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The aim of this study was to determine the effects of different teaching methodologies (comprehensive vs. technical), developed during a unit of ultimate frisbee, on the physical demands, technical–tactical variables, game performance and physical fitness of secondary school children. Forty-seven students were divided into two groups: Comprehensive Teaching Group (CTG; n = 25, Age: 14.5 ± 0.5 years) and Technical Teaching Group (TTG; n = 22, Age: 14.9 ± 0.8 years). The teaching models (CTG vs. TTG) were composed of 8 sessions of 55 min. Physical fitness was developed with the Alpha-Fitness method, while physical variables were analysed using GPS; the technical and tactical variables performed during the matches were recorded using Full-HD video cameras. The results showed that the CTG students had greater mean speed (p < 0.001), mean heart rate (p = 0.006) and covered more total distance/time (p < 0.001) than the TTG students during sessions. After the intervention, the CTG students showed greater values in good passes (p = 0.001), good catches (p = 0.001), good decisions (p = 0.002) and game performance (p < 0.001), while the TTG students only showed higher values in game performance (p = 0.039). In conclusion, the comprehensive teaching model is shown to be an effective pedagogical option to learn ultimate frisbee because the students achieved a higher overall development in the physical demands expressed in the sessions and in the management of the technical–tactical actions in the offensive and defensive phases of the ultimate frisbee game.

The objective of this study was to evaluate the validity of a short assessment MyotonPRO protocol to measure the stiffness of the superficial muscles and tendons of the lower limbs. The stiffness of the dominant lower limb vastus lateralis (VL), rectus femoris (RF) and patellar tendon (PT) was evaluated in 52 healthy participants (26.9 ± 3.4 years) with two MyotonPRO protocols: the standard protocol (10 mechanical taps) and the short protocol (five mechanical taps). The myotonometry was performed at the midpoint of the length from the upper pole of the patella to the greater trochanter for the VL, and to the anterior superior iliac spine for the RF. The PT was evaluated 1 cm caudal from the inferior pole of the patella. Pearson’s correlation coefficients were calculated to determine the relationships between protocols. The validity of the short protocol was evaluated with Student’s t-test. High positive correlations were observed between the short and standard protocols in the stiffness of the VL (r = 0.959; p < 0.001), the RF (r = 0.967; p < 0.001) and the PT (r = 0.953; p < 0.001) and no differences were found between both protocols in the stiffness assessment of the VL, RF and PT (p > 0.05). Therefore, the five-compressions protocol is a valid protocol for the assessment of lower limb mechanical properties.

The aim of this study was to analyze the effects of dry needling (DN) in upper trapezius latent trigger points (LTrPs) on muscle stiffness. A total of 51 recreational physically active subjects with LTrPs in the upper trapezius volunteered to participate and were randomly divided into a DN-group (n = 27) and a sham-DN group (n = 24). Volunteers received 1-session of DN or placebo treatment. Muscle stiffness, measured with strain and shear-wave elastography, pressure pain threshold (PPT), post-needling soreness, and muscle thickness were evaluated before treatment, and at 30-min, 24-hours, and 72-hours follow-up after treatment. The DN-group showed lower values from baseline for muscle stiffness measured with shear-wave elastrography at 24-hours (from 44.44 ± 15.97 to 35.78 ± 11.65 kpa; P Perspective This study found that one session of DN intervention in latent trigger points of the upper trapezius muscle reduced muscle stiffness and the pressure pain threshold for the dry needling group compared to the sham dry needling group.

The aim of the present study was to provide a systematic review and meta-analysis of the main biases in practical applications of the different types of elastography in assessment of the stiffness of healthy patellar tendons. A literature search on four databases (Scopus, Web of Science, Pubmed and SportDiscus) was conducted on March 25, 2020. After analysis of 1,052 resultant articles, studies were included if they met two inclusion criteria: (1) studies were observational or randomized controlled trials; (2) studies included outcomes of patellar tendon stiffness. Twenty-one studies met the inclusion criteria and were included in this meta-analysis. Four meta-analyses were performed with respect to assessment procedure and participant characteristics. This meta-analysis found a low effect of examined portion of patellar tendon (standardized mean difference [SMD] = 0.27, 95% confidence interval [CI]: 0.01-0.54, n = 379, Z = 2.01, p = 0.04) and a high effect of knee flexion angle during assessment (SMD = -2.12; 95% CI: -2.67 to -1.58, n = 97, Z = 7.68, p0.01) in stiffness outcomes. The risk of bias was generally low, but the heterogenicity of the results downgraded the level of evidence. There is evidence in the elastography assessment of patellar tendon suggesting that the knee position and patellar tendon portion evaluated influence stiffness outcomes for patellar tendon in healthy volunteers.

The purpose of this study was to assess the effects of eccentric contraction execution time on the morphological and elastic properties of the patellar tendon (PT) in a six-week, single-leg decline squat (SLDS) exercise training program. In addition, the effects of a six-week detraining period on the same variables were evaluated. Fifty participants were randomized into the control group (CG; n = 15), experimental group 1 (EG6s; n = 17; eccentric contraction execution time = 6 s) and experimental group 2 (EG3s; n = 18; eccentric contraction execution time = 3 s). The thickness and elastographic index (EI) in different regions of interest (ROIs) in the PT were measured after 6 weeks of eccentric training using the single-leg decline squat exercise (three sessions per week, 80% of the eccentric one-repetition maximum) and after 6 weeks of detraining. There was an increase in the thickness of the PT in the different ROIs analyzed in both experimental groups at the end of the training period. Especially worth noting was the increase in the thickness of the PT at the proximal level in EG3s (p = 0.001), and the increase at the distal level in EG6s (p = 0.001). On the other hand, there was a reduction in EI in EG6S at the end of the intervention program (p = 0.021), and both experimental groups increased EI in the three regions of interest analyzed after the detraining period (p < 0.01). In conclusion, the execution time of the eccentric contraction in the SLDS exercise determines the anatomical level of the morphological adaptations in the PT. These morphological adaptations are lost after 6 weeks of detraining, producing an increase in tendon stiffness.

