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1 sheet ([1] p.) ; Place and actual date of publication from Wing. ; Reproduction of the original in the British Library.

Purpose: Gait retraining, comprising bio-feedback and/or an exercise intervention, might reduce the risk of musculoskeletal conditions. The purpose was to examine the effect of a gait retraining program on medial tibial stress syndrome incidence during a 26 week basic military training regimen. Methods: A total of 450 British Army recruits volunteered. On the basis of a baseline plantar pressure variable (mean foot balance during the first 10% of stance), participants classified as at-risk of developing medial tibial stress syndrome (n = 166) were randomly allocated to an intervention (n = 83) or control (n = 83) group. The intervention involved supervised gait retraining, including exercises to increase neuromuscular control and flexibility (3 sessions per week) and bio-feedback enabling internalization of the foot balance variable (1 session per week). Both groups continued with the usual military training regimen. Diagnoses of medial tibial stress syndrome over the 26 week regimen were made by physicians blinded to group assignment. Data were modelled in a survival analysis using Cox regression, adjusting for baseline foot balance and time to peak heel rotation. Results: The intervention was associated with a substantially reduced instantaneous relative risk of medial tibial stress syndrome versus control, with an adjusted hazard ratio of 0.25 (95% confidence interval, 0.05 to 0.53). The number needed to treat to observe one additional injury-free recruit in intervention versus control at 20 weeks was 14 (11 to 23) participants. Baseline foot balance was a nonspecific predictor of injury, with a hazard ratio per 2-SD increment of 5.2 (1.6 to 53.6). Conclusions: The intervention was effective in reducing incidence of medial tibial stress syndrome in an at-risk military sample

Purpose Overuse injury risk increases during periods of accelerated growth which can subsequently impact development in academy soccer, suggesting a need to quantify training exposure. Non-prescriptive development scheme legislation could lead to inconsistent approaches to monitoring maturity and training load. Therefore, this study aims to communicate current practices of UK soccer academies towards biological maturity and training load. Methods Fourty-nine respondents completed an online survey representing support staff from male Premier League academies (n = 38) and female Regional Talent Clubs (n = 11). The survey included 16 questions covering maturity and training load monitoring. Questions were multiple-choice or unipolar scaled (agreement 0-100) with a magnitude-based decision approach used for interpretation. Results Injury prevention was deemed highest importance for maturity (83.0  5.3, mean ±SD) and training load monitoring (80.0  2.8). There were large differences in methods adopted for maturity estimation and moderate differences for training load monitoring between academies. Predictions of maturity were deemed comparatively low in importance for bio-banded (biological classification) training (61.0  3.3) and low for bio-banded competition (56.0  1.8) across academies. Few respondents reported maturity (42%) and training load (16%) to parent/guardians, and only 9% of medical staff were routinely provided this data. Conclusions Although consistencies between academies exist, disparities in monitoring approaches are likely reflective of environment-specific resource and logistical constraints. Designating consistent and qualified responsibility to staff will help promote fidelity, feedback and transparency to advise stakeholders of maturity-load relationships. Practitioners should consider biological categorisation to manage load prescription to promote maturity appropriate dose-responses and help reduce non-contact injury risk.

Purpose: Overuse injury risk increases during periods of accelerated growth, which can subsequently impact development in academy soccer, suggesting a need to quantify training exposure. Nonprescriptive development scheme legislation could lead to inconsistent approaches to monitoring maturity and training load. Therefore, this study aimed to communicate current practices of UK soccer academies toward biological maturity and training load. Methods: Forty-nine respondents completed an online survey representing support staff from male Premier League academies (n = 38) and female Regional Talent Clubs (n = 11). The survey included 16 questions covering maturity and training-load monitoring. Questions were multiple-choice or unipolar scaled (agreement 0-100) with a magnitude-based decision approach used for interpretation. Results: Injury prevention was deemed highest importance for maturity (83.0 [5.3], mean [SD]) and training-load monitoring (80.0 [2.8]). There were large differences in methods adopted for maturity estimation and moderate differences for training-loadmonitoring between academies. Predictions of maturity were deemed comparatively low in importance for bio-banded (biological classification) training (61.0 [3.3]) and low for bio-banded competition (56.0 [1.8]) across academies. Few respondents reported maturity (42%) and training load (16%) to parent/guardians, and only 9% of medical staff were routinely provided this data. Conclusions: Although consistencies between academies exist, disparities in monitoring approaches are likely reflective of environment-specific resource and logistical constraints. Designating consistent and qualified responsibility to staff will help promote fidelity, feedback, and transparency to advise stakeholders of maturity-load relationships. Practitioners should consider biological categorization to manage load prescription to promote maturity-appropriate dose-responses and to help reduce the risk of noncontact injury.

We prepared bulk samples of supercooled liquid water under pressure by isochoric heating of high-density amorphous ice to temperatures of 205 ± 10 kelvin, using an infrared femtosecond laser. Because the sample density is preserved during the ultrafast heating, we could estimate an initial internal pressure of 2.5 to 3.5 kilobar in the high-density liquid phase. After heating, the sample expanded rapidly, and we captured the resulting decompression process with femtosecond x-ray laser pulses at different pump-probe delay times. A discontinuous structural change occurred in which low-density liquid domains appeared and grew on time scales between 20 nanoseconds to 3 microseconds, whereas crystallization occurs on time scales of 3 to 50 microseconds. The dynamics of the two processes being separated by more than one order of magnitude provides support for a liquid-liquid transition in bulk supercooled water.