Bilateral Balance Research Articles

A machine learning based method for tracking of simultaneously imaged neural activity and body posture of freely moving maggot

To understand neural basis of animal behavior, it is necessary to monitor neural activity and behavior in freely moving animal before building relationship between them. Here we use light sheet fluorescence microscope (LSFM) combined with microfluidic chip to simultaneously capture neural activity and body movement in small freely behaving Drosophila larva. We develop a transfer learning based method to simultaneously track the continuously changing body posture and activity of neurons that move together using a sub-region tracking network with a precise landmark estimation network for the inference of target landmark trajectory. Based on the tracking of each labelled neuron, the activity of the neuron indicated by fluorescent intensity is calculated. For each video, annotation of only 20 frames in a video is sufficient to yield human-level accuracy for all other frames. The validity of this method is further confirmed by reproducing the activity pattern of PMSIs (period-positive median segmental interneurons) and larval movement as previously reported. Using this method, we disclosed the correlation between larval movement and left-right asymmetry in activity of a group of unidentified neurons labelled by R52H01-Gal4 and further confirmed the roles of these neurons in bilateral balance of body contraction during larval crawling by genetic inhibition of these neurons. Our method provides a new tool for accurate extraction of neural activities and movement of freely behaving small-size transparent animals.

Cortical gray matter and cerebral white matter atrophy and asymmetry in Parkinson’s disease patients with normal cognitive precede

Background Parkinson’s disease is the second most common neurodegenerative disorder with complex and distributed motor and non-motor symptoms. In this study, cortical gray matter (GM) and cerebral white matter (WM) overall atrophy, and asymmetry of atrophy are investigated in PD with normal cognitive function. Method Forty-eight male Parkinson’s disease(PD) patients with normal cognitive precede (PD-NC), and thirty matched healthy control (HC) subjects were selected from the Parkinson’s Progression Markers Initiative (PPMI) database. Brain structures volumes were extracted using Freesurfer software based on subject 3 tesla MRI images. The normalized volume of cortical GM and cerebral WM were compared in two study groups, and then the asymmetry index (AI) of GM and WM atrophy was also assessed in two groups. Statistical analysis was constructed using a t-test with p < 0.05 of significance. Results No significant difference was observed in the volume of cortical GM and cerebral WM in the two study groups. The cortical GM asymmetry index in the PD-NC group was significantly (p = 0.01) higher than the HC group, however, no difference was observed for the cerebral WM asymmetry index. Conclusion Atrophy in cortical GM and WM was not observed between the PD-NC and the HC group, however, the asymmetry index in GM was significant between the two group. It seems that the brain’s bilateral balance has ruptured in PD. Cortical GM asymmetry in PD-NC can be considered a potent biomarker and should be investigated more in the future. In future studies, construction of a longitudinal study on this issue could be useful.

Investigating the value of balance and proprioception scores to predict lower limb injuries in professional judokas

We investigated the ability of balance and proprioception screening tests to predict lower limb injuries in professional male judokas. Fifty-three male judokas of the national teams (Mean ± SD, age 18.68 ± 3.08 years, weight 75.34 ± 11.62 kg, height 175.28 ± 7.24 cm) participated in this study. Limits of stability (LOS), single leg stability (SLS), and knee joint position sense (JPS) was recorded as the screening tests before starting the 10 month follow up. Lower limb injury was recorded all through the follow up. Fifteen lower limb sport injuries were recorded for 53 judokas during the follow-up recordings. Significant accuracy of SLS, overall bilateral ratio (AUC 0.646, 95% CI 0.452–0.839, p = 0.046), as well as JPS 60° bilateral ratio (AUC 0.657, 95% CI 0.480–0.834, p = 0.044), and LOS overall (AUC 0.696, 95% CI 0.551–0.840, p = 0.031) were revealed discriminating between injured and uninjured judokas. The optimum cut-off of SLS, overall bilateral ratio, JPS 60° bilateral ratio, and LOS overall associated with belonging to uninjured judokas group was ≤ 1.15%, ≤ 1.09%, and ≤ 1.09 respectively (sensitivity, 0.763, 0.711, 0.789 respectively; specificity, 0.600). Although the absolute unilateral balance and proprioception scores were almost the same between injured and non-injured judokas, the bilateral ratio of both these indices were different between the two groups. Lower limbs bilateral balance and proprioception asymmetries is a more important risk factor than the absolute unilateral balance and proprioception scores for sustaining lower limb injuries in professional male judokas. Medical professionals and coaches are suggested to use these findings as pre-participation screening tools identify injury-prone athletes.

