WorldWideScience

Sample records for player head impact

  1. Head Impact Exposure and Neurologic Function of Youth Football Players.

    Science.gov (United States)

    Munce, Thayne A; Dorman, Jason C; Thompson, Paul A; Valentine, Verle D; Bergeron, Michael F

    2015-08-01

    Football players are subjected to repetitive impacts that may lead to brain injury and neurologic dysfunction. Knowledge about head impact exposure (HIE) and consequent neurologic function among youth football players is limited. This study aimed to measure and characterize HIE of youth football players throughout one season and explore associations between HIE and changes in selected clinical measures of neurologic function. Twenty-two youth football players (11-13 yr) wore helmets outfitted with a head impact telemetry (HIT) system to quantify head impact frequency, magnitude, duration, and location. Impact data were collected for each practice (27) and game (9) in a single season. Selected clinical measures of balance, oculomotor performance, reaction time, and self-reported symptoms were assessed before and after the season. The median individual head impacts per practice, per game, and throughout the entire season were 9, 12, and 252, respectively. Approximately 50% of all head impacts (6183) had a linear acceleration between 10g and 20g, but nearly 2% were greater than 80g. Overall, the head impact frequency distributions in this study population were similar in magnitude and location as in high school and collegiate football, but total impact frequency was lower. Individual changes in neurologic function were not associated with cumulative HIE. This study provides a novel examination of HIE and associations with short-term neurologic function in youth football and notably contributes to the limited HIE data currently available for this population. Whereas youth football players can experience remarkably similar head impact forces as high school players, cumulative subconcussive HIE throughout one youth football season may not be detrimental to short-term clinical measures of neurologic function.

  2. Head impact exposure sustained by football players on days of diagnosed concussion.

    Science.gov (United States)

    Beckwith, Jonathan G; Greenwald, Richard M; Chu, Jeffrey J; Crisco, Joseph J; Rowson, Steven; Duma, Stefan M; Broglio, Steven P; McAllister, Thomas W; Guskiewicz, Kevin M; Mihalik, Jason P; Anderson, Scott; Schnebel, Brock; Brolinson, P Gunnar; Collins, Michael W

    2013-04-01

    This study compares the frequency and severity of head impacts sustained by football players on days with and without diagnosed concussion and to identify the sensitivity and specificity of single-impact severity measures to diagnosed injury. One thousand two hundred eight players from eight collegiate football teams and six high school football teams wore instrumented helmets to measure head impacts during all team sessions, of which 95 players were diagnosed with concussion. Eight players sustained two injuries and one sustained three, providing 105 injury cases. Measures of head kinematics (peak linear and rotational acceleration, Gadd severity index, head injury criteria (HIC15), and change in head velocity (Δv)) and the number of head impacts sustained by individual players were compared between days with and without diagnosed concussion. Receiver operating characteristic curves were generated to evaluate the sensitivity and specificity of each kinematic measure to diagnosed concussion using only those impacts that directly preceded diagnosis. Players sustained a higher frequency of impacts and impacts with more severe kinematic properties on days of diagnosed concussion than on days without diagnosed concussion. Forty-five injury cases were immediately diagnosed after head impact. For these cases, peak linear acceleration and HIC15 were most sensitive to immediately diagnosed concussion (area under the curve = 0.983). Peak rotational acceleration was less sensitive to diagnosed injury than all other kinematic measures (P = 0.01), which are derived from linear acceleration (peak linear, HIC15, Gadd severity index, and Δv). Players sustained more impacts and impacts of higher severity on days of diagnosed concussion than on days without diagnosed concussion. In addition, of historical measures of impact severity, those associated with peak linear acceleration are the best predictors of immediately diagnosed concussion.

  3. Symptoms from repeated intentional and unintentional head impact in soccer players.

    Science.gov (United States)

    Stewart, Walter F; Kim, Namhee; Ifrah, Chloe S; Lipton, Richard B; Bachrach, Tamar A; Zimmerman, Molly E; Kim, Mimi; Lipton, Michael L

    2017-02-28

    To determine the rate and differential contribution of heading vs unintentional head impacts (e.g., head to head, goal post) to CNS symptoms in adult amateur soccer players. Amateur soccer players completed baseline and serial on-line 2-week recall questionnaires (HeadCount) and reported (1) soccer practice and games, (2) heading and unintentional soccer head trauma, and (3) frequency and severity (mild to very severe) of CNS symptoms. For analysis, CNS symptoms were affirmed if one or more moderate, severe, or very severe episodes were reported in a 2-week period. Repeated measures logistic regression was used to assess if 2-week heading exposure (i.e., 4 quartiles) or unintentional head impacts (i.e., 0, 1, 2+) were associated with CNS symptoms. A total of 222 soccer players (79% male) completed 470 HeadCount questionnaires. Mean (median) heading/2 weeks was 44 (18) for men and 27 (9.5) for women. One or more unintentional head impacts were reported by 37% of men and 43% of women. Heading-related symptoms were reported in 20% (93 out of 470) of the HeadCounts. Heading in the highest quartile was significantly associated with CNS symptoms (odds ratio [OR] 3.17, 95% confidence interval [CI] 1.57-6.37) when controlling for unintentional exposure. Those with 2+ unintentional exposures were at increased risk for CNS symptoms (OR 6.09, 95% CI 3.33-11.17) as were those with a single exposure (OR 2.98, 95% CI 1.69-5.26) when controlling for heading. Intentional (i.e., heading) and unintentional head impacts are each independently associated with moderate to very severe CNS symptoms. © 2017 American Academy of Neurology.

  4. Safe-Play Knowledge, Aggression, and Head-Impact Biomechanics in Adolescent Ice Hockey Players.

    Science.gov (United States)

    Schmidt, Julianne D; Pierce, Alice F; Guskiewicz, Kevin M; Register-Mihalik, Johna K; Pamukoff, Derek N; Mihalik, Jason P

    2016-05-01

    Addressing safe-play knowledge and player aggression could potentially improve ice hockey sport safety. To compare (1) safe-play knowledge and aggression between male and female adolescent ice hockey players and (2) head-impact frequency and severity between players with high and low levels of safe-play knowledge and aggression during practices and games. Cohort study. On field. Forty-one male (n = 29) and female (n = 12) adolescent ice hockey players. Players completed the Safe Play Questionnaire (0 = less knowledge, 7 = most knowledge) and Competitive Aggressiveness and Anger Scale (12 = less aggressive, 60 = most aggressive) at midseason. Aggressive penalty minutes were recorded throughout the season. The Head Impact Telemetry System was used to capture head-impact frequency and severity (linear acceleration [g], rotational acceleration [rad/s(2)], Head Impact Technology severity profile) at practices and games. One-way analyses of variance were used to compare safe play knowledge and aggression between sexes. Players were categorized as having high or low safe-play knowledge and aggression using a median split. A 2 × 2 mixed-model analysis of variance was used to compare head-impact frequency, and random-intercept general linear models were used to compare head-impact severity between groups (high, low) and event types (practice, game). Boys (5.8 of 7 total; 95% confidence interval [CI] = 5.3, 6.3) had a trend toward better safe-play knowledge compared with girls (4.9 of 7 total; 95% CI = 3.9, 5.9; F1,36 = 3.40, P = .073). Less aggressive male players sustained significantly lower head rotational accelerations during practices (1512.8 rad/s (2) , 95% CI = 1397.3, 1637.6 rad/s(2)) versus games (1754.8 rad/s (2) , 95% CI = 1623.9, 1896.2 rad/s(2)) and versus high-aggression players during practices (1773.5 rad/s (2) , 95% CI = 1607.9, 1956.3 rad/s (2) ; F1,26 = 6.04, P = .021). Coaches and sports medicine professionals should ensure that athletes of all levels

  5. Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players.

    Science.gov (United States)

    Swartz, Erik E; Broglio, Steven P; Cook, Summer B; Cantu, Robert C; Ferrara, Michael S; Guskiewicz, Kevin M; Myers, Jay L

    2015-12-01

    To test a helmetless-tackling behavioral intervention for reducing head impacts in National Collegiate Athletic Association Division I football players. Randomized controlled clinical trial. Football field. Fifty collegiate football players (intervention = 25, control = 25). The intervention group participated in a 5-minute tackling drill without their helmets and shoulder pads twice per week in the preseason and once per week through the season. During this time, the control group performed noncontact football skills. Frequency of head impacts was recorded by an impact sensor for each athlete-exposure (AE). Data were tested with a 2 × 3 (group and time) repeated-measures analysis of variance. Significant interactions and main effects (P football players within 1 season.

  6. The effect of visual and sensory performance on head impact biomechanics in college football players.

    Science.gov (United States)

    Harpham, Jacqueline A; Mihalik, Jason P; Littleton, Ashley C; Frank, Barnett S; Guskiewicz, Kevin M

    2014-01-01

    The development of prevention strategies is critical to address the rising prevalence of sport-related concussions. Visual and sensory performance may influence an individual's ability to interpret environmental cues, anticipate opponents' actions, and create appropriate motor responses limiting the severity of an impending head impact. The purpose of this study was to determine the relationship between traditional and visual sensory reaction time measures, and the association between visual and sensory performance and head impact severity in college football players. Thirty-eight collegiate football players participated in the study. We used real-time data collection instrumentation to record head impact biomechanics during games and practices. Our findings reveal no significant correlations between reaction time on traditional and visual sensory measures. We found a significant association between head impact severity and level of visual and sensory performance for multiple assessments, with low visual and sensory performers sustaining a higher number of severe head impacts. Our findings reveal a link between level of visual and sensory performance and head impact biomechanics. Future research will allow clinicians to have the most appropriate testing batteries to identify at-risk athletes and create interventions to decrease their risk of injurious head impacts.

