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El objetivo principal del presente estudio fue analizar el rendimiento de la técnica del salto y aterrizaje en deportistas adolescentes mediante la versión modificada del Tuck Jump Assessment (TJA). Como objetivo secundario se compararon los resultados obtenidos, según sexo. Se puntuó cada variable de la herramienta mediante el análisis en video de la prueba de los 75 participantes incluidos en el estudio. Las variables contempladas fueron la puntuación global del TJA y cada criterio del instrumento: 1) Valgo de la extremidad inferior en el aterrizaje; 2) Muslos no paralelos (punto máximo de salto); 3) Muslos no alineados durante la fase de vuelo; 4) Mala alineación de los pies con los hombros; 5) Posición de los pies no paralela (de la punta al talón); 6) Contacto desigual de los pies (aterrizaje asimétrico); 7) Demasiado ruido en el aterrizaje; 8) Pausa entre saltos; 9) La técnica empeora antes de los 10 segundos; 10) No aterriza en el mismo punto (salto consistente). Los valores promedios de la puntuación global de la versión modificada del TJA fueron 8.85±2.31 en el total de la muestra (8.85±2.63 hombres vs. 8.86±2.14 mujeres). Los resultados de la comparación según sexo indicaron diferencias significativas en el criterio 1 (χ2=10.288; p< 0.01), en el criterio 2 (χ2=20.788; p< 0.01), en el criterio 4 (χ2=22.587; p< 0.01) y en el criterio 10 (χ2=8.883; p< 0.01). En consecuencia, el análisis del patrón de salto y aterrizaje permite identificar alteraciones neuromusculares y biomecánicas del patrón de salto-aterrizaje. The main objective of the present study was to analyze the performance of the jump and landing technique in adolescent team sports athletes through the modified version of the Tuck Jump Assessment, (TJA). As a secondary objective, the results obtained werecompared, according to sex. Each outcome measure of the tool was scored through video analysis of the test of the 75 participants included in the study. The main outcome measures were the total score of TJA and each of the ten items: Knee valgus at landing (1), thighs do not reach parallel (2), thighs not equal side-to-side (3), foot placement not shoulder width apart (4), foot placement not parallel (5), foot contact timing not equal (6), excessive landing contact noise (7), pause between jumps (8), technique declines prior to ten seconds (9), and does not land in same footprint (10). The variables contemplated were the global score of the TJA and the ten criteria of the instrument. The average values of the global score of the modified version of the TJA were 8.85±2.31 in the total sample (8.85±2.63 men vs. 8.86±2.14 women). The results of the gender comparison indicated significant differences in item 1(χ2=10.288; p< 0.01), item 2 (χ2=20.788; p

The main objective of the present study was to provide seasonal variation data for inter-limb asymmetry in youth elite team-sport athletes. Fifty-nine players performed the single leg countermovement jump (SLCMJ) and the one leg hop for distance (OLHT) tests during pre-season, mid-season and end-season. A repeated-measures analysis of variance was conducted to determine magnitude differences in asymmetry scores between time points. Kappa coefficients (κ) were calculated to determine the levels of agreement for the direction of asymmetry. When comparing inter-limb asymmetry magnitudes across the season, the SLCMJ test showed significantly higher asymmetries at mid-season in comparison with pre-season and end-season (p

The direction of inter-limb asymmetries and the change of direction (COD) deficit are two aspects that have increased in recent years. The main objective of the present study was to assess the magnitude of neuromuscular asymmetries in an elite youth female team-sports sample and determine its directionality. Secondary objectives were to evaluate the relationship between COD deficit, linear speed and COD time performance. Elite female youth basketball and handball players (n = 33, age = 16 ± 1.17 y) performed the Single Leg Countermovement Jump in vertical (SLCJ-V), horizontal (SLCJ-H), and lateral (SLCJ-L) directions, the COD and the 10-m sprint. Results showed statistical differences between limbs in all the neuromuscular tests (p < 0.001). The Kappa coefficient showed poor to fair levels of agreement between tasks (K range = -0.087 to 0.233), indicating that asymmetries rarely favoured the same limb between skills. Additionally, small and non-significant correlations were found between the linear sprint capacity and the COD ability. The findings of the present study highlight the independent directionality of asymmetries across tests. The COD deficit does not appear to be much more advantageous than COD total time to measure asymmetry. Practitioners are encouraged to use a fitness testing battery to detect existing side differences and each ability should be specifically trained with functional tasks.

The main objective of this research was to analyse the match context variables’ influence on individual set-piece’s success in rink-hockey. A sample of 196 matches, including 621 free direct hits (...

