Athletes With Attention-Deficit/Hyperactivity Disorder: Position Statement of the American Medical Society for Sports Medicine.

ABSTRACT: Athletes of all ages may be affected by medical and mental health issues. Sports medicine physicians should be familiar with common conditions that may affect the well-being of athletes, such as attention-deficit/hyperactivity disorder (ADHD). ADHD behaviors have the potential to affect a person's ability to concentrate. It is likely that social and cognitive therapies combined with pharmacotherapy will be the most effective way to treat ADHD in athletes. Medications used for ADHD, especially stimulant types, are known to improve alertness, reaction time, anaerobic performance, and endurance, which would potentially improve athletic performance. Furthermore, stimulant medications may enable student athletes with ADHD to focus on academic studies for longer periods of time, beyond usual levels of fatigue, important for those who may be exhausted after practices and games. The purported performance enhancement effects and potential adverse effects of stimulant medications have prompted many sports governing bodies to ban prescription stimulants or establish strict rules for their use. Athletes taking physician-prescribed stimulants to treat ADHD need to provide the appropriate documentation for approval before competition or risk punitive measures. Physicians should strive to provide a high quality of care to athletes with ADHD through early diagnosis, appropriate and careful multidisciplinary treatment, and complete and timely documentation to facilitate continued sports participation.

Spatiotemporal Parameters of Gait Among Adolescent Athletes with Concussion When Performing a Visuospatial Cognitive Task.

Background: Adolescent athletes aged 10 to 19 years are at the highest risk of experiencing sport-related concussions (SRCs). Despite the known deficits and battery of assessments following concussion, postural stability during dual-task gait remains understudied in this population. Purpose: The purpose of this study was to evaluate the dual-task cost (DTC) in adolescents with an acute or chronic SRC compared to reference values from healthy athlete peers for spatiotemporal parameters of gait during walking with and without a concurrent visuospatial memory task presented on a hand-held tablet. Researchers hypothesized that adolescents during the acute phase of concussion would be likely to experience a greater DTC compared to healthy peers in at least one spatiotemporal parameter of gait when walking within the dual-task paradigm. Study Design: Cross-sectional, observational cohort design. Methods: Adolescents with concussion were recruited to participate. Subjects were divided into acute and chronic categories based on significant differences in the neuropsychological function after a period of 28 days. They walked at a self-selected speed along the 5.186-meter GAITRite® Walkway System with and without a concurrent visuospatial cognitive task presented on a hand-held tablet. Outcomes included normalized velocity (m/s), step length (m), and double limb (DLS) and single limb support (SLS) (defined as the percent of a gait cycle [%GC]). The data were then compared to the previously published reference values established using the same methods in the healthy athlete participants for all spatiotemporal parameters of gait. Results: Data was collected on 29 adolescent athletes with SRC. Among males (15.53+/-1.12 years) with SRC, 20% of acute and 10% of chronic cases experienced a greater DTC compared to healthy athlete reference values. A similarly increased DTC was experienced by 83% of acute and 29% of chronic SRC cases for females (15.58+/-1.16 years). Conclusions: Adolescent athletes with concussion may continue demonstrating deficits in gait capabilities even in the chronic phase, and compensatory gait strategies were not the same between males and females. Dual-task cost assessment using the GAITRite® may be a valuable adjunct to comprehensive analysis of gait following SRC. Level of Evidence: 2.

Maximal Speed for Macroscopic Particle Transport in the Bose-Hubbard Model.

The Lieb-Robinson bound asserts the existence of a maximal propagation speed for the quantum dynamics of lattice spin systems. Such general bounds are not available for most bosonic lattice gases due to their unbounded local interactions. Here we establish for the first time a general ballistic upper bound on macroscopic particle transport in the paradigmatic Bose-Hubbard model. The bound is the first to cover a broad class of initial states with positive density including Mott states, which resolves a longstanding open problem. It applies to Bose-Hubbard-type models on any lattice with not too long-ranged hopping. The proof is rigorous and rests on controlling the time evolution of a new kind of adiabatic spacetime localization observable via iterative differential inequalities.

Static and Dynamic Balance Assessment in Healthy and Concussed Adolescent Athletes.

