Lower limbs micro-loading acutely attenuates repeated change-of-direction performance in male youth during small-sided soccer games.

BACKGROUND: Soccer players often wear light-weighted wearable resistance (WR) attached to different body parts during the warm-up period with the aim to improve measures of physical fitness. However, the effect of WR on physical performance is unknown. This study evaluated the effects of WR with different micro-loadings on repeated change-of-direction (RCoD) performance while executing small-sided soccer games (SSG). METHODS: Twenty male soccer players aged 16.0 ± 1.5 years (body mass 74.0 ± 7.4 kg, body-height 175.0 ± 10.0 cm) volunteered to participate in this study. Following a within-subject study design, players performed four specific warm-up protocols in randomized order with a rest of 72 h between protocols: (1) WR micro-loadings with 0.1% of body mass (WR0.1); (2) WR micro-loadings with 0.2% of body mass (WR0.2); (3) WR micro-loadings with 0.3% of body mass (WR0.3); (4) no WR (control = CONT). After the warm-up protocols, players performed 2 sets of 20-min SSG. The RCoD was collected at the 8th min of SSG (SSG 1-8 min), the 15th min of SSG1 (SSG1-15 min), and at the 15th min of SSG2 (SSG2-15 min). Outcomes included mean and total RCoD indices (i.e., mean time and total time for each condition). RESULTS: Based on the outcomes of a two-way repeated measures analysis of variance (ANOVA), WR0.1 and WR0.2 were more effective than control in dampening the decrease of RCoD's total time during SSG1-8 min, and SSG2-15 min (small ES: 0.24-0.35; p < 0.05). However, no significant differences were observed between WR0.3 and control. In addition, WR0.1 and WR0.2 significantly affected the decreases in RCoD's mean best time during SSG1 and SSG2 which was observed in the unloaded condition (CONT) and consequently displayed a lower rate of RCoD performance decrease. CONCLUSION: This study reports that wearing lower extremity WRs with micro-loads of 0.1% or 0.2% of body mass attenuates physical fatigue indicated in attenuated RCoD performance while executing SSG.

Effects of Unloaded vs. Ankle-Loaded Plyometric Training on the Physical Fitness of U-17 Male Soccer Players.

The aim of this study was to compare the impact of two differing plyometric training programs (loaded plyometrics (with 2.5% of body mass placed above the ankle joint) vs. unloaded plyometrics), performed biweekly for 10 weeks, on the physical fitness of elite junior male soccer players. Participants aged 16.0 ± 0.5 years were randomly assigned between unloaded plyometrics (UP; n = 12), loaded plyometrics (LP; n = 14) and control (C; n = 12) groups. Two-way analyses of performance (group x time) were assessed by 40-m sprint times; 9-3-6-3-9 m sprints with 180° turns (S180°); 9-3-6-3-9 m sprints with backward and forward running (SBF); and 4 × 5 m sprints (S4 × 5 m); four jump tests; measures of static and dynamic balance; repeated change of direction tests and the Yo-Yo intermittent recovery test. Both LP and UP enhanced sprinting performance relative to C (p < 0.05) but performance increased more in LP relative to UP (p < 0.05) in all sprints except 40 m. Change of direction times were also significantly shortened by LP relative to UP (p < 0.05) and C (p < 0.01) in all tests, with no significant differences between UP and C. Jumps heights increased similarly in both LP and UP relative to C (p < 0.05), with no significance between LP and UP. LP and UP also enhanced repeated change of direction scores relative to C (p < 0.01) with greater changes in LP than in UP (p < 0.01). Finally, LP enhanced some balance scores relative to UP (p < 0.05) and C (p < 0.05). We conclude that the introduction of 10 weeks of in-season loaded plyometrics into the regimen of U17 male soccer players yields gains in several physical performance scores relative to either unloaded plyometrics or the control training regimen.

Influência do peso adicional no alcance manual de lactentes a termo e pré-termo: análise de variáveis categóricas do movimento / Influence of additional weight in the reaching behavior of full-term and preterm infants: analysis of categorical variables of movement

Resumo Objetivo: Investigar o efeito do peso adicional nos ajustes proximais e distais do alcance em lactentes a termo (AT) e pré-termo tardios (PTT). Método: Foram avaliados 10 lactentes AT e 9 PTT dos 5 aos 7 meses de idade. As variáveis analisadas foram: a) ajustes proximais: unimanuais ou bimanuais; b) ajustes distais: abertura das mãos (aberta, fechada ou semiaberta) e orientação das mãos (horizontalizada, verticalizada ou oblíqua). Os procedimentos analisados foram: P1 (linha de base) e P2 (acréscimo de 20% da massa do membro superior de peso adicional). Para verificar a associação entre os procedimentos e as variáveis dependentes utilizou-se o Teste Qui-quadrado (p<0,05). Resultados: O peso adicional proporcionou a diminuição de alcances bimanuais aos 5 e 7 meses no grupo PTT, o aumento da frequência de mão verticalizada e a diminuição da frequência de mão aberta no início do movimento, aos 6 meses. No grupo AT, o peso implicou no aumento da mão verticalizada no início e no fim do movimento, aos 5 meses, e ao final do movimento, aos 7 meses, e diminuiu a frequência de mão aberta no início e final do alcance, aos 6 meses. Conclusão: O peso adicional favoreceu um movimento mais maduro na maioria das variáveis analisadas e, de forma mais expressiva, no grupo prematuro. Assim, pode tornar-se um instrumento para o treino inicial do alcance, quando o objetivo for a estimulação de alcances unimanuais com a mão verticalizada.