Introduction Two of the main modifiable risk factors for suffering an injury in the anterior cruciate ligament are known to be the Hamstring-to-Quadriceps (H/Q) Ratio and neuromuscular fatigue. The main purpose of this research was to study the effect of neuromuscular fatigue on the H/Q Ratio and the maximum isometric strength of the quadriceps and hamstrings in teenage female basketball and handball players. Material and methods This is an experimental, pre-post intervention study with a sample of 19 female basketball players and 11 female handball players (17.02 ± 1.19 yo, 177.8 ± 7.2 cm and 68.6 ± 9.3 kg). To assess muscle strength, a maximum isometric strength test was performed in a 90° hip and 60° knee position. The H/Q Ratio was then calculated. The 30–15 Intermittent Fatigue Test (30–15 IFT) was used to induce fatigue, measured using the Rating of Perceived Exertion (RPE) scale. A descriptive analysis and a Student's t-test were performed to study the differences in the H/Q Ratio, muscle strength and pre-post intervention fatigue. Results Although the H/Q Ratio decreased after the 30–15 IFT, the differences were not statistically significant. Regarding strength values, the right and left quadriceps presented strength reductions of 4.52% and 5.55%, respectively. The reduction in strength was statistically significant (p ≤ 0.05), especially in the right hamstring (7.3%) and in the left hamstring (7.5%). The study conclusions suggest that leg muscular strength decreases after a fatigue test and that there is a tendency for the H/Q Ratio to decrease also.

Font-Llado, R, Lopez-Ros, V, Montalvo, AM, Sinclair, G, Prats Puig, A, and Fort-Vanmeerhaeghe, A. A pedagogical approach to integrative neuromuscular training to improve motor competence in children: a RCT. J Strength Cond Res 34(11): 3078-3085, 2020-To assess the effectiveness of a pedagogical approach to an integrative neuromuscular training (INT) program as a warm-up in physical education (PE) lessons in healthy children: (a) to improve the level of motor competence (MC) and (b) to master fundamental motor skills (FMS) patterns, considering the baseline MC level and the time spent when performing different motor tasks. One hundred ninety students (7.43 ± 0.32 years; 52% girls) were included in this randomized controlled trail and grouped up according to MC basal levels (L1-L4). Motor competence and FMS patterns (CAMSA protocol) were assessed before and after the intervention in a group-based INT warm-up (n = 97) and a group-based conventional warm-up (n = 93). The INT program improved MC (p < 0.001; d = 0.71) and FMS (p < 0.001, d = 0.52). The independent predictors of MC change were: baseline MC level (β = -196; p < 0.012), time spent to perform the task (β = -0.235 p < 0.003), and participation in the INT program (β = 0.201; p < 0.005), explaining 71% of its variability. The INT warm-up shows correlations between improvements in MC in relation to time reduction (L1 p = 0.016, d, L2 p = 0.001, and L4 = 0.001) and FMS patterns (L1 p < 0.001, L2 p < 0.003, L3 p < 0.005, and L4 < 0.001) Moreover, only L3, it showed correlation between changes in time and FMS mastery (p = 0.001). Our results showed that a pedagogical approach to an INT program developed as a warm-up in primary school PE lessons can improve MC and FMS patterns in all subjects, independent of the initial MC level. More interestingly, only in L3, the improvement in MC can be explained by the balance in time required to perform the task and the level of improvement in FMS patterns.

Madruga-Parera, M, Bishop, C, Fort-Vanmeerhaeghe, A, Beltran-Valls, MR, Gonzalo-Skok, O, and Romero-Rodriguez, D. Interlimb asymmetries in youth tennis players: relationships with performance. J Strength Cond Res 34(10): 2815-2823, 2020-Change of direction speed (CODS) has been highlighted as a critical component of tennis. Interlimb asymmetries have been commonly studied in jump tests, but less attention given to the topic during CODS. The aim of this study was to quantify interlimb asymmetries in jumping and CODS (during traditional and isoinertial tests) and establish their relationship with measures of physical performance. Twenty-two elite youth tennis players (16.3 ± 1.4 years) performed single-leg countermovement jump (SLCMJ), single-leg broad jump, and single-leg lateral jump, a double 180° turn CODS test, and shuffle lateral step and crossover step with an isoinertial resistance device. Paired-samples t-tests revealed significant differences between limbs for all tests (p < 0.05). Interlimb asymmetry scores ranged from 1.83 to 15.03%, and a 1-way repeated-measures analysis of variance showed significant differences between interlimb asymmetry scores across multiple tests (p < 0.05). Spearman's rank order r correlations showed significant negative relationships between CODS asymmetry and SLCMJ performance on both limbs (r = -0.50; p = 0.02 and r = -0.53; p = 0.01) and CODS performance on both limbs (r = 0.50; p = 0.02 and r = 0.63; p = 0.002). These results show the test-specific nature of asymmetries in youth tennis athletes, with the SLCMJ presenting the greatest magnitude of asymmetry. Furthermore, interlimb differences during CODS were associated with reduced performance during jumping and CODS tests, suggesting the monitoring of asymmetries within this population may therefore be warranted.

