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Background/Objectives: The triple jump is included in the Paralympic Athletics competition. The aim of the research was to examine the relationship of the phase ratios and the inter-limb asymmetry in the spatiotemporal parameters of the approach run in Paralympic and international-level Class T46/T47 triple jumpers. Methods: Eleven Class T46/T47 male athletes were recorded during the examined competitions. Step length (SL), frequency (SF), and average velocity (ASV) for the late approach run as well as the length and the percentage distribution of each jumping phase (hop, step, jump) were measured using a panning video analysis method. The inter-limb asymmetry was estimated using the symmetry angle. Results: No significant inter-limb asymmetry was found (p > 0.05). In addition, SL, SF, and ASV were not different (p > 0.05) between the steps initiated from the ipsilateral and the contralateral leg regarding the impaired arm. However, the direction of asymmetry for SF was towards the ipsilateral leg to the impaired arm in the majority of the examined athletes. The maximum speed of the approach was correlated with the triple jump distance and the magnitude of asymmetry for AVS was correlated with the vertical take-off velocity and angle for the step. Conclusions: Since the distance of the triple jump related with the peak approach speed added the negative correlation of peak approach speed with the magnitude of the symmetry angle for SL, it is suggested to minimize the asymmetries in the step characteristics during the approach run to improve triple jump performance in Class T46/T47 jumpers. [ABSTRACT FROM AUTHOR]

Abstract The relationship between structural and functional of parameters of skeletal muscles in young athletes needs further observations. The analyses of their age-group differences, sexual dimorphism, asymmetry characteristics in body regions, in sports having different pattern of physical loading could serve important information in this topic. 175 elite Hungarian handball players aged between 14 and 21 years were examined in 2023. Muscle mass component of the body segments was estimated by DEXA method and muscle thickness of the anterior mid-thigh region was measured by a new ultrasonic technique. The strength of knee extensor muscles was assessed by using an isokinetic protocol (Kineosystem dynamometer). A strong association between muscle robusticity and strength in the thigh region was confirmed in males, but not in females. Asymmetry in muscle mass reflected in the asymmetry in the knee extensor strength. A new predictive equation of muscle mass in the jumping leg and the total body from the muscle thickness in the anterior mid-thigh region of jumping leg was introduced. The exploration and understanding of asymmetric structural and functional adaptations can help athletes and trainers in planning the training and training interventions to reduce the risk of injuries.

Abstract Objective Tennis is characterised by repetitive serves and strokes predominately performed with one arm. This can lead to differences in upper quarter mobility/stability between the stroke and non-stroke arm, which could even enlarge with increasing training experience and negatively affect serve velocity. Thus, we determined side differences (i.e., limb symmetry index) in upper quarter mobility/stability and their association with flat and slice serve velocity in advanced (ITN ≤ 4) female and male tennis players (N = 42, mean age = 23.9 ± 9.3 years) with different levels of training experience (

This study aims to (1) assess the inter-limb asymmetry in hip, knee, and ankle strength and countermovement jump (CMJ) performance among adolescent basketball players and (2) examine the relationship between inter-limb asymmetry and CMJ performance. Moreover, 30 adolescent basketball players (15 boys and 15 girls) aged 14 to 15 years participated in this study. The strength of the lower limb joints was measured using an isokinetic dynamometer at a speed of 60 degrees per second. Three maximal CMJs were performed, and the highest jump was used for the final analysis. The subjects were median-split into high-asymmetry (n = 15) and low-asymmetry (n = 15) groups based on the calculated strength asymmetry scores. The asymmetry scores were calculated using the formula: (dominant–non-dominant)/dominant* 100%. The inter-limb asymmetry data ranged from 12.2% to 21.6%. A Spearman correlation analysis showed that only the inter-limb asymmetry of the ankle plantar flexor was significantly correlated with the CMJ heights (ρ = −0.56, p = 0.001). An independent t-test revealed no significant differences in strength asymmetry between boys and girls (all p > 0.05). The low-asymmetry group demonstrated significantly greater CMJ performance compared to the high-asymmetry group (ES = 1.11, 95% CI = 0.34–1.87, p = 0.007), indicating that inter-limb asymmetry of the ankle plantar flexor has a significant negative impact on CMJ performance. Coaches should focus on enhancing both the strength and symmetry of the ankle joints to improve athletic performance and prevent injuries in sports, where jumping is a common movement. [ABSTRACT FROM AUTHOR]

