Individual Responses to an 8-Week Neuromuscular Training Intervention in Trained Pre-Pubescent Female Artistic Gymnasts

This study examined individual responses in leg stiffness, reactive strength index (RSI), movement proficiency (deep overhead squat and in-line lunge), and trunk muscular endurance (flexor and extensor tests) in young female gymnasts following an 8-week neuromuscular training intervention. Thirty-four pre-peak height velocity (PHV) female gymnasts were divided into either an experimental group (EXP n = 17) or control group (CON n = 17). The EXP replaced their normal gymnastics physical preparation with a neuromuscular training program, while the CON continued with their habitual gymnastics program. Chi square analysis showed that the EXP resulted in significantly more positive responders compared to CON for measures of leg stiffness (41% versus 12% responded positively), extensor muscular endurance, (76% versus 29%), and competency in the deep overhead squat, (76% versus 29%) and in-line lunge (left lead leg) (65% versus 18%). Conversely, the number of positive responders for RSI (53% versus 61%), the flexor endurance test (88% versus 53%), and the right in-line lunge (47% versus 35%) were not significantly different between groups. These findings suggest that most young gymnasts responded positively to neuromuscular training from the perspective of improving movement proficiency and trunk endurance; however, changes in leg stiffness and RSI were more variable and may require higher intensities to realise further adaptations

Bio-banding in Sport: Applications to Competition, Talent Identification, and Strength and Conditioning of Youth Athletes

Bio-banding is the process of grouping athletes on the basis of attributes associated with growth and maturation, rather than chronological age. Children of the same age may vary considerably in biological maturation with some individuals maturing well in advance or delay of their peers. The timing of maturation has important implications for competition, talent identification and training. Increased awareness and interest in the subject of maturation has sparked a renewed interest in the study and application of bio-banding. This overview describes the purpose and process of bio-banding, potential benefits and limitations, and also presents some recent advances in its application in youth sports

Laser Peening to Improve Fatigue Strength and Lifetime of Critical Components1

AbstractFatigue failure is typically driven by component geometric requirements that result in local areas of high tensile loading stress. Within this paper we discuss the deep protective stress generated by laser peening and show examples of using a newly developed finite element predictive strain and stress tool that accurately models laser peening. The analysis tool and robust process enable the accurate engineering of local compressive stress into critical areas of diverse/all(?) ferrous and non-ferrous materials in a well-defined manner that significantly improves fatigue life and strength. This capability opens the potential for advanced designs with increased performance, enhanced reliability and reduced system weight

Asymmetry During Maximal Sprint Performance in 11- to 16-Year-Old Boys

Purpose: The aim of this study was to examine the influence of age and maturation upon magnitude of asymmetry in the force, stiffness and the spatiotemporal determinants of maximal sprint speed in a large cohort of boys. Methods: 344 boys between the ages of 11 and 16 years completed an anthropometric assessment and a 35 m sprint test, during which sprint performance was recorded via a ground-level optical measurement system. Maximal sprint velocity, as well as asymmetry in spatiotemporal variables, modeled force and stiffness data were established for each participant. For analysis, participants were grouped into chronological age, maturation and percentile groups. Results: The range of mean asymmetry across age groups and variables was 2.3–12.6%. The magnitude of asymmetry in all the sprint variables was not significantly different across age and maturation groups (p > .05), except relative leg stiffness (p < .05). No strong relationships between asymmetry in sprint variables and maximal sprint velocity were evident (rs < .39). Conclusion: These results provide a novel benchmark for the expected magnitude of asymmetry in a large cohort of uninjured boys during maximal sprint performance. Asymmetry in sprint performance is largely unaffected by age or maturation and no strong relationships exist between the magnitude of asymmetry and maximal sprint velocity

Effects of rising temperatures and [CO2] on the physiology of tropical forest trees

Using a mixture of observations and climate model outputs and a simple parametrization of leaf-level photosynthesis incorporating known temperature sensitivities, we find no evidence for tropical forests currently existing ‘dangerously close’ to their optimum temperature range. Our model suggests that although reductions in photosynthetic rate at leaf temperatures (TL) above 30°C may occur, these are almost entirely accountable for in terms of reductions in stomatal conductance in response to higher leaf-to-air vapour pressure deficits D. This is as opposed to direct effects of TL on photosynthetic metabolism. We also find that increases in photosynthetic rates associated with increases in ambient [CO2] over forthcoming decades should more than offset any decline in photosynthetic productivity due to higher D or TL or increased autotrophic respiration rates as a consequence of higher tissue temperatures. We also find little direct evidence that tropical forests should not be able to respond to increases in [CO2] and argue that the magnitude and pattern of increases in forest dynamics across Amazonia observed over the last few decades are consistent with a [CO2]-induced stimulation of tree growth