BACKGROUND: Whole-body electromyostimulation (WB-EMS) is a new tendency in training used to complement conventional training. OBJECTIVE: The aim was to analyze the effects of training with WB-EMS on body composition, strength and balance in middle-aged women. METHODS: Twenty-eight women were randomly assigned to two groups: the WB-EMS group (age = 48.1 ± 4.3 years) or the control group (CG) (age = 51.1 ± 5.4 years). All participants continued their training of 2 days⋅week-1 and 60 min⋅day-1 of endurance-dynamic strength exercises and additionally did 20 minutes more of dynamic strength exercises one day⋅week-1: the WB-EMS group did the additional training with WB-EMS and the CG did the same training but without WB-EMS. Body composition, muscle isokinetic strength of the knee flexors/extensors and postural stability were measured before and after 8 weeks of training. RESULTS: After the training program, the WB-EMS group showed lower values for the waist circumference (83.00 ± 7.37 vs. 78.50 ± 7.30 cm; p< 0.01), hip circumference (104.80 ± 8.61 vs. 101.00 ± 6.78 cm; p< 0.05) and total fat mass (37.04 ± 6.08 vs. 36.26 ± 5.78%; p< 0.05). In balance stability the WB-EMS group reduced their Fall Risk Index (1.70 ± 0.51 vs. 1.30 ± 0.38 AU; p< 0.01) and deviation (1.50 ± 0.43 vs. 1.03 ± 0.74 AU; p< 0.01) after training and showed lower values in the Fall Risk Index (p= 0.007) and deviation (p= 0.024). CONCLUSIONS: The WB-EMS training program helps reduce the risk of falling and improves body composition variables and balance results in middle-aged physically active women.

Introduction: The aim of this study was to determine the effects of muscular injuries in the lower limbs on the technical and physical performance of professional soccer players when they return to...

Background Plyometric training (PT) has been widely studied in sport science. However, there is no review that determines the impact of PT on the structural variables and mechanical properties of the lower limbs and physical performance. Objective The aim of this systematic review and meta-analysis was to determine the effects of PT on lower body muscle architecture, tendon structure, stiffness and physical performance. Methods Five electronic databases were analysed. The inclusion criteria were: (1) Availability in English; (2) Experimental studies that included a PT of at least eight sessions; and (3) Healthy adults subjects. Four meta-analyses were performed using Review Manager software: (1) muscle architecture; (2) tendon structure; (3) muscle and tendon stiffness; (4) physical performance. Results From 1008 search records, 32 studies were eligible for meta-analysis. Muscle architecture meta-analysis found a moderate effect of PT on muscle thickness (Standard Mean Difference (SMD): 0.59; [95% Confidence Interval (CI) 0.47, 0.71]) and fascicle length (SMD: 0.51; [95% CI 0.26, 0.76]), and a small effect of PT on pennation angle (SMD: 0.29; [95% CI 0.02, 0.57]). The meta-analysis found a moderate effect of PT on tendon stiffness (SMD: 0.55; [95% CI 0.28, 0.82]). The lower body physical performance meta-analysis found a moderate effect of PT on jumping (SMD: 0.61; [95% CI 0.47, 0.74]) and strength (SMD: 0.57; [95% CI 0.42, 0.73]). Conclusion PT increased the thickness, pennation angle and fascicle length of the evaluated muscles. In addition, plyometrics is an effective tool for increasing tendon stiffness and improving jump and strength performance of the lower body.

Background: Rhythmic gymnastics performance is characterized by technical elements involving flexibility, aerobic capacity and strength. Increased core strength in rhythmic gymnastics could lead to improved sporting performance. Objective: The aim of this study was to analyze the effect of 12 weeks of core muscle training on core muscle performance in rhythmic gymnasts. Methods: A randomized controlled study involving 24 rhythmic gymnastics was conducted. Participants were randomly assigned to a control group (CG, n = 12, age 13.50 ± 3.17 years) or a training group (TG, age 14.41 ± 2.35 years). Body composition, isometric strength of trunk, core endurance and core muscle electromyographic activity were measured (EMG) after 12 weeks of core training. Independent sample t-tests were carried out to compare baseline values between groups. A two-way repeated-measures analysis of variance (ANOVA) (time × group) was applied. Results: The TG improved body composition, trunk lean mass (mean differences MD = −0.31, p = 0.040), lean mass (MD = 0.43, p = 0.037) and bone mass (MD = −0.06, p &lt, 0.001) after training. Core training increased isometric strength of trunk, flexion test (MD = −21.53, p = 0.019) and extension test (MD = 22.7, p = 0.049), as well as the prone bridge core endurance test (MD = −11.27, p = 0.040). The EMG values also increased in the TG in prone bridge for front trunk (MD = −58.58, p = 0.026). Conclusions: Core strength training leads to improvements in body composition, as well as improvements in trunk strength and increases in muscle electromyographic activity. These improvements could therefore improve performance during competitive rhythmic gymnastics exercises.

The purpose of this study was to determine the evolution of the age of badminton players in the top 100 of the World Ranking for men and women from 1994 to 2020. Data were collected from badminton players participating in the top 100 World Rankings (4800 entries: 1233 players, 595 men and 638 women) from 1994 to 2020. The mean age of the top 100 and the average highest ranking of the players were analysed for both genders. The mean age of the male players in the World Ranking increased from 23.7 ± 3.2 years in 1994 to 26.3 ± 4.4 years in 2020 (p &lt, 0.001) and in female players, from 22.8 ± 3.8 years in 1994 to 24.7 ± 3.3 years in 2020 (p &lt, 0.001). In addition, women recorded a younger age at entry into the top 100 and when reaching their best ranking. Additionally, there has been a clear increase in Asian players in the top 100 of the World Ranking in recent years, reaching over 60%. These data could be used to develop and organise training plans in this sport, optimising and maximising players’ performance.