Comparison of balance and function in the long term after all arthroscopic ATFL repair surgery.

We compared the balance, ROM, clinical scores, kinesiophobia and functional outcomes of patients after all-arthroscopic ATFL repair surgery with the non-operated side and healthy control group. Twenty-five patients with follow up time 37.32 ± 12.51months and twenty-five healthy controls participated in the study. Postural stability was evaluated with the Biodex® balance system by measuring overall (OSI), anterior-posterior (API), and mediolateral (MLI) stability index. Dynamic balance and function were measured using the Y-balance test (YBT) and single-leg hop test (SLH). Limb symmetry index for SLH and contralateral comparisons (YBT, OSI, API, MLI) was performed. The AOFAS score and the Tampa Scale of Kinesiophobia (TSK) were applied. Two subgroups were created (with OLT and without OLT). There was no statistically significant difference between subgroups. There was no statistically significant difference between bilateral OSI, API, MLI values and YBT anterior reach distances of all groups. Single leg OSI (0.78 ± 0.27/0.55 ± 0.12), API (0.55 ± 0.22/0.41 ± 0.10), and MLI (0.40 ± 0.16/ 0.26 ± 0.08) values were significantly worse and YBT posteromedial (73.88 ± 15.70/89.62 ± 12.25), posterolateral reach (78.03 ± 14.08/92.62 ± 8.25) and the SLH distance (117.14 ± 27.84/165.90 ± 20.91) were significantly lower on the patients than controls (p < 0.05), respectively. In contralateral comparisons, all reach distances on YBT were similar and SLH limb symmetry index of the operated side was 98.25%. AOFAS scores of the patients were 92.62 ± 11.13, TSK scores were 46.45 ± 11.32, and 21 patients (84%) had kinesiophobia. AOFAS score, limb symmetry index, and bilateral balance of the patients were successful; however, there is single-leg postural stability insufficiency and kinesiophobia. Although the extremity symmetry index of the operated side of the patients was 98.25, the fact that these values are lower than those of the healthy control may have been caused by kinesiophobia. During the long-term rehabilitation, kinesiophobia should be considered and single-leg balance exercises should be monitored during the rehabilitation period. Level III.

Dynamometric Strength Profile of Hip Muscles in Youth Soccer Players.

Soccer is the most widely practiced sport in the world, demanding high-speed activities such as jumps, sprints and changes of direction. Therefore, having optimal levels of muscle strength improves performance and reduces the injury rate. The objectives of our study were (i) to determine the dynamometric profile of hip muscle strength in young soccer players by position, evaluated at different isokinetic speeds, (ii) to describe the conventional and functional unilateral muscle strength ratios, (iii) to analyze the bilateral balance. Thirty-seven male soccer players (age 17.02 ± 0.92 years) participated in the study. Strength assessment was performed with a functional electromechanical dynamometer, and concentric and eccentric strength of abductors, adductors, extensors and hip flexors were measured bilaterally at 0.5 m/s and 1 m/s. For eccentric right hip abduction at 0.5 m/s, defenders are significantly stronger than midfielders (p = 0.013) and stronger than forwards (p = 0.140). For eccentric right hip adduction at 0.5 m/s, defenders are significantly stronger than midfielders (p = 0.005) and stronger than forwards (p = 0.253), as for eccentric right hip adduction at 1 m/s, defenders are significantly stronger than midfielders (p = 0.014) and stronger than forwards (p = 0.084). There is a significant effect for the conventional strength ratio of left abduction/adduction at 1 m/s. The conventional strength ratio of forwards is significantly higher than that of defenders (p = 0.045) and higher than that of midfielders (p = 0.152). Concentric and eccentric hip strength values differ according to playing position.