  7. Impact forces and neck muscle activity in heading by collegiate female soccer players.

    Science.gov (United States)

    Bauer, J A; Thomas, T S; Cauraugh, J H; Kaminski, T W; Hass, C J

    2001-03-01

    Three soccer header types (shooting, clearing and passing) and two heading approaches (standing and jumping) were manipulated to quantify impact forces and neck muscle activity in elite female soccer players. The 15 participants were Division I intercollegiate soccer players. Impact forces were measured by a 15-sensor pressure array secured on the forehead. The electromyographic (EMG) activity of the left and right sternocleidomastoid and trapezius muscles was recorded using surface electrodes. Maximum impact forces and impulses as well as the EMG data were analysed with separate repeated-measures analyses of variance. Impact forces and impulses did not differ among the header types or approaches. Higher values were found for jumping versus standing headers in the mean normalized EMG for the right sternocleidomastoid. In addition, the integrated EMG was greater for the right sternocleidomastoid and right and left trapezius (P head and body, thereby increasing the stability of the head-neck complex.

  8. Comparison of head impact location during games and practices in Division III men's lacrosse players.

    Science.gov (United States)

    O'Day, Kathleen M; Koehling, Elizabeth M; Vollavanh, Lydia R; Bradney, Debbie; May, James M; Breedlove, Katherine M; Breedlove, Evan L; Blair, Price; Nauman, Eric A; Bowman, Thomas G

    2017-03-01

    Head impacts have been studied extensively in football, but little similar research has been conducted in men's lacrosse. It is important to understand the location and magnitude of head impacts during men's lacrosse to recognize the risk of head injury. Descriptive epidemiology study set on collegiate lacrosse fields. Eleven men's lacrosse players (age=20.9±1.13years, mass=83.91±9.04kg, height=179.88±5.99cm) volunteered to participate. We applied X2 sensors behind the right ear of participants for games and practices. Sensors recorded data on linear and rotational accelerations and the location of head impacts. We calculated incidence rates per 1000 exposures with 95% confidence intervals for impact locations and compared the effect of impact location on linear and rotational accelerations with Kruskal-Wallis tests. We verified 167 head impacts (games=112; practices=55). During games, the incidence rate was 651.16 (95% confidence interval=530.57-771.76). The high and low incidence rates for head impact locations during games were: side=410.7 (95% confidence interval=292.02-529.41) and top=26.79 (95% confidence interval=3.53-57.10). For games and practices combined, the impact locations did not significantly affect linear (χ(2)3=6.69, P=0.08) or rotational acceleration (χ(2)3=6.34, P=0.10). We suggest further research into the location of head impacts during games and practices. We also suggest player and coach education on head impacts as well as behavior modification in men's lacrosse athletes to reduce the incidence of impacts to the side of the head in an effort to reduce potential injury. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Football Players' Head-Impact Exposure After Limiting of Full-Contact Practices.

    Science.gov (United States)

    Broglio, Steven P; Williams, Richelle M; O'Connor, Kathryn L; Goldstick, Jason

    2016-07-01

    Sporting organizations limit full-contact football practices to reduce concussion risk and based on speculation that repeated head impacts may result in long-term neurodegeneration. To directly compare head-impact exposure in high school football players before and after a statewide restriction on full-contact practices. Cross-sectional study. High school football field. Participants were varsity football athletes from a single high school. Before the rule change, 26 athletes (age = 16.2 ± 0.8 years, height = 179.6 ± 6.4 cm, weight = 81.9 ± 13.1 kg) participated. After the rule change, 24 athletes (age = 15.9 ± 0.8 years, height = 178.3 ± 6.5 cm, weight = 76.2 ± 11.6 kg) participated. Nine athletes participated in both years of the investigation. Head-impact exposure was monitored using the Head Impact Telemetry System while the athletes participated in football games and practices in the seasons before and after the rule change. Head-impact frequency, location, and magnitude (ie, linear acceleration, rotational acceleration, and Head Impact Telemetry severity profile [HITsp], respectively) were measured. A total of 15 398 impacts (592 impacts per player per season) were captured before the rule change and 8269 impacts (345 impacts per player per season) after the change. An average 42% decline in impact exposure occurred across all players, with practice-exposure declines occurring among linemen (46% decline); receivers, cornerbacks, and safeties (41% decline); and tight ends, running backs (including fullbacks), and linebackers (39% decline). Impact magnitudes remained largely unchanged between the years. A rule change limiting full-contact high school football practices appears to have been effective in reducing head-impact exposure across all players, with the largest reduction occurring among linemen. This finding is likely associated with the rule modification, particularly because the coaching staff and offensive scheme remained consistent, yet how

  10. Instrumented mouthguard acceleration analyses for head impacts in amateur rugby union players over a season of matches.

    Science.gov (United States)

    King, Doug; Hume, Patria A; Brughelli, Matt; Gissane, Conor

    2015-03-01

    Direct impacts with the head (linear acceleration or pressure) and inertial loading of the head (rotational acceleration or strain) have been postulated as the 2 major mechanisms of head-related injuries such as concussion. Although data are accumulating for soccer and American football, there are no published data for nonhelmeted collision sports such as rugby union. To quantify head impacts via instrumented mouthguard acceleration analyses for rugby union players over a season of matches. Descriptive epidemiology study. Data on impact magnitude and frequency were collected with molded instrumented mouthguards worn by 38 premier amateur senior rugby players participating in the 2013 domestic season of matches. A total of 20,687 impacts >10g (range, 10.0-164.9g) were recorded over the duration of the study. The mean ± SD number of impacts per player over the duration of the season of matches was 564 ± 618, resulting in a mean ± SD of 95 ± 133 impacts to the head per player, per match over the duration of the season of matches. The impact magnitudes for linear accelerations were skewed to the lower values (Sp = 3.7 ± 0.02; P rugby union players over a season of matches, measured via instrumented mouthguard accelerations, were higher than for most sports previously reported. Mean linear acceleration measured over a season of matches was similar to the mean linear accelerations previously reported for youth, high school, and collegiate American football players but lower than that for female youth soccer players. Mean rotational acceleration measured over a season of matches was similar to mean rotational accelerations for youth, high school, and collegiate American football players but less than those for female youth soccer players, concussed American collegiate players, collegiate American football players, and professional American football players. © 2014 The Author(s).

  11. Laboratory Validation of Two Wearable Sensor Systems for Measuring Head Impact Severity in Football Players.

    Science.gov (United States)

    Siegmund, Gunter P; Guskiewicz, Kevin M; Marshall, Stephen W; DeMarco, Alyssa L; Bonin, Stephanie J

    2016-04-01

    Wearable sensors can measure head impact frequency and magnitude in football players. Our goal was to quantify the impact detection rate and validity of the direction and peak kinematics of two wearable sensors: a helmet system (HITS) and a mouthguard system (X2). Using a linear impactor, modified Hybrid-III headform and one helmet model, we conducted 16 impacts for each system at 12 helmet sites and 5 speeds (3.6-11.2 m/s) (N = 896 tests). Peak linear and angular accelerations (PLA, PAA), head injury criteria (HIC) and impact directions from each device were compared to reference sensors in the headform. Both sensors detected ~96% of impacts. Median angular errors for impact directions were 34° for HITS and 16° for X2. PLA, PAA and HIC were simultaneously valid at 2 sites for HITS (side, oblique) and one site for X2 (side). At least one kinematic parameter was valid at 2 and 7 other sites for HITS and X2 respectively. Median relative errors for PLA were 7% for HITS and -7% for X2. Although sensor validity may differ for other helmets and headforms, our analyses show that data generated by these two sensors need careful interpretation.

  12. Measurement of head impacts in collegiate football players: clinical measures of concussion after high- and low-magnitude impacts.

    Science.gov (United States)

    McCaffrey, Meghan A; Mihalik, Jason P; Crowell, Dean H; Shields, Edgar W; Guskiewicz, Kevin M

    2007-12-01

    It has been speculated that a theoretical injury threshold of 70 to 75 g may exist for concussions in football players. We aimed to investigate acute balance and neurocognitive performance after head impacts exceeding a theoretical injury threshold in the absence of both self-reported symptoms and a concussion diagnosis 24 hours before testing. Forty-three Division I collegiate football players participated in this double-blind, repeated-measures study. Subjects participated in three test sessions (baseline, low impact, and high impact) separated by at least 2 weeks. The Head Impact Telemetry System (Simbex, Lebanon, NH) recorded real-time head impacts sustained during practices and games. The Automated Neuropsychological Assessment Metrics assessed neurocognitive performance. The NeuroCom Sensory Organization Test (NeuroCom International Inc., Clackamas, OR) assessed postural stability. The Graded Symptom Checklist evaluated symptom presence and severity in our participants. After the low-impact test session (90 g) with improvements in Math Processing (F(1, 22) = 16.629; P < 0.001), Procedural Reaction Time (F(1, 22) = 14.668; P < 0.001), and the total number of symptoms reported (F(1, 22) = 10.267; P = 0.004). Neurocognitive improvements were likely attributed to a learning effect. Our findings suggest that sustaining an impact greater than 90 g does not result in acute observable balance and neurocognitive deficits within 24 hours of sustaining the impact. Although previous studies have suggested a theoretical injury threshold, none have been founded on empirical data collected on the playing field in real-time. Future studies should consider the cumulative effects of impacts of varying magnitudes.