α-Actinin-3 is a protein with a structural role at the sarcomeric Z-line in skeletal muscle. As it is only present in fast-type muscle fibers, α-actinin-3 is considered a key mechanical component to produce high-intensity muscle contractions and to withstand external tension applied to the skeletal muscle. α-Actinin-3 is encoded by the gene ACTN3, which has a single-nucleotide polymorphism (p.R577X; rs1815739) that affects the expression of α-actinin-3 due to the presence of a stop codon. Individuals homozygous for the 577R allele (i.e., RR genotype) and RX heterozygotes express functional α-actinin-3, while those homozygous for the 577X (i.e., XX genotype) express a non-functional protein. There is ample evidence to support the associations between the ACTN3 genotype and athletic performance, with higher frequencies of the 577R allele in elite and professional sprint and power athletes than in control populations. This suggests a beneficial influence of possessing functional α-actinin-3 to become an elite athlete in power-based disciplines. However, no previous investigation has determined the frequency of the ACTN3 genotypes in elite badminton players, despite this sport being characterized by high-intensity actions of intermittent nature such as changes of direction, accelerations, jumps and smashes. The purpose of this study was to analyze ACTN3 R577X genotype frequencies in professional badminton players to establish whether this polymorphism is associated with elite athlete status. A total of 53 European Caucasian professional badminton players competing in the 2018 European Badminton Championships volunteered to participate in the study. Thirty-one were men (26.2 ± 4.4 years) and twenty-two were women (23.4 ± 4.5 years). Chi-squared tests were used to analyze the differences in the distribution of ACTN3 genotypes (RR, RX and XX) between categories and sexes. The ACTN3 RR genotype was the most frequent in the sample of professional badminton players (RR = 49.1%, RX = 22.6% and XX = 28.3%). None of the badminton players ranked in the world’s top ten possessed the XX genotype (RX = 60%, RR = 40%). The distribution of the ACTN3 genotypes was similar between male and female professional badminton players (men: RR = 45.2%, RX = 25.8% and XX = 29.0%; women: RR = 54.5%, RX = 18.2% and XX = 27.3%; χ2 = 0.58; p = 0.750). The distribution of the ACTN3 genotypes in badminton players was different from the 1000 genome database for the European population (χ2 = 15.5; p < 0.001), with an overrepresentation of the RR genotype (p < 0.05) and an underrepresentation of the RX genotype (p < 0.01). In conclusion, the expression of functional α-actinin-3, associated with RR and RX genotypes in the ACTN3 gene may confer an advantage for reaching the status of elite athlete in badminton, and especially the world’s top-ten ranking. Large-scale studies with different ethnic backgrounds are needed to confirm the association of the R allele of ACTN3 with badminton performance.

Objetivo: Analizar la morfología del raquis en escolares, comparar su forma en función del género y relacionar la aparición de anomalías con el peso de sus mochilas y el grado de incapacidad física. Material y Métodos: Se sometió a 219 escolares de entre 12 y 15 años (127 chicos y 92 chicas) a una medición de la situación de los cuerpos vertebrales y de la angulación de la columna torácica, lumbar y sacro-cadera mediante el uso del Spinal Mouse®, se pesaron sus mochilas y respondieron el cuestionario de Roland-Morris. Resultados: Las chicas presentaron mayor angulación en la zona torácica con unos valores de 24.4 ± 16.4º frente a 11.4 ± 17.9º de los chicos (p

Abián-Vicén, J, Martínez, F, Jiménez, F, and Abián, P. Effects of eccentric single-leg decline squat training performed with different execution times on maximal strength and muscle contraction properties of the knee extensor muscles. J Strength Cond Res 36(11): 3040-3047, 2022-The eccentric phase of the single-leg decline squat (SLDS e ) has been described as a method to maximally load the knee extensor and has been used as an easy and effective rehabilitation exercise for patellar tendinopathy. The purpose of this study was to examine the impact of 6-week SLDS e training with 2 technical execution times on changes related to strength and muscle contractile properties. Thirty-six healthy volunteers were randomly divided into 3 groups: a control group (CG, n = 13, no training), a slow training group ( n = 11, SLDS e in 6 seconds), and a fast training group ( n = 12, SLDS e in 3 seconds). Subjects completed a 6-week SLDS e training program (80% of eccentric one repetation maximum [1RM]) 3 days a week. Pre, post, and 6-week follow-up of maximal dynamic and isometric strength and muscle contractile properties were assessed. After 6 weeks, training maximal loads showed a significant increase ( p0.05) in 1RM of the SLDS e (∼92-95%), the concentric peak torque at 180°·s -1 (∼38%) and 60°·s -1 (∼25%), and the extension isometric peak torque (∼12%), with no differences between both experimental groups. Moreover, a decrease ( p0.05) was found in the contraction time of the vastus medialis (VM) and the response time of the 3 analyzed quadriceps muscles. After the 6-week detraining period, there was a decrease in strength in all tests and in both experimental groups (1RM = 28-37%, isometric and isokinetic tests = 7-17%) and all contractile properties returned to baseline, except for the response time of the vastus lateralis in the fast training group and the contraction time of the VM in the STG. In conclusion, the SLDS e training protocol produced significant increases in muscle strength, showing important neuromuscular changes regardless of the technical execution time. It was also found that the training reduced the response and contraction time of the knee extensor musculature.

