Kinematic differences between professionals and young players in the tennis serve

The aim of the present study was to measure and examine the differences in lower limb kinematics between the flat, slice and topspin serves, in the kinematic features of the lower limbs, at two different times of the service movement, maximum knee bending and point of contact of the racket with the ball, in 12 young tennis athletes, aged 12-16 years and in 12 professional players that they were playing on the main draw of Roland Garros. The results showed no significant differences in time between the three types of service in young athletes. Comparing the time of young athletes 34.56ms with the time of high level athletes with 30.67ms, the results showed that the professionals performed the service faster than the young athletes having a significant difference.

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Unilateral and Bilateral Strength Asymmetry among Young Elite Athletes of Various Sports

Medicina ◽

10.3390/medicina56120683 ◽

2020 ◽

Vol 56 (12) ◽

pp. 683

Author(s):

Maros Kalata ◽

Tomas Maly ◽

Mikulas Hank ◽

Jakub Michalek ◽

David Bujnovsky ◽

...

Keyword(s):

Lower Limb ◽

Elite Athletes ◽

Lower Limbs ◽

Knee Extensors ◽

Young Athletes ◽

Lower Limb Muscles ◽

Significant Difference ◽

Strength Asymmetry ◽

Main Factor ◽

Objective Type

Background and objective: Type of physical activity may influence morphological and muscular asymmetries in the young population. However, less is known about the size of this effect when comparing various sports. The aim of this study was to identify the degree of bilateral asymmetry (BA) and the level of unilateral ratio (UR) between isokinetic strength of knee extensors (KE) and flexors (KF) among athletes of three different types of predominant locomotion in various sports (symmetric, asymmetric and hybrid). Material and methods: The analyzed group consisted of young elite athletes (n = 50). The maximum peak muscle torque of the KE and KF in both the dominant (DL) and non-dominant (NL) lower limb during concentric muscle contraction at an angular velocity of 60°·s−1 was measured with an isokinetic dynamometer. Results: Data analysis showed a significant effect of the main factor (the type of sport) on the level of monitored variables (p = 0.004). The type of sport revealed a significant difference in the bilateral ratio (p = 0.01). The group of symmetric and hybrid sports achieved lower values (p = 0.01) of BA in their lower limb muscles than those who played asymmetric sports. The hybrid sports group achieved higher UR values (p = 0.01) in both lower limbs. Conclusions: The results indicate that sports with predominantly symmetrical, asymmetrical, and hybrid types of locomotion affected the size of the BA, as well as the UR between KE and KF in both legs in young athletes. We recommend paying attention to regular KE and KF strength diagnostics in young athletes and optimizing individual compensatory exercises if a higher ratio of strength asymmetry is discovered.

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Lower-limb kinematics and kinetics during continuously varying human locomotion

Scientific Data ◽

10.1038/s41597-021-01057-9 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Emma Reznick ◽

Kyle R. Embry ◽

Ross Neuman ◽

Edgar Bolívar-Nieto ◽

Nicholas P. Fey ◽

...

Keyword(s):

Lower Limb ◽

Human Locomotion ◽

Lower Limbs ◽

Stair Climbing ◽

Constant Acceleration ◽

Stair Ascent ◽

Limb Kinematics ◽

Kinetics Of ◽

Lower Limb Kinematics ◽

Kinematics And Kinetics

AbstractHuman locomotion involves continuously variable activities including walking, running, and stair climbing over a range of speeds and inclinations as well as sit-stand, walk-run, and walk-stairs transitions. Understanding the kinematics and kinetics of the lower limbs during continuously varying locomotion is fundamental to developing robotic prostheses and exoskeletons that assist in community ambulation. However, available datasets on human locomotion neglect transitions between activities and/or continuous variations in speed and inclination during these activities. This data paper reports a new dataset that includes the lower-limb kinematics and kinetics of ten able-bodied participants walking at multiple inclines (±0°; 5° and 10°) and speeds (0.8 m/s; 1 m/s; 1.2 m/s), running at multiple speeds (1.8 m/s; 2 m/s; 2.2 m/s and 2.4 m/s), walking and running with constant acceleration (±0.2; 0.5), and stair ascent/descent with multiple stair inclines (20°; 25°; 30° and 35°). This dataset also includes sit-stand transitions, walk-run transitions, and walk-stairs transitions. Data were recorded by a Vicon motion capture system and, for applicable tasks, a Bertec instrumented treadmill.

