Review on the development of truly portable and in-situ capillary electrophoresis systems

Capillary electrophoresis (CE) is a technique which uses an electric field to separate a mixed sample into its constituents. Portable CE systems enable this powerful analysis technique to be used in the field. Many of the challenges for portable systems are similar to those of autonomous in-situ analysis and therefore portable systems may be considered a stepping stone towards autonomous in-situ analysis. CE is widely used for biological and chemical analysis and example applications include: water quality analysis; drug development and quality control; proteomics and DNA analysis; counter-terrorism (explosive material identification) and corrosion monitoring. The technique is often limited to laboratory use, since it requires large electric fields, sensitive detection systems and fluidic control systems. All of these place restrictions in terms of: size, weight, cost, choice of operating solutions, choice of fabrication materials, electrical power and lifetime. In this review we bring together and critique the work by researchers addressing these issues. We emphasize the importance of a holistic approach for portable and in-situ CE systems and discuss all the aspects of the design. We identify gaps in the literature which require attention for the realization of both truly portable and in-situ CE systems

THE INFLUENCE OF CHANGES IN SPRINT ABlLlN ON THE SLED VELOCIN PROFILE DURING THE SKELETON START

Sprint times are key predictors of skeleton start petformance, but the effect of enhancing sprint ability on the development of sled velocity is unknown. Twelve well-trained skeleton athletes performed three dry-land push-starts and three 30-m sprints before and after 16 training weeks. Sled velocity profiles were characterised using three descriptors (pre-load velocity, pre-load distance and load effectiveness) and a sled acceleration index was used to evaluate performance. Increases in pre-load velocity and distance were related to improved sprint times. However, enhanced sprint ability did not guarantee a faster start as reductions in load effectiveness were also observed when higher velocities were attained. Coaches could supplement physical conditioning with load technique training to potentially improve the transfer of training-induced sled velocity increases across the loading phase

An integrated measurement system for analysing impact biomechanics in the rugby scrum

As part of a wider project investigating the biomechanics of the rugby scrum within rugby union, the focus of the present study was to design, realise and test an unobtrusive measurement system for assessing the kinematics and kinetics of rugby forwards while scrummaging on the pitch in realistic environmental conditions. Currently the study investigates one forward pack (eight players) scrummaging against an instrumented scrum machine, a training aid used widely throughout rugby. The measurement system integrates three different subsystems for: (1) measuring forces exerted by players; (2) capturing players’ movements; and, (3) triggering/synchronising all the sensors involved in (1) and (2). Applied three-dimensional forces were measured by strain gauge circuits attached to each pusher arm of the machine and then summed to produce the components of overall force. Multiple camera views allowed the recording and subsequent analysis of player movements, in the primary transverse (50 Hz and 200 Hz) and sagittal (50 Hz) planes of motion. A control system executed pre-recorded audio commands to players with consistent timings, sent trigger pulses to acquisition devices and collected analogue data at 500 Hz. The overall system has been applied successfully in the field to record data from rugby union forward packs across a range of playing levels and initial results confirm that the measurement system will be useful for its desired purpose to compare the biomechanics of different scrum engagement techniques

Effectiveness of the <i>Activate </i>injury prevention exercise programme to prevent injury in schoolboy rugby union

Objective The efficacious Activate injury prevention exercise programme has been shown to prevent injuries in English schoolboy rugby union. There is now a need to assess the implementation and effectiveness of Activate in the applie setting. Methods This quasi-experimental study used a 24-hour time-loss injury definition to calculate incidence (/1000 hours) and burden (days lost/1000 hours) for individuals whose teams adopted Activate (used Activate during season) versus non-adopters. The dose-response relationship of varying levels of Activate adherence (median Activate sessions per week) was also assessed. Player-level rugby exposure, sessional Activate adoption and injury reports were recorded by school gatekeepers. Rate ratios (RR), adjusted by cluster (team), were calculated using backwards stepwise Poisson regression to compare rates between adoption and adherence groups. Results Individuals in teams adopting Activate had a 23% lower match injury incidence (RR 0.77, 95% CI 0.55 to 1.07), 59% lower training injury incidence (RR 0.41, 95% CI 0.17 to 0.97) and 26% lower match injury burden (95% CI 0.46 to 1.20) than individuals on non-adopting teams. Individuals with high Activate adherence (>= 3 sessions per week) had a 67% lower training injury incidence (RR 0.33, 95% CI 0.12 to 0.91) and a 32% lower match injury incidence (RR 0.68, 95% CI 0.50 to 0.92) than individuals with low adherence (<1 session per week). While 65% of teams adopted Activate during the season, only one team used Activate three times per week, using whole phases and programme progressions. Conclusion Activate is effective at preventing injury in English schoolboy rugby. Attention should focus on factors influencing programme uptake and implementation, ensuring Activate can have maximal benefit

Training load and injury risk in elite Rugby Union:The largest investigation to date