Madruga-Parera, M, Bishop, C, Fort-Vanmeerhaeghe, A, Beato, M, Gonzalo-Skok, O, and Romero-Rodriguez, D. Effects of 8-weeks of Isoinertial vs. Cable-resistance Training on Motor Skills Performance and Interlimb Asymmetries. J Strength Cond Res XX(X): 000–000, 2020—The aim of this study was to compare the effects of 8 weeks of isoinertial vs. cable-resistance training on motor skills performance and interlimb asymmetries in handball players. Thirty-four young male handball players (mean ± SD: age: 15.96 ± 1.39 years; height: 1.74 ± 0.73 m; body mass: 70.5 ± 13.3 kg) participated in a randomized trial. The players performed an isoinertial program using a portable flywheel device or a cable-resistance device. Performance variations and interlimb asymmetries in dominant (D) and nondominant (ND) limb means of the unilateral countermovement jump (UCMJ), the unilateral lateral jump (ULJ), the unilateral broad jump (UBJ), handball throwing (HT), change of direction speed (COD180), the linear sprint (S20), the V-CUT test, and the repeated change of direction (RCOD) were recorded. Significant interactions were shown in RCODD (p = 0.003, ηp = 0.25), HT (p = 0.015, ηp = 0.17) and UCMJASY (p = 0.037, ηp = 0.13). Post-hoc testing revealed higher effect sizes in the isoinertial group (p < 0.05) for the performance improvements in RCODD (−1.35 large vs. −0.22, small) and HT (0.88, moderate vs. 0.00, trivial), in addition to interlimb asymmetry reductions in UCMJASY (−0.70 moderate vs. −0.32, small). Significant main effects of time in COD180, RCOD, UCMJ, and UBJ for both limbs (p < 0.05, from moderate to large effect size), and in ULJND (p < 0.001, large), UCMJASY (p < 0.001, moderate), V-CUT (p = 0.014, small), and HT (p = 0.015, large) were found. The effect sizes revealed greater magnitudes in the isoinertial group. In conclusion, although both resistance training programs improve players' to physical performance and reduce interlimb asymmetries, greater improvements were recorded with the isoinertial resistance training than with the cable-resistance methodology.

Background Eccentric hamstring strength seems important in reducing the odds of future hamstring injuries. While age and previous injury are well-known risk factors for future hamstring injuries, the association of age and previous hamstring injury with eccentric hamstring strength in the following season is unknown. Purpose To investigate the association of age and previous hamstring injury with preseason eccentric hamstring strength in soccer players, and to investigate the association between previous hamstring injury duration and preseason eccentric hamstring strength. Study design Descriptive, cross-sectional study. Methods A convenience sample of 284 male amateur soccer players (age 18-38 years) was included in the analyses. Self-reported information about previous season hamstring injury and its duration (three weeks or less; more than three weeks) was collected. Preseason eccentric hamstring strength was obtained during the Nordic hamstring exercise using a field-based device. Results Age had a negative association with preseason eccentric hamstring strength with 0.9% reduction per year. Players with a previous hamstring injury duration of more than three weeks (n=27) had 13% lower preseason eccentric hamstring strength compared to players without previous hamstring injury. Conclusion Older players have lower preseason eccentric hamstring strength than younger players. Players with a previous hamstring injury duration of more than three weeks have lower preseason eccentric hamstring strength than the rest of the players. These results highlight the need to monitor and address the identified weaknesses in eccentric hamstring strength in amateur soccer players, with specific emphasis on older players with a previous hamstring injury of longer duration. Level of evidence 2b.

The main objective of this study was to analyze the influence of individual set-pieces (Free Direct Hits and Penalties) in elite rink hockey match outcomes in different game situations. A sample of 161 matches played between high-standard teams during ten consecutive seasons (2009–2010 to 2018–2019) were analyzed using a binary logistic regression. The full evaluated model was composed of an explanatory variable (set-pieces scored) and five potential confounding and interaction variables (match location, match level, match importance, extra time, and balanced score). However, the final model only included one significant interaction variable (balanced score). The results showed that scoring more individual set-pieces than the opponent was associated with victory (OR = 6.1; 95% CI: 3.7, 10.0) and was more relevant in unbalanced matches (OR = 19.5; 95% CI: 8.6, 44.3) than in balanced matches (OR = 2.3; 95% CI: 1.2, 4.5). These findings indicate that individual set-pieces are strongly associated with match outcomes in matches played between high-standard teams. Therefore, it is important for teams to excel in this aspect, and it is suggested that these data can encourage coaches to reinforce the systematic practice of individual set-pieces in their training programs. Additionally, it is suggested that teams have specialist players in this kind of action to mainly participate in these specific match moments. The study was supported and funded by the Faculty of Psychology, Education Sciences and Sport Blanquerna, Ramon Llull University, Barcelona, Spain, grant number PIF20-21-GRIES.