  13. Frequency of head-impact-related outcomes by position in NCAA division I collegiate football players.

    Science.gov (United States)

    Baugh, Christine M; Kiernan, Patrick T; Kroshus, Emily; Daneshvar, Daniel H; Montenigro, Philip H; McKee, Ann C; Stern, Robert A

    2015-03-01

    Concussions and subconcussive impacts sustained in American football have been associated with short- and long-term neurological impairment, but differences in head impact outcomes across playing positions are not well understood. The American Medical Society for Sports Medicine has identified playing position as a key risk factor for concussion in football and one for which additional research is needed. This study examined variation in head impact outcomes across primary football playing positions in a group of 730 National Collegiate Athletic Association Division I Football Championship Series athletes, using a self-report questionnaire. Although there were no significant differences between position groups in the number of diagnosed concussions during the 2012 football season, there were significant differences between groups in undiagnosed concussions (p=0.008) and "dings" (pfootball season, with offensive linemen reporting significantly more symptoms compared to most other groups. There were also positional differences in frequency of returning to play while symptomatic (p<0.001) and frequency of participating in full-contact practice (p<0.001). Offensive linemen reported having returned to play while experiencing symptoms more frequently and participating in more full-contact practices than other groups. These findings suggest that offensive linemen, a position group that experiences frequent, but low-magnitude, head impacts, develop more postimpact symptoms than other playing positions, but do not report these symptoms as a concussion.

  14. Biomechanics of heading a soccer ball: implications for player safety.

    Science.gov (United States)

    Babbs, C F

    2001-08-08

    To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton's second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player"s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater "touch" and "playability", measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

  15. Biomechanics of Heading a Soccer Ball: Implications for Player Safety

    Directory of Open Access Journals (Sweden)

    Charles F. Babbs

    2001-01-01

    Full Text Available To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton�s second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player�s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater “touch” and “playability”, measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

  16. Modeling heading in adult soccer players.

    Science.gov (United States)

    Ponce, Ernesto; Ponce, Daniel; Andresen, Max

    2014-01-01

    Heading soccer balls can generate mild brain injuries and in the long run can lead to difficulty in solving problems, memory deficits, and language difficulties. Researchers evaluated the effects on the head for both correct and incorrect heading techniques. They based the head's geometry on medical images. They determined the injury's magnitude by comparing the neurological tissue's resistance with predictions of the generated stresses. The evaluation examined fast playing conditions in adult soccer, taking into account the ball's speed and the type of impact. Mathematical simulations using the finite element method indicated that correctly heading balls arriving at moderate speed presents a low risk of brain injury. However, damage can happen around the third cervical vertebra. These results coincide with medical studies. Incorrect heading greatly increases the brain injury risk and can alter the parietal area.

  17. Evaluating the heading in professional soccer players by playing positions.

    Science.gov (United States)

    Erkmen, Nurtekin

    2009-09-01

    The aim of this study is to evaluate the accuracy and coordination of heading in professional soccer players of different positions. A total of 243 professional soccer players were examined for the study. The Federation Internationale de Football Association Medical Assessment and Research Center (F-MARC) test battery was used to evaluate heading in soccer players. In the heading of the ball thrown from middle of the goal, forwards were better than goalkeepers (p heading of the ball thrown from the right side of the goalpost, defenders were better than goalkeepers (p heading of goalkeepers being worse than the others; goalkeepers use their hands in both training and matches, whereas for forwards and defensive players being better than goalkeepers depends mainly on their positions in soccer. Trainers and coaches should give place specific training programs to improve heading ability in the training schedule of soccer players at a professional level.

  18. Teardrop fracture following head-first impact in an ice hockey player: Case report and analysis of injury mechanisms.

    Science.gov (United States)

    Yue, James J; Ivancic, Paul C; Scott, David L

    2016-01-01

    We report a case of a young male athlete who sustained a three column displaced teardrop fracture of the C5 vertebra due to a head-first impact in hockey, suffered neurapraxia, yet made full neurological recovery. This full recovery was in sharp contrast to multiple case series which reported permanent quadriplegia in the vast majority of teardrop fracture patients. We investigate the etiology and biomechanical mechanisms of injury. Admission imaging revealed the teardrop fracture which consisted of: a frontal plane fracture which separated an anterior quadrilateral-shaped fragment from the posterior vertebral body; a vertical fracture of the posterior vertebral body in the sagittal plane; and incomplete fractures of the neural arch that initiated superiorly at the anterior aspect of the spinous process and left lamina adjacent to the superior facet. Epidural hematoma in the region of the C5 vertebra was observed in addition to disc and ligamentous disruptions at C4-5 and C5-6. Our patient was ultimately treated surgically with anterior fusion from C4 through C6 and subsequently with bilateral posterior fusion at C5-6. The injuries were caused by high-energy axial compression with the neck in a pre-flexed posture. The first fracture event consisted of the anterior vertebral body fragment being sheared off of the posterior fragment under the compression load due in part to the sagittal plane concavity of the C5 inferior endplate. The etiology of the vertical fracture of the posterior vertebral body fragment in the sagittal plane was consistent with a previously described hypothesis of the mechanistic injury events. First, the C4-5 disc height decreased under load which increased its hoop stress. Next, this increased hoop stress transferred lateral forces to the C5 uncinate processes which caused their outward expansion. Finally, the outward expansion of the uncinate processes caused the left and right sides of the vertebral body to split and spread. Evidence in

  19. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  20. Quantifying Head Impact Exposure in Collegiate Women's Soccer.

    Science.gov (United States)

    Press, Jaclyn N; Rowson, Steven

    2017-03-01

    The aim of this study was to quantify head impact exposure for a collegiate women's soccer team over the course of the 2014 season. Observational and prospective study. Virginia Tech women's soccer games and practices. Twenty-six collegiate level women's soccer players with a mean player age of 19 ± 1. Participating players were instrumented with head impact sensors for biomechanical analysis. Video recordings of each event were used to manually verify each impact sustained. Head impact counts by player position and impact situation. The sensors collected data from a total of 17 865 accelerative events, 8999 of which were classified as head impacts. Of these, a total of 1703 impacts were positively identified (19% of total real impacts recorded by sensor), 90% of which were associated with heading the ball. The average number of impacts per player per practice or game was 1.86 ± 1.42. Exposure to head impact varied by player position. Head impact exposure was quantified through 2 different methods, which illustrated the challenges associated with autonomously collecting acceleration data with head impact sensors. Users of head impact data must exercise caution when interpreting on-field head impact sensor data.

  1. Maneuvering impact boring head

    Science.gov (United States)

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  2. Validation and calibration of HeadCount, a self-report measure for quantifying heading exposure in soccer players.

    Science.gov (United States)

    Catenaccio, E; Caccese, J; Wakschlag, N; Fleysher, R; Kim, N; Kim, M; Buckley, T A; Stewart, W F; Lipton, R B; Kaminski, T; Lipton, M L

    2016-01-01

    The long-term effects of repetitive head impacts due to heading are an area of increasing concern, and exposure must be accurately measured; however, the validity of self-report of cumulative soccer heading is not known. In order to validate HeadCount, a 2-week recall questionnaire, the number of player-reported headers was compared to the number of headers observed by trained raters for a men's and a women's collegiate soccer teams during an entire season of competitive play using Spearman's correlations and intraclass correlation coefficients (ICCs), and calibrated using a generalized estimating equation. The average Spearman's rho was 0.85 for men and 0.79 for women. The average ICC was 0.75 in men and 0.38 in women. The calibration analysis demonstrated that men tend to report heading accurately while women tend to overestimate. HeadCount is a valid instrument for tracking heading behaviour, but may have to be calibrated in women.

  3. Force, Frequency of Head Hits Jump as Young Football Players Get Older

    Science.gov (United States)

    ... Force, Frequency of Head Hits Jump as Young Football Players Get Older Findings confirm that these injuries ... 27, 2017 (HealthDay News) -- As kids who play football get older, head hits during play become more ...

  4. Head impacts in a junior rugby league team measured with a wireless head impact sensor: an exploratory analysis.

    Science.gov (United States)

    King, Doug; Hume, Patria; Gissane, Conor; Clark, Trevor

    2017-01-01

    OBJECTIVE The aim of this study was to investigate the frequency, magnitude, and distribution of head impacts sustained by players in a junior rugby league over a season of matches. METHODS The authors performed a prospective cohort analysis of impact magnitude, frequency, and distribution on data collected with instrumented XPatches worn behind the ear of players in an "under-11" junior rugby league team (players under 11 years old). RESULTS A total of 1977 impacts were recorded. Over the course of the study, players sustained an average of 116 impacts (average of 13 impacts per player per match). The measured linear acceleration ranged from 10g to 123g (mean 22g, median 16g, and 95th percentile 57g). The rotational acceleration ranged from 89 rad/sec(2) to 22,928 rad/sec(2) (mean 4041 rad/sec(2), median 2773 rad/sec(2), and 95th percentile 11,384 rad/sec(2)). CONCLUSIONS The level of impact severity based on the magnitude of impacts for linear and rotational accelerations recorded was similar to the impacts reported in studies of American junior and high school football, collegiate football, and youth ice hockey players, but the players in the rugby league cohort were younger, had less body mass, and played at a slower speed than the American players. Junior rugby league players are required to tackle the player to the ground and use a different tackle technique than that used in American football, likely increasing the rotational accelerations recorded at the head.

  5. Head injuries in youth soccer players presenting to the emergency department.

    Science.gov (United States)

    Pickett, W; Streight, S; Simpson, K; Brison, R J

    2005-04-01

    There has been recent concern about neuropsychological injuries experienced by soccer players, particularly related to the purposeful heading of the ball. There are few population based analyses examining whether this is a legitimate concern. To explore, using an existing injury surveillance system, one of many parts of this issue: acute injuries requiring emergency medical care experienced by youth soccer players. Descriptive epidemiological analysis of emergency department injury surveillance data (1996-2001) for youths aged 10-24 years from the Kingston sites of the Canadian Hospital Injury Reporting and Prevention Program. A total of 1714 cases of soccer injury were identified (mean 286 a year); 235 (13.7%) involved diagnoses of injuries to the head. Leading mechanical factors resulting in head injury were contact with other players or persons (153/235; 65.1%) and balls (62/235; 26.4%). Heading was reported in 4/62 (6%) of the ball contact injuries, and attempted heading was reported in 15/153 (9.8%) of the cases involving person to person contact. Unspecified head to head contact between players was reported in 39 cases. Minor head injuries that result in emergency medical treatment do not happen often in youth soccer, and very few can be attributed to the purposeful heading of the ball. Player contact injuries appear to be a more important injury control concern. This study informs one of many aspects of the soccer heading injury debate.