Determinants of Bilateral Trade Balance Between Georgia and China

This paper aims to empirically examine the drivers of the bilateral balance of the trade model for the Georgian-Chinese economy from 2000 to 2020 and the influence of the Georgia-China free trade agreement on the Georgian-Chinese balance of trade. The Error Correction Model (ECM) of the ARDL was used to see if the balance of trade and its predictors have a long-term relationship. One of the ARDL’s defining properties is that it may be utilized in circumstances when there is minimal data, regardless of the level of variable integration. According to the findings, a perceived effective exchange rate has a statistically significant positive impact on the balance of trade in the long run and a statistically significant negative impact on the balance of trade in the short run. The output is shaped to favor the presence of the elasticity attitude’s J-Curve impact. The study also found that the comparative supply of money (MS) and GDP have only a minor impact on the trade balance in the medium and long run. The sponging and monetary methods are ineffective in characterizing the bilateral trade deficit between Georgia and China.

Combined driving: task-specific position impacts grip strength of equestrian athletes

BackgroundLoss of hand strength is a predictor of mortality in aging populations. Despite reliance on the hands to participate in equestrian driving activity, no existing studies focus on associations of hand strength to athletic performance. Therefore, this study 1) established baseline handgrip of equestrian combined drivers in standing and task-specific positions, 2) determined endurance of task-specific handgrip, 3) compared handgrip strength to normative data, and 4) evaluated associations of handgrip and equestrian-specific variables.MethodsThere were 51 combined drivers (9 males, 42 females) ages 21–78 who completed a survey, standing handgrip, and grip strength and endurance in a task-specific position. Sixty-three percent of participants were 50 years or older. The dynamometer grip bar was normalized by hand size for standing tests; to duplicate sport-specific tasks, the bar was set to the closest setting. Significances were determined at p < 0.05.ResultsDrivers with more than 30 years of experience demonstrated highest summed standing (73.1 ± 5.2 kg) and summed sitting (59.9 ± 6.3 kg) grip strength. Females 60-years and older had greater handgrip endurance (Χ2 = 8.323, df = 2, p = .0156) in non-dominant (left) hands. Males (60%) reported more cold weather fatigue than females. Glove wearing was associated with bilateral endurance balance; a higher proportion of endurance balance between dominant and non-dominant (49% high-high and 29% low-low; Χ2 = 11.047, df = 1, p = .0009) was realized. There were no associations of handgrip and prior injury.ConclusionsOur results have implications in understanding task-specific and normative grip strengths in aging equestrian populations. Bilateral balance in handgrip strength and endurance is important particularly in maintaining strength in non-dominant hands over time. Equestrian driving sport promotes greater endurance in older females. Strength can be improved by participating in combined driving, and engagement in this sport over several years’ benefits hand strength over time. This cohort of equestrian participants provides evidence that participating in hand-specific activities promotes greater strength, which has been previously shown to improve aging outcomes.

Assessment of changes in muscle activity using electromyography in patients undergoing orthognathic surgery

The aim of the present clinical trial study is to evaluate the effect of double jaw orthognathic surgery (OGS) on electromyographic activity of the masseter, anterior temporal, digastric, and sternocleidomastoid muscles in skeletal Class III patients. This prospective study included 10 patients who underwent Lefort 1 osteotomy of the maxilla and genioplasty of the mandible to correct skeletal dental class III malocclusion and presurgical and postsurgical EMG data were analyzed and compared. The participants underwent bilateral surface electromyography activity evaluation with a focus on the masseter, anterior temporalis, digastric and sternocleidomastoid muscles. Recordings were made each during 3 jaw positions: clench, resting and swallowing positions. The pre-surgical EMG data were compared with the post-surgical EMG data taken after 1 month to evaluate any changes in muscle activity. A significant increase in the average EMG activity after an orthognathic corrective surgery was observed. There were no significant postoperative changes in the EMG potentials of the anterior temporalis and masseter bilateral balance in the pre-op and post-op clench positions. Significant muscle posturing was observed in the post-op resting position with bilateral masseter, sternocleidomastoid, and right temporalis values&gt;2mcv with mandible and rest.

