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

Medicina ◽  
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.

scholarly journals Kinematic differences between professionals and young players in the tennis serve

2021 ◽  
Vol 29 (83) ◽  
pp. 25-27
Author(s):  
Christos Mourtzios ◽  
Ioannis Athanailidis ◽  
Eleftherios Kellis ◽  
Vasileia Arvanitidou
Keyword(s):  
Lower Limb ◽  
Lower Limbs ◽  
Young Athletes ◽  
Significant Difference ◽  
Tennis Serve ◽  
Limb Kinematics ◽  
High Level ◽  
Lower Limb Kinematics

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.

Fatigue-related firing of muscle nociceptors reduces voluntary activation of ipsilateral but not contralateral lower limb muscles

2015 ◽  
Vol 118 (4) ◽  
pp. 408-418 ◽  
Author(s):  
David S. Kennedy ◽  
Siobhan C. Fitzpatrick ◽  
Simon C. Gandevia ◽  
Janet L. Taylor
Keyword(s):  
Lower Limb ◽  
Femoral Nerve ◽  
Central Fatigue ◽  
Muscle Afferents ◽  
Voluntary Contraction ◽  
Lower Limbs ◽  
Voluntary Activation ◽  
Knee Extensors ◽  
Group Iii ◽  
Lower Limb Muscles

During fatiguing upper limb exercise, maintained firing of group III/IV muscle afferents can limit voluntary drive to muscles within the same limb. It is not known if this effect occurs in the lower limb. We investigated the effects of group III/IV muscle afferent firing from fatigued ipsilateral and contralateral extensor muscles and ipsilateral flexor muscles of the knee on voluntary activation of the knee extensors. In three experiments, we examined voluntary activation of the knee extensors by measuring changes in superimposed twitches evoked by femoral nerve stimulation. Subjects attended on 2 days for each experiment. On one day a sphygmomanometer cuff occluded blood flow of the fatigued muscles to maintain firing of group III/IV muscle afferents. After a 2-min extensor contraction ( experiment 1; n = 9), mean voluntary activation was lower with than without maintained ischemia (47 ± 19% vs. 87 ± 8%, respectively; P < 0.001). After a 2-min knee flexor maximal voluntary contraction (MVC) ( experiment 2; n = 8), mean voluntary activation was also lower with than without ischemia (59 ± 21% vs. 79 ± 9%; P < 0.01). After the contralateral (left) MVC ( experiment 3; n = 8), mean voluntary activation of the right leg was similar with or without ischemia (92 ± 6% vs. 93 ± 4%; P = 0.65). After fatiguing exercise, activity in group III/IV muscle afferents reduces voluntary activation of the fatigued muscle and nonfatigued antagonist muscles in the same leg. However, group III/IV muscle afferents from the fatigued left leg had no effect on the unfatigued right leg. This suggests that any “crossover” of central fatigue in the lower limbs is not mediated by group III/IV muscle afferents.

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

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.

Deficits in anticipatory inhibition of postural muscle activity associated with load release while standing in individuals with spastic diplegic cerebral palsy

2013 ◽  
Vol 109 (8) ◽  
pp. 1996-2006 ◽  
Author(s):  
Hidehito Tomita ◽  
Yoshiki Fukaya ◽  
Kenji Totsuka ◽  
Yuri Tsukahara
Keyword(s):  
Cerebral Palsy ◽  
Lower Limb ◽  
Muscle Activity ◽  
Erector Spinae ◽  
Lower Limbs ◽  
Control Group ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Postural Muscle ◽  
Load Release

This study aimed to determine whether individuals with spastic diplegic cerebral palsy (SDCP) have deficits in anticipatory inhibition of postural muscle activity. Nine individuals with SDCP (SDCP group, 3 female and 6 male, 13–24 yr of age) and nine age- and sex-matched individuals without disability (control group) participated in this study. Participants stood on a force platform, which was used to measure the position of the center of pressure (CoP), while holding a light or heavy load in front of their bodies. They then released the load by abducting both shoulders. Surface electromyograms were recorded from the rectus abdominis, erector spinae (ES), rectus femoris (RF), medial hamstring (MH), tibialis anterior (TA), and gastrocnemius (GcM) muscles. In the control group, anticipatory inhibition before load release and load-related modulation of the inhibition were observed in all the dorsal muscles recorded (ES, MH, and GcM). In the SDCP group, similar results were obtained in the trunk muscle (ES) but not in the lower limb muscles (MH and GcM), although individual differences were seen, especially in MH. Anticipatory activation of the ventral lower limb muscles (RF and TA) and load-related modulation of the activation were observed in both participant groups. CoP path length during load release was longer in the SDCP group than in the control group. The present findings suggest that individuals with SDCP exhibit deficits in anticipatory inhibition of postural muscles at the dorsal part of the lower limbs, which is likely to result in a larger disturbance of postural equilibrium.