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Functional mobility in walking adult population with ataxia of Charlevoix-Saguenay

Orphanet Journal of Rare Diseases ◽

10.1186/s13023-021-02054-2 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Isabelle Lessard ◽

Raphaël St-Gelais ◽

Luc J. Hébert ◽

Isabelle Côté ◽

Jean Mathieu ◽

...

Keyword(s):

Lower Limb ◽

Autosomal Recessive ◽

Adult Population ◽

Functional Mobility ◽

Lower Limbs ◽

Mobility Limitations ◽

Significant Difference ◽

High Level ◽

Walking Aid ◽

Better Than

Abstract Background This study aimed to describe lower limbs impairments, balance and activity limitations related to indoor mobility in adult walkers with autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). Results Twenty-five participants were recruited with a mean age of 32.2 (± 10.4) years with 45.7% using a walking aid. There is a significant difference between participants with and without a walking aid in terms of lower limbs coordination, balance and mobility. Although participants who walk without a walking aid perform better than the others and they are below predictive or reference values. Despite significant mobility limitations, only mild spasticity and passive range of motion limitations were observed. However, there is a significant difference between unaffected individuals and participants with ARSACS for lower limb muscle cocontraction. Conclusions Results show a high level of lower limb impairments, balance and mobility limitation in adults’ participants with ARSACS that are still walking, including people not using a walking aid. One of the most original finding is the presence of excessive cocontraction and a relatively mild level of spasticity in the lower limbs muscles. Results of this study better circumscribes the impairments and activities that should be the focus of intervention including rehabilitation in ARSACS.

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Functional Mobility in Walking Adult Population With Ataxia of Charlevoix-Saguenay

10.21203/rs.3.rs-390512/v1 ◽

2021 ◽

Author(s):

Isabelle Lessard ◽

Raphaël St-gelais ◽

Luc J Hébert ◽

Isabelle Coté ◽

Jean Mathieu ◽

...

Keyword(s):

Lower Limb ◽

Autosomal Recessive ◽

Adult Population ◽

Functional Mobility ◽

Lower Limbs ◽

Mobility Limitations ◽

Significant Difference ◽

High Level ◽

Walking Aid ◽

Better Than

Abstract Background: This study aimed to describe lower limbs impairments, balance and activity limitations related to indoor mobility in adult walkers with autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). Results: Twenty-five participants were recruited with a mean age of 32.2 (±10.4) years with 45.7 % using a walking aid. There is a significant difference between participants with and without a walking aid in terms of lower limbs coordination, balance and mobility. Although participants who walk without a walking aid perform better than the others and they are below predictive or reference values. Despite significant mobility limitations, only mild spasticity and passive range of motion limitations were observed. However, there is a significant difference between unaffected individuals and participants with ARSACS for lower limb muscle cocontraction. Conclusions: Results show a high level of lower limb impairments, balance and mobility limitation in adults’ participants with ARSACS that are still walking, including people not using a walking aid. One of the most original finding is the presence of excessive cocontraction and a relatively mild level of spasticity in the lower limbs muscles. Results of this study better circumscribes the impairments and activities that should be the focus of intervention including rehabilitation in ARSACS.

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Estimating Lower Limb Kinematics using a Lie Group Constrained EKF and a Reduced Wearable IMU Count

2020 8th IEEE RAS/EMBS International Conference for Biomedical Robotics and Biomechatronics (BioRob) ◽

10.1109/biorob49111.2020.9224342 ◽

2020 ◽

Author(s):

Luke Sy ◽

Nigel H. Lovell ◽

Stephen J. Redmond

Keyword(s):

Lie Group ◽

Lower Limb ◽

Limb Kinematics ◽

Lower Limb Kinematics

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Effect of medial foot loading self-practice on lower limb kinematics in young individuals with asymptomatic varus knee alignment

The Knee ◽

10.1016/j.knee.2021.04.018 ◽

2021 ◽

Vol 30 ◽

pp. 305-313

Author(s):

Seobin Choi ◽

Gwanseob Shin

Keyword(s):

Lower Limb ◽

Varus Knee ◽

Knee Alignment ◽

Limb Kinematics ◽

Foot Loading ◽

Lower Limb Kinematics

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Computed tomography angiography and microsurgical flaps for traumatic wounds: What is the added value?

Clinical Hemorheology and Microcirculation ◽

10.3233/ch-200986 ◽

2021 ◽

pp. 1-9

Author(s):

Lucas Sousa Macedo ◽

Renato Polese Rusig ◽

Gustavo Bersani Silva ◽

Alvaro Baik Cho ◽

Teng Hsiang Wei ◽

...

