Context: Single- versus double-leg landing events occur the majority of the time in a netball match. Landings are involved in large proportions of netball noncontact knee injury events. Of all landing-induced anterior cruciate ligament injuries, most occur during single-leg landings. Knowledge of whether different single-leg functional performance tests capture the same or different aspects of lower-limb motor performance will therefore inform clinicians’ reasoning processes and assist in netball noncontact knee injury prevention screening. Objective: To determine the correlation between the triple hop for distance (THD), single hop for distance (SHD), and vertical hop (VH) for the right and left lower limbs in adult female netball players. Design: Cross-sectional. Setting: Local community netball club. Participants: A total of 23 players (age 28.7 [6.2] y; height 171.6 [7.0] cm; mass 68.2 [9.8] kg). Interventions: There were 3 measured trials (right and left) for THD, SHD, and VH, respectively. Main Outcome Measures: Mean hop distance (percentage of leg length [%LL]), Pearson intertest correlation (r), and coefficient of determination (r 2). Results: Values (right and left; mean [SD]) were as follows: THD, 508.5 (71.8) %LL and 510.9 (56.7) %LL; SHD, 183.4 (24.6) %LL and 183.0 (21.5) %LL; and VH, 21.3 (5.2) %LL and 20.6 (5.0) %LL. All correlations were significant (P ≤ .05), r/r 2 values (right and left) were THD–SHD, .91/.83 and .87/.76; THD–VH, .59/.35 and .51/.26; and SHD–VH, .50/.25 and .37/.17. A very large proportion of variance (76%–83%) was shared between the THD and SHD. A small proportion of variance was shared between the THD and VH (25%–35%) and SHD and VH (17%–25%). Conclusion: The THD and SHD capture highly similar aspects of lower-limb motor performance. In contrast, the VH captures aspects of lower-limb motor performance different to the THD or SHD. Either the THD or the SHD can be chosen for use within netball knee injury prevention screening protocols according to which is reasoned as most appropriate at a specific point in time. The VH, however, should be employed consistently alongside rather than in place of the THD or SHD.
Nicholas C. Clark and Elaine M. Mullally
Kolbjørn Lindberg, Ingrid Eythorsdottir, Paul Solberg, Øyvind Gløersen, Olivier Seynnes, Thomas Bjørnsen, and Gøran Paulsen
Purpose: The aim of this study was to examine the concurrent validity of force–velocity (FV) variables assessed across 5 Keiser leg press devices. Methods: A linear encoder and 2 independent force plates (MuscleLab devices) were mounted on each of the 5 leg press devices. A total of 997 leg press executions, covering a wide range of forces and velocities, were performed by 14 participants (29  y, 181  cm, 82  kg) across the 5 devices. Average and peak force, velocity, and power values were collected simultaneously from the Keiser and MuscleLab devices for each repetition. Individual FV profiles were fitted to each participant from peak and average force and velocity measurements. Theoretical maximal force, velocity, and power were deduced from the FV relationship. Results: Average and peak force and velocity had a coefficient of variation of 1.5% to 8.6%, near-perfect correlations (.994–.999), and a systematic bias of 0.7% to 7.1% when compared with reference measurements. Average and peak power showed larger coefficient of variations (11.6% and 17.2%), despite excellent correlations (.977 and .952), and trivial to small biases (3.9% and 8.4%). Extrapolated FV variables showed near-perfect correlations (.983–.997) with trivial to small biases (1.4%–11.2%) and a coefficient of variation of 1.4% to 5.9%. Conclusions: The Keiser leg press device can obtain valid measurements over a wide range of forces and velocities across different devices. To accurately measure power, theoretical maximal power calculated from the FV profile is recommended over average and peak power values from single repetitions, due to the lower random error observed for theoretical maximal power.