  6. Head, Neck, Face, and Shoulder Injuries in Female and Male Rugby Players.

    Science.gov (United States)

    Havkins, Sabina B.

    1986-01-01

    Injuries to 150 players in the Southern California Rugby Football Union were studied in order to compare head, neck, face, and shoulder injury rates for female and male players. While overall rates did not differ significantly, women received fewer disabling injuries. Ways to decrease injuries are recommended. (Author/MT)

  7. Head, Neck, Face, and Shoulder Injuries in Female and Male Rugby Players.

    Science.gov (United States)

    Havkins, Sabina B.

    1986-01-01

    Injuries to 150 players in the Southern California Rugby Football Union were studied in order to compare head, neck, face, and shoulder injury rates for female and male players. While overall rates did not differ significantly, women received fewer disabling injuries. Ways to decrease injuries are recommended. (Author/MT)

  8. Head Start Impact Study

    Data.gov (United States)

    U.S. Department of Health & Human Services — Nationally representative, longitudinal information from an evaluation where children were randomly assigned to Head Start or community services as usual;direct...

  9. Practice type effects on head impact in collegiate football.

    Science.gov (United States)

    Reynolds, Bryson B; Patrie, James; Henry, Erich J; Goodkin, Howard P; Broshek, Donna K; Wintermark, Max; Druzgal, T Jason

    2016-02-01

    OBJECT IVE: This study directly compares the number and severity of subconcussive head impacts sustained during helmet-only practices, shell practices, full-pad practices, and competitive games in a National Collegiate Athletic Association (NCAA) Division I-A football team. The goal of the study was to determine whether subconcussive head impact in collegiate athletes varies with practice type, which is currently unregulated by the NCAA. Over an entire season, a cohort of 20 collegiate football players wore impact-sensing mastoid patches that measured the linear and rotational acceleration of all head impacts during a total of 890 athletic exposures. Data were analyzed to compare the number of head impacts, head impact burden, and average impact severity during helmet-only, shell, and full-pad practices, and games. Helmet-only, shell, and full-pad practices and games all significantly differed from each other (p ≤ 0.05) in the mean number of impacts for each event, with the number of impacts being greatest for games, then full-pad practices, then shell practices, and then helmet-only practices. The cumulative distributions for both linear and rotational acceleration differed between all event types (p football players.

  10. Frequency, magnitude, and distribution of head impacts in Pop Warner football: the cumulative burden.

    Science.gov (United States)

    Wong, Ricky H; Wong, Andrew K; Bailes, Julian E

    2014-03-01

    A growing body of research suggests that subconcussive head impacts or repetitive mild Traumatic Brain Injury (mTBI) can have cumulative and deleterious effects. Several studies have investigated head impacts in football at the professional, collegiate, and high school levels, in an attempt to elucidate the biomechanics of head impacts among football players. Youth football players, generally from 7 to 14 years of age, constitute 70% of all football players, yet burden of, and susceptibility to, head injury in this population is not well known. A novel impact sensor utilizing binary force switches (Shockbox(®)) was used to follow an entire Pop Warner football team consisting of twenty-two players for six games and five practices. The impact sensor was designed to record impacts with linear accelerations over 30g. In addition, video recording of games and practices were used to further characterize the head impacts by type of position (skilled versus unskilled), field location of impact (open field versus line of scrimmage), type of hit (tackling, tackled, or hold/push), and whether the impact was a head-to-head impact or not. We recorded a total of 480 head impacts. An average of 21.8 head impacts occurred per practice, while 61.8 occurred per game. Players had an average of 3.7 head impacts per game and 1.5 impacts per practice (p80g) was 11. Two concussions were diagnosed over the course of the season. However, due to technical reasons the biomechanics of those hits resulting in concussions were not captured. Despite smaller players and slower play when compared to high school, collegiate or professional players, those involved in youth football sustain a moderate number of head impacts per season with several high magnitude impacts. Our results suggest that players involved in open-field, tackling plays that have head-to-head contact sustain impacts with the highest linear accelerations. Our data supports previously published data that suggests changes to the

  11. Serum S-100B protein levels in young amateur soccer players after controlled heading and normal exercise.

    Science.gov (United States)

    Mussack, T; Dvorak, J; Graf-Baumann, T; Jochum, M

    2003-10-22

    Repeated impacts by heading might lead to significant head injuries in soccer players comparable to those of patients with accidental minor traumatic brain injury (TBI). The neuroprotein S-100B released into the circulation is suggested to be a reliable marker indicating brain damage. The objective was to evaluate the neuroprotein S-100B serum levels in young amateur soccer players early after controlled heading compared to early measurements after normal exercise as well as in other patients after minor TBI. Sixty-one male amateur soccer players (median age 15.3 years) performed controlled heading aimed at the forehead for 55 minutes. Data were compared to 58 male amateur soccer players (15.9 years) performing 61 minutes of normal exercise training without head contact and 81 young male patients early after TBI who underwent computed tomography (CCT) for detection of intracranial lesions. First venous blood samples were drawn before the training sessions, second and third samples 60 and 360 minutes after heading or 64 and 355 minutes after exercise, respectively, 65 and 366 minutes after TBI. Median S-100B serum levels of the heading group only slightly increased from 0.15 ng/ml to 0.18 ng/ml 60 minutes after end of training. Within 360 minutes S-100B values decreased again to 0.15 ng/ml reaching the initial values. S-100B serum values of the exercise group showed a similar transient increase exhibiting significant lower levels before exercise (0.10 ng/ml) as well as 64 minutes (0.11 ng/ml) and 355 minutes after exercise (0.09 ng/ml) compared to the heading group. According to age stratification in the heading group, starting median S-100B levels were significantly higher in subjects with 12-13 years (0.22 ng/ml) and 14-15 years (0.17 ng/ml) compared to those with 16-17 years of age (0.06 ng/ml). None of the subcollectives did reach median S-100B levels of the CCT+ group (n = 20) at admission (0.62 ng/ml) or 366 minutes later (0.32 ng/ml), which were significantly

  12. Drill-specific head impact exposure in youth football practice.

    Science.gov (United States)

    Campolettano, Eamon T; Rowson, Steven; Duma, Stefan M

    2016-11-01

    OBJECTIVE Although 70% of football players in the United States are youth players (6-14 years old), most research on head impacts in football has focused on high school, collegiate, or professional populations. The objective of this study was to identify the specific activities associated with high-magnitude (acceleration > 40g) head impacts in youth football practices. METHODS A total of 34 players (mean age 9.9 ± 0.6 years) on 2 youth teams were equipped with helmet-mounted accelerometer arrays that recorded head accelerations associated with impacts in practices and games. Videos of practices and games were used to verify all head impacts and identify specific drills associated with each head impact. RESULTS A total of 6813 impacts were recorded, of which 408 had accelerations exceeding 40g (6.0%). For each type of practice drill, impact rates were computed that accounted for the length of time that teams spent on each drill. The tackling drill King of the Circle had the highest impact rate (95% CI 25.6-68.3 impacts/hr). Impact rates for tackling drills (those conducted without a blocker [95% CI 14.7-21.9 impacts/hr] and those with a blocker [95% CI 10.5-23.1 impacts/hr]) did not differ from game impact rates (95% CI 14.2-21.6 impacts/hr). Tackling drills were observed to have a greater proportion (between 40% and 50%) of impacts exceeding 60g than games (25%). The teams in this study participated in tackling or blocking drills for only 22% of their overall practice times, but these drills were responsible for 86% of all practice impacts exceeding 40g. CONCLUSIONS In youth football, high-magnitude impacts occur more often in practices than games, and some practice drills are associated with higher impact rates and accelerations than others. To mitigate high-magnitude head impact exposure in youth football, practices should be modified to decrease the time spent in drills with high impact rates, potentially eliminating a drill such as King of the Circle

  13. Relationship of soccer heading to computerized neurocognitive performance and symptoms among female and male youth soccer players.

    Science.gov (United States)

    Kontos, Anthony P; Dolese, Angela; Elbin, R J; Covassin, Tracey; Warren, Barbara L

    2011-01-01

    The purpose of this study was to investigate the relationship between soccer heading and computerized neurocognitive performance and symptoms in female and male youth soccer players. Cross-sectional and prospective design. A total of 63 (27 females, 36 males) youth soccer players aged 13-18 years (M = 15.89, SD = 1.17) participated in the study. Participants completed the Immediate Post-concussion Assessment and Cognitive Test (ImPACT) and symptom report. Computerized neurocognitive performance (e.g., verbal and visual memory, motor processing, and reaction time) and symptoms. There were no differences in neurocognitive performance or symptoms among low-, moderate-, and high-exposure header groups. The current sample outperformed the 10th percentile norms for neurocognitive and symptom scores. Males headed the ball more frequently and reported lower verbal and visual memory and motor processing speed scores than females. The current findings did not support a relationship between soccer heading and computerized neurocognitive performance and symptoms. The researchers suggest that any purported effects of soccer heading in youth are subtle and may affect only a small number of athletes. The reported sex differences in heading exposure warrant further attention.

