Shannon and Renyi Entropies to Classify Effects of Mild Traumatic Brain Injury on Postural Sway

Background: Mild Traumatic Brain Injury (mTBI) has been identified as a major public and military health concern both in the United States and worldwide. Characterizing the effects of mTBI on postural sway could be an important tool for assessing recovery from the injury. Methodology/Principal Findings: We assess postural sway by motion of the center of pressure (COP). Methods for data reduction include calculation of area of COP and fractal analysis of COP motion time courses. We found that fractal scaling appears applicable to sway power above about 0.5 Hz, thus fractal characterization is only quantifying the secondary effects (a small fraction of total power) in the sway time series, and is not effective in quantifying long-term effects of mTBI on postural sway. We also found that the area of COP sensitively depends on the length of data series over which the COP is obtained. These weaknesses motivated us to use instead Shannon and Renyi entropies to assess postural instability following mTBI. These entropy measures have a number of appealing properties, including capacity for determination of the optimal length of the time series for analysis and a new interpretation of the area of COP. Conclusions: Entropy analysis can readily detect postural instability in athletes at least 10 days post-concussion so that it appears promising as a sensitive measure of effects of mTBI on postural sway

An Examination of Youth Sport Specialization Patterns and Perceptions Between Developmental Stages and Competitive Contexts

Background: Youth sport specialization remains a concerning trend for developing young people, as early and intensive specialization has linked to harmful physical and psychosocial outcomes. Further research is merited to determine how participants’ perceptions of sport specialization may be driving their decision of whether to specialize, as well as how these perceptions and specialization patterns may differ based on their developmental level (ie., elementary, middle, or high school), and their competitive context (ie., recreational/community-based, club/travel, or interscholastic). Purpose: To compare youth athletes’ degree of sport specialization and their perceptions of sport specialization based on their developmental level and competitive context. Methods: Athletes completed a self-administered survey comprised of 1) Demographic characteristics and sport participation history; 2) The 3-item Jayanthi “degree” of sport specialization scale; 3) The Youth Sport Specialization Perceptions Survey, which quantifies athletes’ sport specialization attitudes on a continuum from extremely unfavorable (low scores) to extremely favorable (high scores). Descriptive analyses were conducted for demographic and sport participation characteristics. One-way ANOVAs were conducted to examine group differences based on developmental stage and competitive context. To examine group differences in the athletes’ degree of specialization classification, chi-squared tests were performed for both developmental stage and competitive context. Results: 559 participants (n = 209 (37.39%) were female) completed this survey. The results of the one-way ANOVA for developmental stage indicated that the groups did not significantly differ in their perceptions of sport specialization (F = .191; p = .826). Similarly, no significant group differences emerged in perceptions of sport specialization based on competitive context (F = 1.43; p = .239). However, the athletes’ degree of specialization significantly differed both by their developmental stage ( χ 2 (6, N = 559) = 103.41, p&lt;.001) and by competitive context ( χ 2 (6, N = 559) = 124.51, p&lt;.001). Conclusion: Though athletes’ perceptions of sport specialization were similar across developmental stage and competitive context, adopted patterns of specialization differed by group. Our results suggest that athletes are more likely to adopt a specialized pathway as they develop, and athletes in the club and interscholastic contexts tend to be more specialized than those in recreational/community-based programs. In sum, our findings indicate that participant’s attitudes toward specialization are less salient in their decision of whether to specialize when compared to their developmental stage and competitive context. This underscores the importance of not only promoting healthy specialization attitudes, but also in creating environments that are conducive to non-specialized participation. [Table: see text][Table: see text][Table: see text][Table: see text] </jats:sec

EXPLORING PARENT-ATHLETE DYADS’ PERCEPTIONS OF SPORTS SPECIALIZATION AND SPORT EXPERIENCES IN AN EARLY YOUTH COMMUNITY-BASED SPORT PROGRAM

Background: Early, intensive sports specialization has been positioned as a potentially harmful pattern of participation for developing youth athletes; however, it remains largely unknown how youth sport families decide if and when an athlete will specialize. Areas lacking in the literature include exploration of the prevalence of specialization for elementary-school-aged athletes and in the community-based recreational context, current and prospective experiences of sport families, and comparisons between stakeholder groups regarding their perceptions of sport specialization. Purpose: To explore and compare early youth sport parent-athlete dyads’ perceived sport participation characteristics, attitudes, and experiences related to youth sport specialization. Methods: Youth sport parents and athletes completed a sport participation survey designed to examine 1) Demographic characteristics of the youth sport family and their context; 2) Characteristics of the youth athlete’s current (ie, degree of specialization) and planned sport participation pathway (ie, if and when they plan to specialize); 3) Perceptions of the athletes’ sport experience, with an emphasis on sport specialization. Descriptive analyses were conducted for demographic and sport participation characteristics, and paired-samples t-tests were conducted to compare sport-related attitudes and perceptions of sport specialization in matched parent-athlete dyads (p≤.05). Results: Ninety-six total participants (48 parent-athlete dyads; 66.7% of athletes (n=32) were male) from a single community-based early youth sport program completed the sport participation survey. 85.4% (n=72) of total participants rated the athlete’s current degree of specialization as low or not at all, though participants more commonly anticipated specializing in middle school (48.9%; n=44) and high school (52.2%; n=47). In comparing the parent-athlete dyads, these groups did not significantly differ in their perceptions of sport specialization, perceived pathway enjoyment, or their plans to specialize in the future. However, athletes were significantly more likely to identify as currently specialized (p&lt;.01), perceive a higher degree of current specialization (p=.047), and rate themselves as more burned out (p&lt;.01) than their parents. Conclusion: These findings indicate that parents and athletes generally possess similar attitudes toward sport specialization and perceptions of athletes’ sport experiences during their early youth participation. While youth sport families are not commonly engaging in specialization during these elementary school years, many plan an eventual sport pathway for their athlete that involves specializing in a main sport. Lastly, it appears that even at an early age, athletes may perceive their sport experience as more specialized and more taxing than their parents, highlighting the need for open communication and understanding within these dyads. Tables: [Table: see text][Table: see text][Table: see text] </jats:sec