Biomechanical study of transsacral-transiliac screw fixation versus lumbopelvic fixation and bilateral triangular fixation for \u201cH\u201d- and \u201cU\u201d-type sacrum fractures with traumatic spondylopelvic dissociation: a finite element analysis study

ObjectiveTo compare the biomechanical stability of transsacral-transiliac screw fixation and lumbopelvic fixation for “H”- and “U”-type sacrum fractures with traumatic spondylopelvic dissociation.MethodsFinite element models of “H”- and “U”-type sacrum fractures with traumatic spondylopelvic dissociation were created in this study. The models mimicked the standing position of a human. Fixation with transsacral-transiliac screw fixation, lumbopelvic fixation, and bilateral triangular fixation were simulated. Biomechanical tests of instability were performed, and the fracture gap displacement, anteflexion, rotation, and stress distribution after fixation were assessed.ResultsFor H-type fractures, the three kinds of fixation ranked by stability were bilateral triangular fixation > lumbopelvic fixation > transsacral-transiliac screw fixation in the vertical and anteflexion directions, bilateral triangular fixation > transsacral-transiliac S1 and S2 screw fixation > lumbopelvic fixation in rotation. The largest displacements in the vertical, anteflexion, and rotational directions were 0.57234 mm, 0.37923 mm, and 0.13076 mm, respectively. For U-type fractures, these kinds of fixation ranked by stability were bilateral triangular fixation > lumbopelvic fixation > transsacral-transiliac S1 and S2 screw fixation > transsacral-transiliac S1 screw fixation in the vertical, anteflexion, and rotational directions. The largest displacements in the vertical, anteflexion, and rotational directions were 0.38296 mm, 0.33976 mm, and 0.05064 mm, respectively.ConclusionAll these kinds of fixation met the mechanical criteria for clinical applications. The biomechanical analysis showed better bilateral balance with transsacral-transiliac screw fixation. The maximal displacement for these types of fixation was less than 1 mm. Percutaneous transsacral-transiliac screw fixation can be considered the best option among these kinds of fracture fixation.

Isokinetic Muscular Strength and Aerobic Physical Fitness in Recreational Long-Distance Runners: A Cross-Sectional Study.

Andrade, MS, Silva, WA, de Lira, CAB, Mascarin, NC, Vancini, RL, Nikolaidis, PT, and Knechtle, B. Isokinetic muscular strength and aerobic physical fitness in recreational long-distance runners: A cross-sectional study. J Strength Cond Res 36(3): e73-e80, 2022-Muscular strength, bilateral asymmetry, and imbalance between antagonist muscles have been considered as risk factors for knee injuries. Moreover, muscular strength has also been associated with aerobic performance. The aim of the study was to investigate bilateral muscular symmetry and muscular strength balance assessed by isokinetic dynamometry in recreational long-distance runners and to verify whether knee muscular strength would be associated with maximal oxygen uptake (V̇o2max), anaerobic threshold (AT), and running economy (RE). Thirty-nine runners (male [n = 24]: age, 30 ± 8 years; height, 176.0 ± 7.3 cm; body mass, 70.3 ± 8.0 kg; race pace below 4:30 min·km-1 and female [n = 15]: age, 31 ± 7 years; height, 163.0 ± 3.8 cm; body mass, 55.9 ± 4.7 kg; race pace below 5:00 min·km-1) participated in this study. Comparing the conventional knee balance ratio with the literature recommendation (60%), male runners presented significantly lower values for the nondominant side (55.5 ± 7.3%; p = 0.001; d = 0.85; confidence interval [CI] = 0.47 to 1.20) but not for the dominant side (58.1 ± 6.8%; p = 0.208; d = 0.37; CI = -0.12 to 0.86). Female runners presented lower values for both sides (52.1 ± 7.1%; p = 0.001; d = 1.55; CI = 0.86 to 2.20 and 50.7 ± 8.0%; p = 0.001; d = 1.62; CI = 0.90 to 2.30 for dominant and nondominant sides, respectively). Female and male runners presented nonfunctional ratio imbalance and asymmetry of bilateral strength. Strength outcomes were not associated with V̇o2max, AT, or RE. In conclusion, recreational runners were characterized by an imbalance in muscular strength between knee flexor and extensor muscles, which was more obvious in female runners, and by symmetrical thigh muscle strength values. Moreover, muscular isokinetic knee flexor and extensor muscle strength was not associated with aerobic fitness parameters.

Early warning of systemic risk in global banking: eigen-pair R number for financial contagion and market price-based methods

We analyse systemic risk in the core global banking system using a new network-based spectral eigen-pair method, which treats network failure as a dynamical system stability problem. This is compared with market price-based Systemic Risk Indexes (SRIs), viz. Marginal Expected Shortfall (MES), Delta Conditional Value-at-Risk (Delta-CoVaR), and Conditional Capital Shortfall Measure of Systemic Risk (SRISK) in a cross-border setting. Unlike paradoxical market price based risk measures, which underestimate risk during periods of asset price booms, the eigen-pair method based on bilateral balance sheet data gives early-warning of instability in terms of the tipping point that is analogous to the R number in epidemic models. For this regulatory capital thresholds are used. Furthermore, network centrality measures identify systemically important and vulnerable banking systems. Market price-based SRIs are contemporaneous with the crisis and they are found to covary with risk measures like VaR and betas.