Isokinetic metrics are suggested to be related to vertical jump performance, but little is known about the possible sex differences in this relationship in adolescent track and field athletes. The aim of the study was to examine the possible sex differences in the strength of the relationship between the kinetic parameters of the vertical squat jump with arms akimbo, the countermovement jump with arms akimbo, and the countermovement jump with free arm swing with the isokinetic parameters of the knee extensor and flexor muscles (angular velocities: 60°/s and 300°/s). In total, 35 (males: 21, females: 14) U18 track and field athletes were examined. The results revealed that the Men U18 group had higher vertical jump performance, higher values in the kinetic parameters of the vertical jump tests, higher knee extensor torque, and higher knee flexor torque in the non-dominant leg compared to the Women U18 group. Significant (p < 0.05) sex differences were observed in the relationship between the isokinetic parameters and the vertical jump performance metrics, as the Women U18 athletes relied more on the knee flexor torque than Men U18 athletes, and demonstrated a stronger negative relationship between selected isokinetic metrics and the pre-stretch gain in the vertical jump tests. In conclusion, it is recommended that young female track and field athletes minimize interlimb asymmetry and improve the convention ratio in their non-dominant leg to optimize vertical jump performance. [ABSTRACT FROM AUTHOR]

Asymmetries in sports are common and can lead to various issues; however, different training programs can facilitate change. This study aimed to assess the effects of opposing plyometric programs on tensiomyography lateral symmetry (TMG LS)/inter-limb asymmetry in female athletes' lower-body muscles, alongside kinematic and body composition parameters. Twenty female subjects from basketball, volleyball, and track and field (sprinting disciplines) were divided into two experimental groups (n = 10 each). Two six-week plyometric programs (two sessions/week) were implemented: the first program (E1) focused on eccentric exercises, depth landings, while the second (E2) emphasized concentric exercises, squat jumps. TMG assessed LS in six muscles: vastus lateralis, vastus medialis, biceps femoris, semitendinosus, gastrocnemius lateralis, and gastrocnemius medialis. A kinematic analysis of the countermovement jump (CMJ) and body composition was conducted using "Kinovea; Version 0.9.4" software and InBody 770, respectively. The results showed significant increases in LS percentages (E1—VL 9.9%, BF 18.0%, GM 10.6% and E2—BF 22.5%, p < 0.05), and a significant large effect in E1 for VL, and in E2 for BF, p < 0.01). They also showed that E1 had a significant effect on VL, and that E2 had a significant large effect on BF (p < 0.01). E1 also led to increased lean muscle mass in both legs (left: 1.88%, right: 2.74%) and decreased BMIs (−0.4, p < 0.05). Both programs improved LS, with E1 enhancing muscle mass and lower-body positioning in CMJ. We recommend future studies use varied jump tests, incorporate 3D kinematic analysis, include male subjects, and examine more muscles to enhance TMG LS analysis. [ABSTRACT FROM AUTHOR]

Objective: Tennis is characterised by repetitive serves and strokes predominately performed with one arm. This can lead to differences in upper quarter mobility/stability between the stroke and non-stroke arm, which could even enlarge with increasing training experience and negatively affect serve velocity. Thus, we determined side differences (i.e., limb symmetry index) in upper quarter mobility/stability and their association with flat and slice serve velocity in advanced (ITN ≤ 4) female and male tennis players (N = 42, mean age = 23.9 ± 9.3 years) with different levels of training experience (< 2 years: n = 14, 2–5 years: n = 17, 6–8 years: n = 11). Results: Y Balance Test-Upper Quarter (YBT-UQ) side difference (i.e., composite score) and performances (i.e., medial reach) were largest in players with the lowest level of training experience (i.e., < 2 years). Further, YBT-UQ performances (i.e., medial reach and composite score) but not side differences were significantly correlated with flat and slice serve velocity, particularly in less experienced players. Our results suggest that significant side differences in upper quarter mobility/stability occur in less experienced players (indicative of increased injury risk) but they are not related to tennis-specific performance (i.e., serve velocity). [ABSTRACT FROM AUTHOR]

Featured Application: This work investigates the influence of a single session of hand exercise on physiological hand tremors. The key future directions involve developing a protocol evaluating the fine motor skills starting from wobble-board hand exercises. Physiological hand tremors appear to be one of the most common types of tremors that occur during the lifespan. Activities most prominently affected by hand tremors are those involving the movement of small muscles, such as fine motor skills, which in turn could be influenced by several factors, including lateral dominance. The difference in skills due to lateral dominance is defined as inter-limb imbalance or inter-limb asymmetry. When this asymmetry is attributed to the tremor and the difference in tremor between the limbs, it could be defined as the inter-limb asymmetry of tremors. This study aimed to evaluate the acute effects of wobble-board hand exercise training on the inter-limb asymmetry of tremors. Thirty-two (eighteen males and fourteen females) participants (age: 25.2 ± 2.6 years, weight: 63.9 ± 10.5 kg, height: 1.66 ± 0.8 m, and BMI: 22.8 ± 2.3 kg/m2) were involved in the study. Before (PRE) and after (POST) the wobble-board hand exercises, postural hand tremor was evaluated using a tri-axial accelerometer fixed under the palm. Recordings were taken for 15 s. One-way Analysis of Variance (ANOVA) was used to examine the effects of hand exercises on inter-limb (dominant vs. non-dominant) asymmetry of tremor in testing time (PRE vs. POST) in relation to sex (male vs. female). The statistical significance was set at p < 0.05. Significant differences were found in physiological hand tremors between limbs (dominant vs. non-dominant) in the PRE evaluation (p = 0.03) independently from sex while no differences were found in the POST evaluation. A significant difference emerged in the PRE evaluation for males (p = 0.04) and females (p = 0.03) in relation to the testing time and preferred hand. This difference was no longer present in the POST evaluation. In conclusion, wobble-board hand exercises could represent an effective strategy to reduce inter-limb asymmetry. These results emphasize the importance of task-specific training to maximize the reduction in inter-limb asymmetry of tremors following wobble-board hand exercises. [ABSTRACT FROM AUTHOR]