scholarly journals The Activity of Surface Electromyographic Signal of Selected Muscles during Classic Rehabilitation Exercise

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jinzhuang Xiao ◽  
Jinli Sun ◽  
Junmin Gao ◽  
Hongrui Wang ◽  
Xincai Yang
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Activity Level ◽  
Core Stability ◽  
Median Frequency ◽  
Low Back ◽  
Lower Limb Muscles ◽  
Significant Difference ◽  
Limb Muscles ◽  
Rehabilitation Exercises

Objectives. Prone bridge, unilateral bridge, supine bridge, and bird-dog are classic rehabilitation exercises, which have been advocated as effective ways to improve core stability among healthy individuals and patients with low back pain. The aim of this study was to investigate the activity of seven selected muscles during rehabilitation exercises through the signal of surface electromyographic. Approaches. We measured the surface electromyographic signals of four lower limb muscles, two abdominal muscles, and one back muscle during rehabilitation exercises of 30 healthy students and then analyzed its activity level using the median frequency method. Results. Different levels of muscle activity during the four rehabilitation exercises were observed. The prone bridge and unilateral bridge caused the greatest muscle fatigue; however, the supine bridge generated the lowest muscle activity. There was no significant difference (P>0.05) between left and right body side muscles in the median frequency slope during the four rehabilitation exercises of seven muscles. Conclusions. The prone bridge can affect the low back and lower limb muscles of most people. The unilateral bridge was found to stimulate muscles much more active than the supine bridge. The bird-dog does not cause much fatigue to muscles but can make most selected muscles active.

Develop a Flexible Regenerative Exoskeleton to Assist Walking

2018 ◽  
Author(s):  
Longhan Xie ◽  
Xiaodong Li
Keyword(s):  
Kinetic Energy ◽  
Human Body ◽  
Lower Limb ◽  
Metabolic Cost ◽  
Lower Limbs ◽  
Metabolic Energy ◽  
Lower Limb Exoskeleton ◽  
Negative Work ◽  
Lower Limb Muscles ◽  
Assisting Device

During walking, human lower limbs accelerate and decelerate alternately, during which period the human body does positive and negative work, respectively. Muscles provide power to all motions and cost metabolic energy both in accelerating and decelerating the lower limbs. In this work, the lower-limb biomechanics of walking was analyzed and it revealed that if the negative work performed during deceleration can be harnessed using some assisting device to then assist the acceleration movement of the lower limb, the total metabolic cost of the human body during walking can be reduced. A flexible lower-limb exoskeleton was then proposed; it is worn in parallel to the lower limbs to assist human walking without consuming external power. The flexible exoskeleton consists of elastic and damping components that are similar to physiological structure of a human lower limb. When worn on the lower limb, the exoskeleton can partly replace the function of the lower limb muscles and scavenge kinetic energy during lower limb deceleration to assist the acceleration movement. Besides, the generator in the exoskeleton, serving as a damping component, can harvest kinetic energy to produce electricity. A prototype of the flexible exoskeleton was developed, and experiments were carried out to validate the analysis. The experiments showed that the exoskeleton could reduce the metabolic cost by 3.12% at the walking speed of 4.5 km/h.

scholarly journals The Comparison between Isokinetic Knee Muscles Strength in the Ipsilateral and Contralateral Limbs and Correlating with Function of Patients with Stroke

2019 ◽  
Vol 10 (04) ◽  
pp. 683-689
Author(s):  
Fayaz Khan ◽  
Haris Anjamparuthikal ◽  
Mohamed Faisal Chevidikunnan
Keyword(s):  
Lower Limb ◽  
Knee Flexion ◽  
Peak Torque ◽  
Lower Limbs ◽  
Isokinetic Strength ◽  
Isokinetic Dynamometer ◽  
Knee Strength ◽  
Torque Measurements ◽  
Significant Difference ◽  
Knee Muscle

Abstract Objective The aim of this study is to compare the isokinetic knee muscles peak torque measurements and proprioception between the affected and intact limbs of patients with stroke, in addition to finding the correlation between knee muscles strength and lower limb function. Methods Twelve patients with stroke (mean age 64.33 ± 6.140 years), with 3 to 7 months poststroke who can walk 25 feet independently without using or using assistive devices and full passive range of motion were included in the study. Biodex isokinetic dynamometer was used for measuring isokinetic strength at 90°/s, 120°/s, and 150°/s and isometric strength at 60°/s in both flexors and extensors of the knee, whereas proprioception was measured at 45°/s knee flexion, all for affected and intact limbs. Functional measurements were assessed using the Fugl-Meyer Assessment for Lower Limb scale and Barthel Index (BI). Results The differences shown were found to be statistically significant between affected and intact limbs in isokinetic 90°/s flexion (p = 0.005), extension (p = 0.0013), and isometric at 60°/s flexion (p < 0.0001) knee muscle strengths and also the proprioception (p = 0.05). Significant positive correlation was found between isokinetic affected side knee flexion at 90°/s (r = 0.903) with BI (r = 0.704). Conclusion There is a significant difference in peak torque measurements between affected and normal lower limbs of poststroke patients, as well as a significant correlation between the knee strength and lower limb functions. Furthermore, it can also be concluded that the differences in knee proprioception between the affected and intact limbs were shown to be significant.