  14. Head impact exposure in youth football: middle school ages 12-14 years.

    Science.gov (United States)

    Daniel, Ray W; Rowson, Steven; Duma, Stefan M

    2014-09-01

    The head impact exposure experienced by football players at the college and high school levels has been well documented; however, there are limited data regarding youth football despite its dramatically larger population. The objective of this study was to investigate head impact exposure in middle school football. Impacts were monitored using a commercially available accelerometer array installed inside the helmets of 17 players aged 12-14 years. A total of 4678 impacts were measured, with an average (±standard deviation) of 275 ± 190 impacts per player. The average of impact distributions for each player had a median impact of 22 ± 2 g and 954 ± 122 rad/s², and a 95th percentile impact of 54 ± 9 g and 2525 ± 450 rad/s². Similar to the head impact exposure experienced by high school and collegiate players, these data show that middle school football players experience a greater number of head impacts during games than practices. There were no significant differences between median and 95th percentile head acceleration magnitudes experienced during games and practices; however, a larger number of impacts greater than 80 g occurred during games than during practices. Impacts to the front and back of the helmet were most common. Overall, these data are similar to high school and college data that have been collected using similar methods. These data have applications toward youth football helmet design, the development of strategies designed to limit head impact exposure, and child-specific brain injury criteria.

  15. Purposeful heading during a season does not influence cognitive function or balance in female soccer players.

    Science.gov (United States)

    Kaminski, Thomas W; Wikstrom, April M; Gutierrez, Gregory M; Glutting, Joseph J

    2007-10-01

    Soccer participation, especially among females, is growing in popularity in the United States. Purposeful heading, an important soccer skill, has recently been scrutinized for safety reasons. The purpose of this study was to determine whether there was a relationship between purposeful heading and scores on cognitive function and balance in high school and collegiate female soccer players. Prior to and following the soccer season, all players and members of the control group were given a battery of neuropsychological and balance tests. There were no significant correlations found between the total number of game headers and performance on either balance or neuropsychological testing.Differences were noted in adjusted balance scores postseason between the collegiate players and the other two groups.However, no differences were revealed in neurocognitive performance between the three groups. ©2007 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business

  16. How soccer players head the ball: a test of Optic Acceleration Cancellation theory with virtual reality.

    Science.gov (United States)

    McLeod, Peter; Reed, Nick; Gilson, Stuart; Glennerster, Andrew

    2008-06-01

    We measured the movements of soccer players heading a football in a fully immersive virtual reality environment. In mid-flight the ball's trajectory was altered from its normal quasi-parabolic path to a linear one, producing a jump in the rate of change of the angle of elevation of gaze (alpha) from player to ball. One reaction time later the players adjusted their speed so that the rate of change of alpha increased when it had been reduced and reduced it when it had been increased. Since the result of the player's movement was to regain a value of the rate of change close to that before the disturbance, the data suggest that the players have an expectation of, and memory for, the pattern that the rate of change of alpha will follow during the flight. The results support the general claim that players intercepting balls use servo control strategies and are consistent with the particular claim of Optic Acceleration Cancellation theory that the servo strategy is to allow alpha to increase at a steadily decreasing rate.

  17. Does Game Participation Impact Cognition and Symptoms in Elite Football Players?

    Science.gov (United States)

    Mrazik, Martin; Naidu, Dhiren; Manning, David E; Brooks, Brian L

    2016-09-01

    To measure neurocognitive functioning in college and professional football players after game participation. Retrospective, cross-sectional cohort design. Ninety-four male university and professional football players. All participants completed Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) testing at baseline, and either at postconcussion (group 1) or postgame (group 2) participation. Results from the 5 ImPACT composite scores (Verbal Memory, Visual Memory, Visual Motor Speed, Reaction Time and Impulse Control) and Total Symptom Score. Repeated-measures analysis of variance demonstrated a significant main effect for time (improvements) in 3 of 5 domains for the postconcussion group, but no improvements in the postgame group. The postconcussion group presented with significantly improved results on 4 of 5 ImPACT domains compared with the postgame group at the follow-up time interval. Participation in a football game with potential cumulative head contacts did not yield increased symptoms or cognitive impairment. However, the absence of improvement in cognitive functioning in noninjured football players, which was found in those players who were returned to play after an injury, may suggest that there is a measureable impact as a result of playing football.

  18. Validation of HeadCount-2w for estimation of two-week heading: Comparison to daily reporting in adult amateur player.

    Science.gov (United States)

    Lipton, Michael L; Ifrah, Chloe; Stewart, Walter F; Fleysher, Roman; Sliwinski, Martin J; Kim, Mimi; Lipton, Richard B

    2017-08-24

    To validate the HeadCount-2w questionnaire for estimation of 2-week soccer heading by comparison to daily electronic diary reporting over the same two-week period. Prospective observational study. Adult amateur soccer players completed HeadCount-daily, comprising 14 daily at-home assessments of soccer play and heading via a tablet PC. Following the 14day period, players completed HeadCount-2w, a web-based two-week-recall questionnaire on soccer and heading. intraclass correlation coefficient (ICC) was estimated between HeadCount-daily, the reference standard, and HeadCount-2w estimates of heading during the same 2-week period. 53 participants (38 men) reported a mean of 24.36 (median=11.76) headers during 2 weeks via HeadCount-daily and a mean of 38.34 (median=15.0) headers for the same 2 weeks via HeadCount-2w. The ICC comparing 2-week heading from HeadCount-daily and HeadCount-2w was 0.85. Linear regression of the log-transformed Headcount-daily on HeadCount-2w data yielded a slope of 0.71 (pheading tends to be over-estimated by HeadCount-2w relative to HeadCount-daily. Slope estimates for men (0.65) and women (0.71) were similar. HeadCount, a self-administered web-based survey, is valid for self-reporting 2-week heading in adult amateur players, supporting its use in future research and as a simple and low-cost technique for exposure monitoring. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  19. Effects of Sex and Event Type on Head Impact in Collegiate Soccer

    Science.gov (United States)

    Reynolds, Bryson B.; Patrie, James; Henry, Erich J.; Goodkin, Howard P.; Broshek, Donna K.; Wintermark, Max; Druzgal, T. Jason

    2017-01-01

    Background: The effects of head impact in sports are of growing interest for clinicians, scientists, and athletes. Soccer is the most popular sport worldwide, but the burden of head impact in collegiate soccer is still unknown. Purpose: To quantify head impact associated with practicing and playing collegiate soccer using wearable accelerometers. Study Design: Descriptive epidemiological study. Methods: Mastoid patch accelerometers were used to quantify head impact in soccer, examining differences in head impact as a function of sex and event type (practice vs game). Seven female and 14 male collegiate soccer players wore mastoid patch accelerometers that measured head impacts during team events. Data were summarized for each athletic exposure, and statistical analyses evaluated the mean number of impacts, mean peak linear acceleration, mean peak rotational acceleration, and cumulative linear and rotational acceleration, each grouped by sex and event type. Results: There were no differences in the frequency or severity of head impacts between men’s and women’s soccer practices. For men’s soccer, games resulted in 285% more head impacts than practices, but there were no event-type differences in mean impact severity. Men’s soccer games resulted in more head impacts than practices across nearly all measured impact severities, which also resulted in men’s soccer games producing a greater cumulative impact burden. Conclusion: Similar to other sports, men’s soccer games have a greater impact burden when compared with practices, and this effect is driven by the quantity rather than severity of head impacts. In contrast, there were no differences in the quantity or severity of head impacts in men’s and women’s soccer practices. These data could prompt discussions of practical concern to collegiate soccer, such as understanding sex differences in head impact and whether games disproportionately contribute to an athlete’s head impact burden. PMID:28491885

  20. No neuropsychological consequence in male and female soccer players after a short heading training.

    Science.gov (United States)

    Rieder, Cornelia; Jansen, Petra

    2011-11-01

    The impact of heading on neuropsychological performance is a subject of controversy. In this experimental study, a controlled group design was used to investigate the possible effects of a short heading training session on neuropsychological performance. Ninety-one participants matched by age, sex, and intelligence were assigned to one of the following groups: A heading-training group, a placebo control group, and a waiting control group. All participants completed a neuropsychological test battery for attention and working memory (D2 Test, Benton Visual Retention Test, Paced Auditory Serial Addition Task Test). After 1 week, they received heading training, football (e.g., soccer) training without heading, or no training. Immediately after this training, the neuropsychological tests were conducted again. There was no neuropsychological deficit which could only be attributed to the heading training. However, within the heading group, women complained more about headache than men.

  1. Head impact exposure in youth football: high school ages 14 to 18 years and cumulative impact analysis.

    Science.gov (United States)

    Urban, Jillian E; Davenport, Elizabeth M; Golman, Adam J; Maldjian, Joseph A; Whitlow, Christopher T; Powers, Alexander K; Stitzel, Joel D

    2013-12-01

    Sports-related concussion is the most common athletic head injury with football having the highest rate among high school athletes. Traditionally, research on the biomechanics of football-related head impact has been focused at the collegiate level. Less research has been performed at the high school level, despite the incidence of concussion among high school football players. The objective of this study is to twofold: to quantify the head impact exposure in high school football, and to develop a cumulative impact analysis method. Head impact exposure was measured by instrumenting the helmets of 40 high school football players with helmet mounted accelerometer arrays to measure linear and rotational acceleration. A total of 16,502 head impacts were collected over the course of the season. Biomechanical data were analyzed by team and by player. The median impact for each player ranged from 15.2 to 27.0 g with an average value of 21.7 (±2.4) g. The 95th percentile impact for each player ranged from 38.8 to 72.9 g with an average value of 56.4 (±10.5) g. Next, an impact exposure metric utilizing concussion injury risk curves was created to quantify cumulative exposure for each participating player over the course of the season. Impacts were weighted according to the associated risk due to linear acceleration and rotational acceleration alone, as well as the combined probability (CP) of injury associated with both. These risks were summed over the course of a season to generate risk weighted cumulative exposure. The impact frequency was found to be greater during games compared to practices with an average number of impacts per session of 15.5 and 9.4, respectively. However, the median cumulative risk weighted exposure based on combined probability was found to be greater for practices vs. games. These data will provide a metric that may be used to better understand the cumulative effects of repetitive head impacts, injury mechanisms, and head impact exposure of

