular skills during dominant leg kicking.