Maximal sprint speed in boys of increasing maturity

The purpose of this study was to examine the natural development of the mechanical features of sprint performance in relation to maturation within a large cohort of boys. Three hundred and thirty-six boys (11–15 years) were analyzed for sprint performance and maturation. Maximal speed, stride length (SL), stride frequency (SF), flight time (FT) and contact time (CT) were assessed during a 30m sprint. Five maturation groups (G1–5) were established based on age from peak height velocity (PHV) where G1=>2.5years pre-PHV, G2 = 2.49–1.5years pre-PHV, G3 = 1.49–0.5years pre-PHV, G4 = 0.49years pre- to 0.5years post-PHV and G5 = 0.51–1.5years post-PHV. There was no difference in maximal speed between G1, G2 and G3 but those in G4 and G5 were significantly faster (p .05). SF decreased while CT increased (both p .05) were observed for either variable between G3, G4 and G5. While G1–3 increased their SL, concomitant decreases in SF and increases in CT prevented them from improving maximal speed. Maximal sprint speed appears to develop around and post-PHV as SF and CT begin to stabilize, with increases in maximal sprint speed in maturing boys being underpinned by increasing SL

The Influence of Maturity Offset, Strength, and Movement Competency on Motor Skill Performance in Adolescent Males

This study aimed to examine the extent to which maturity offset, strength, and movement competency influences motor skill performance in adolescent boys. One hundred and eight secondary school boys completed anthropometric and physical testing on two non-consecutive days for the following variables: maturity offset, isometric mid-thigh pull absolute (IMTPABS) and relative (IMTPREL) peak force, resistance training skills quotient, 10-, 20- and 30-meter sprint time, countermovement jump height, horizontal jump distance, anaerobic endurance performance, and seated medicine ball throw (SMBT). The IMTPREL displayed significant small to large correlations with all performance variables (r = 0.27-0.61) whereas maturity offset was significantly correlated with IMTPABS (r = 0.69), sprint (r = 0.29-0.33), jump (r = 0.23-0.34), and SMBT (r = 0.32). Absolute and relative strength were the strongest predictors of all performance variables and combined with maturity to explain 21-76% of the variance. Low and average relative strength boys were nearly eight times (odds ratio: 7.80, confidence interval: 1.48-41.12, p < 0.05) and nearly four times (odds ratio: 3.86, confidence interval: 0.95-15.59, p < 0.05) more likely to be classified as lower competency compared to high relative strength boys. Relative strength has more influence on motor skill performance than maturity when compared with movement competency

Hopping and landing performance in male youth soccer players: Effects of age and maturation

Quantifying hopping and landing performances can assist coaches in identifying young male soccer players who may be at increased risk of injury. The influence of chronological age and maturation on these measures in this population is unknown. Single leg hop for distance (SLHD) and 75% horizontal hop and stick landing force (75%Hop) were examined in a cross-sectional sample (N=400) of elite male youth soccer players. Between-group differences for both chronological age (U11–U18) and stage of maturation (pre-, circa- or post-peak height velocity (PHV)) were analyzed. Absolute 75%Hop increased with both age and maturation. Apart from the U18s, pre-PHV and U11–U12 players displayed the greatest relative landing forces compared to all other groups (p<0.001; d=0.56–0.93). Absolute and relative SLHD were greatest in the U18s and post-PHV players (p<0.001; d=0.35–2.04). A trend showed increased SLHD with each consecutive age group although a reduction in performance was identified in the U13s (d=0.50–0.59). High volumes of accumulated soccer participation in the U18s may lead to altered landing strategies indicative of high injury risk. A temporary reduction in hop performance in the U13s may also be linked to a period of adolescent awkwardness

Supporting the library and information needs of UWE health and social care students on placement

© 2017 Health Libraries Group Objective: The aim of this research was to explore the library and information needs of health and social care students whilst on placement. Methods: Both desk and primary research were conducted and included an online questionnaire to students and semi-structured interviews. Results: The questionnaire was completed by 252 students from a variety of programmes, equivalent to a 10% response rate. The results indicate a wide range of factors impacting on the library and information experiences of students. Whilst differences in the availability of a physical library in hospital or community locations still exist, these are mitigated by technology and a preference for home study. A significant result is that 77% (n=193) of students on placement study at home, using a variety of Internet-connected devices. This highlights a marked change in practice and underlines the need for mobile-compliant e-resources and accessible at-a-distance services. Conclusion: As a result of this research, practical recommendations on how library support can be improved were developed including enhanced collaboration and learning with NHS colleagues, and knowledge sharing with other departments within the University who support our students