  2. Impact of Increased Football Field Width on Player High-Speed Collision Rate.

    Science.gov (United States)

    Joseph, Jacob R; Khalsa, Siri S; Smith, Brandon W; Park, Paul

    2017-07-01

    High-acceleration head impact is a known risk for mild traumatic brain injury (mTBI) based on studies using helmet accelerometry. In football, offensive and defensive players are at higher risk of mTBI due to increased speed of play. Other collision sport studies suggest that increased playing surface size may contribute to reductions in high-speed collisions. We hypothesized that wider football fields lead to a decreased rate of high-speed collisions. Computer football game simulation was developed using MATLAB. Four wide receivers were matched against 7 defensive players. Each offensive player was randomized to one of 5 typical routes on each play. The ball was thrown 3 seconds into play; ball flight time was 2 seconds. Defensive players were delayed 0.5 second before reacting to ball release. A high-speed collision was defined as the receiver converging with a defensive player within 0.5 second of catching the ball. The simulation counted high-speed collisions for 1 team/season (65 plays/game for 16 games/season = 1040 plays/season) averaged during 10 seasons, and was validated against existing data using standard field width (53.3 yards). Field width was increased in 1-yard intervals up to 58.3 yards. Using standard field width, 188 ± 4 high-speed collisions were seen per team per season (18% of plays). When field width increased by 3 yards, high-speed collision rate decreased to 135 ± 3 per team per season (28% decrease; P football field width can lead to substantial decline in high-speed collisions, with potential for reducing instances of mTBI in football players. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Theoretical study of the effect of ball properties on impact force in soccer heading.

    Science.gov (United States)

    Queen, Robin M; Weinhold, Paul S; Kirkendall, Donald T; Yu, Bing

    2003-12-01

    The objective of this study was to theoretically model, based on the Hertz contact theory, the impact force and contact time, as well as the linear and angular head accelerations during heading in children using two neck stiffness conditions (infinite and negligible stiffness). The following mathematical model inputs were obtained: elastic modulus and mass of size three, four, and five balls at inflation pressures of 10, 12, and 14 psi, head modulus, head mass, head length, head and trunk moment of inertia, and the precontact ball velocity. The model outputs consisted of linear and angular head acceleration, impact force, contact time between the ball and head, and head impact criteria (HIC) all at the point of impact. Head mass and length were obtained as a percentage of body weight and height, respectively, based on age. With an increase in head mass, there is a decrease in the linear and angular head acceleration. With an increase in ball size, for the same head mass, there is an increase in the contact time between the head and the ball. Changing ball inflation pressure has little effect on the impact characteristics. Infinite neck stiffness decreased linear and angular head acceleration and HIC. Head mass and ball size have an effect on linear and angular head acceleration and contact time, respectively, whereas ball inflation pressure has a minimal effect on the impact characteristics. These results indicate that children should be restricted to using the appropriate ball for their age. Smaller head size within an age group is an underemphasized though important identifier of a player's injury risk.

  4. Similar head impact acceleration measured using instrumented ear patches in a junior rugby union team during matches in comparison with other sports.

    Science.gov (United States)

    King, Doug A; Hume, Patria A; Gissane, Conor; Clark, Trevor N

    2016-07-01

    OBJECTIVE Direct impact with the head and the inertial loading of the head have been postulated as major mechanisms of head-related injuries, such as concussion. METHODS This descriptive observational study was conducted to quantify the head impact acceleration characteristics in under-9-year-old junior rugby union players in New Zealand. The impact magnitude, frequency, and location were collected with a wireless head impact sensor that was worn by 14 junior rugby players who participated in 4 matches. RESULTS A total of 721 impacts > 10g were recorded. The median (interquartile range [IQR]) number of impacts per player was 46 (IQR 37-58), resulting in 10 (IQR 4-18) impacts to the head per player per match. The median impact magnitudes recorded were 15g (IQR 12g-21g) for linear acceleration and 2296 rad/sec(2) (IQR 1352-4152 rad/sec(2)) for rotational acceleration. CONCLUSIONS There were 121 impacts (16.8%) above the rotational injury risk limit and 1 (0.1%) impact above the linear injury risk limit. The acceleration magnitude and number of head impacts in junior rugby union players were higher than those previously reported in similar age-group sports participants. The median linear acceleration for the under-9-year-old rugby players were similar to 7- to 8-year-old American football players, but lower than 9- to 12-year-old youth American football players. The median rotational accelerations measured were higher than the median and 95th percentiles in youth, high school, and collegiate American football players.

  5. Soccer Players Cultural Capital and Its Impact on Migration

    Science.gov (United States)

    Leskošek, Bojan; Vodičar, Janez; Topič, Mojca Doupona

    2016-01-01

    Abstract The purpose of this study was to identify factors that constituted the cultural capital among soccer players. We assumed that in the increasingly globalized world of professional soccer, a player’s success would often depend on migrating and adjusting to life in other countries. Willingness to migrate and successful adjustment are tied to player’s previous attitudes and/or behaviours (habitus), significant support from others, including family members, and previous experiences and success in sports and education. Our hypothesised model of the cultural capital was based on the Pierre Bourdieu’s theoretical framework. It consisted of 26 variables related to three sets of factors: soccer experiences, a family context and support, and educational achievements of the players and their parents. The model was tested using a sample of 79 current soccer coaches who also had been players at the elite level. A factor analysis was used to empirically verify the content of the hypothetical model of the soccer players’ cultural capital. Nine latent factors were extracted and together, they accounted for 55.01% of the total model variance. Individual factors obtained showed a sufficient level of substantial connection. The Cronbach’s alpha value of 0.77 confirmed the internal consistency of the operationalised variables in the hypothetical model. In addition, the impact of these aforementioned life dimensions on the migration of soccer players was studied. The results of the binary logistic regression analysis showed that the first factor of the hypothetical model (F1) had 2.2 times and the second factor (F8) had 3.9 times higher odds for migration abroad. Sociocultural findings using this new assessment approach could help create better “success conditions” in the talent development of young players. PMID:28031770

  6. The relationship between impact force, neck strength, and neurocognitive performance in soccer heading in adolescent females.

    Science.gov (United States)

    Gutierrez, Gregory M; Conte, Catherine; Lightbourne, Kristian

    2014-02-01

    Head impacts are common in contact sports, but only recently has there been a rising awareness of the effects of subconcussive impacts in adolescent athletes. A better understanding of how to attenuate head impacts is needed and therefore, this study investigated the relationship between neck strength, impact, and neurocognitive function in an acute bout of soccer heading in a sample of female high school varsity soccer players. Seventeen participants completed the ImPACT neurocognitive test and had their isometric neck strength tested (flexion, extension, and bilateral flexion) before heading drills. Each participant was outfitted with custom headgear with timing switches and a three-dimensional accelerometer affixed to the back of the head, which allowed for measurement of impact during heading. Participants performed a series of 15 directional headers, including 5 forward, 5 left and 5 right headers in a random order, then completed the ImPACT test again. Neurocognitive tests revealed no significant changes following heading. However, there were statistically significant, moderate, negative correlations (r = -0.500:-0.757, p head injury prevention/reduction program.

  7. The effect of head protection on the hearing of rugby players.

    Science.gov (United States)

    Kieran, S M; Dunne, J; Hughes, J P; Fenton, J E

    2008-09-01

    Professional rugby players utilise various methods of head protection to prevent against the development of a pinna haematoma. This study tests the hypothesis that these measures, whilst preventing injury, decrease the wearers' hearing threshold and therefore their performance. Eight patients had free field audiometry performed in a soundproof room, with warble tones. All patients were young men (mean 24.75 years (range 22-34)). No participant had ear symptomatology or a past history of ear surgery. Three separate audiological assessments were performed on each patient: normal free field audiometry in a sound field room, following application of adhesive tape and whilst wearing a scrum cap. All measurements were performed by a single audiological scientist. A significant clinical drop in hearing threshold was defined as an increase of 10 dB. No patient demonstrated a significant drop in hearing threshold following the application of either tape or a scrum cap, nor was there a significant difference in the mean (SD) warble tone average: air 7.03 (5.47); tape 7.19 (6.40); scrum cap 6.56 (5.58). Theoretical concerns that "ear taping" and scrum caps affect hearing of rugby players are unfounded and should not discourage their use.

  8. Recent and Long-Term Soccer Heading Exposure Is Differentially Associated With Neuropsychological Function in Amateur Players.

    Science.gov (United States)

    Levitch, Cara F; Zimmerman, Molly E; Lubin, Naomi; Kim, Namhee; Lipton, Richard B; Stewart, Walter F; Kim, Mimi; Lipton, Michael L

    2017-08-22

    The present study examined the relative contribution of recent or long-term heading to neuropsychological function in amateur adult soccer players. Soccer players completed a baseline questionnaire (HeadCount-12m) to ascertain heading during the prior 12 months (long-term heading, LTH) and an online questionnaire (HeadCount-2w) every 3 months to ascertain heading during the prior 2 weeks (recent heading, RH). Cogstate, a battery of six neuropsychological tests, was administered to assess neuropsychological function. Generalized estimating equations were used to test if LTH or RH was associated with neuropsychological function while accounting for the role of recognized concussion. A total of 311 soccer players completed 630 HeadCount-2w. Participants had an average age of 26 years. Participants headed the ball a median of 611 times/year (mean=1,384.03) and 9.50 times/2 weeks (mean=34.17). High levels of RH were significantly associated with reduced performance on a task of psychomotor speed (p=.02), while high levels of LTH were significantly associated with poorer performance on tasks of verbal learning (p=.03) and verbal memory (p=.04). Significantly better attention (p=.02) was detectable at moderately high levels of RH, but not at the highest level of RH. One hundred and seven (34.4%) participants reported a lifetime history of concussion, but this was not related to neuropsychological function and did not modify the association of RH or LTH with neuropsychological function. High levels of both RH and LTH were associated with poorer neuropsychological function, but on different domains. The clinical manifestations following repetitive exposure to heading could change with chronicity of exposure. (JINS, 2017, 23, 1-9).