This investigation presents a comparison of calcaneus bone stiffness of endurance runners of different ages and age-matched controls. We found that there was an age-associated decline in calcaneus bone stiffness in the control group while endurance runners prevented this decline, with a higher effect as the participants increased their age.Previous investigations have found that endurance runners have higher bone mineral density and other bone quality variables in mechanically loaded bones. However, it is unknown if endurance running might counteract the decline in bone stiffness that occurs with age. The purpose of this study was to compare calcaneus bone stiffness of endurance runners of different ages to age-matched controls.In a descriptive cross-sectional study, 182 endurance-trained male runners and 116 healthy untrained male controls underwent an ultrasonographic assessment of the calcaneus bone in the right and left heels. Calcaneal bone stiffness was calculated from assessments of the broadband ultrasound attenuation and the speed of sound.The line of best fit for the association between age and calcaneus stiffness was different between marathoners and controls (Z = - 2.1, P = 0.02). A two-way ANCOVA (condition × age) with body mass, and body mass index as covariates, revealed that there were main effects of condition (F = 26.8, P 0.01) and age (F = 4.2, P 0.01) for calcaneus stiffness, with a significant interaction between these two factors (F = 2.8, P = 0.03). The post hoc analysis revealed that calcaneus stiffness was significantly higher in marathoners of 40-44 years (121.5 ± 18.2 vs 101.1 ± 21.3 arbitrary units [A.U.], P = 0.01), 45-49 years (121.5 ± 19.7 vs 104.3 ± 13.4 A.U., P = 0.04), and 50 years (111.2 ± 17.9 vs 92.4 ± 16.0 A.U., P 0.01) than their untrained counterparts of the same age with no statistically significant differences in the remaining age groups.Endurance runners of 40 years had higher values of calcaneus stiffness than controls, providing evidence to support the potential effect of endurance running to reduce the age-related decline on calcaneus bone stiffness.

Background: Cross-education of strength refers to the strength gain that is transferred to the contralateral limb after a unilateral training program. Hypothesis: Unilateral eccentric training using different muscle contraction times would improve the structural and functional properties of the untrained contralateral limb. Study Design: Randomized controlled trial. Level of Evidence: Level 2. Methods: Thirty-six participants were randomized into a control group, experimental group 1 (EG6s; eccentric contraction runtime = 6 seconds) and experimental group 2 (EG3s; eccentric contraction runtime = 3 seconds). The thickness and elastographic index of the patellar tendon (PT), lean mass and fat percentage of the thigh, contractile properties of the vastus lateralis (VL), as well as isometric, concentric, and eccentric knee extensor peak torques, and eccentric single-leg decline squat (SLDSe) 1 repetition maximum (1-RM) were measured after 6 weeks of SLDSe training (3 times per week, 80% of 1-RM) and after 6 weeks of detraining in the untrained contralateral limb. Results: After training, there was an increase in lean thigh mass of the untrained limb in both groups: EG6s (0.17 ± 0.29 kg; P = 0.03; effect size [ES] = 0.15) and EG3s (0.15 ± 0.23 kg; P = 0.04; ES = 0.19). Likewise, both EG6s (62.30 ± 19.09 kg; P < 0.001; ES = 4.23) and EG3s (68.09 ± 27.49 kg; P < 0.001; ES = 3.40) increased their 1-RM, isometric (EG6s: 48.64 ± 44.82 N·m, P < 0.001, ES = 0.63; EG3s: 34.81 ± 47.30 N·m, P = 0.004, ES = 0.38), concentric at 60 deg/s and 180 deg/s and eccentric at 60 deg/s and 180 deg/s knee extensor peak torques ( P < 0.05) in the untrained limb. However, no differences were found in the contractile properties of the VL or in the thickness of the PT after eccentric training in either of the 2 experimental groups. Conclusion: Regardless of the runtime of the contraction, 6 weeks of SLSDe was effective for inducing structural and strength adaptations in the contralateral untrained limb. However, most of these adaptations were lost after 6 weeks of detraining. Clinical Relevance: Our study suggests that cross-education training can be of great importance for clinical application and musculoskeletal and neuromuscular rehabilitative processes after unilateral injury.

The aim of this study was to analyse the association of the use of the mobile phone with physical fitness (PF) and academic performance in secondary school students and its gender-related differences. A total of 501 high school students participated in the study (236 girls and 265 boys, 12&ndash, 18 years). Use of the mobile phone and sample distributions were done with the Mobile-Related Experience Questionnaire (CERM): low use of mobile phone (LMP = 10&ndash, 15 points), medium use of mobile phone (MMP = 16&ndash, 23 points) and high use of mobile phone (HMP = 24&ndash, 40 points). PF via Eurofit test battery and academic performance were recorded, and gender was used as a differentiating factor. The HMP group registered lower values than the LMP group for academic performance (Spanish: 4.78 &plusmn, 2.26 vs. 3.90 &plusmn, 1.96 points, p = 0.007, Mathematics: 4.91 &plusmn, 2.23 vs. 4.00 &plusmn, 1.84 points, p = 0.007) and PF (Abdominals: 6.83 &plusmn, 2.40 vs. 5.41 &plusmn, 2.46 points, p &lt, 0.001, Broad jump: 6.24 &plusmn, 3.02 vs. 4.94 &plusmn, 2.28 points, p = 0.013). The boy students showed greater values than girl students for PF in the LMP (medicine-ball-throw: 6.34 &plusmn, 2.24 vs. 5.28 &plusmn, 1.86 points, p = 0.007) and MMP (medicine-ball-throw: 6.49 &plusmn, 2.52 vs. 5.02 &plusmn, 1.68 points, 0.001) groups, but no gender-related differences were found in the HMP group. In conclusion, high use of the mobile phone was related to worse results in the PF tests and academic performance. Gender-related differences were found for academic performance regardless of the use of the mobile, but for physical fitness no gender differences were found in HMP group.