Abstract Objective: The aim of this work is to investigate the effects of additional weight in the proximal and distal adjustments of the reaching behavior of full-term and preterm infants. Method: We evaluated 10 full-term and 9 low risk preterm infants from 5 to 7 months age. The following variables were analyzed: a) proximal adjustments: unimanual or bimanual; b) distal adjustments: hand opening (open, closed, semi-open) and hand orientation (horizontal, vertical, oblique). Variables were analyzed in two procedures: P1 (baseline) and P2 (addition of 20% of the total mass of the infant's upper limb). To verify the association between procedures and dependent variables was applied Chi-Square Test (p<0,05). Results: Additional weight decreased of bimanual frequency for the preterm group at 5 and 7 months old, increased vertical hand frequency and decreased open hand frequency at 6 months. In the full-term group, additional weight increased the vertical hand frequency at the initiation and at the end of the movement at 5 months and at the end of the movement at 7 months. It also decreased open hand frequency at the initiation and at the end of the reaching at 6 months. Conclusion: Additional weight favored a more mature movement in the majority of variables analyzed, more expressively in the preterm group. Therefore, it can become an instrument of training this skill in the beginning of the reaching, when looking for verticalized hand unimanual reaching stimulation.

Multiscale investigation on the effects of additional weight bearing in combination with low-magnitude high-frequency vibration on bone quality of growing female rats.

This study aimed to explore the effects of additional weight bearing in combination with low-magnitude high-frequency vibration (LMHFV; 45 Hz, 0.3 g) on bone quality. One hundred twenty rats were randomly divided into ten groups; namely, sedentary (SED), additional weight bearing in which the rat wears a backpack whose weight is x% of the body weight (WBx; x = 5, 12, 19, 26), basic vibration (V), and additional weight bearing in combination with LMHFV in which the rat wears a backpack whose weight is x% of the body weight (Vx; x = 5, 12, 19, 26). The experiment was conducted for 12 weeks, 7 days per week, and 15 min per day. A three-point bending mechanical test, micro computed tomography, and a nanoindentation test were used. Serum samples were analyzed chemically. Failure load in V19 rats was significantly lower than that in SED rats (P < 0.05). Vx (x = 5, 12, 19, 26) rats showed poor microarchitectures. The content of tartrate-resistant acid phosphatase 5b was significantly higher in Vx (x = 5, 12, 19, 26) rats than that in SED rats (P < 0.05). V26 rats demonstrated comparatively better nanomechanical properties of materials than the other vibrational groups. Additional weight bearing in combination with LMHFV negatively affected the macromechanical properties and microarchitecture of bone. Heavy additional weight bearing, such as 26% of body weight, in combination with LMHFV was able to improve the nanomechanical properties of growing bone material compared with LMHFV. A combined mechanical stimulation was used, which may provide useful information to understand the mechanism of this mechanical stimulation on bone.

Influence of Additional Ankle Weights on Kinematic Variables of Late Preterm Infants Aged 3-4 Months.

The authors analyzed and compared the effect of additional weight on the spatiotemporal parameters of the kicking movement of late preterm and full-term infants. The experiment was divided into 4 conditions: training, baseline, weight, and postweight. In the W condition, a weight of one third the lower limb mass was added to the infant's ankle. During the baseline and postweight conditions, the ankle weight was removed. Late preterm infants do not differ from full-term infants in relation to spatiotemporal variables at 3 and 4 months. However, during the weight condition, the straightness index and the hip-ankle and knee-ankle correlations decreased in the preterm infants at both ages. In contrast, the straightness index increased in the postweight condition compared to the baseline values at both ages.

Long-term results after revisions of failed primary vertical banded gastroplasty.

AIM: To compare the results after revision of primary vertical banded gastroplasty (Re-VBG) and conversion to sleeve gastrectomy (cSG) or gastric bypass (cRYGB). METHODS: In this retrospective single-center study, all patients with a failed VBG who underwent revisional surgery were included. Medical charts were reviewed and additional postal questionnaires were sent to update follow-up. Weight loss, postoperative complications and long-term outcome were assessed. RESULTS: A total 152 patients were included in this study, of which 21 underwent Re-VBG, 16 underwent cSG and 115 patients underwent cRYGB. Sixteen patients necessitated a second revisional procedure. No patients were lost-to-follow-up. Two patients deceased during the follow-up period, 23 patients did not return the questionnaire. Main reasons for revision were dysphagia/vomiting, weight regain and insufficient weight loss. Excess weight loss (%EWL) after Re-VBG, cSG and cRYGB was, respectively, 45%, 57% and 72%. Eighteen patients (11.8%) reported postoperative complications and 27% reported long-term complaints. CONCLUSION: In terms of additional weight loss, postoperative complaints and reintervention rate, Roux-en-Y gastric bypass seems feasible as a revision for a failed VBG.