OBJECTIVE: The purpose of this study was to explore the utilization of the Y Balance Test (YBT) alongside the Balance Error Scoring System (BESS) during examination of healthy adolescent athletes (14-18 year old) as well as those with acute and chronic concussion. DESIGN: A repeated-measures study of balance in a cross-sectional convenience sample of adolescents participating in high-school athletics. SETTING: Data were collected on healthy athletes in their school setting for comparison purposes and on concussed athletes in the physical therapy rehabilitation center at the hospital. PARTICIPANTS: Participants were a convenience sample of male and female athletes between the ages of 14 to 18 year old [180 healthy (111 male, 69 female) and 44 (28 male, 16 female) with concussion]. ASSESSMENT OF RISK FACTORS: All participants were cleared for participation by preparticipation examination or by the treating sport medicine physician. MAIN OUTCOME MEASURES: Healthy athletes performed the YBT, a dynamic assessment of balance. Athletes with concussion also performed the BESS, a static assessment of balance. RESULTS: Means for each YBT reach direction were statistically different for both healthy males and females ( P < 0.05). Within both the acute and chronic subsets of the concussed sample, some participants performed over the median value for the BESS but not the YBT. CONCLUSIONS: These data may suggest that dynamic balance testing in conjunction with static balance testing could be valuable in both the acute and chronic phases of concussion to ensure a comprehensive assessment of the necessary balance skills for athletic play.

Sport Participation and Specialization Characteristics Among Pediatric Soccer Athletes.

BACKGROUND: Soccer is an increasingly popular sport for children and adolescents in the United States. Little is known about participation patterns related to sport specialization. PURPOSE: To investigate soccer participation levels and sport specialization characteristics among youth soccer athletes. STUDY DESIGN: Cross-sectional study. METHODS: Adolescent athletes aged between 12 and 18 years completed an online survey addressing participant demographics, sports and soccer participation history, and level of specialization. Descriptive analyses characterized participation, while chi-square and Kruskal-Wallis tests assessed the influence of specialization, sex, and grade on survey variables. RESULTS: Overall, 83.7% of 746 respondents participated in an organized soccer league outside of school, and 37% played in multiple leagues concurrently. Nearly three-quarters of respondents trained in soccer more than 8 months of the year, with those who participated in club soccer being more likely to train more than 8 months of the year. More respondents were classified as high specialization (37.5%), followed by moderate (35.6%) and low (28.6%) specialization. No differences between sexes were noted for level of specialization or quitting other sports to specialize in soccer, but male athletes were more likely to train more than 8 months per year compared with female athletes. Respondents in older grades (9th-10th and 11th-12th grades) were more likely to be highly specialized and quit other sports to focus on soccer. No differences between grade levels were found among respondents training more than 8 months per year. CONCLUSION: The study findings suggest that many youth soccer athletes participated in multiple teams or leagues at the same time and trained more than 8 months of the year. Characteristics including participation on a club team, level of specialization, and male sex were associated with a greater likelihood of exceeding the 8-month training recommendation.

Strain differences in sucrose- and fructose-conditioned flavor preferences in mice.

Genetic factors strongly influence the intake and preference for sugar and saccharin solutions in inbred mouse strains. The present study determined if genetic variance also influences the learned preferences for flavors added to sugar solutions. Conditioned flavor preferences (CFPs) are produced in rodents by adding a flavor (CS+) to a sugar solution and a different flavor (CS-) to a saccharin solution (CS-) in one-bottle training trials; the CS+ is subsequently preferred to the CS- when both are presented in saccharin solutions in two-bottle tests. With some sugars (e.g., sucrose), flavor preferences are reinforced by both sweet taste and post-oral nutrient effects, whereas with other sugars (e.g., fructose), sweet taste is the primary reinforcer. Sucrose and fructose were used in three experiments to condition flavor preferences in one outbred (CD-1) and eight inbred strains which have "sensitive" (SWR/J, SJL/J, C57BL/10J, C57BL/6J) or "sub-sensitive" (DBA/2J, BALB/cJ, C3H/HeJ, 129P3/J) sweet taste receptors (T1R2/T1R3). Food-restricted mice of each strain were trained (1 h/day) to drink flavored 16% sucrose (CS+ 16S, Experiment 1), 16% fructose (CS+ 16F, Experiment 2) or 8% fructose+0.2% saccharin (CS+ 8F, Experiment 3) solutions on five alternate days and a differently flavored saccharin solution (0.05% or 0.2%, CS-) on the other five alternating days. The CS+ and CS- flavors were presented in 0.2% saccharin for two-bottle testing over six days. All strains preferred the CS+ 16S to CS- although there were significant strain differences in the magnitude and persistence of the sucrose preference. The strains also differed in the magnitude and persistence of preferences for the CS+ 16F and CS+ 8F flavors over the CS- with two strains failing to prefer the fructose-paired flavors. Sucrose conditioned stronger preferences than did fructose which is attributed to differences in the taste and post-oral actions of the sugars. These differential training intakes may not have influenced the sucrose-CFP because of the post-oral reinforcing actions of sucrose. Overall, sweet sensitive and sub-sensitive mice did not differ in sucrose-CFP, but unexpectedly, the sub-sensitive mice displayed stronger fructose-CFP. This may be related to differential training intakes of CS+ and CS- solutions: sweet sensitive mice consumed more CS- than CS+ during training while sub-sensitive mice consumed more CS+.