Context: Understanding how neuromuscular and biomechanical deficits that are associated with knee injuries change as youth mature may improve injury prevention strategies in this population. Objective: To investigate sex and maturation differences in jump-landing technique performance in youths using a practical clinical tool. Design: Cross-sectional study. Setting: High Performance Center Laboratory. Participants: A total of 165 youth athletes were included in this study. Main Outcome Measures: The main outcome measures were each of the 10 items of the modified tuck jump assessment and the total score. These measures include (1) knee valgus at landing, (2) thighs do not reach parallel, (3) thighs not equal side to side, (4) foot placement not shoulder width apart, (5) foot placement not parallel, (6) foot contact timing not equal, (7) excessive landing contact noise, (8) pause between jumps, (9) technique declines prior to 10 seconds, and (10) does not land in same footprint. Results: Only knee valgus at landing had a significant sex × maturation interaction. The main effect of maturation was significant for items 2, 3, 6, 7, 9, and total score. Plyometric technique performance improved with increasing maturation. The main effect of sex was significant for items 1 and 9, with males performing better than females. Conclusions: Female athletes demonstrate increased knee valgus at landing and fatigue relative to males during jump-landing performance. Overall, there was a trend of improved jump-landing performance with maturation.

The purpose of the present study was to determine the relationship between physical fitness and academic achievement in a sample of primary-school children. Data of 116 sixth-grade primary-school students (68 girls, 48 boys) from Barcelona (Catalonia, Spain) with a mean (SD) age of 11.4 years (0.4) was analyzed. To determine academic achievement, proficiency scores in the subjects Catalan language, Spanish language, English language, and Maths were derived from the Test de Compètencies Bàsiques. Physical fitness was assessed using the Cooper test (aerobic capacity), 20-m sprint test (linear velocity), and 4 × 10-m test (agility). The results showed that participants with a higher performance in the Cooper and 20-m sprint tests had significantly better academic achievement in the assessed subjects (p < 0.05; d range = 0.93 to −2.98). The findings of this investigation are interesting from a curricular perspective since a positive association between academic achievement and physical fitness indicates a strong reason to raise the physical education status in educational systems, a subject that has traditionally been considered less important by the educational community.

The magnitude of inter-limb asymmetries has been reported in several studies in different team sports but only some of them have analysed their effects on sports performance. The main purpose of this cross-sectional study was to determine inter-limb asymmetries and examine their relationship with different physical performance tests in rink hockey players. Nineteen rink hockey players (age: 23.37 &plusmn, 4.82 years, body height: 1.75 &plusmn, 0.06 cm, body mass: 73.16 &plusmn, 9.87 kg) performed a mid-season battery of fitness tests consisting of 30 m sprint, countermovement jump (CMJ), and half back squat. Inter-limb asymmetries were assessed using the single leg vertical countermovement jump test (SLCJ-V), single leg horizontal countermovement jump test (SLCJ-H), and 180&deg, change of direction test (COD). Results show a significant relationship between asymmetry in the SLCJ-H test, 30 m sprint (r = 0.63, p &lt, 0.01) and CMJ performances (r = &minus, 0.52, p &lt, 0.05). Additionally, asymmetry in the SLCJ-V showed a significant relationship with CMJ performance (r = &minus, 0.46, p &lt, 0.05). These findings suggest that training programs should aim to reduce the inter-limb asymmetries in rink hockey players to improve their performance. Practitioners and coaches can use this information to assess the potential impact of asymmetries on physical performance in rink hockey players.

The aims of this study were to investigate changes in selected performance measures during an off-season period, their association, and the potential role of age and previous hamstring injury in semi-professional and amateur football players. Seventy-four male players (age: 25 ± 4 years, stature: 178.0 ± 6.6 cm, body mass: 74.9 ± 8.1 kg) were assessed at the beginning and end of the off-season summer-period for sprint, change-of-direction performance and eccentric hamstring strength. Small to medium increases in sprint times were observed at 5 (d = 0.26, p = 0.057), 10 (d = 0.42, p < 0.001) and 30 m (d = 0.64, p < 0.001). Small (d = −0.23, p = 0.033) improvements were observed for COD performance, and no changes in eccentric hamstring strength (d = 0.10, p = 0.317). The changes in the outcomes were not affected by age (p = 0.449 to 0.928) or previous hamstring injury (p = 0.109 to 0.995). The impaired sprint performance was not related to changes in eccentric hamstring strength (r = −0.21 to 0.03, p = 0.213 to 0.856), instead, changes in COD performance were associated with changes in eccentric hamstring strength (r = −0.42, p = 0.008).

This study aimed to understand the acute responses on the muscular activity of primary movers during the execution of a half-squat under different unstable devices. Fourteen male and female high-standard track and field athletes were voluntarily recruited. A repeated measures design was used to establish the differences between muscle activity of the primary movers, the body centre of mass acceleration and the OMNI-Perceived Exertion Scale for Resistance Exercise (OMNI-Res) in a half-squat under four different stability conditions (floor, foam, BOSU-up and BOSU-down). A significant correlation was found between the highest performance limb muscle activity and body centre of mass acceleration for half-squat floor (r = 0.446, p = 0.003), foam (r = 0.322, p = 0.038), BOSU-up (r = 0.500, p = 0.001), and BOSU-down (r = 0.495, p = 0.001) exercises. For the exercise condition, the half-squat BOSU-up and BOSU-down significantly increased the muscle activity compared to half-squat floor (vastus medialis: p = 0.020, d = 0.56, vastus lateralis: p = 0.006, d = 0.75, biceps femoris: p = 0.000&ndash, 0.006, d = 1.23&ndash, 1.00) and half-squat foam (vastus medialis: p = 0.005&ndash, 0.006, d = 0.60&ndash, 1.00, vastus lateralis: p = 0.014, d = 0.67, biceps femoris: p = 0.002, d = 1.00) activities. This study contributes to improving the understanding of instability training, providing data about the acute muscular responses that an athlete experiences under varied stability conditions. The perturbation offered by the two BOSU conditions was revealed as the most demanding for the sample of athletes, followed by foam and floor executions.

