data collection. Procedures At the initial visit, participants were fitted with a wrist-worn tri-axial accelerometer (ActiGraph GT3X+, dynamic range ±6 g, sampling rate 30 Hz) to wear on their non-dominant wrist 24 hrs/day for a week (including sleep and showering). Participants were instructed to
Laura D. Ellingson, Paul R. Hibbing, Gregory J. Welk, Dana Dailey, Barbara A. Rakel, Leslie J. Crofford, Kathleen A. Sluka and Laura A. Frey-Law
Wendy L. Hurley
The agreement of clinical judgments of endfeel between certified athletic trainers and orthopedic surgeons is not known.
To examine agreement of clinical judgments of endfeel between sample populations and explore the influence of clinician technique on sensitivity for determining ACL injury when performing an isolated examination procedure.
Randomized, blinded, controlled clinical trials.
1 orthopedic surgeon, 22 certified athletic trainers, and 12 model patients.
Main Outcome Measures:
Kappa coefficients were calculated to determine the agreement of clinical judgments of endfeel between the 2 populations sampled. Lachman-test sensitivity was measured using true positive and false negative interpretations.
Concurrence was poor for clinical judgments of endfeel. Sensitivity varied according to clinician technique.
Agreement between the 2 populations sampled was influenced by the examiners’ diagnostic skills and their capacity to properly perform and interpret the Lachman test.
Steve Hansen, Spencer J. Hayes and Simon J. Bennett
The current study examined the effect of interocular delay in a manual aiming task that required accurate end-point placement, but not precise control of a grip aperture. Participants aimed in binocular, monocular, or alternating monocular vision conditions. For the latter, 25ms monocular samples were provided to alternate eyes without delay (0ms), or a delay of 25 or 50ms. The interocular delay resulted in a longer movement time, caused by a longer time-to-peak and time-after-peak velocity, and a reduction in peak velocity. We suggest that the change in kinematics reflect a strategic response to preserve terminal aiming accuracy and variability when faced with an informational perturbation. These findings indicate that the response to the interocular delay between alternating monocular samples depends on the task-specific information used to control that behavior.
Paul J. McCarthy and Marc V. Jones
This focus group study examined the sources of enjoyment and nonenjoyment among younger and older English children in the sampling years of sport participation (ages 7–12). Concurrent inductive and deductive content analysis revealed that, consistent with previous research, younger and older children reported sources of enjoyment such as perceived competence, social involvement and friendships, psychosocial support, and a mastery-oriented learning environment. Nonenjoyment sources included inappropriate psychosocial support, increasing competitive orientation, negative feedback and reinforcement, injuries, pain, and demonstrating a lack of competence. Differences between younger and older children’s sources of enjoyment and nonenjoyment also emerged. Younger children reported movement sensations as a source of enjoyment and punishment for skill errors and low informational support as nonenjoyment sources. Older children reported social recognition of competence, encouragement, excitement, and challenge as sources of enjoyment with rivalry, overtraining, and high standards as sources of nonenjoyment. These differences underscore the importance of tailoring youth sport in the sampling years to the needs of the child.
Jacky J. Forsyth, Chris Mann and James Felix
In rowing ergometry, blood for determining lactate concentration can be removed from the toe tip without the rower having to stop. The purpose of the study was to examine whether sampling blood from the toe versus the earlobe would affect lactate threshold (Tlac) determination.
Ten physically active males (mean ± age 21.2 ± 2.3 y; stature 179.2 ± 7.5 cm; body mass 81.7 ± 12.7 kg) completed a multistage, 3 min incremental protocol on the Concept II rowing ergometer. Blood was sampled simultaneously from the toe tip and earlobe between stages. Three different methods were used to determine Tlac.
There were wider variations due to the method of Tlac determination than due to the sample site; for example, ANOVA results for power output were F(1.25, 11.25) = 11.385, P = .004 for method and F(1, 9) = 0.633, P = .45 for site. The greatest differences in Tlac due to sample site in rowing occurred when Tlac was determined using an increase in blood lactate concentration by >1 mmol/L from baseline (TlacΔ1).
The toe tip can be used as a suitable sample site for blood collection during rowing ergometry, but caution is needed when using the earlobe and toe tip interchangeably to prescribe training intensities based on Tlac, especially when using TlacΔ1 or at lower concentrations of lactate.
Lindsy Kass and Roger Carpenter
To compare blood lactate concentration ([Bla]) at 15 s and 45 s during the 1-min rest period between each stage of an incremental test in rowers and to establish the validity of using interchangeable sampling times.
Seventeen male club rowers (mean ± SD, age 28.8 ± 5.7 years, height 186.9 ± 5.1 cm, body mass 85.4 ± 6.6 kg) performed an incremental rowing ergometer test, consisting of five stages of 4 min corresponding to approximately 80% HRmax. A 10-µL earlobe blood sample was collected from each subject at 15 s and again at 45 s in the final minute of each test stage and analyzed in duplicate. A maximum of 10 s was allowed for blood collection.