Anna Baylis, David Cameron-Smith, and Louise M. Burke
Many athletes report using a wide range of special sports foods and supplements. In the present study of 77 elite Australian swimmers, 99% of those surveyed reported the use of these special preparations, with 94% of swimmers reporting the use of non-food supplements. The most popular dietary supplements were vitamin or mineral supplements (used by 94% of the group), herbal preparations (61%), and creatine (31%). Eighty-seven percent of swimmers reported using a sports drink or other energy-providing sports food. In total, 207 different products were reported in this survey. Sports supplements, particularly supplements presented as pills or other non-food form, are poorly regulated in most countries, with little assurance of quality control. The risk of an inadvertent “positive doping test” through the use of sports supplements or sports foods is a small but real problem facing athletes who compete in events governed by anti-doping rules. The elite swimmers in this survey reported that information about the “doping safety” of supplements was important and should be funded by supplement manufacturers. Although it is challenging to provide such information, we suggest a model to provide an accredited testing program suitable for the Australian situation, with targeted athlete education about the “sports safety” of sports supplements and foods.
This article examines elite athletes’ understandings of the relationship between sport participation and health. Data are taken from interviews with 20 male and female athletes. Athletes’ assessments of the impact of sport on health and wellbeing include attributions of negative, positive, and, most often, mixed outcomes. In these elite athletes’ conceptualizations of health, injury and illness are subordinated to a view of health as capacity, and the primary frame of reference in which they consider capacity is their immediate competitive careers. Respondents’ accounts of efforts to manage the threats to their health that are posed by their sporting activity frequently convey a disembodied notion of the athletic body as an object to be managed.
D. Enette Larson-Meyer, Kathleen Woolf, and Louise Burke
Nutrition assessment is a necessary first step in advising athletes on dietary strategies that include dietary supplementation, and in evaluating the effectiveness of supplementation regimens. Although dietary assessment is the cornerstone component of the nutrition assessment process, it should be performed within the context of a complete assessment that includes collection/evaluation of anthropometric, biochemical, clinical, and environmental data. Collection of dietary intake data can be challenging, with the potential for significant error of validity and reliability, which include inherent errors of the collection methodology, coding of data by dietitians, estimation of nutrient composition using nutrient food tables and/or dietary software programs, and expression of data relative to reference standards including eating guidance systems, macronutrient guidelines for athletes, and recommended dietary allowances. Limitations in methodologies used to complete anthropometric assessment and biochemical analysis also exist, as reference norms for the athlete are not well established and practical and reliable biomarkers are not available for all nutrients. A clinical assessment collected from history information and the nutrition-focused physical exam may help identify overt nutrient deficiencies but may be unremarkable in the well-trained athlete. Assessment of potential food-drug interactions and environmental components further helps make appropriate dietary and supplement recommendations. Overall, the assessment process can help the athlete understand that supplement intake cannot make up for poor food choices and an inadequate diet, while a healthy diet helps ensure maximal benefit from supplementation. Establishment of reference norms specifically for well-trained athletes for the nutrition assessment process is a future research priority.
International Olympic Committee Expert Group on Dietary Supplements in Athletes
the elite athlete. Assessment of the evidence requires a consideration of potential limitations to study design, including confounding variables and bias, and of the relevance to real-life practices of elite athletes, as well as the need for verification of the composition of supplements used
Shona L. Halson and David T. Martin
, scientists hired, and athlete assessment and development methodologies refined, all with the objective of producing Olympic gold medals. In the lead-up to the Sydney 2000 Olympic Games, something interesting happened at the Australian Institute of Sport. The Olympic Athlete Program (OAP) was formed, and
Ahmad F. Mohd Kassim and Ian D. Boardley
athlete-level outcomes that should result from effective coaching: competence, confidence, connection, and character. Consistent with these proposed outcomes, research on coaching effectiveness has identified significant associations between athletes’ assessments of their coach’s effectiveness and
Nessan Costello, Jim McKenna, Louise Sutton, Kevin Deighton, and Ben Jones
interventions had failed to result in substantial BM gains. Written informed consent was provided and ethics approval granted by Leeds Beckett University, United Kingdom. Athlete Assessment Anthropometric and Strength Assessment Anthropometric and strength characteristics were assessed at baseline and at the
Liam Anderson, Graeme L. Close, Matt Konopinski, David Rydings, Jordan Milsom, Catherine Hambly, John Roger Speakman, Barry Drust, and James P. Morton
replace the damaged ACL. The player was not immobilized at any point during the rehabilitation, although he spent 6 days postoperation nonweight bearing on his injured limb. Overview of Athlete Assessments As part of the club’s regular monitoring processes, a whole-body fan beam dual-energy X