Fort-Vanmeerhaeghe, A, Milà-Villarroel, R, Pujol-Marzo, M, Arboix-Alió, J, and Bishop, C. Higher vertical jumping asymmetries and lower physical performance are indicators of increased injury incidence in youth team-sport athletes. J Strength Cond Res 36(8): 2204-2211, 2022-To date, the literature about the association between injury-risk factors and actual injury incidence in young elite team-sports athletes is scarce. The main objective of this study was to examine how modifiable factors may affect injury incidence. Eighty-one young elite team-sports athletes (age: under-14 to under-18) performed the countermovement jump (CMJ), a single leg CMJ (SLCMJ), the one-legged hop test (OLHT), a 30-m sprint test, the V-cut test, a repeated sprint ability, and the 30-15 intermittent fitness test (IFT) during the pre-season period. Interlimb asymmetries were calculated for SLCMJ and OLHT. Injuries were recorded prospectively for the entirety of the 2017-2018 season. Comparison of injury and noninjury data was performed using a two-way analysis of variance (ANOVA). Results of the ANOVA according to injury showed significant differences in CMJ ( p = 0.01), SLCMJ on the lowest performing limb ( p = 0.03), and SLCMJ asymmetry (0.001). Sex × injury interaction was significant from CMJ ( p = 0.018) and 30-15 IFT ( p =0.001). In conclusion, this study indicated that athletes with greater interlimb asymmetries, less vertical jump capacity, and lower intermittent aerobic fitness had a greater predisposition to injury. Therefore, monitoring CMJ, aerobic performance, and interlimb asymmetries is recommended given their sensitivity to detect significant differences between injured and healthy youth athletes.

Objectives The aim of this study was to quantify and analyze the presence and type of self-acknowledged limitations (SALs) in a sample of manual therapy (MT) randomized controlled trials. Study Design and Setting We randomly selected 120 MT trials. We extracted data related to SALs from the original reports and classified them into 12 categories. After data extraction, specific limitations within each category were identified. A descriptive analysis was performed using frequencies and percentages for qualitative variables. Results The number of SALs per trial article ranged from 0 to 8, and more than two-thirds of trials acknowledged at least two different limitations. Despite its small proportion, 9% of trials did not report SALs. The most common limitation declared, in almost half of our sample, related to sample size (47.5%) followed by limitations related to study length and follow-up (33.3%) and inadequate controls (32.5%). Conclusion Our results indicate that at least two different limitations are consistently acknowledged in MT trial reports, the most common being those related to sample size, study length, follow-up, and inadequate controls. Analysis of the reasons behind the SALs gives some insights about the main difficulties in conducting research in this field and may help develop strategies to improve future research.

Actually, there is scarce literature looking for the relationship between inter-limb asymmetries and performance in youth elite team sports. The main purpose of this cross-sectional study was to examine the relationships between inter-limb asymmetries and physical performance in youth elite team-sports players. A secondary objective was to evaluate the presence of between-sexes differences in inter-limb asymmetries in elite youth team sports players. Eighty-one young elite team-sports athletes (age: u-14 to u-18) performed the star excursion balance test in the anterior direction (SEBT ANT), a single leg vertical countermovement jump test (SLCMJ), the one leg hop test for distance (OLHT), a 30 m sprint test, and the V-cut test. Inter-limb asymmetries were calculated for SEBT ANT, SLCMJ and OLHT. Pearson r was used to analyse the relationships between inter-limb asymmetries and physical performance. Results showed significant (p < 0.05) but small (r = 0.26) relationships between SLCMJ asymmetries and 30 m sprint time for the total group. Significant negative correlations with small to moderate magnitude of correlation were also found between SLCMJ asymmetries and SLCMJ performance on the lowest performing limb for the total group (p < 0.05; r = -0.26), males (p < 0.01; r = -0.48) and females (p < 0.05; r = -0.30). Moreover, significant negative correlations with moderate and large magnitude were also present between OLHT asymmetries and OLHT performance on the lowest performing limb for the total group (p < 0.01; r = -0.44), males (p < 0.01; r = -0.56) and females (p < 0.01; r = -0.64). No correlations were observed between asymmetries and either the V-cut test or SEBT ANT performance. No correlation were observed between SEBT ANT asymmetries and physical performance. In addition, when comparing asymmetry values between sexes there were no significant differences in vertical (p = 0.06) and horizontal (p = 0.61) jumping tests. However, there were significant differences in asymmetry between sexes in the ANT SEBT (p = 0.04). In conclusion, the current study indicated that jumping asymmetries were associated with decrements in sprint speed and jumping performance. Therefore, assessing inter-limb asymmetries would be recommended to improve training interventions for youth elite team-sports athletes.