Statistical analysis using limits of agreement and correlation indicated a high level of agreement between the two [Bla] samples for all fve test stages (agreement >95%, confidence intervals [CI] = -0.5 to 1.5, r = .97, P < .05).
These results suggest that a sampling time between 15 s and 45 s may be recommended for the valid assessment of the [Bla] threshold in rowing performance monitoring. This extends the current sampling time of 30 s used by physiologists and coaches for National and club-level Rowers.
Stephen W. Garland and Greg Atkinson
To assess the effect of sample site (earlobe vs toe) and incremental exercise protocol (continuous vs discontinuous) on training zone prescription in rowing.
Twenty-six rowers performed two incremental exercise tests on an ergometer: (1) a five-step discontinuous test with 4-min stages and 30-W increment, with blood samples taken from the earlobe and toe at the start of the 1-min break between steps; (2) a continuous test, with 2-min stages and 30-W increment, with blood samples taken from the right first toe at the end of each stage. Blood was analyzed for lactate concentration.
At a lactate concentration of 2 mmol·L−1, the mean (95% CI) power output was 8.1 (± 15.4) W greater for the continuous protocol, the random error between the methods (1.96 × SD of differences) was ± 58.8 W, and there was no evidence of any relationship between power output and error between methods. At a lactate concentration of 4 mmol·L−1, the mean (95% CI) power output was 24.2 (± 17.0) W greater for the continuous protocol, and the random error was ± 64.8 W. At 4 mmol·L−1, systematic bias between methods increased with high power outputs.
The continuous protocol with toe sampling led to higher power outputs for a given lactate concentration compared with the discontinuous protocol with earlobe sampling. This was partly due to the choice of sample site and largely due to the choice of protocol. This bias, and also random variability, makes direct comparison of these tests inappropriate.
Cheryl Mallen, Julie Stevens and Lorne J. Adams
This study systematically examined the extent of environmental sustainability (ES) research within the sport-related journal sample of academic literature to identify areas of under-emphasis and recommend directions for future research. The data collection and analysis followed a content analysis framework. The investigation involved a total of 21 sport-related academic journals that included 4,639 peer-reviewed articles published from 1987 to 2008. Findings indicated a paucity of sport-ES research articles (n = 17) during this time period. Further analysis compared the sport-ES studies within the sample to research in the broader management literature. A research agenda is suggested to advance sport-ES beyond the infancy stage.
Renee Beach Sample, Kurt Jackson, Allison L. Kinney, Wiebke S. Diestelkamp, Senia Smoot Reinert and Kimberly Edginton Bigelow
Falls occur in 33% of older adults each year, some leading to moderate to severe injuries. To reduce falls and fall-related injuries, it is important to identify individuals with subtle risk factors elevating their likelihood of falling. The objective of this study was to determine how postural sway measures differed between fallers and nonfallers under standard and dual-task conditions. Quietstanding posturography measures were collected from 150 older adults during standard, cognitive, manual, and cognitive+manual tasks, and analyzed through traditional and nonlinear analyses. Of the traditional measures, M/L sway range and 95% confidence ellipse sway area showed statistically significant differences in all 4 test conditions between fallers and nonfallers. Although the manual dual task showed the most stable balance, effect sizes demonstrated larger differences between fallers and nonfallers. Nonlinear analysis revealed M/L sample entropy and M/L α-scaling exponent differentiating between fallers and nonfallers, with the cognitive task demonstrating larger differences. Based on the results, it is recommended to: (1) apply M/L sway range and 95% confidence ellipse area, (2) use the manual task to differentiate between fallers and nonfallers when using traditional analyses, and (3) use the cognitive task and M/L alpha and M/L sample entropy when using nonlinear analyses.
Fuzhong Li and Peter Harmer
This study was designed to assess the factorial construct validity of the Group Environment Questionnaire (GEQ; Carron, Widmeyer, & Brawley, 1985) within a hypothesis-testing framework. Data were collected from 173 male and 148 female intercollegiate athletes. Based on Carron et al.’s (1985) conceptual model of group cohesion, the study examined (a) the extent to which the first-order four-factor model could be confirmed with an intercollegiate athlete sample and (b) the degree to which higher order factors could account for the covariation among the four first-order factors. The a priori models of GEQ, including both the first- and second-order factor models, were tested through confirmatory factor analysis (CFA). CFA results showed that the theoretically specified first- and second-order factor models fit significantly better than all alternative models. These results demonstrated that the GEQ possesses adequate factorial validity and reliability as a measure of the sport group cohesion construct for an intercollegiate athlete sample.