To identify inter-limb asymmetries through the knee's muscular and lower limb functional performance in young male soccer athletes. Twenty male soccer athletes aged 17 to 19 from an under-20 team performed isokinetic tests at 60°/s., 120°/s., 180°/s., and 240°/s. To assess the knee extensors and flexors muscles and functional tests (hop tests and Y-balance test). There were no significant differences between the dominant limb (DL) and non-dominant limb (NDL) in the knee extensors and flexors peak torque and hamstrings (H)/quadriceps(Q) conventional ratio. Moreover, no angular velocities observed inter-limb asymmetries seen by values higher than 10% in the isokinetic parameters. However, the H/Q conventional ratio shows borderline values in low angular velocities (60°/s. and 120°/s.). No significant changes were observed in the functional test performance between the DL and NDL. Furthermore, we did not see inter-limb asymmetries in both hop and Y-balance tests. On the contrary, the anterior distance reached was lower than found in the literature, and the composite score of the Y-balance test demonstrated values below the normative (>94%). The data demonstrated that soccer athletes have muscular and functional inter-limb symmetry. However, they tend to have knee muscle imbalance in low velocities and dynamic balance deficits that might increase the risk of musculoskeletal injury. [ABSTRACT FROM AUTHOR]

The aim of the study was to examine the inter-limb asymmetry in force application in a 1-s maximum isometric leg press test (ISOM) and vertical jump tests without an arm swing (VJ)of male long jumpers. Nine experienced jumpers (age: 18–30 y, LJ personal best: 6.50–8.05 m) were examined. Participants performed: (a) bilateral VJs from the squatting position (SQJ) and with a countermovement (CMJ), (b) unilateral CMJ from the take-off (TOL) and swing (SWL) leg used in the LJ take-off, and c) bilateral 1-s ISOM tests. Data were collected for each lower limb with separate force dynamometers (sampling frequency: VJs = 1 kHz, ISOM = 500 Hz). The inter-limb asymmetry of the peak applied force was evaluated using the symmetry angle. The paired samples T-test revealed non-significant (p > 0.05) inter-limb differences for the force output in the bilateral jump tests, in the unilateral jump tests, and in the ISOM. In conclusion, despite the fact that a powerful unilateral take-off is required for the optimization of long jump performance, no asymmetry was found in the examined tests, suggesting that the dominant/take-off leg was not stronger than the contra-lateral leg. This is possibly due to the intensive execution of other bilateral tasks involved, like the approach run.

The purpose of this study was to evaluate the inter-limb asymmetry in the kinematic parameters of the approach run in elite-level female Class T63/T64 long jumpers and its relationship to performance. Three Class T63 and nine Class T64 female long jumpers were examined during a competition. The temporal and kinematic parameters of their approach steps (step length: SL; step frequency: SF; average step velocity: SV) were measured using a panning video method and speed radar. The symmetry angle was the measure of inter-limb asymmetry. The results revealed that SF and SV were significantly (p < 0.05) larger in the intact lower limb. Significant (p < 0.05) asymmetry was revealed for SL, SF, and SV in 2/12, 3/12, and 1/12 jumpers, respectively. The direction of asymmetry for SF was towards the leg wearing the prosthesis for all examined jumpers. The official jump distance was significantly (p < 0.05) positively correlated with the maximum velocity attained during the approach and negatively correlated with the symmetry angle for SF. It is concluded that the observed asymmetry in SF was compensated for by the modifications observed in the SL that consequently resulted in no asymmetry in SV, leading the participants to effectively utilize their approach speed optimally in terms of long jump performance. [ABSTRACT FROM AUTHOR]

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Study purpose. The aim of the study was to evaluate jumping performance and lower limbs strength asymmetry in young soccer players by comparing this movement performed on both a conventional surface and a sand surface. Materials and methods. 20 young soccer players under 17 years old randomly performed a standing long jump, a single hop jump in the sagittal plane (Hop Jump Test) and a single side hop jump in the frontal plane (Side Hop Jump Test), first on a conventional surface (natural grass) and then on sand. The jump distance and strength asymmetry was calculated using the formula: (NDL / DL) x 100. Results. The values from the two different jumping conditions showed a statistically significant decrease in the Broad Jump Test (p