In the second part of this evidence- and experience-based guide, we present a progressive framework for return-to-sport following anterior cruciate ligament reconstruction in team sport athletes. This framework guides programs that return athletes to competition at maximum performance while minimizing risk of reinjury. We have built onto a framework typically used in team sports that proposes progress move from general to specific. The progression is accomplished through the use of motor learning principles and attention to hypercomplexity, which characterizes situation sports. The framework focuses on preparing players to withstand repeated high-intensity actions, combining jumps, accelerations, decelerations and changes of direction with dribbling, passing, receiving, shooting and/or reacting to their teammates and opponents while minimizing risk of reinjury.

El objetivo de este trabajo fue comparar y cuantificar las asimetrías neuromusculares entre las extremidades inferiores que presentan los jugadores de hockey sobre patines. Un objetivo secundario fue correlacionar el índice de asimetrías (ASI) entre las diferentes pruebas neuromusculares testadas. Un total de 27 jugadores de sexo masculino de hockey sobre patines (edad = 20,59 ± 3,81 años) realizaron diferentes pruebas neuromusculares de forma unilateral: 1) Test de salto vertical con contra-movimiento (SLCJ), 2) Batería de saltos horizontales (Hop test: single, triple y crossover hop test) y 3) Prueba de velocidad con cambio de dirección (COD test). Se observaron diferencias significativas (p 10% en el test de SLCJ, situación considerada como posible factor de riesgo de lesión. Solamente se obtuvo una correlación significativa entre el SLCJ y el COD test. En consecuencia, y con el objetivo de identificar las asimetrías entre miembros inferiores, es importante considerar la valoración de las diferencias capacidades neuromusculares. Abstract The aim of the current study was to compare and quantify the neuromuscular lower limb asymmetries present in roller hockey players and its link to high risk of injury. A secondary purpose was to correlate the index of asymmetries (ASI) between the different neuromuscular tests performed. 27 male roller hockey players (age = 20.59 ± 3.81 years) performed the single leg countermovement jump (SLCJ), the Hop Test battery (single hop test, triple hop test and crossover hop test) and the change of direction test (COD test). Significant differences were observed (p 10% in the SLCJ, a situation considered as an injury risk factor. Only a significant correlation was obtained between the SLCJ and the COD test. Consequently, it is suggested that the complete neuromuscular profile between lower limbs be evaluated with the different tests, for both in the conditioning programs and in the injury prevention and return-to- play.

There is a high incidence of non-contact anterior cruciate ligament (ACL) injury in team sports, especially among adolescent females. This injury is associated with an increased risk of developing osteoarthritis later in life and a decrease in lifetime physical activity. Traditionally, return-to-sport (RTS) programs following ACL injury have focused on restoring the athlete's general health and tissue healing. We will propose a framework that views RTS as a two-part process: first, recovery of general health after ACL reconstruction (ACL-R) (rehabilitation) and then return to competition (RTC) after ACL-R, all of which occurs on a continuum. The objective of Part I is to stablish the foundation to propose an evidence- and experience-based guide on RTS following ACL reconstruction in athletes participating in team sports, specifically for later phases. First, we describe the causes of and risk factors associated with ACL injury. Next, we describe the specific characteristics of team sports that predispose athletes to ACL injury. Finally, we present a progressive framework to successfully return athletes to a pre-injury level of competition that also minimizes risk of reinjury. In Part II we will focus on how to put the proposed framework into practice when return team sport athletes to play following ACL-R.

Introduction Monitoring load has been a key point in team sports during last years. This study aimed to determine the relationship between the external and internal training load during full basketball practices in elite female youth basketball players. Material and methods Thirteen elite female youth basketball players (age 16.3±1 years, height 181.7±5.8cm and body mass 71.2±9.6kg) had physical and physiological monitored over seven weeks. Players’ internal load was assessed using the session-rating of perceived exertion (sRPE), the Edward's summated heart rate zones model (SHRZ) and, the Banister's training impulse (TRIMPB). The external load was determined through: 1) total accelerations (TA); the sum of all accelerations and decelerations; 2) maximal accelerations and decelerations (TAMax); 3) total accelerations per minutes (TA·min−1); 4) accelerations per minute (Acc·min−1); and 5) decelerations per minute (Dec·min−1). Heart rate-based and accelerometry models were assessed via Polar Pro technology. Results Correlations between variables revealed different magnitudes. SHRZ model showed a positive correlation with TA (0.63); the TRIMPB model showed a high degree of correlation with TA (0.78); the sRPE model also presented a high correlation with TA (0.62). Conclusion Our study establishes different levels of association between external and internal load models in elite female youth basketball players. However, we cannot assume that a high relationship between internal and external loads exists, as both models should be considered as different constructs.