Volleyball players and gymnasts need strength training to achieve their optimum sport performance. The aims of this study were to describe body composition, strength, performance, and characteristics of trunk muscle activation in volleyball players and gymnasts, and to analyze the differences between the sports. The sample consisted of 40 female athletes: rhythmic gymnasts (n = 24, age 13.95 &plusmn, 2.77 years) and volleyball players (n = 16, age 19.81 &plusmn, 5.55 years). Body composition, maximum voluntary contraction (MVC) of isometric tests in an isokinetic dynamometer, McGill core endurance test, and surface electromyography (EMGrms) of the trunk muscle during the McGill test and isometric tests were recorded. Rhythmic gymnasts presented lower body composition values than volleyball players (p &lt, 0.05). The volleyball players presented higher isometric strength than rhythmic gymnasts in terms of MVC in trunk flexion (p &lt, 0.05, d = 1.3) and trunk extension (p &lt, 0.001, d = 1.3). EMGrms from the rhythmic gymnasts were greater for trunk flexor muscles (p &lt, 0.01, d = 0.7) and trunk extensor muscles (p &lt, 0.001, d = 1.3) during McGill endurance tests compared to the volleyball players. In the isometric test, EMGrms from the rhythmic gymnasts were greater for trunk flexor muscles in flexion (p &lt, 0.01, d = 0.9) and extension tests (p &lt, 0.05, d = 0.7). In conclusion, the volleyball players exhibited higher peak strength, despite the fact that the gymnasts showed greater muscle activity during the maximum voluntary contraction.

BACKGROUND The aim of this study was to describe the differences in structural and mechanical properties between operated and non-injured Achilles tendons in senior badminton players who had had Achilles tendon surgery and had returned to play. METHODS Eighteen players (age = 48.9(10.0)years), assigned to the unilateral Achilles tendon rupture group and 177 non-injured players (age = 55.4(9.4)years), assigned to the control group. A Logiq®S8 ultrasound was used to study tendon structure and elastography index values and a Myoton®PRO hand-held myotonometer was used to record the stiffness of the Achilles tendon. FINDINGS In Achilles tendon rupture group, operated tendons showed higher values than non-injured ones in thickness (Operated = 9.03(2.67)mm vs. non-injured = 5.88(0.88)mm; P

Regular sport practice could prevent age-related changes in tendinous tissues. The purpose of the study was to investigate the effect of regular badminton practice on patellar and Achilles tendon mechanical properties in senior competitive badminton players (>35 years old) and to compare the results with physically active people matched by age. One hundred ninety-two badminton players and 193 physically active people were divided by age into four groups, between 35 and 44 (U45), between 45 and 54 (U55), between 55 and 64 (U65), and over 65 (O65) years old. A LogiqS8 transducer in elastography mode and a MyotonPRO myotonometer were used to assess patellar and Achilles mechanical properties. Achilles tendon stiffness was higher in the control group than the badminton players for the U45, U55, and O65 age groups (p p

Objective The main objective of this systematic review and meta-analysis was to determine the short-, medium-, and long-term effectiveness of dry needling (DN) applied by physical therapists to myofascial trigger points for the treatment of pain. Methods PubMed, Scopus, SportDiscus, and Web of Science databases were searched from their inception to February 2020. Randomized controlled trials that compared DN with other treatments or placebo and measured pain with a visual analog Scale or another numerical pain rating scale were included. Two authors used a personalized form to collect the following data relevant to the objectives of the review from each article independently: study design, purpose, sample size, diagnosis, characteristics of DN intervention, characteristics of placebo intervention, outcome measures, period of assessment, body region, DN technique, and number of sessions. The initial search identified 1771 articles. After the selection, 102 articles were assessed for eligibility; 42 of these articles measuring pain were used for the meta-analysis. Four meta-analyses were performed according to the follow-up period from the last reported treatment. Results This meta-analysis found a large effect to decrease pain within 72 hours (standardized mean difference [SMD] = −0.81; 95% CI = −1.21 to −0.40), a moderate effect in 1 to 3 weeks (SMD = −0.69; 95% CI = −1.02 to −0.35), a large effect in 4 to 12 weeks (SMD = −0.85; 95% CI = −1.30 to −0.40), and a large effect in 13 to 24 weeks (SMD = −0.81; 95% CI = −1.64 to −0.03). The risk of bias was generally low; however, the heterogeneity of the results downgraded the level of evidence. Conclusions Low-quality evidence that the immediate to 72-hour (large) effect, 4- to 12-week (large) effect, 13- to 24-week (large) effect, and moderate-quality 1- to 3-week (moderate) effect suggested that DN performed by physical therapists was more effective than no treatment, sham DN, and other therapies for reducing pain. Impact DN is commonly used by physical therapists to treat musculoskeletal pain, and it is very important for physical therapists to know the clinical conditions and time periods for which DN is effective in reducing pain in their patients.

The aim of the present study was to investigate the effect of secondary school students’ fitness profile on physical and technical–tactical performance in simulated competition conditions of ultimate frisbee when there is no previous experience in the practice of the sport. Forty-three secondary school students participated in this research. The students were divided into two groups according to their results in the Assessing Levels of Physical Activity and fitness test battery (ALPHA fitness test): poor physical fitness (PPF) (N = 24; age: 14.9 ± 0.8 years; height: 166.1 ± 10.9 cm; body mass: 62.2 ± 11.0 kg; ALPHA fitness score: 2.7 ± 0.7 points) and good physical fitness (GPF) (N = 19; age: 14.5 ± 0.6 years; height: 165.9 ± 5.8 cm; body mass: 58.9 ± 7.5 kg; ALPHA fitness score: 4.4 ± 0.3 points). Physical variables during the ultimate frisbee match were assessed using Global Positioning System technology. The matches were video-recorded, and individual technical actions were noted afterwards. The GPF group showed higher values for running (p = 0.039), high-speed running (p = 0.015), sprinting (p = 0.022) and total distance covered (p = 0.025) than the PPF group. In addition, more passes (p = 0.019), offensive decision making (p = 0.009) and player participation (p = 0.046) were recorded in the GPF group than the PPF group. Correlational analysis revealed a positive relationship (p < 0.05) between individual participation and the meters covered for jogging, running, running at high speed and sprinting during the game. In conclusion, although the students were novices in ultimate frisbee, the high physical fitness level had a positive effect on the game performance. Physical education teachers should consider this information when introducing new sports into their physical education classes.