The aim of the study was to examine the inter-limb asymmetry in force application in a 1-s maximum isometric leg press test (ISOM) and vertical jump tests without an arm swing (VJ)of male long jumpers. Nine experienced jumpers (age: 18–30 y, LJ personal best: 6.50–8.05 m) were examined. Participants performed: (a) bilateral VJs from the squatting position (SQJ) and with a countermovement (CMJ), (b) unilateral CMJ from the take-off (TOL) and swing (SWL) leg used in the LJ take-off, and c) bilateral 1-s ISOM tests. Data were collected for each lower limb with separate force dynamometers (sampling frequency: VJs = 1 kHz, ISOM = 500 Hz). The inter-limb asymmetry of the peak applied force was evaluated using the symmetry angle. The paired samples T-test revealed non-significant (p > 0.05) inter-limb differences for the force output in the bilateral jump tests, in the unilateral jump tests, and in the ISOM. In conclusion, despite the fact that a powerful unilateral take-off is required for the optimization of long jump performance, no asymmetry was found in the examined tests, suggesting that the dominant/take-off leg was not stronger than the contra-lateral leg. This is possibly due to the intensive execution of other bilateral tasks involved, like the approach run. [ABSTRACT FROM AUTHOR]

Study purpose. The aim of the study was to evaluate jumping performance and lower limbs strength asymmetry in young soccer players by comparing this movement performed on both a conventional surface and a sand surface. Materials and methods. 20 young soccer players under 17 years old randomly performed a standing long jump, a single hop jump in the sagittal plane (Hop Jump Test) and a single side hop jump in the frontal plane (Side Hop Jump Test), first on a conventional surface (natural grass) and then on sand. The jump distance and strength asymmetry was calculated using the formula: (NDL / DL) x 100. Results. The values from the two different jumping conditions showed a statistically significant decrease in the Broad Jump Test (p<0.001, ES: 3.56), Hop Jump Test left limb (p<0.001, ES: 4.99), Hop Jump Test right limb (p<0.001, ES: 3.95), Side Hop Jump Test left limb (p<0.001, ES: 4.67) and Side Hop Jump Test right limb (p<0.001, ES: 2.98) in the sand condition. The asymmetry values in the Hop Jump Test and the Side Hop Jump Test showed a statistically significant increase (+21.5%, p<0.001, ES: 3.66 and +41.1%, p<0.001, ES: 1.99, respectively) when comparing the performance on grass and sand. Conclusions. This different performance response in the two different jumping modes leads to the hypothesis that young soccer players who want to stress their explosive strength ability and joint stability should favor the use of oneleg rather than two-leg jumps. The values described in the study lead to the hypothesis that training on sand should be suggested when the young soccer player presents modest values of inter-limb asymmetry measured on a conventional surface. [ABSTRACT FROM AUTHOR]

The purpose of the study was to identify the interaction of step characteristics, along with the direction and magnitude of their asymmetry of elite male and female pole vaulters between successful and failed attempts. It was hypothesized that step characteristics and the magnitude of asymmetry between the two legs would interact with the outcome of the attempt. The approach runs of 12 pole vaulters (7 males, 5 females) were recorded during an indoor international competition. The leg used by the athlete for taking-off was defined as the non-pole-carrying leg, while the other was the pole-carrying leg. Using spatiotemporal information obtained from recordings with a panning camera (300 fps), the last steps of each athlete's approach run were analyzed for length, frequency, average velocity, and inter-limb asymmetry. There was no inter-limb difference (p > 0.05) in the absolute values of step length or step velocity between successful and failed attempts. However, the pole-carrying leg presented significantly (p < 0.05) higher step frequency values at the failed attempts. There was no significant difference (p > 0.05) in asymmetry values for step length, frequency, and average velocity between successful and failed attempts. Although step velocity remained unaffected, failed attempts were characterized by a perturbation in the interaction of step frequency and step length. The present findings suggest that although high velocity at the final phase of the approach is essential, it is not the sole determining factor for a successful attempt. [ABSTRACT FROM AUTHOR]