Effects of additional external weight on posture and movement adaptations to fatigue induced by a repetitive pointing task.

Fatigue and additional weight are risk factors of injuries by falls. Posture and trunk movement changes occur with fatigue induced by a repetitive pointing task. These changes facilitate arm movement but they may also jeopardize postural stability. When equilibrium is challenged, e.g. with additional weight, strategies that represent less postural threat could develop with fatigue. Nineteen participants performed two sessions (without, with 20% body weight added load (Load)) of a repetitive pointing task until shoulder fatigue (8 on Borg CR-10). There was no difference in time to fatigue between the two sessions. Anterior deltoid, biceps and upper trapezius muscle activity significantly increased with fatigue. Peak medial-lateral center-of-pressure (CoP) velocity and the mean vertical position of the reaching shoulder were both significantly lower with fatigue, though these fatigue-induced decreases were smaller with the added load. Reach-to-reach variability in CoP displacement significantly increased with fatigue, and more so with the added load. With fatigue, significant contralateral shifts occurred at the reaching shoulder and elbow joints, and ranges of motion (RoM) significantly increased at most joints but not at the center-of-mass (CoM). Conversely, Load main effects were mostly seen in CoM dependent measures. Significantly increased variability in mean and range values was seen with fatigue and Load in most of our kinematic and CoP dependent measures, with the most notable effects on CoM dependent measures. Findings suggest that the postural control system adapts to combined perturbing factors of fatigue and added load, likely by using parallel control mechanisms.

Influência do peso adicional nos chutes de lactentes pré-termo e de termo / Influence of additional weight on kicks of preterm and full-term infants

Introdução: O objetivo do estudo foi analisar e comparar padrões de chutes com e sem peso adicional em lactentes pré-termo e de termo aos 3 e 4 meses de idade. Materiais e métodos: Foram filmados 26 lactentes aos 3 e 4 meses de idade, divididos em Grupo Experimental, 12 lactentes pré-termo sem idade corrigida;e Grupo Controle, 14 lactentes de termo. O experimento foi subdividido em quatro condições, a saber: 1)Treinamento (T): o pesquisador tocava os pés dos lactentes no painel, elevando-o; 2) Linha de Base (LB):movimentos livres de chutes, podendo o lactente elevar ou não o painel com os pés; 3) Peso (P): acréscimo de tornozeleira pesando 1/3 da massa do membro inferior; 4) Pós-Peso (PP): idêntica à LB. Resultados: Na variável frequência de chutes, constatou-se diferença entre as idades [F(5,72) = 5,620; p = 0,0035] e entre ascondições LB-P (p = 0,023) e P-PP (p < 0,001). Na variável frequência de contato, obteve-se diferença entre as condições LB-P (p = 0,002) e P-PP (p < 0,001). Na variável sucesso ao elevar o painel, constatou-se diferença entre os grupos (x²₍₁₎ = 4,341; p = 0,0013) e as condições LB-P (p = 0,003), LB-PP (p = 0,002) e P-PP(p = 0,002) aos 3 meses de idade. Na variável duração de chute, constatou-se diferença entre as condições LB-P (p = 0,023) e P-PP (p = 0,010). Conclusão: Os chutes de lactentes pré-termo se diferenciam dos termos dependendo das características intrínsecas e extrínsecas

INTRODUCTION: The aim of this study was to analyze and compare patterns of kicks with and without additional weight in preterm and full-term infants of 3 and 4 months old. MATERIALS AND METHODS: Twenty-six infants were filmed at 3 and 4 months of age, divided into experimental group, 12 preterm infants without corrected age, and control group, 14 infants full-term. The experiment was subdivided into four conditions, namely: 1) Training (T): the investigator touched the infants' feet on the panel, raising it; 2) Baseline (B): free movements of kicks, the infant may raise or not the panel with feet, 3) Weight (W): addition of anklet weighing 1/3 the mass of lower limb, 4) Post-weight (PW): identical to B.RESULTS: Difference was found in the variable frequency of kicks, considering ages [F (5,72) = 5.620, p = 0.0035] and conditions B-W (p = 0.023) and W-PW (p < 0.001). In the variable frequency of contact difference was obtained considering conditions B-W (p = 0.002) and W-PW (p < 0.001). In the variable success in raising the panel, difference was found between groups (x2(1) = 4.341, p = 0.0013) and conditions B-W (p = 0.003), B-W (p = 0.002) and W-PW (p = 0.002) at 3 months of age. The variable length of the kick presented a difference between conditions B-W (p = 0.023) and W-PW (p = 0.010).CONCLUSION: The kicks of preterm infants differ depending on the intrinsic and extrinsic characteristics.