The purpose was to compare the timing factors of top world-level badminton in men’s and women’s doubles matches in the Olympic Games in Beijing, London and Rio to observe the evolution of t...

Background Previous studies have reported the factors contributing to chronic ankle instability, which could lead to more effective treatments. However, factors such as the reflex response and ankle muscle strength have not been taken into account in previous investigations. Methods Fifty recreational athletes with chronic ankle instability and 55 healthy controls were recruited. Peroneal reaction time in response to sudden inversion, isokinetic evertor muscle strength and dynamic balance with the Star Excursion Balance Test and the Biodex Stability System were measured. The relationship between the Cumberland Ankle Instability Tool score and performance on each test was assessed and a backward multiple linear regression analysis was conducted. Findings Participants with chronic ankle instability showed prolonged peroneal reaction time, poor performance in the Biodex Stability System and decreased reach distance in the Star Excursion Balance Test. No significant differences were found in eversion and inversion peak torque. Moderate correlations were found between the Cumberland Ankle Instability Tool score and the peroneal reaction time and performance on the Star Excursion Balance Test. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test accounted for 36% of the variance in the Cumberland Ankle Instability Tool. Interpretation Dynamic balance deficits and delayed peroneal reaction time are present in participants with chronic ankle instability. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test were the main contributing factors to the Cumberland Ankle Instability Tool score. No clear strength impairments were reported in unstable ankles.

Context: Deficits in the propioceptive system of the ankle contribute to chronic ankle instability (CAI). Recently, whole-body–vibration (WBV) training has been introduced as a preventive and rehabilitative tool. Objective: To evaluate how a 6-week WBV training program on an unstable surface affected balance and body composition in recreational athletes with CAI. Design: Randomized controlled clinical trial. Setting: Research laboratory. Patients or Other Participants: Fifty recreational athletes with self-reported CAI were randomly assigned to a vibration (VIB), nonvibration (NVIB), or control group. Intervention(s): The VIB and NVIB groups performed unilateral balance training on a BOSU 3 times weekly for 6 weeks. The VIB group trained on a vibration platform, and the NVIB group trained on the floor. Main Outcome Measure(s): We assessed balance using the Biodex Balance System and the Star Excursion Balance Test (SEBT). Body composition was measured by dual-energy x-ray absorptiometry. Results: After 6 weeks of training, improvements on the Biodex Balance System occurred only on the Overall Stability Index (P = .01) and Anterior-Posterior Stability Index (P = .03) in the VIB group. We observed better performance in the medial (P = .008) and posterolateral (P = .04) directions and composite score of the SEBT in the VIB group (P = .01) and in the medial (P < .001), posteromedial (P = .002), and posterolateral (P = .03) directions and composite score of the SEBT in the NVIB group (P < .001). No changes in body composition were found for any of the groups. Conclusions: Only the VIB group showed improvements on the Biodex Balance System, whereas the VIB and NVIB groups displayed better performance on the SEBT.

Background Latent trigger point (LTrP) can cause motor dysfunction and disturb normal patterns of motor recruitment. Objective To analyze the effects of DN in the upper trapezius (UT) LTrP on pain and the mechanical and contractile properties of the muscle. Design A randomized, double-blinded, parallel-group-trial. Methods Fifty healthy volunteers with LTrPs in the UT were randomly divided into a DN-group (n = 26) and a Sham-DN-group (n = 24) and received one session of DN or placebo treatment. Mechanical and contractile properties of the muscle and pressure pain perception (PPP) were evaluated before treatment and in a 30min, 24 h and 72 h follow-up after treatment. Results In the mechanical properties, the DN-group showed lower values than the Sham-DN-group for dynamic stiffness at 72 h (p = 0.04). The DN-group showed lower values for dynamic stiffness at 72 h from baseline (278.74 ± 38.40 to 261.54 ± 33.64 N/m; p = 0.01) and for tone at 72 h from 30min (16.62 ± 1.27 to 15.88 ± 1.31 Hz; p = 0.01). In the contractile properties, the DN-group showed higher values for maximal radial displacement (Dm) of the muscle belly at 72 h from baseline (5.38 ± 1.67 to 6.13 ± 1.70 mm; p = 0.04), higher values for contraction time at 30min (28.53 ± 8.80 s; p = 0.03) and lower ones at 72 h (24.74 ± 4.36 s; p = 0.04) from baseline (26.97 ± 6.63 s). The DN-group showed a decrease of PPP from baseline to 72 h after treatment (5.16 ± 1.33 to 4.02 ± 0.97 mm; p Conclusion The application of DN in healthy volunteers over LTrPs in the UT decreased dynamic stiffness, tone and contraction time and increased Dm at 72 h after treatment. Additionally, the PPP showed a decrease at 72 h after needling. CLINICALTRIALS.GOV: NCT04466813.