Study the Effects of Bilateral Balanced Occlusion and Canine Guidance on Masseter and Temporalis Muscle Activity in Implant-Retained Overdentures Constructed with Open and Closed Tray Impression

The aim of the study was to investigate the effects of balanced occlusion and canine guidance on masseter muscle activity in implant- retained overdentures constructed with open and closed tray impression. Material and methods: For the current study Twelve completely edentulous patients were selected from the Outpatient Clinic of Removable Prosthodontic Department, Faculty of Dental Medicine, Al Azhar University (Assiut branch) according to special inclusion and exclusion criteria. All procedures were explained to all the patients and informed consent was assigned by each patient before the commencement of the investigation. All patients were divided into two groups; with the first group open tray impression techniques was used. While the second group used close tray impression techniques.For each group two dentures were constructed; the first denture was constructed with bilateral balanced occlusion, while the second denture was constructed with canine guidance.Conclusion: Successful implant overdenture has a positive effect on the masticatory efficiency regardless of the type of impression used. Masticatory efficiency improved with closed tray impression method together with bilateral balance occlusion had the best masticatory efficiency during chewing soft food or hard food than any other impression method (close-open tray impression) with any other occlusion (bilateral balance-canine guided occlusion) during chewing soft or hard food.

Boxing training in patients with stroke causes improvement of upper extremity, balance, and cognitive functions but should it be applied as virtual or real?

ABSTRACT Background: Upper extremity hemiparesis is one of the most common post-stroke disabilities requiring rehabilitation. Objective: To compare the effects of virtual and real boxing training in addition to neurodevelopmental treatment on the upper extremity, balance, and cognitive functions in hemiparetic stroke patients. Methods: Forty hemiparetic stroke patients were assigned to either real boxing group-RBG (n=20) or virtual boxing group-VBG (n=20), for a total of 24 sessions (3 sessions/week for 8 weeks). The primary outcome was upper extremity motor ability (Wolf Motor Function Test-WMFT). The secondary outcomes were arm-hand dexterity (Manual Dexterity Test-MMDT), goal-oriented performance (Video Boxing Analysis-VBA), balance functions (Fullerton Advanced Balance Scale-FAB-T), and cognitive functions (Addenbrooke’s Cognitive Examination-Revised-ACE-R). Results: There was small treatment effect on ACE-R, small-medium effect for WFMT and MMDT and large effect on bilateral punching time [VBA (Cohen’s d- VBG=0.83; RBG=0.95)] and balance [FAB-T (Cohen’s d - VBG=0.89; RBG=0.82)] after treatment in both groups. No significant differences were found for training effects between the groups for upper extremity functions [WMFT (p=0.799; Cohen’s d=-0.07), MMDT-PT (p=0.327; Cohen’s d=-0.10), MMDT-THTPT (p=0.779; Cohen’s d=-0.17) and VBA bilateral punch number (p=0.068; Cohen's d=0.15)], balance functions [FAB-T (p=0.602; Cohen’s d=-0.19)] and cognitive functions [ACE-R total (p=0.947, Cohen’s d=0.09)]. Conclusion: The study showed that virtual and real boxing training methods, in addition to neurodevelopmental treatment, are effective in improving upper extremity, balance, and cognitive functions in patients with hemiparetic stroke. The training effects were higher on bilateral punching time and balance functions for both groups. There was no superiority of either approach.

A Case for Geoeconomic Restraint: Offensive Realism and the Inflated Threat of Chinese Economic Initiatives

ABSTRACT Many analysts and practitioners argue that the United States should actively engage in geoeconomic competition with China. This article suggests that an argument against this claim can be counter-intuitively derived from offensive realism – an influential international relations theory known for its pessimism on great power relations. Offensive realism suggests that a great power should try to maximize its material capacity and pay careful attention to the balance of material power between major states. It also suggests that a great power should avoid spending its limited resources in influence or legitimacy competition in the peripheries. In this context, offensive realism prescribes that the United States should not actively oppose Chinese economic initiatives unless those projects have meaningful impact on the bilateral balance of power and its security. On the contrary, Washington should encourage China to expand its investments in geoeconomic initiatives since China is likely to end up spending a large amount of its resources in regions that do not have significant implications to the balance of material power. For offensive realists, a great power should take balance of power competition in major regions seriously, not influence competition around the globe. Accordingly, the United States should restrain itself and avoid geoeconomically confronting China.

