Dazed and confused: sports medicine, conflicts of interest, and concussion management

Professional sports with high rates of concussion have become increasingly concerned about the long-term effects of multiple head injuries. In this context, return-to-play decisions about concussion generate considerable ethical tensions for sports physicians. Team doctors clearly have an obligation to the welfare of their patient (the injured athlete) but they also have an obligation to their employer (the team), whose primary interest is typically success through winning. At times, a team's interest in winning may not accord with the welfare of an injured player, particularly when it comes to decisions about returning to play after injury. Australia's two most popular professional football codes-rugby league and Australian Rules football-have adopted guidelines that prohibit concussed players from continuing to play on the same day. I suggest that conflicts of interest between doctors, patients, and teams may present a substantial obstacle to the proper adherence of concussion guidelines. Concussion management guidelines implemented by a sport's governing body do not necessarily remove or resolve conflicts of interest in the doctor-patient-team triad. The instigation of a concussion exclusion rule appears to add a fourth party to this triad (the National Rugby League or the Australian Football League). In some instances, when conflicts of interest among stakeholders are ignored or insufficiently managed, they may facilitate attempts at circumventing concussion management guidelines to the detriment of player welfare

Climate, Geography and the Propensity to Walk: environmental factors and walking trip rates in Brisbane

Transport planners and health promoters are presently concerned with increasing the proportion of walking trips made in urban areas in order to increase efficiencies in the transport system and rates of physical activity. However, there are numerous 'barriers to walking' that need to be overcome in order to increase walking trip rates in cities, including several environmental factors relating to the 'natural environment'. Natural environment factors include topography, and climatic variables such as heat and humidity, precipitation, and daylight availability. This study has sought to develop appropriate variables from available data sources and to synthesise them with household travel survey data so as to examine the influence of environmental factors on a person's propensity to walk in Brisbane, Australia. The primary purpose of the study was developing and testing new methods to identify the influences of environmental factors, rather than undertaking more extensive and rigorous research to provide precise measurements. Despite this, the results reveal a new set of insights into walking in this sub-tropical city that at times confirm and at other times confound popular assumptions about pedestrian activity. The belief that Brisbane's sub-tropical summer weather and hilly terrain are not conducive to non-motorised travel is not supported by these preliminary findings. Indeed the natural environmental conditions in the city appear to have little influence on the propensity of persons to walk.Griffith Sciences, Griffith School of EnvironmentFull Tex

Mechanisms of anterior cruciate ligament injuries in elite women’s netball:A systematic video analysis

This study involved a systematic video analysis of 16 anterior cruciate ligament (ACL) injuries sustained by elite-level netball players during televised games in order to describe the game situation, the movement patterns involved, the player’s behaviour, and a potential injury mechanism. Eight of the ACL injuries were classified as “indirect contact” and eight as “non-contact”. Two common scenarios were identified. In Scenario A the player was jumping to receive or intercept a pass and whilst competing for the ball experienced a perturbation in the air. As a result the player’s landing was unbalanced with loading occurring predominantly on the knee of the injured side. In Scenario B the player was generally in a good position at ground contact, but then noticeably altered the alignment of the trunk before the landing was completed. This involved rotating and laterally flexing the trunk without altering the alignment of the feet. Apparent knee valgus collapse on the knee of the injured side was observed in 3/6 Scenario A cases and 5/6 Scenario B cases. Players may benefit from landing training programmes that incorporate tasks that use a ball and include decision-making components or require players to learn to cope with being unbalanced.</p

Exploring the justifications for selecting a drop landing task to assess injury biomechanics:A narrative review and analysis of landings performed by female netball players

When assessing biomechanics in a laboratory setting, task selection is critical to the production of accurate and meaningful data. The injury biomechanics of landing is commonly investigated in a laboratory setting using a drop landing task. However, why this task is so frequently chosen is unclear. Therefore, this narrative review aimed to (1) identify the justification/s provided within the published literature as to why a drop landing task was selected to investigate the injury biomechanics of landing in sport and (2) use current research evidence, supplemented by a new set of biomechanical data, to evaluate whether the justifications are supported. To achieve this, a comprehensive literature search using Scopus, PubMed, and SPORTDiscus online databases was conducted for studies that had collected biomechanical data relating to sport injuries using a drop landing task. In addition, kinematic and kinetic data were collected from female netball players during drop landings and maximum-effort countermovement jumps from the ground to grab a suspended ball. The literature search returned a total of 149 articles that were reviewed to determine the justification for selecting a drop landing task. Of these, 54% provided no explicit justification to explain why a drop landing task was chosen, and 15% stated it was selected because it had been used in previous research. Other reasons included that the drop landing provides high experimental control (16%), is a functional sports task (11%), and is a dynamic task (6%). Evidence in the literature suggests that the biomechanical data produced with drop landings may not be as externally valid as more sport-specific tasks. Biomechanical data showed that the drop landing may not control center of mass fall height any better than maximum-effort countermovement jumps from the ground. Further, the frequently used step-off technique to initiate drop landings resulted in kinematic and kinetic asymmetries between lower limbs, which would otherwise be symmetrical when performing a countermovement jump from the ground. Researchers should consider the limitations of a drop landing task and endeavor to improve the laboratory tasks used to collect biomechanical data to examine the injury biomechanics of landing.</p

Do the landing mechanics of experienced netball players differ from those of trained athletes competing in sports that do not require frequent landings?

Objectives: This study examined whether young (15–19 years old) high-performance netball players exhibit different landing mechanics compared to female controls who do not participate in sports requiring frequent landings. Design: Comparative, cross-sectional. Methods: Lower limb kinematics and kinetics from 23 youth high performance female netball players (age: 17.5 ± 1.7 years, height: 1.77 ± 0.06 m, mass: 66.5 ± 6.33 kg, netball experience: 8.5 ± 2.3 years) were compared to data from 23 females (age: 22.0 ± 3.2 years, height: 1.70 ± 0.05 m, mass: 64.4 ± 6.7 kg) who were involved in competitive sport, but had minimal experience playing a jump-landing sport. The jump landing task required participants to perform a countermovement jump and grab a netball suspended at 85% of the participant's maximum jump height. On random trials the ball was raised rapidly to 100% maximum jump height as the participant initiated her jump. Results: The netball group landed with significantly less contribution from the knee extensors to total work for the non-preferred leg (P < 0.001, ds = 1.10) than the inexperienced group. Although no other significant differences were found between groups, there were several small to moderate differences in several of the key biomechanical variables identified as being risk factors for ACL injury or associated with ACL strain. Conclusions: Both groups had similar knee valgus and internal rotation angles and moments, with nearly all participants presenting with relatively poor frontal plane knee control. Overall, results suggest that experience playing a netball may not be enough to develop low-risk landing mechanics.</p