Background Badminton is a highly demanding sport characterized by intermittent efforts with energy being provided by both the aerobic and anaerobic systems. To date, no incremental badminton field test has been developed that can be easily used by badminton coaches that requires accessible material for anyone. Objectives The purpose of this study was to develop a practical and reliable easy-to use intermittent endurance badminton test for estimating maximal oxygen uptake (VO2max). Methods Thirty six Spanish badminton players (age: 24.1±10.3 years) performed, on different days of the same week, four incremental protocols to exhaustion in randomized order: a treadmill incremental test, a Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1) and twice the Abian intermittent recovery badminton test (AIR-BT). Oxygen uptake was determined with a breath-by-breath gas analyzer during the incremental treadmill test, and performance in the Yo-yo IR1 and AIR-BT was recorded. Results Significant correlations (p2max in the Treadmill Test: r = 0.87, distance in the Yo-Yo IR1: r = 0.86). The regression equation to calculate the VO2max from the AIR-BT time [VO2max = 0.023*(AIR-BT time in seconds)+31.334] showed an adjusted R2 of 0.76 and a SEE of 3.34 ml·kg-1·min-1. There was no significant difference between VO2max obtained by the incremental treadmill test and VO2max calculated using the regression equation (p = 0.644). A paired t-test reported no significant differences between day 1 and day 2 in the AIR-BT time (p = 0.753), the Pearson correlation coefficient between both days was: r = 0.88 (p Conclusions The AIR-BT is a valid and reliable on-court test for assessing VO2max in badminton players and may be utilized by coaches and physical trainers for cross-sectional comparison of players and for evaluation of longitudinal changes.

Portillo, J, Del Coso, J, and Abian-Vicen, J. Effects of caffeine ingestion on skill performance during an international female rugby sevens competition. J Strength Cond Res 31(12): 3351-3357, 2017-The aim of this study was to establish the effects of a caffeine-containing energy drink on skills and technical performance during a match in female elite rugby sevens players. On 2 nonconsecutive days of a friendly tournament, 16 women from the Spanish national rugby sevens team (mean age = 23 ± 2 years) ingested 3 mg of caffeine per kilogram of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 minutes for caffeine absorption, participants played 3 rugby sevens matches against another national team. Body impacts during the matches were assessed by triaxial accelerometers. The matches were videotaped, and each individual technical action was notated afterward by 2 experienced observers. In comparison with the placebo drink, the ingestion of the caffeinated energy drink increased the rate of body impacts in zone 1 (16.1 ± 4.9 vs. 20.8 ± 9.9 impacts/min, p < 0.05), zone 2 (12.2 ± 10.6 vs. 16.2 ± 15.2 impacts/min, p < 0.05), zone 3 (3.8 ± 1.5 vs. 4.7 ± 2.6 impacts/min, p < 0.05), and zone 5 (0.8 ± 0.4 vs. 1.1 ± 0.6 impacts/min, p < 0.05). The pre-exercise ingestion of the caffeinated energy drink did not affect the frequency or the quality of any rugby-specific technical actions during the games. In conclusion, the ingestion of 3 mg·kg of caffeine in the form of an energy drink increased the number of body impacts during a rugby sevens international competition which suggests a higher engagement of the players during the game. However, the caffeine ingestion did not influence the quality of the technical actions performed during the competition.

The aim of the present investigation was to compare physical and technical performance in two types of small sided games (7-a-side and 8-a-side) during official under 12 soccer matches. 154 male un...

Puente, C, Abián-Vicén, J, Areces, F, López, R, and Del Coso, J. Physical and physiological demands of experienced male basketball players during a competitive game. J Strength Cond Res 31(4): 956-962, 2017-The aim of this investigation was to analyze the physical and physiological demands of experienced basketball players during a real and competitive game. Twenty-five well-trained basketball players (8 guards, 8 forwards, and 9 centers) played a competitive game on an outdoor court. Instantaneous running speeds, the number of body impacts above 5 g, and the number of accelerations and decelerations were assessed by means of a 15-Hz global Positioning System accelerometer unit. Individual heart rate was also recorded using heart rate monitors. As a group mean, the basketball players covered 82.6 ± 7.8 m·min during the game with a mean heart rate of 89.8 ± 4.4% of maximal heart rate. Players covered 3 ± 3% of the total distance running at above 18 km·h and performed 0.17 ± 0.13 sprints per minute. The number of body impacts was 8.2 ± 1.8 per minute of play. The running pace of forwards was higher than that of centers (86.8 ± 6.2 vs. 76.6 ± 6.0 m·min; p ≤ 0.05). The maximal speed obtained during the game was significantly higher for guards than that for centers (24.0 ± 1.6 km·h vs. 21.3 ± 1.6 km·h; p ≤ 0.05). Centers performed a lower number of accelerations/decelerations than guards and forwards (p ≤ 0.05). In conclusion, the extraordinary rates of specific movements performed by these experienced basketball players indicate the high physiological demands necessary to be able to compete in this sport. The centers were the basketball players who showed lower physiological demands during a game, whereas there were no differences between guards and forwards. These results can be used by coaches to adapt basketball training programs to the specific demands of each playing position.

Objectives: The aim of this study was to analyze the plantar pressures and bone stiffness of the calcaneus in badminton players compare to healthy participants, as well as to detect possible asymmetries and chronic adaptations derived from the prolonged practice of badminton.Methods: Twenty-two badminton players (35.2 ± 13.6 years, 169.4 ± 8.2 cm, 67.6 ± 13.7 kg) and 30 healthy controls (32.2 ± 12.8 years, 170.7 ± 9.5 cm, 66.25 ± 14.84 kg) volunteered to participate in this investigation. A Footwork® Pro pressure platform was used to study plantar pressures and an Achilles® bone scanner was used to record the bone stiffness of the calcaneus. The variables analyzed were plantar surface, percentage of force per area (forefoot and hindfoot), distance between the center of pressure and the projection of the center of mass in standing, and calcaneal bone stiffness.Results: The values of bone stiffness of the calcaneus were higher in badminton players than control group in the dominant lower limb (Badminton = 114.32 ± 18.97 U.A. vs. Control = 102.07 ± 16.36 U.A.; p = 0.019) and non-dominant lower limb (Badminton = 115.12 ± 21.95 U.A. vs Control = 101.37 ± 15.72 U.A.; p = 0.014). Badminton players showed asymmetric values in mean pressure (dominant = 35.41 ± 6.05 Kpa vs. non-dominant = 39.21 ± 6.54 Kpa; p = 0.011) and distance among center of pressure of each foot and center of mass (dominant = 11.28 ± 1.65 cm vs. non-dominant = 10.48 ± 1.63 cm; p = 0.025).Conclusions: The calcaneal stiffness of the badminton players was higher than control group, which places badminton in the category of osteogenic sports. The badminton players showed an asymmetric pattern during the static balance, which may be an indicative of asymmetries derived from the continued practice of badminton.