scholarly journals Asymmetry and changes in the neuromuscular profile of short-track athletes as a result of strength training

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261265
Author(s):  
Paweł Pakosz ◽  
Anna Lukanova-Jakubowska ◽  
Edyta Łuszczki ◽  
Mariusz Gnoiński ◽  
Oscar García-García
Keyword(s):  
Strength Training ◽  
Lower Limb ◽  
Female Athletes ◽  
Lower Limbs ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Before And After ◽  
Monthly Period ◽  
Track Athletes ◽  
The Right

Background The purpose of this study was to identify the biomedical signals of short-track athletes by evaluating the effects of monthly strength training on changes in their neuromuscular profile, strength, and power parameters of the lower limb muscles. Muscle asymmetry, which can cause a risk of injury, was also evaluated. Methods and results This study involved female athletes, age 18.8 ± 2.7 years, with a height of 162 ± 2.4 cm, and weight of 55.9 ± 3.9 kg. Before and after the monthly preparatory period prior to the season, strength measurements were assessed through the Swift SpeedMat platform, and reactivity of the lower limb muscles was assessed with tensiomyography (TMG). The athletes were also tested before and after the recovery training period. In the test after strength training, all average countermovement jump (CMJ) results improved. Flight time showed an increase with a moderate to large effect, using both legs (5.21%). Among the TMG parameters, time contraction (Tc) changed globally with a decrease (-5.20%). Changes in the results of the test after recovery training were most often not significant. Conclusion A monthly period of strength training changes the neuromuscular profile of short-track female athletes, with no significant differences between the right and left lower limbs.

scholarly journals Intermittent Claudication in Physiotherapists’ Practice

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Anna Spannbauer ◽  
Maciej Chwała ◽  
Tomasz Ridan ◽  
Arkadiusz Berwecki ◽  
Piotr Mika ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Intermittent Claudication ◽  
Lower Limb ◽  
Systemic Disease ◽  
Significant Risk ◽  
Arterial Disease ◽  
Lower Limbs ◽  
Lower Limb Muscles ◽  
Limb Muscles ◽  
Peripheral Arterial

Intermittent claudication is a symptom of atherosclerosis of the lower limbs (peripheral arterial disease (PAD)) and is characterized by pain and cramps of lower limb muscles during exercise. Claudication leads to a reduction in physical activity of patients. PAD is a systemic disease. Atherosclerotic lesions located in the arteries of the lower limbs not only pose the risk of the ischemic limb loss, but above all, they are an important prognostic factor. Patients with claudication are at significant risk of cardiovascular complications such as infarcts or strokes. Comprehensive rehabilitation of patients with intermittent claudication based on the current TASC II (Inter-Society Consensus for the Management of Peripheral Arterial Disease) guidelines, ESC (European Society of Cardiology) guidelines, and AHA (American Heart Association) guidelines includes supervised treadmill training, training on a bicycle ergometer, Nordic Walking, resistance exercises of lower limb muscles, and exercises of upper limbs. A trained, educated, and motivated patient has a chance to improve life quality as well as life expectancy.

scholarly journals Interlimb neural interactions in corticospinal and spinal reflex circuits during preparation and execution of isometric elbow flexion

2020 ◽  
Vol 124 (3) ◽  
pp. 652-667
Author(s):  
Atsushi Sasaki ◽  
Naotsugu Kaneko ◽  
Yohei Masugi ◽  
Matija Milosevic ◽  
Kimitaka Nakazawa
Keyword(s):  
Lower Limb ◽  
Elbow Flexion ◽  
Motor Preparation ◽  
Lower Limbs ◽  
Spinal Reflex ◽  
Upper Limbs ◽  
Limb Muscle ◽  
Motor Execution ◽  
Lower Limb Muscles ◽  
Neural Interactions

We found that upper limb muscle contractions facilitated corticospinal circuits controlling lower limb muscles even during motor preparation, whereas motor execution of the task was required to facilitate spinal circuits. We also found that facilitation did not depend on whether contralateral or ipsilateral hands were contracted or if they were contracted bilaterally. Overall, these findings suggest that training of unaffected upper limbs may be useful to enhance facilitation of affected lower limbs in paraplegic individuals.

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