Resumen La competencia motriz (CM) es la manifestacion de la habilidad motriz (HM) como respuesta contextualizada. La CM contribuye a que los jovenes dispongan de un mayor repertorio de opciones motrices en la que se sientan competentes. En sentido opuesto, la incompetencia motriz puede llevar a una inhibicion o inactividad progresiva que a la vez genera mas incompetencia y menos adherencia a la actividad fisica (AF) en la infancia y la edad adulta. La evidencia cientifica muestra como la inclusion de AF orientada a la vivencia de experiencias ricas en HM, desarrollada por especialistas en educacion fisica, favorecen el desarrollo de la CM en los jovenes. A su vez, existen evidencias de que el trabajo neuromuscular integrado mejora la salud y el rendimiento de las HM. En esta linea, el presente trabajo tiene un enfoque triple: (a) definir la relacion entre la CM y la practica de AF saludable (b) justificar la necesidad de establecer un diagnostico para el desorden por deficit de ejercicio, y (c) proponer el trabajo neuromuscular integrado como metodologia para mejorar la condicion fisica y la CM de los ninos y adolescentes.

The Tuck Jump Assessment (TJA) is a clinician-friendly screening tool that was designed to support practitioners with identification of neuromuscular deficits associated with anterior cruciate ligament injury. This study aimed to evaluate the inter- and intra-rater reliability of the modified scoring (0 to 2) TJA to add an additional range of objectivity for each criterion. A total of 24 elite youth volleyball athletes (12 males and 12 females) were included in this study. Each participant’s recorded performance of the TJA was scored independently by two raters across ten criteria using the modified scale. The two raters then scored the same videos one week later. Another investigator who was blind to the identity of the raters analyzed the scores from both raters for each participant. Kappa coefficient (k) and percentage of exact agreement (PEA) for both intra- and inter-rater reliability were analyzed for each item. Intraclass correlation coefficients (ICC) were calculated to determine intra- and inter-rater reliability of the modified TJA total score. Intra- and inter-rater k was good to excellent for most items (0.65-0.91). Average PEA between the two raters and two sessions ranged from 83.3 to 100% in all scored items. The ICC for the total score was excellent in both inter- and inter-rater correlations (0.94-0.96). This research demonstrated that the modified version of the TJA predominantly shows good to excellent intra- and inter-rater reliability in all analyzed criteria.

Madruga-Parera, M, Bishop, C, Beato, M, Fort-Vanmeerhaeghe, A, Gonzalo-Skok, O, and Romero-Rodriguez, D. Relationship between inter-limb asymmetries and speed and change of direction speed in youth handball players. J Strength Cond Res XX(X): 000-000, 2019-The aims of the present study were to quantify interlimb asymmetry from jumping, change of direction speed (CODS), and iso-inertial tests and to establish the association between those asymmetry scores and performance during speed and CODS tests in youth handball athletes. Twenty-six youth handball players (age: 16.2 ± 0.9 years) volunteered to participate in this study and performed single-leg countermovement jumps, single-leg broad jumps, single-leg lateral jumps, CODS tests at 180° (CODS180) and 90° (CODS90), change of direction actions with iso-inertial overload (crossover step [CRO] and lateral shuffle step), and a 20-m sprint test. Excellent intraclass correlation coefficient (ICC) values were found for all tests (ICC = 0.96-1.00) with the exception of the dominant limb during the CODS90 test (ICC = 0.69). Interlimb asymmetry scores ranged from 3.66 to 12.67%. Iso-inertial asymmetry values were higher than those found during jumping tasks (9.8-12.7% vs. 3.66-8.76%). Spearman's r correlations showed significant relationships between CRO asymmetry and CODS90 performance on both limbs (r = 0.48-0.51; p < 0.05) and CODS180 (r = 0.41-0.51; p < 0.05) and a sprint test (r = 0.46; p < 0.05). These results show the test-specific nature of asymmetries in youth handball players, with iso-inertial device and CODS deficit presenting the greatest magnitude of asymmetries. Furthermore, interlimb differences during iso-inertial device (CRO) were associated with reduced CODS and sprint performance. These results suggest that the use of iso-inertial devices for the detection of interlimb asymmetry may be more effective than the total time during traditional CODS tests and that larger imbalances are associated with reduced athletic performance in youth handball players.

Objective The aim of this review was to evaluate a selection of major reporting aspects in manual therapy (MT) trials, before and after the publication of the CONSORT extension for nonpharmacological trials (CONSORTnpt) Study Design and Setting We randomly selected 100 MT trials published between 2000 and 2015 and divided them into a pre-CONSORTnpt (n = 50) and a post-CONSORTnpt (n = 50) group. We extracted data on relevant issues of internal validity, reliability, and description of interventions. Two authors extracted data independently. Percentages were used for descriptive analyses, and Fisher’s exact test and the chi-square test were used for group comparisons. Results Six different types of MT interventions with up to 20 controls were analyzed. The most common populations/conditions studied were healthy subjects and subjects with lower back or neck pain. Over 70% of studies included multi-session interventions, and 42% of studies reported long-term followup. The only significant differences between groups were the inclusion of a flowchart diagram, the estimated effect size, precision descriptions, and the description of intervention procedures. Conclusion Our findings suggest that trials in MT show poor reporting even after the availability of standardized guidelines.