AbstractTraining load monitoring has grown in recent years with the acute:chronic workload ratio (ACWR) widely used to aggregate data to inform decision-making on injury risk. Several methods have been described to calculate the ACWR and numerous methodological issues have been raised. Therefore, this study examined the relationship between the ACWR and injury in a sample of 696 players from 13 professional rugby clubs over two seasons for 1718 injuries of all types and a further analysis of 383 soft tissue injuries specifically. Of the 192 comparisons undertaken for both injury groups, 40% (all injury) and 31% (soft tissue injury) were significant. Furthermore, there appeared to be no calculation method that consistently demonstrated a relationship with injury. Some calculation methods supported previous work for a “sweet spot” in injury risk, while a substantial number of methods displayed no such relationship. This study is the largest to date to have investigated the relationship between the ACWR and injury risk and demonstrates that there appears to be no consistent association between the two. This suggests that alternative methods of training load aggregation may provide more useful information, but these should be considered in the wider context of other established risk factors.</jats:p

Utilising a Behaviour Change Model to Improve Implementation of the Activate Injury Prevention Exercise Programme in Schoolboy Rugby Union

The Health Action Process Approach (HAPA) is a behaviour change model showing promise in positively changing youth sport coaches’ injury prevention behaviours. This study incorporated the HAPA model into coach training workshops for Activate, an efficacious rugby injury prevention programme. Primary aims were to investigate the effect of the workshop on schoolboy rugby union coaches’ (1) perceptions towards injury risk and prevention, (2) Activate adoption and adherence. Secondary aims were to (3) assess the differences in post-season HAPA constructs between workshop attendees and non-attendees, (4) explore associations between HAPA constructs and Activate adherence. In the pre-season, all participants (n = 76) completed a baseline survey, with 41 coaches electing to attend a workshop. Participants completed a post-season survey assessing HAPA constructs and Activate adoption and adherence throughout the season. The workshop did not affect coach perceptions of injury risk and prevention. Attendees had significantly greater rates of Activate adoption (95% vs. 54% χ2 = 17.42, p < 0.01) and adherence (median = 2 sessions vs. ≤1 session per week; z = 3.45, p = 0.03) than non-attendees. At post-season, attendees had significantly greater task self-efficacy (z = −3.46, p < 0.05) and intention (z = −4.33, p < 0.05) to use Activate. These results support the delivery of coach workshops that utilise a behaviour change model to maximise programme implementatio

Eight Weeks of Self-Resisted Neck Strength Training Improves Neck Strength in Age-Grade Rugby Union Players:A Pilot Randomized Controlled Trial

BACKGROUND: Greater neck strength is associated with fewer head and neck injuries. Neck-strengthening programs are commonly burdensome, requiring specialist equipment or significant time commitment, which are barriers to implementation. HYPOTHESIS: Completing a neck-strengthening program will increase isometric neck strength in age-group rugby players. STUDY DESIGN: A pilot randomized controlled exercise intervention study. LEVEL OF EVIDENCE: Level 2. METHODS: Twenty-eight U18 (under 18) male regional age-group rugby union players were randomized (intervention n =15/control n = 13). An 8-week exercise program was supervised during preseason at the regional training center. Control players continued their “normal practice,” which did not include neck-specific strengthening exercises. The 3-times weekly trainer-led intervention program involved a series of 15-second self-resisted contractions, where players pushed maximally against their own head, in forward, backward, left, and right directions. OUTCOME MEASURE: Peak isometric neck strength (force N) into neck flexion, extension, and left and right side flexion was measured using a handheld dynamometer. RESULTS: Postintervention between-group mean differences (MDs) in isometric neck strength change were adjusted for baseline strength and favored the intervention for total neck strength (effect size [ES] = 1.2, MD ± 95% CI = 155.9 ± 101.9 N, P = 0.004) and for neck strength into extension (ES = 1.0, MD ± 95% CI = 59.9 ± 45.4 N, P = 0.01), left side flexion (ES = 0.7, MD ± 95% CI = 27.5 ± 26.9 N, P = 0.05), and right side flexion (ES = 1.3, MD ± 95% CI = 50.5 ± 34.4 N, P = 0.006). CONCLUSION: This resource-efficient neck-strengthening program has few barriers to implementation and provides a clear benefit in U18 players’ neck strength. While the present study focused on adolescent rugby players, the program may be appropriate across all sports where head and neck injuries are of concern and resources are limited. CLINICAL RELEVANCE: Greater neck strength is associated with fewer head and neck injuries, including concussion. Performing this neck exercise program independently, or as part of a whole-body program like Activate, an interactive guide for players and coaches, could contribute to lower sports-related head and neck injuries

The effect of altering loading distance on skeleton start performance: Is higher pre-load velocity always beneficial?

Athletes initiating skeleton runs differ in the number of steps taken before loading the sled. We aimed to understand how experimentally modifying loading distance influenced sled velocity and overall start performance. Ten athletes (five elite, five talent; 67% of all national athletes) underwent two to four sessions, consisting of two dry-land push starts in each of three conditions (preferred, long and short loading distances). A magnet encoder on the sled wheel provided velocity profiles and the overall performance measure (sled acceleration index). Longer pre load distances (12% average increase from preferred to long distances) were related to higher pre-load velocity (r = 0.94), but lower load effectiveness (r = 0.75; average reduction 29%). Performance evaluations across conditions revealed that elite athletes’ preferred distance push starts were typically superior to the other conditions. Short loading distances were generally detrimental, whereas pushing the sled further improved some talent-squad athletes’ performance. Thus, an important trade-off between generating high pre load velocity and loading effectively was revealed, which coaches should consider when encouraging athletes to load later. This novel intervention study conducted within a real-world training setting has demonstrated the scope to enhance push-start performance by altering loading distance, particularly in developing athletes with less extensive training experience