Physiological hand tremors appear to be one of the most common types of tremors that occur during the lifespan. Activities most prominently affected by hand tremors are those involving the movement of small muscles, such as fine motor skills, which in turn could be influenced by several factors, including lateral dominance. The difference in skills due to lateral dominance is defined as inter-limb imbalance or inter-limb asymmetry. When this asymmetry is attributed to the tremor and the difference in tremor between the limbs, it could be defined as the inter-limb asymmetry of tremors. This study aimed to evaluate the acute effects of wobble-board hand exercise training on the inter-limb asymmetry of tremors. Thirty-two (eighteen males and fourteen females) participants (age: 25.2 ± 2.6 years, weight: 63.9 ± 10.5 kg, height: 1.66 ± 0.8 m, and BMI: 22.8 ± 2.3 kg/m2) were involved in the study. Before (PRE) and after (POST) the wobble-board hand exercises, postural hand tremor was evaluated using a tri-axial accelerometer fixed under the palm. Recordings were taken for 15 s. One-way Analysis of Variance (ANOVA) was used to examine the effects of hand exercises on inter-limb (dominant vs. non-dominant) asymmetry of tremor in testing time (PRE vs. POST) in relation to sex (male vs. female). The statistical significance was set at p < 0.05. Significant differences were found in physiological hand tremors between limbs (dominant vs. non-dominant) in the PRE evaluation (p = 0.03) independently from sex while no differences were found in the POST evaluation. A significant difference emerged in the PRE evaluation for males (p = 0.04) and females (p = 0.03) in relation to the testing time and preferred hand. This difference was no longer present in the POST evaluation. In conclusion, wobble-board hand exercises could represent an effective strategy to reduce inter-limb asymmetry. These results emphasize the importance of task-specific training to maximize the reduction in inter-limb asymmetry of tremors following wobble-board hand exercises.

Background: As inter-limb asymmetries can be associated with higher injury risk, we aimed to investigate their role in Achilles tendinopathy patients. Methods: In Achilles tendinopathy patients (n = 41), we assessed inter-limb asymmetries of mechanical, material, and morphological musculoskeletal properties and function and how those were affected by 12 weeks of exercise intervention (high-load protocol, n = 13; Alfredson protocol, n = 11). Moreover, we assessed whether asymmetry reductions correlated with improved Patient-Reported Outcomes (VISA-A score). Results: At baseline, tendinopathic tendons demonstrated lower tendon force (p = 0.017), lower tendon stress (p < 0.0001), larger tendon cross-sectional area (CSA) (p < 0.001), and increased intratendinous (p = 0.042) and tendon overall (p = 0.021) vascularization. For the high-load group, PRE-to-POST asymmetry comparisons revealed an asymmetry increase for the counter-movement jump (CMJ) (p = 0.034) and PRE-to-POST VISA-A score improvements correlated with CSA asymmetry reductions (p = 0.024). Within the Alfredson group, PRE-to-POST VISA-A score improvements correlated with CMJ asymmetry reductions (p = 0.044) and tendon stiffness asymmetry increases (p = 0.037). POST-to-POST in-between group comparisons revealed lower asymmetry in the high-load group for tendon elongation (p = 0.021) and tendon strain (p = 0.026). Conclusions: The tendinopathic limb differs from the asymptomatic limb while therapeutic exercise interventions have little effect on asymmetries. Asymmetry reductions are not necessarily associated with tendon health improvements. [ABSTRACT FROM AUTHOR]

Quantifying asymmetries between dominant and non‐dominant limbs is a common research objective aimed at identifying systematic differences between limbs and establishing normative ranges of asymmetry. Multiple methods for classifying limb dominance exist, and it is unclear how different methods relate to directional asymmetries during change of direction (CoD). This study aimed to determine whether different methods of classifying limb dominance, including a novel CoD task‐specific method, identified significant inter‐limb asymmetries during a 90° CoD task. Fifty participants completed a testing battery consisting of jumping, hopping, CoD, and isokinetic dynamometry. Limb dominance was classified for each participant according to preferred kicking limb, vertical jump height, horizontal hop distance, initial force plate contact during landing, max isokinetic knee extensor strength, and turning velocity. Asymmetries in whole‐body and joint‐level mechanics were defined using each method. No method for classifying limb dominance was associated with consistent inter‐limb biomechanical asymmetries during CoD, and no method was related to any other method. The magnitude of asymmetry relative to the magnitude of absolute asymmetry present within the cohort suggests that using these tasks to classify the dominant limb in this CoD is akin to assigning dominance to a randomly selected limb. Previous observations of group symmetry during CoD may be statistical artifacts as opposed to a true indication of normative movement. Until an appropriate means of classifying limbs during CoD is established, quantifying normative asymmetry based on limb dominance should be done with caution. [ABSTRACT FROM AUTHOR]

Bilateral asymmetry in lower-limb power and dynamic balance has been associated with increased risk of sport injury, whereas there is a lack of research examining this asymmetry for child athletes. Twenty-eight fencers (19 boys and 9 girls, aged 9.71 ± 1.08 years) and 28 Taekwondo athletes (19 boys and 9 girls, aged 9.71 ± 1.08 years) were examined on the single-leg jump and Star Excursion Balance Test (SEBT) performance. A mixed model design ANOVA (2 [Sex: Boys, Girls] × 2 [Sport group: Fencing, Taekwondo] × 2 [Limb: Dominant, Non-dominant Leg]) was conducted to examine for difference for each test. There was a significant main effect of limb on hop and triple hop distance (p < 0.05). A significant limb by sex interaction (p = 0.000) was shown for the single-leg countermovement jump (CMJ) performance, wherein a bilateral difference was only shown in boys. In SEBT, a main effect (p = 0.007) of limb was identified for posterolateral (PL) reach distance. A limb by sex interaction (p = 0.009) was also shown for posteromedial (PM) reach distance, wherein a bilateral difference was only shown in girls. These findings suggest that child athletes in both laterally dominant and non-laterally dominant sports showed inter-limb asymmetry of leg power and dynamic balance. Sex should be an important consideration when evaluating bilateral difference of leg power and dynamic balance for child athletes. [ABSTRACT FROM AUTHOR]