Cutaneous Inputs to Dorsal Column Nuclei in Adult Macaque Monkeys Subjected to Unilateral Lesion of the Primary Motor Cortex or of the Cervical Spinal Cord and Treatments Promoting Axonal Growth.

The highly interconnected somatosensory and motor systems are subjected to connectivity changes at close or remote locations following a central nervous system injury. What is the impact of unilateral injury of the primary motor cortex (hand area; MCI) or of the cervical cord (hemisection at C7-C8 level; SCI) on the primary somatosensory (cutaneous) inputs to the dorsal column nuclei (DCN) in adult macaque monkeys? The effects of treatments promoting axonal growth were assessed. In the SCI group (n = 4), 1 monkey received a control antibody and 3 monkeys a combination treatment of anti-Nogo-A antibody and brain-derived neurotrophic factor (BDNF). In the MCI group (n = 4), 2 monkeys were untreated and 2 were treated with the anti-Nogo-A antibody. Using trans-ganglionic transport of cholera toxin B subunit injected in the first 2 fingers and toes on both sides, the areas of axonal terminal fields in the cuneate and gracile nuclei were bilaterally compared. Unilateral SCI at C7-C8 level, encroaching partially on the dorsal funiculus, resulted in an ipsilesional lower extent of the inputs from the toes in the gracile nuclei, not modified by the combined treatment. SCI at C7-C8 level did not affect the bilateral balance of primary inputs to the cuneate nuclei, neither in absence nor in presence of the combined treatment. MCI targeted to the hand area did not impact on the primary inputs to the cuneate nuclei in 2 untreated monkeys. After MCI, the administration of anti-Nogo-A antibody resulted in a slight bilateral asymmetrical extent of cutaneous inputs to the cuneate nuclei, with a larger extent ipsilesionally. Overall, remote effects following MCI or SCI have not been observed at the DCN level, except possibly after MCI and anti-Nogo-A antibody treatment.

Choosing the denture occlusion - A Systematic review.

Aim:The aim of the study is to acquire evidence for the choice of occlusion with anatomic/modified anatomic teeth in complete denture prosthesis.Settings and Design:Systematic review following PRISMA guidelines.Materials and Methods:The study reviewed original articles on various occlusal schemes bilateral balance occlusion (BBO), lingual occlusion (LO), Canine guided occlusion (CG), posterior group function occlusion (PGFO) have been applied to the complete dentures and were analyzed for the objective or subjective or both evaluations. The data were collected in standard format with the needed information such as year of publication, type of study, occlusal schemes compared, test methodology used, sample size for experiment and control, assessment of retention, stability, and other factors which determine the quality of life and period of follow-up. The risk of bias was calculated using tools RoB2.0 and robvis. At all stages, the inclusion and exclusion of studies were discussed among the reviewers.Statistical Analysis used:Due to the heterogeneity in the data of the included studies no statistical analysis was used.Results:Of the 1896 articles screened only 17 studies were included in the systematic review. These were discussed amongst the reviewers regarding the various occlusion schemes used. The subjective and objective criteria used in the studies was tabulated separately. They were then analyzed for the risk of bias using the robvis 2 tool.Conclusion:No scheme is more superior to the other with the anatomic tooth forms. The use of alternative unbalanced schemes produces a similar satisfactory clinical outcome. The ridge classification also has a significant role to play in the preference for an occlusal scheme.

How Fast Could the Bilateral Balance of Trade Between the US and China Be Brought Down to Zero?

Der Handelskonflikt zwischen den USA und China hat sich in den letzten Monaten deutlich verschärft. Seit dem WTO-Beitritt 2001 hat China seinen Überschuss gegenüber den USA kontinuierlich erhöht. 2018 erreichte er mit 420 Mrd. US-$ ein Rekordniveau. Die US-Regierung verfolgt nun mithilfe von Strafzöllen das Ziel, die bilaterale Handelsbilanz beim Warenhandel zu reduzieren.