  9. Effect of soccer heading ball speed on S100B, sideline concussion assessments and head impact kinematics.

    Science.gov (United States)

    Dorminy, Millie; Hoogeveen, Ashley; Tierney, Ryan T; Higgins, Michael; McDevitt, Jane K; Kretzschmar, Jan

    2015-05-25

    To examine the effect of soccer heading ball speed on S-100B serum concentration, concussion sideline assessments and linear head impact acceleration. Sixteen division I soccer players participated in this pre-test post-test design study. Athletes performed five standing headers over a 10 minute period at 30 (n = 5), 40 (n = 5) or 50 (n = 6) miles per hour (mph) (randomized). S-100B serum concentration (ng mL(-1)) and sideline concussion assessments were measured prior to and post-heading. Peak resultant linear head acceleration (gravitational units; g) was measured during soccer heading. No statistically significant interaction effects were identified between ball velocity groups over time on S100B (effect sizes ranged from 0.03-0.23) or concussion assessments tests. There was a non-significant increase (p = 0.06) in head impact acceleration from the 30 (30.6; SD = 6.2 g) to 50 mph (50.7; SD = 7.7 g) ball speed. In this controlled setting, an acute bout of soccer heading across various ball velocities did not affect S100B or concussion assessment test scores. These findings are preliminary, as the small sample size in each group may have played a role in the lack of significant findings.

  10. Effect of Repetitive Sub-concussive Head Impacts on Ocular Near Point of Convergence.

    Science.gov (United States)

    Kawata, K; Tierney, R; Phillips, J; Jeka, J J

    2016-05-01

    This study intended to examine effects of repetitive sub-concussive head impacts on ocular near point of convergence (NPC). 20 healthy young adult soccer players were assigned to either a heading or control group. Heading subjects completed 10 headers of soccer balls projected at a speed of 11.2 m/s. Control subjects did not perform heading. Linear head acceleration was measured with a triaxial accelerometer. The NPC assessment was performed at pre-, 0 h post-, and 24 h post-heading. During the NPC assessment participants were seated and a visual target was moved towards the eyes at 1cm/sec. The participant signaled when he/she experienced diplopia or deviation of the eye was observed, and the distance was recorded. The assessment was repeated twice and average NPC scores were used for further analysis. Soccer heading induced mean group head accelerations of 14.49±5.4 g. Mild head impacts led to an increased NPC distance, which was supported by a significant Group x Time interaction. In the heading group, 0 h post- and 24 h post-heading NPC scores were significantly receded compared to baseline. Conversely, NPC scores for the control group showed no difference over time. Our findings indicate that mild frontal head impacts affekt NPC for a minimum of 24 h-post heading, suggesting that oculomotor processes are disrupted, at least transiently, by repetitive mild head impact. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Rotational head kinematics in football impacts: an injury risk function for concussion.

    Science.gov (United States)

    Rowson, Steven; Duma, Stefan M; Beckwith, Jonathan G; Chu, Jeffrey J; Greenwald, Richard M; Crisco, Joseph J; Brolinson, P Gunnar; Duhaime, Ann-Christine; McAllister, Thomas W; Maerlender, Arthur C

    2012-01-01

    Recent research has suggested a possible link between sports-related concussions and neurodegenerative processes, highlighting the importance of developing methods to accurately quantify head impact tolerance. The use of kinematic parameters of the head to predict brain injury has been suggested because they are indicative of the inertial response of the brain. The objective of this study is to characterize the rotational kinematics of the head associated with concussive impacts using a large head acceleration dataset collected from human subjects. The helmets of 335 football players were instrumented with accelerometer arrays that measured head acceleration following head impacts sustained during play, resulting in data for 300,977 sub-concussive and 57 concussive head impacts. The average sub-concussive impact had a rotational acceleration of 1230 rad/s(2) and a rotational velocity of 5.5 rad/s, while the average concussive impact had a rotational acceleration of 5022 rad/s(2) and a rotational velocity of 22.3 rad/s. An injury risk curve was developed and a nominal injury value of 6383 rad/s(2) associated with 28.3 rad/s represents 50% risk of concussion. These data provide an increased understanding of the biomechanics associated with concussion and they provide critical insight into injury mechanisms, human tolerance to mechanical stimuli, and injury prevention techniques.

  12. Frequency of Head-Impact–Related Outcomes by Position in NCAA Division I Collegiate Football Players

    Science.gov (United States)

    Kiernan, Patrick T.; Kroshus, Emily; Daneshvar, Daniel H.; Montenigro, Philip H.; McKee, Ann C.; Stern, Robert A.

    2015-01-01

    Abstract Concussions and subconcussive impacts sustained in American football have been associated with short- and long-term neurological impairment, but differences in head impact outcomes across playing positions are not well understood. The American Medical Society for Sports Medicine has identified playing position as a key risk factor for concussion in football and one for which additional research is needed. This study examined variation in head impact outcomes across primary football playing positions in a group of 730 National Collegiate Athletic Association Division I Football Championship Series athletes, using a self-report questionnaire. Although there were no significant differences between position groups in the number of diagnosed concussions during the 2012 football season, there were significant differences between groups in undiagnosed concussions (p=0.008) and “dings” (pfootball season, with offensive linemen reporting significantly more symptoms compared to most other groups. There were also positional differences in frequency of returning to play while symptomatic (p<0.001) and frequency of participating in full-contact practice (p<0.001). Offensive linemen reported having returned to play while experiencing symptoms more frequently and participating in more full-contact practices than other groups. These findings suggest that offensive linemen, a position group that experiences frequent, but low-magnitude, head impacts, develop more postimpact symptoms than other playing positions, but do not report these symptoms as a concussion. PMID:25155288

  13. Analysis of postural stability in collegiate soccer players before and after an acute bout of heading multiple soccer balls.

    Science.gov (United States)

    Mangus, Brent C; Wallmann, Harvey W; Ledford, Matthew

    2004-07-01

    The aim of our study was to determine if any immediate changes in balance were discernable in college soccer players after a specially designed heading session. Eight male and two female skilled collegiate soccer players had a baseline balance pre-test using the Balance Master, followed by heading 20 balls kicked consecutively by a teammate from the touchline to a point near the goal, which was followed by a post-test using the same testing technique. Paired t-tests were used to compare balance ability between pre- and post-test conditions. There was no difference in balance pre- to post-test (85.3% and 86.2% respectively). No significant difference was noted from pre- to post-test in the mean equilibrium scores for conditions three through six on the Sensory Organization Test, with the exception of condition four, which revealed a significant increase from pre- to post-test. We concluded that an acute session of heading soccer balls may not result in balance changes in collegiate soccer players.

  14. Pre-training perceived wellness impacts training output in Australian football players.

    Science.gov (United States)

    Gallo, Tania F; Cormack, Stuart J; Gabbett, Tim J; Lorenzen, Christian H

    2016-08-01

    The impact of perceived wellness on a range of external load parameters, rating of perceived exertion (RPE) and external load:RPE ratios, was explored during skill-based training in Australian footballers. Fifteen training sessions involving 36 participants were analysed. Each morning before any physical training, players completed a customised perceived wellness questionnaire (sleep quality, fatigue, stress, mood and muscle soreness). Microtechnology devices provided external load (average speed, high-speed running distance, player load and player load slow). Players provided RPE using the modified Borg category-ratio 10 RPE scale. Mixed-effect linear models revealed significant effects of wellness Z-score on player load and player load slow. Effects are reported with 95% confidence limits. A wellness Z-score of -1 corresponded to a -4.9 ± 3.1 and -8.6 ± 3.9% reduction in player load and player load slow, respectively, compared to those without reduced wellness. Small significant effects were also seen in the average speed:RPE and player load slow:RPE models. A wellness Z-score of -1 corresponded to a 0.43 ± 0.38 m·min(-1) and -0.02 ± 0.01 au·min(-1) change in the average speed:RPE and player load slow:RPE ratios, respectively. Magnitude-based analysis revealed that the practical size of the effect of a pre-training perceived wellness Z-score of -1 would have on player load slow was likely negative. The results of this study suggests that monitoring pre-training perceived wellness may provide coaches with information about the intensity of output that can be expected from individual players during a training session.

  15. Heading and head injuries in soccer.

    Science.gov (United States)

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  16. Cortical thinning in former professional soccer players.

    Science.gov (United States)

    Koerte, Inga K; Mayinger, Michael; Muehlmann, Marc; Kaufmann, David; Lin, Alexander P; Steffinger, Denise; Fisch, Barbara; Rauchmann, Boris-Stephan; Immler, Stefanie; Karch, Susanne; Heinen, Florian R; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

    2016-09-01

    Soccer is the most popular sport in the world. Soccer players are at high risk for repetitive subconcussive head impact when heading the ball. Whether this leads to long-term alterations of the brain's structure associated with cognitive decline remains unknown. The aim of this study was to evaluate cortical thickness in former professional soccer players using high-resolution structural MR imaging. Fifteen former male professional soccer players (mean age 49.3 [SD 5.1] years) underwent high-resolution structural 3 T MR imaging, as well as cognitive testing. Fifteen male, age-matched former professional non-contact sport athletes (mean age 49.6 [SD 6.4] years) served as controls. Group analyses of cortical thickness were performed using voxel-based statistics. Soccer players demonstrated greater cortical thinning with increasing age compared to controls in the right inferolateral-parietal, temporal, and occipital cortex. Cortical thinning was associated with lower cognitive performance as well as with estimated exposure to repetitive subconcussive head impact. Neurocognitive evaluation revealed decreased memory performance in the soccer players compared to controls. The association of cortical thinning and decreased cognitive performance, as well as exposure to repetitive subconcussive head impact, further supports the hypothesis that repetitive subconcussive head impact may play a role in early cognitive decline in soccer players. Future studies are needed to elucidate the time course of changes in cortical thickness as well as their association with impaired cognitive function and possible underlying neurodegenerative process.