Change of direction (COD) ability is essential for sport performance in high level team sports such as basketball, however, the influence of asymmetries on COD ability is relatively unknown. Forty-three junior and senior level elite basketball players performed isometric hip and trunk strength testing, passive hip and trunk range of motion testing, and unilateral horizontal and vertical jumps, as well as the T-test to measure COD performance. Mean asymmetry values ranged from 0.76% for functional leg length up to 40.35% for rate of torque development during hip flexion. A six-variable regression model explained 48% (R2 = 0.48; p < 0.001) of variation in COD performance. The model included left hip internal/external rotation strength ratio, and inter-limb asymmetries in hip abduction rate of torque development, hip flexion range of motion, functional leg length, single leg triple jump distance, and peak torque during trunk lateral flexion. Results suggest that the magnitude of asymmetries is dependent of task and parameter, and using universal asymmetry thresholds, such as <10 %, is not optimal. The regression model showed the relationship between asymmetries and COD performance. None of tests were sufficient to explain a complex variable like COD performance. [ABSTRACT FROM AUTHOR]

Background: The identification of asymmetrical inter-limb ankle dorsiflexion range of motion (DF ROM) has the potential to influence the course of treatment during the rehabilitation process, with limitations in ankle DF ROM potentially increasing injury risk. However, reliability for methods to identify ankle DF ROM asymmetries remain under described in the literature. Purpose: To determine the reliability of the trigonometric calculation method for measuring ankle DF ROM during the weight-bearing lunge test (WBLT) for both a single limb and the symmetry values. The secondary purpose was to establish values of ankle DF ROM asymmetry and identify the influence of leg dominance on ankle DF ROM. Study Design: Cross-sectional study. Methods: Ankle DF ROM was measured bilaterally in 50 healthy and recreationally active participants (28 men, 22 women, age = 22 ± 4 years, height = 172.8 ± 10.8 cm, body mass 71.5 ± 15.1 kg), using the trigonometric measurement method during the WBLT. Each ankle was measured twice in a single testing session to establish within-session reliability. Results: Values are presented for asymmetries in DF ROM. No differences were identified between the dominant and nondominant limb (p = 0.862). Within-session reliability for measuring a single limb was classified as 'good' (ICC = 0.98) with a minimal detectable change value of 1.7°. For measuring ankle DF ROM asymmetry, reliability was established as 'good' (ICC = 0.85) and a minimal detectable change value of 2.1° was determined. Conclusions: Although symmetry in ankle DF ROM may not be assumed, the magnitude of asymmetry may be less than previously reported in a population of recreationally active individuals. Discrepancies between previous research and the findings of the present study may have been impacted by differences in measurement methods. Furthermore, clinicians should be aware that the error associated with measures of asymmetry for ankle DF ROM during the WBLT is greater than that of a single limb. [ABSTRACT FROM AUTHOR]

Change of direction (COD) ability is essential for sport performance in high level team sports such as basketball, however, the influence of asymmetries on COD ability is relatively unknown. Forty-three junior and senior level elite basketball players performed isometric hip and trunk strength testing, passive hip and trunk range of motion testing, and unilateral horizontal and vertical jumps, as well as the T-test to measure COD performance. Mean asymmetry values ranged from 0.76% for functional leg length up to 40.35% for rate of torque development during hip flexion. A six-variable regression model explained 48% (R2 = 0.48; p < 0.001) of variation in COD performance. The model included left hip internal/external rotation strength ratio, and inter-limb asymmetries in hip abduction rate of torque development, hip flexion range of motion, functional leg length, single leg triple jump distance, and peak torque during trunk lateral flexion. Results suggest that the magnitude of asymmetries is dependent of task and parameter, and using universal asymmetry thresholds, such as