Bilateral Lean Mass and Dynamic Balance Asymmetry in Collegiate Athletes

Bilateral Lean Mass and Dynamic Balance Asymmetry in Collegiate Athletes

An Investigation of the Effects of Exercises Applied on Unstable Surfaces on High School Students

In this study, it was aimed to determine the effects of plyometric exercises applied on unstable platforms on static and dynamic balances of soccer players who continued their high school education. In the study, male soccer players with similar socio-economic status between the ages of 14 and 16 formed the study group (SG; n=24; age=15.08±1.36) and the control group (CG; n=22; age=15.22±1.62). Static Balance Eyes Open (SB-EO), Static Balance Eyes Closed (SB-EC) and Dynamic Balance tests (DB) were applied on the SG and CG as pre- and post-tests for both dominant leg (DL) and non-dominant leg (NDL). SG athletes were subjected to plyometric exercises on unstable surfaces for sixteen sessions that were integrated into the physical education lessons in high school while CG athletes performed only a traditional soccer training program. As a result of the statistical analyses, when the pre-post test scores of the SG were examined, dynamic balance-dominant leg (DB-DL; p=0.03), dynamic balance-non-dominant leg (DB-NDL; p=0.03), static balance eyes open-dominant leg (SB-EO-DL; p=0 01), static balance eyes closed -dominant leg (SB-EC-DL; p=0.03) and static balance eyes closed-non-dominant leg (SB-EC-NDL; p=0.01) measurements were found statistically significant (p&lt;0.05) while the CG had statistical improvements only in SB-EO-DL measurements (p=0.03). When the differences between the two groups were examined, only SB-EC-DL measurements were found statistically significant in favor of the SG (p=0.03). In conclusion, especially the improvement of DL observed in the SG is important for optimum performance considering that it is necessary to use both legs effectively in soccer. Considering the multitude of activities performed on a single leg in soccer, it is thought that the increase in bilateral balance can improve the skills that determine soccer performance in difficult conditions such as dribbling, shooting and passing.

Effects of a 12-Month Complex Proprioceptive-Coordinative Training Program on Soccer Performance in Prepubertal Boys Aged 10–11 Years

Boraczyński, MT, Sozański, HA, and Boraczyński, TW. Effects of a 12-month complex proprioceptive-coordinative training program on soccer performance in prepubertal boys aged 10-11 years. J Strength Cond Res 33(5): 1380-1393, 2019-The aim was to examine the effects of a series of on-field proprioceptive-coordinative (P-C) exercises on motor performance (MP) in prepubertal soccer players. Fifty-three male soccer players aged 10.1-11.8 years were randomized among 2 experimental programs receiving P-C training (P-CT; n = 26) or regular training (RT; n = 27). A control group (C; n = 22) consisted of age-matched (10.3-11.9 years) cohorts not involved in any regular physical activity. Both experimental groups completed an identical 12-month comprehensive soccer program except training in P-CT was modified to substitute small-sided conditioning games with 24 multimode P-C exercises with modulated exercise intensity (every 8-9 weeks based on predicted maximal heart rate [HRmax]). Pre-, peri-, and posttraining measures included anthropometry and 5 tests assessing soccer-specific MP: movement rhythm (turning the ball backwards-T1), motor adaptation (running with the ball around poles-T2), spatial orientation (running to sequentially numbered balls-T3), balance (single-leg static balance-T4), and kinesthetic differentiation of movement (landing the ball on a 2 × 2 m sector-T5). Repeated-measures analysis of variance revealed no significance between-group differences for age, anthropometry, and body-fat percentage at baseline. Significant main effects for group (P-CT vs. RT) were found in all tests (T1-T5) and main effects for time (group P-CT) in T3-T5, whereas a significant group × time interaction was observed only in T4 (F = 2.98, p = 0.0204). Post hoc tests indicated that P-CT attained significantly better results than RT at peritraining (by 26.4%; p < 0.01) and posttraining (by 31.9%, p < 0.01). Modulated exercise intensity had little effect on soccer performance (T1-T3, T5). Based on the results, it is recommended that the training of young soccer players be supplemented with the bilateral balance exercises and games used in the study. Furthermore, the suitability of monitoring HR in P-C exercises targeting the analyzed MP skills is questionable.