There is a need for brief, portable performance measures that are free of practice effects but that reliably show the impact of sleep loss on performance during sustained work. Reaction time (RT) tasks hold considerable promise in meeting this need, if the extensive number of responses they typically yield can be processed in ways that quickly provide the essential analyses. While testing the utility of a portable visual RT task during a sustained, quasi-continuous work schedule of 54 h, we developed a microcomputer software system that inputs, edits, transforms, analyzes, and reduces the data from the RT portable audiotapes, for each lO-min trial on the task. With relatively minor modifications, the software system can be used on a minimally configured microcomputer system that supports BASIC. The software is flexible and capable of retrieving distorted data, and it generates a variety of dependent variables reflecting intratrial optimum response capacity, lapsing, and response slowing.Some of the more useful measures of performance during sustained operations are those known to be sensitive to sleep loss; in particular, tasks that are portable and brief and that are without practice effects are most important. Reaction time tasks have the potential of meeting these three criteria. Lisper and Kjellberg (1972) demonstrated that a simple, lO-min auditory reaction time (ART) task was sensitive to 24-h sleep loss. Based on this study, Wilkinson and Houghton (1982) developed a portable, 10-min simple visual reaction time (VRT) device and showed that performance on it was sensitive to as little as one night without sleep (Glenville, Broughton, Wing, & Wilkinson, 1978).Application of this portable VRT task to an experimental protocol involving quasi-continuous performance demands for sustained periods beyond 24 h has been underway in our laboratory. We are interested in determining whether aspects of VRT performance can serve as sensitive indices of sleep tendency and overall performance capacity during sustained operations. Accordingly, we sought to have VRT task performance yield in each trial dependent variables that reflected the extent of lapsing (Williams, Lubin, & Goodnow, 1959), optimum response slowing (Dinges, Orne, & Orne, 1983), and habituation This research was supported in part by Office of Naval Research Contract NOOOI4-80-C-0380 to the first author and in part by a grant from the Institute for Experimental Psychiatry. We thank Robert Wilkinson of the MRC Applied Psychology Unit, Psychophysiology Section, for developing the VRT device and for suggestions regarding its use, and Stephen R. Fairbrother for contributing to the development of the analyses; we acknowledge the helpful comments of Emily Carota Orne, Wayne G. Whitehouse, Martin T. Orne, and David A. Soskis. Reprint requests should be sent to D. F. Dinges, Unit for Experimental Psychiatry, III N. 49th Street, Philadelphia, PA 19139-2798. (Kjellberg, 1977. For practicality we sought to generate these performance parameters by computer analyses o...

Rates of MTBI vary among sports and none of the 10 popular high school sports we studied is without the occurrence of an MTBI. Continued involvement of high school sports sponsors, researchers, medical professionals, coaches, and sports participants is essential to help minimize the risk of MTBI.

High school athletes who had suffered mild concussion demonstrated significant declines in memory processes relative to a noninjured control group. Statistically significant differences between preseason and postinjury memory test results were still evident in the concussion group at 4 and 7 days postinjury. Self-reported neurological symptoms such as headache, dizziness, and nausea resolved by Day 4. Duration of on-field mental status changes such as retrograde amnesia and posttraumatic confusion was related to the presence of memory impairment at 36 hours and 4 and 7 days postinjury and was also related to slower resolution of self-reported symptoms. The results of this study suggest that caution should be exercised in returning high school athletes to the playing field following concussion. On-field mental status changes appear to have prognostic utility and should be taken into account when making return-to-play decisions following concussion. Athletes who exhibit on-field mental status changes for more than 5 minutes have longer-lasting postconcussion symptoms and memory decline.

This cohort observational study was undertaken to test the hypothesis that the incidence of injuries for girls participating in high school sports is greater than that for boys. From 1995 through 1997, players were included in our study if they were listed on the school's varsity team roster for boys' or girls' basketball, boys' or girls' soccer, boys' baseball, or girls' softball. Injuries and opportunities for injury were recorded daily. Certified athletic trainers reported injury and exposure data. Based on 39,032 player-seasons and 8988 reported injuries, the injury rates per 100 players for softball (16.7) and for girls' soccer (26.7) were higher than for baseball (13.2) and boys' soccer (23.4). The knee injury rates per 100 players for girls' basketball (4.5) and girls' soccer (5.2) were higher than for their male counterparts. Major injuries occurred more often in girls' basketball (12.4%) and soccer (12.1%) than in boys' basketball (9.9%) and soccer (10.4%). Baseball players (12.5%) had more major injuries than softball players (7.8%). There was a higher number of surgeries, particularly knee and anterior cruciate ligament surgeries, for female basketball and soccer players than for boys or girls in other sports.

The professional football players most vulnerable to concussions are quarterbacks, wide receivers, and defensive secondaries. Concussions involved 2.74 symptoms/injury, and players were generally removed from the game. More than one-half of the players returned to play within 1 day, and symptoms resolved in a short time in the vast majority of cases.

Hip injuries represent a small but substantial percentage of injuries that occur in the NFL. A majority of these injuries are minor, with a return to play within 2 weeks. Intra-articular injuries are more serious and result in a significant loss of playing time. The "sports hip triad" (labral tear, adductor strain, and rectus strain) is described as a common injury pattern in the elite athlete.

Hamstring strains are a considerable cause of disability in football, with the majority of injuries occurring during the short preseason. In particular, the speed position players, such as the wide receivers and defensive secondary, as well as players on the special teams units, are at elevated risk for injury. These positions and situations with a higher risk of injury provide foci for preventative interventions.

The study provides data on the rotational traction of shoe-surface interfaces currently employed in football. As football shoe and surface designs continue to be updated, new evaluations of their performance must be assessed under simulated loading conditions to ensure that player performance needs are met while minimizing injury risk.