Chronic inter-limb joint mechanical asymmetry has been reported following total knee arthroplasty (TKA) during low-demand mobility tasks such as level walking. However, no study has compared the inter-limb asymmetry during a high-demand mobility task such as decline walking. The objective of this cross-sectional study was to compare inter-limb asymmetry differences during both level and decline walking tasks at six months following TKA compared to asymmetry present in an age, gender, body mass index and activity level matched healthy cohort. Kinetic and kinematic gait analysis was conducted on 42 patients with TKA and 15 healthy-matched peers. Our inter-limb asymmetry results demonstrated significantly (p<0.05) greater combined limb support moment (MS) (mean differences [MD]=0.17; 95% CI=0.07, 0.22), knee extensor moment (MK) (MD=0.05; 95% CI=0.02, 0.09) and vertical ground reaction force (vGRF) (MD=0.03; 95% CI=0.01, 0.08) differences during decline walking compared to level walking in patients with TKA. Greater MS (MD=0.24; 95% CI=0.13, 0.35), MK (MD=0.08; 95% CI=0.03, 0.18), vGRF (MD=0.04; 95% CI=0.01, 0.08) and knee joint angle (MD=2.4; 95% CI=0.37, 3.80) differences were present in patients with TKA compared to healthy-matched peers during decline walking. Greater MS (MD=0.13; 95% CI=0.05, 0.20) and plantarflexor moment (MD=0.06; 95% CI=0.04, 0.16) differences were present in patients with TKA compared to healthy-matched peers during level walking. Post-TKA inter-limb asymmetry during level walking worsens as the physical demands of the task are increased. Thus, even patients with good self-reported outcomes after TKA exhibit substantial deficits in their mobility reserves that could limit their independence and community mobility as they age. [ABSTRACT FROM AUTHOR]

Inter-limb asymmetries are the difference in performance in one limb with respect to the other. Running events in track and field are considered symmetrical while jumping and throwing events are considered asymmetrical. It is unknown if competing in these different events result in differences in inter-limb asymmetries, thus, this study compared the magnitude of jump, sprint, and morphological asymmetries in track and field athletes who compete in symmetrical and asymmetrical events. Forty-six Division I track and field athletes performed a series of vertical jumps (VJ) and broad jumps (BJ) with force platforms measuring peak force of each limb, and 30-meter fly sprints with kinematics (step length (SL), flight time (FT), and contact time (CT)) recorded during the sprints. Additionally, thirty-eight of these subjects underwent body composition analysis via dual x-ray absorptiometry to determine morphological asymmetries. Asymmetries were calculated using the symmetry index and the asymmetry measures were compared between sprinters, distance runners, throwers, and jumpers utilizing a one-way analysis of variance or Kruskal-Wallis tests with post-hoc comparisons as necessary. There were no differences in VJ, BJ, and sprint kinematic asymmetries found between groups but there were differences in leg fat mass asymmetries (H(3)=8.259, p=0.041, eta2= 0.101) as well as arm lean mass (H(3)=9.404, p=0.024, eta2=0.152), fat mass (H(3)=17.822, p<0.001, eta2=0.353), and tissue mass (H(3)=11.632, p=0.009, eta2=0.206) asymmetry measures. While morphological asymmetry differences may be present in athletes competing in different events, there does not appear to be differences in asymmetries during the VJ, BJ, and 30-m fly sprint.

Total hip arthroplasty (TGA) is a successful surgical procedure to treat patients with hip osteoarthritis. Clinicians use different questionnaires to evaluate these patients. Gait velocity and these questionnaires; usually show significant improvement after TGA . This clinical evaluation does, however, not provide objective, quantifiable information about the movement patterns underlying the functional capacity, which is clinically important and can currently only be obtained in a gait laboratory. There is a need to improve patient instructions and to quantify the rehabilitation process. The sit-to-stand (STS) movement is an objective performance-based task, whose assessment is related with the evaluation of functional recovery. Twenty two patients with hip osteoarthritis participated in this study. For each patient, validated questionnaires were administered and gait velocity was measured. Time, ground reaction forces, and lower limb asymmetry parameters were calculated using the instrumented force shoes (IFS) during STS movement with and without armrest. Significant inter-limb asymmetry was observed. No correlation was found between any parameter and gait velocity and questionnaires outcomes. Significant differences in time and force parameters between with/without armrest were found. Concluding, inter-limb asymmetry can be evaluated with the IFS supplying important additional information not represented by gait velocity and questionnaires usually used. [ABSTRACT FROM AUTHOR]

Deficits in maximal and explosive knee extensor strength, which are usually assessed with unilateral tasks, are substantial in patients with knee osteoarthritis (KOA). The aim of this study was to investigate the clinical relevance of unilateral vs. bilateral tasks for assessing knee extensor strength in patients with KOA. This was achieved primarily by comparing unilateral and bilateral inter-limb strength asymmetries and secondarily by examining the relationship between unilaterally and bilaterally measured strength, and performance-based and self-reported function. Twenty-four patients with unilateral KOA (mean age: 65 ± 7 years) performed isometric gradual and explosive maximal voluntary contractions to assess, respectively their maximal and explosive strength. Performance-based and self-reported function were also evaluated with standard functional tests and questionnaires, respectively. Inter-limb asymmetries of maximal and explosive strength did not differ significantly between unilateral (mean asymmetry: 26 ± 15%) and bilateral tasks (22 ± 21%). In the same way, the relationships between knee extensor strength—measured either unilaterally or bilaterally—and performance-based or self-reported function were not influenced by the type of task. In conclusion, it does not seem to make a difference in terms of clinical relevance whether maximal and explosive knee extensor strength are evaluated with unilateral or bilateral tasks in KOA patients. [ABSTRACT FROM AUTHOR]