Keyword(s):

Computed Tomography ◽

Upper Limb ◽

Computed Tomography Angiography ◽

Lower Limb ◽

High Energy ◽

Lower Limbs ◽

Added Value ◽

Vascular Lesions ◽

Limb Injuries ◽

Significant Difference

BACKGROUND: Microsurgical flaps are widely used to treat complex traumatic wounds of upper and lower limbs. Few studies have evaluated whether the vascular changes in preoperative computed tomography angiography (CTA) influence the selection of recipient vessel and type of anastomosis and the microsurgical flaps outcomes including complications. OBJECTIVE: The aim of this study was to evaluate if preoperative CTA reduces the occurrence of major complications (revision of the anastomosis, partial or total flap failure, and amputation) of the flaps in upper and lower limb trauma, and to describe and analyze the vascular lesions of the group with CTA and its relationship with complications. METHODS: A retrospective cohort study was undertaken with all 121 consecutive patients submitted to microsurgical flaps for traumatic lower and upper limb, from 2014 to 2020. Patients were divided into two groups: patients with preoperative CTA (CTA+) and patients not submitted to CTA (CTA–). The presence of postoperative complications was assessed and, within CTA+, we also analyzed the number of patent arteries on CTA and described the arterial lesions. RESULTS: Of the 121 flaps evaluated (84 in the lower limb and 37 in the upper limb), 64 patients underwent preoperative CTA. In the CTA+ group, 56% of patients with free flaps for lower limb had complete occlusion of one artery. CTA+ patients had a higher rate of complications (p = 0.031), which may represent a selection bias as the most complex limb injuries and may have CTA indicated more frequently. The highest rate of complications was observed in chronic cases (p = 0.034). There was no statistically significant difference in complications in patients with preoperative vascular injury or the number of patent arteries. CONCLUSIONS: CTA should not be performed routinely, however, CTA may help in surgical planning, especially in complex cases of high-energy and chronic cases, since it provides information on the best recipient artery and the adequate level to perform the microanastomosis, outside the lesion area.

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Analysis of the Relationships between Balance Ability and Walking in Terms of Muscle Activities and Lower Limb Kinematics and Kinetics

Biomechanics ◽

10.3390/biomechanics1020016 ◽

2021 ◽

Vol 1 (2) ◽

pp. 190-201

Author(s):

Pathmanathan Cinthuja ◽

Graham Arnold ◽

Rami J. Abboud ◽

Weijie Wang

Keyword(s):

Regression Analysis ◽

Lower Limb ◽

Linear Regression Analysis ◽

Multivariate Linear Regression Analysis ◽

Vastus Medialis ◽

Balance Test ◽

Balance Ability ◽

Limb Kinematics ◽

Lower Limb Kinematics ◽

Kinematics And Kinetics

There is a lack of evidence about the ways in which balance ability influences the kinematic and kinetic parameters and muscle activities during gait among healthy individuals. The hypothesis is that balance ability would be associated with the lower limb kinematics, kinetics and muscle activities during gait. Twenty-nine healthy volunteers (Age 32.8 ± 9.1; 18 males and 11 females) performed a Star Excursion Balance test to measure their dynamic balance and walked for at least three trials in order to obtain a good quality of data. A Vicon® 3D motion capture system and AMTI® force plates were used for the collection of the movement data. The selected muscle activities were recorded using Delsys® Electromyography (EMG). The EMG activities were compared using the maximum values and root mean squared (RMS) values within the participants. The joint angle, moment, force and power were calculated using a Vicon Plug-in-Gait model. Descriptive analysis, correlation analysis and multivariate linear regression analysis were performed using SPSS version 23. In the muscle activities, positive linear correlations were found between the walking and balance test in all muscles, e.g., in the multifidus (RMS) (r = 0.800 p < 0.0001), vastus lateralis (RMS) (r = 0.639, p < 0.0001) and tibialis anterior (RMS) (r = 0.539, p < 0.0001). The regression analysis models showed that there was a strong association between balance ability (i.e., reaching distance) and the lower limb muscle activities (i.e., vastus medialis–RMS) (R = 0.885, p < 0.0001), and also between balance ability (i.e., reaching distance) and the lower limb kinematics and kinetics during gait (R = 0.906, p < 0.0001). In conclusion, the results showed that vastus medialis (RMS) muscle activity mainly contributes to balance ability, and that balance ability influences the lower limb kinetics and kinematics during gait.

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