Neuromuscular asymmetries have been previously associated with reduced performance. Similarly, maturation has shown that youth athletes may experience a loss of motor control, which could also lead to compromised physical performance. The present study aimed to evaluate and quantify the level of asymmetry among chronological and maturational groups. Forty-one youth tennis players performed the single leg countermovement jump (SLCMJ), star excursion balance test (SEBT) and a change of direction speed (CODS) test. Differences were found between the strongest and weakest limbs across all tests (p &lt, 0.001), and also for SEBT in the posteromedial direction (p = 0.02), SEBT composite score (p &lt, 0.01) in maturation groups, and for SEBT posterolateral direction (p = 0.03) and SEBT composite score (p = 0.01) in chronological groups. The SLCMJ showed the largest inter-limb asymmetries for the circa peak height velocity (PHV) group (19.31 &plusmn, 12.19%) and under-14 (U14) group (17.55 &plusmn, 9.90%). Chronological and maturation groups followed similar trends for inter-limb asymmetries, but the biological index showed larger asymmetry scores in the jumping test at PHV compared to that found in the chronological group (U14). These results show that inter-limb differences may be heightened during PHV. Practitioners can use this information to inform the decision-making process when prescribing training interventions in youth tennis players.

The forces exerted on a suspension device have been examined in the upper body exercises such as push-ups or inverted row. However, there is a lack of evidence with regard to the effects of a suspension device on force production in lower limb exercises. For this reason, this aim of this study was to determine the effects of body position, contraction patterns and pace on force production by the lower limb during the execution of suspended lunge exercises. Ten physically active male university students (n = 10, age = 23.70±2.83 years old) performed sixteen suspended lunges in four different positions and at three different paces (60, 70, and 80 beats per minute). A load cell was used to assess the forces exerted on the suspension device. Force data were analysed with factorial repeated measurements (ANOVA). Significant main effects for position in concentric force (p= .000), average force (p= .002), and for frequency in peak force (p= .004) were found. Peak force was significantly higher in all positions for dynamic contraction type than for isometric suspended lunge. In conclusion, a greater distance of the feet, frequencies around 70 beats per minute and the dynamic contraction type all contributed to enhancing the forces exerted on the suspension strap in the performance of the lunge exercise. Les forces exercides sobre un dispositiu de suspensió han estat examinades en exercicis com les flexions de braços o el rem invertit. No obstant això, hi ha una manca d’evidències investigant l’efecte dels dispositius de suspensió sobre la producció de força a l’extremitat inferior. Per aquesta raó, l’objectiu de l’estudi va ser determinar els efectes de la posició corporal, els règims de contracció i la velocitat d’execució sobre la producció de força de l’extremitat inferior durant l’exercici del lunge en suspensió. Es van reclutar joves universitaris físicament actius (n= 10, edat = 23.70±2.83 anys) per fer setze lunges en suspensió en quatre posicions i tres ritmes diferents (60, 70, i 80 batecs per minut). Es va utilitzar una cèl·lula de força per valorar les forces exercides sobre el dispositiu de suspensió. Les dades de força es van analitzar amb l’ANOVA factorial de mesures repetides. Es va obtenir un efecte principal per la posició en la força concèntrica (p= .000), força mitjana (p= .002), i per la freqüència en el pic de força (p= .004). El pic de força va ser significativament més alt durant la contracció dinàmic en comparació amb la isomètrica en totes les posicions. Les posicions amb amplituds més grans entre cames, freqüències al voltant dels 70 batecs per minut i el règim de contracció dinàmic milloren les forces exercides sobre el dispositiu de suspensió en l’exercici de lunge.

There were two aims of this study: first, to investigate physical fitness and match performance differences between under-16 (U16) and under-18 (U18) female basketball players, and second, to evaluate the relationship between physical fitness and game-related performances. Twenty-three young, female, elite Spanish basketball players (16.2 1.2 years) participated in the study. The sample was divided into two groups: U16 and U18 players. The average scores from pre- and post-season physical fitness measurements were used for subsequent analyses. Anthropometric variables were also measured. To evaluate game performance, game-related statistics, including the number of games and minutes played, points, rebounds, assists, steals and blocks per game, were recorded for every competitive match in one season. When anthropometric and physical performance variables were compared between groups, the U18 group demonstrated significantly (p

THE SECOND PART OF THIS REVIEW PROVIDES A FLEXIBLE APPROACH TO INTEGRATIVE NEUROMUSCULAR TRAINING (INT) WITH THE GOALS TO IMPROVE INJURY RESILIENCE AND TO ENHANCE SPORT AND MOTOR PERFORMANCE ABILITIES IN YOUTH POPULATIONS. THE PROPOSED MODEL OF INT IN THIS MANUSCRIPT PRESENTS 6 ESSENTIAL COM

Article published in Strength and Conditioning Journal on 01 June 2016 (online), available at: https://doi.org/10.1519/SSC.0000000000000229.