Movement asymmetries between lower limbs are commonly exhibited by adults after transtibial amputation. However, the degree of movement asymmetry between low- and high-demand functional tasks remains unknown. Kinematic and kinetic data were collected during overground walking (low-demand) and step ascent (high-demand) tasks for two groups: 1) persons with transtibial amputation and 2) healthy matched peers. Analysis of covariance was used to compare sagittal-plane peak knee moment and joint angle (primary) and hip and ankle moments and joint angles, vertical ground reaction force and impulse (secondary). Within transtibial amputation group comparisons showed significantly greater between-limb asymmetry in peak knee moment (p <.01), vertical impulse (p <.01), peak vertical ground reaction force (p =.05), peak ankle angle (p <.01) and peak ankle moment (p <.01) with the step ascent task compared to overground walking. The transtibial amputation group had greater between-limb asymmetry during step ascent in peak knee moment (p <.01), vertical impulse (p <.01), peak vertical ground reaction force (p =.04) and peak ankle angle (p <.01) than healthy matched peers. During overground walking, the transtibial amputation group had greater between-limb asymmetry in peak vertical impulse (p =.05) and peak ankle moment (p <.01) than healthy matched peers. Movement asymmetry is increased during step ascent compared to overground walking for adults with transtibial amputation. While the restoration of overground walking is the focus of post-amputation rehabilitation and prosthetic design, higher demand tasks should also be considered to maximize mobility for adults with transtibial amputation. • Movement asymmetries increase during step ascent compared to overground walking. • During step ascent, limited amputated limb loading drives increased asymmetry. • Walking kinetics can be asymmetrical despite symmetrical walking kinematics. • High demand functional tasks may require specific retraining during rehabilitation. [ABSTRACT FROM AUTHOR]

The aims of the present study were to analyze mobility, dynamic balance and lower-limb strength and the prevalence of asymmetry according to the type of sport and assess the association between inter-limb asymmetry and sports performance. A total of 23 basketball and 25 handball players performed a test battery consisting of functional movements and a jump test. Inter-limb asymmetry was calculated using a standard percentage difference equation. A between-groups comparison analysis was carried out, and Pearson's correlation coefficients (r) were calculated to establish a relationship between asymmetries and physical performance. The results found athletes in different sports to exhibit different performance in functional movements and the jump test, but no bilateral asymmetries. The reactive strength index (RSI) and stiffness asymmetries were significantly associated with the anterior reach Y-balance test (YBT) (r = -0.412; p < 0.01 and r = -0.359; p < 0.05, respectively), and the unilateral triple hop test (THTU) was negatively correlated to anterior reach, posterior lateral reach YBT and YBT composite YBT (r = -0.341 to -0.377; p < 0.05). These findings suggest that the asymmetries exhibited important dispersion not dependent upon the type of sport but on each individual and the applied test. In addition, asymmetry in anterior direction YBT showed the strongest association to the rest of the sports performance variables.

Background: The identification of asymmetrical inter-limb ankle dorsiflexion range of motion (DF ROM) has the potential to influence the course of treatment during the rehabilitation process, with limitations in ankle DF ROM potentially increasing injury risk. However, reliability for methods to identify ankle DF ROM asymmetries remain under described in the literature., Purpose: To determine the reliability of the trigonometric calculation method for measuring ankle DF ROM during the weight-bearing lunge test (WBLT) for both a single limb and the symmetry values. The secondary purpose was to establish values of ankle DF ROM asymmetry and identify the influence of leg dominance on ankle DF ROM., Study Design: Cross-sectional study., Methods: Ankle DF ROM was measured bilaterally in 50 healthy and recreationally active participants (28 men, 22 women, age = 22 ± 4 years, height = 172.8 ± 10.8 cm, body mass 71.5 ± 15.1 kg), using the trigonometric measurement method during the WBLT. Each ankle was measured twice in a single testing session to establish within-session reliability., Results: Values are presented for asymmetries in DF ROM. No differences were identified between the dominant and non-dominant limb ( p = 0.862). Within-session reliability for measuring a single limb was classified as 'good' (ICC = 0.98) with a minimal detectable change value of 1.7 °. For measuring ankle DF ROM asymmetry, reliability was established as 'good' (ICC = 0.85) and a minimal detectable change value of 2.1 ° was determined., Conclusions: Although symmetry in ankle DF ROM may not be assumed, the magnitude of asymmetry may be less than previously reported in a population of recreationally active individuals. Discrepancies between previous research and the findings of the present study may have been impacted by differences in measurement methods. Furthermore, clinicians should be aware that the error associated with measures of asymmetry for ankle DF ROM during the WBLT is greater than that of a single limb., Level of Evidence: 2b., Competing Interests: The authors have no conflict of interest., (© 2020 by the Sports Physical Therapy Section.)