The purpose of the study was to describe the differences between the dominant and non-dominant leg regarding contractility response and quadriceps strength and the morphology and stiffness of the patellar tendon (PT) in a group of physically active men and women. Fifty physically active subjects (36 men and 14 women) were evaluated for morphology and stiffness of the PT, contractility response of the rectus femoris of the quadriceps, isometric strength of the quadriceps and hamstrings, and isokinetic strength (concentric and eccentric) at 60°/s of the knee extensors. The measurements were made on the subject’s dominant and non-dominant leg. The men showed a greater thickness of the PT in both legs compared to the women. Regarding the contractility response, the women recorded a 10.1 ± 16.2% (p = 0.038) greater contraction time (ct) in the dominant versus the non-dominant leg and the men recorded 11.9% (p = 0.040) higher values in the dominant leg compared to the women. In all the absolute strength measurements the men recorded higher values (p &lt, 0.05) than the women, however, when the values were normalised with respect to the muscle mass of the leg these differences disappeared. The dominant leg showed values of isometric strength and eccentric strength at 60°/s (p &lt, 0.05) greater than the non-dominant leg. The reference values provided in this study of the knee extensors and PT may be useful for detecting possible muscular or tendinous anomalies.

Context:Although caffeine is one of the most commonly used substances in combat sports, information about its ergogenic effects on these disciplines is very limited.Purpose:To determine the effectiveness of ingesting a moderate dose of caffeine to enhance overall performance during a simulated Brazilian jiu-jitsu (BJJ) competition.Methods:Fourteen elite BJJ athletes participated in a double-blind, placebo-controlled experimental design. In a random order, the athletes ingested either 3 mg/kg body mass of caffeine or a placebo (cellulose, 0 mg/kg) and performed 2 simulated BJJ combats (with 20 min rest between them), following official BJJ rules. Specific physical tests such as maximal handgrip dynamometry, maximal height during a countermovement jump, permanence during a maximal static-lift test, peak power in a bench-press exercise, and blood lactate concentration were measured at 3 specific times: before the first combat and immediately after the first and second combats. The combats were video-recorded to analyze fight actions.Results:After the caffeine ingestion, participants spent more time in offensive actions in both combats and revealed higher blood lactate values (P < .05). Performance in all physical tests carried out before the first combat was enhanced with caffeine (P < .05), and some improvements remained after the first combat (eg, maximal static-lift test and bench-press exercise; P < .05). After the second combat, the values in all physical tests were similar between caffeine and placebo.Conclusions:Caffeine might be an effective ergogenic aid for improving intensity and physical performance during successive elite BJJ combats.

Scientific information about the effects of caffeine intake on combat sport performance is scarce and controversial. The aim of this study was to investigate the effectiveness of caffeine to improve Brazilian Jiu-jitsu (BJJ)-specific muscular performance. Fourteen male and elite BJJ athletes (29.2 ± 3.3 years; 71.3 ± 9.1 kg) participated in a randomized double-blind, placebo-controlled and crossover experiment. In two different sessions, BJJ athletes ingested 3 mg kg(-1) of caffeine or a placebo. After 60 min, they performed a handgrip maximal force test, a countermovement jump, a maximal static lift test and bench-press tests consisting of one-repetition maximum, power-load, and repetitions to failure. In comparison to the placebo, the ingestion of the caffeine increased: hand grip force in both hands (50.9 ± 2.9 vs. 53.3 ± 3.1 kg; respectively p .05), countermovement jump height (40.6 ± 2.6 vs. 41.7 ± 3.1 cm; p = .02), and time recorded in the maximal static lift test (54.4 ± 13.4 vs. 59.2 ± 11.9 s; p .01).The caffeine also increased the one-repetition maximum (90.5 ± 7.7 vs. 93.3 ± 7.5 kg; p = .02), maximal power obtained during the power-load test (750.5 ± 154.7 vs. 826.9 ± 163.7 W; p .01) and mean power during the bench-press exercise test to failure (280.2 ± 52.5 vs. 312.2 ± 78.3 W; p = .04). In conclusion, the pre-exercise ingestion of 3 mg kg(-1) of caffeine increased dynamic and isometric muscular force, power, and endurance strength in elite BJJ athletes. Thus, caffeine might be an effective ergogenic aid to improve physical performance in BJJ.

This paper presents a new method to automatically obtain linguistic descriptions from a multivariate time series. The first step consists of the induction from the multivariate time series of a fuzzy model called the temporal fuzzy model. Later this fuzzy model is analyzed in order to obtain trends based on the output variable. With this information, the trends for the input variables are also obtained and together with the output variable trends are represented in such a way that the temporal evolution of the trend is stored within the own-trends. In a trend there are always some elements or points of interest that are more relevant than others for generating a relevant final description. These elements are also extracted and stored, making the final description generation process more efficient. An event search process generates the final linguistic description. The events are identified in the trends or in the structure containing the points of interest previously selected. Once an event is identified, new text is added at the end of the linguistic description. The design of the events and the text related to each event is made with the cooperation of experts in the field of application. The presented approach is checked in sports, more concretely, in countermovement jumping.