  17. Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate.

    Science.gov (United States)

    Kerr, Zachary Y; Littleton, Ashley C; Cox, Leah M; DeFreese, J D; Varangis, Eleanna; Lynall, Robert C; Schmidt, Julianne D; Marshall, Stephen W; Guskiewicz, Kevin M

    2015-07-15

    Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information related to primary position played and participation in games and practice contacts during the pre-season, regular season, and post-season of each year of their high school, college, and professional football careers. Spring football for college was also included. We calculated contact exposure estimates for 64 former football players (n = 32 college football only, n = 32 professional and college football). The head impact exposure estimate (HIEE) discriminated between individuals who stopped after college football, and individuals who played professional football (p < 0.001). The HIEE measure was independent of concussion history (p = 0.82). Estimating total hours of contact exposure may allow for the detection of differences between individuals with variation in subconcussive impacts, regardless of concussion history. This measure is valuable for the surveillance of subconcussive impacts and their associated potential negative effects.

  18. Dynamic biomechanics of the human head in lateral impacts

    OpenAIRE

    Zhang, Jiangyue; Yoganandan, Narayan; Pintar, Frank A.

    2009-01-01

    The biomechanical responses of human head (translational head CG accelerations, rotational head accelerations, and HIC) under lateral impact to the parietal-temporal region were investigated in the current study. Free drop tests were conducted at impact velocities ranging from 2.44 to 7.70 m/s with a 40 durometer, a 90 durometer flat padding, and a 90 durometer cylinder. Specimens were isolated from PMHS subjects at the level of occipital condyles, and the intracranial substance was replaced ...

  19. Effect of head impacts on diffusivity measures in a cohort of collegiate contact sport athletes

    Science.gov (United States)

    Ford, James C.; Flashman, Laura A.; Maerlender, Arthur; Greenwald, Richard M.; Beckwith, Jonathan G.; Bolander, Richard P.; Tosteson, Tor D.; Turco, John H.; Raman, Rema; Jain, Sonia

    2014-01-01

    Objective: To determine whether exposure to repetitive head impacts over a single season affects white matter diffusion measures in collegiate contact sport athletes. Methods: A prospective cohort study at a Division I NCAA athletic program of 80 nonconcussed varsity football and ice hockey players who wore instrumented helmets that recorded the acceleration-time history of the head following impact, and 79 non–contact sport athletes. Assessment occurred preseason and shortly after the season with diffusion tensor imaging and neurocognitive measures. Results: There was a significant (p = 0.011) athlete-group difference for mean diffusivity (MD) in the corpus callosum. Postseason fractional anisotropy (FA) differed (p = 0.001) in the amygdala (0.238 vs 0.233). Measures of head impact exposure correlated with white matter diffusivity measures in several brain regions, including the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory. Conclusion: This study suggests a relationship between head impact exposure, white matter diffusion measures, and cognition over the course of a single season, even in the absence of diagnosed concussion, in a cohort of college athletes. Further work is needed to assess whether such effects are short term or persistent. PMID:24336143

  20. EFFECTS OF REPEATEDLY HEADING A SOCCER BALL ON SERUM LEVELS OF TWO NEUROTROPHIC FACTORS OF BRAIN TISSUE, BDNF AND NGF, IN PROFESSIONAL SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    B. Bamac

    2011-09-01

    Full Text Available The present study determined the effects of heading training on serum nerve growth factor (NGF and brain-derived neurotrophic factor (BDNF levels in soccer players. Seventeen professional level male soccer players (mean ± SD, age 24 ± 4.4 years, were recruited from a 3rd league team. Each player completed 15 approved headings in about 20-25 minutes. Venous blood samples were obtained from soccer players before and after the heading training for analysis. Levels of NGF and BDNF in the serum were determined by a commercially available enzyme-linked immunosorbent assay (ELISA kit. Mean ± SD serum NGF levels were 18.71 ± 3.36 pg·ml-1 before training and 31.41 ± 7.89 pg·ml-1 after training (p=0.000. Mean ± SD serum BDNF levels were 22.32 ± 3.62 pg·ml-1 before training and 55.41 ± 12.59 pg·ml-1 after training (p=0.000. In this study heading a soccer ball was found to cause an increase in serum concentrations of NGF and BDNF. We suggest that the microtrauma caused by repetitive heading and/or the course of survival of the injured neurons may lead to increased NGF and BDNF levels.

  1. Evaluation of a laboratory model of human head impact biomechanics.

    Science.gov (United States)

    Hernandez, Fidel; Shull, Peter B; Camarillo, David B

    2015-09-18

    This work describes methodology for evaluating laboratory models of head impact biomechanics. Using this methodology, we investigated: how closely does twin-wire drop testing model head rotation in American football impacts? Head rotation is believed to cause mild traumatic brain injury (mTBI) but helmet safety standards only model head translations believed to cause severe TBI. It is unknown whether laboratory head impact models in safety standards, like twin-wire drop testing, reproduce six degree-of-freedom (6DOF) head impact biomechanics that may cause mTBI. We compared 6DOF measurements of 421 American football head impacts to twin-wire drop tests at impact sites and velocities weighted to represent typical field exposure. The highest rotational velocities produced by drop testing were the 74th percentile of non-injury field impacts. For a given translational acceleration level, drop testing underestimated field rotational acceleration by 46% and rotational velocity by 72%. Primary rotational acceleration frequencies were much larger in drop tests (~100 Hz) than field impacts (~10 Hz). Drop testing was physically unable to produce acceleration directions common in field impacts. Initial conditions of a single field impact were highly resolved in stereo high-speed video and reconstructed in a drop test. Reconstruction results reflected aggregate trends of lower amplitude rotational velocity and higher frequency rotational acceleration in drop testing, apparently due to twin-wire constraints and the absence of a neck. These results suggest twin-wire drop testing is limited in modeling head rotation during impact, and motivate continued evaluation of head impact models to ensure helmets are tested under conditions that may cause mTBI. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. A heads-up no-limit Texas Hold'em poker player: Discretized betting models and automatically generated equilibrium-finding programs

    DEFF Research Database (Denmark)

    Gilpin, Andrew G.; Sandholm, Tuomas; Sørensen, Troels Bjerre

    2008-01-01

    We present Tartanian, a game theory-based player for heads-up no-limit Texas Hold'em poker. Tartanian is built from three components. First, to deal with the virtually infinite strategy space of no-limit poker, we develop a discretized betting model designed to capture the most important strategic...

  3. Head Impact Exposure During a Weekend Youth Soccer Tournament.

    Science.gov (United States)

    Chrisman, Sara P D; Mac Donald, Christine L; Friedman, Seth; Andre, Jalal; Rowhani-Rahbar, Ali; Drescher, Sara; Stein, Elizabeth; Holm, Matthew; Evans, Nicole; Poliakov, Andrew V; Ching, Randal P; Schwien, Christina C; Vavilala, Monica S; Rivara, Frederick P

    2016-07-01

    Concussion is a known risk in youth soccer, but little is known about subconcussive head impacts. The authors provided a prospective cohort study measuring frequency and magnitude of subconcussive head impacts using accelerometry in a middle school-age soccer tournament, and association between head impacts and changes in (1) symptoms, (2) cognitive testing, and (3) advanced neuroimaging. A total of 17 youth completed the study (41% female, mean 12.6 years). There were 73 head impacts >15g measured (45% headers) and only 2 had a maximum peak linear acceleration >50g No youth reported symptoms consistent with concussion. After correction for multiple comparisons and a sensitivity analysis excluding clear outliers, no significant associations were found between head impact exposure and neuropsychological testing or advanced neuroimaging. The authors conclude that head impacts were relatively uncommon and low in acceleration in youth playing a weekend soccer tournament. This study adds to the limited data regarding head impacts in youth soccer. © The Author(s) 2016.

  4. Impact of Fitness Characteristics on Tennis Performance in Elite Junior Tennis Players.

    Science.gov (United States)

    Ulbricht, Alexander; Fernandez-Fernandez, Jaime; Mendez-Villanueva, Alberto; Ferrauti, Alexander

    2016-04-01

    The impact of fitness characteristics on tennis performance in adolescent players is not clearly understood. Therefore, the aim of the present study was to test whether physical characteristics are related to players' competitive level (i.e., national youth ranking). A secondary aim was to compare adolescent tennis players by performance level (i.e., regional selected players and the national team). A total of 902 male and female junior players (aged, 11-16 years) in Germany were evaluated using a physical testing battery: grip strength; countermovement jump; 10 and 20-m sprint; tennis-specific sprint; overhead, forehand, and backhand medicine ball throws (MBT); serve velocity and tennis-specific endurance test (hit and turn tennis test). Results showed that serve velocity (r = -0.43 to 0.64 for female subjects [♀]; r = -0.33 to 0.49 for male subjects [♂]) and upper-body power (e.g., MBT r = -0.26 to -0.49 ♀; r = -0.20 to -0.49 ♂) were the most correlated predictors of tennis performance (i.e., national youth ranking) in both female and male tennis players. Moreover, national selected players showed better performance levels than their regional counterparts, mainly in the most predictive physical characteristics (i.e., serve velocity: effect size [ES], 0.78-1.04 ♀; ES 0.92-1.02 ♂, MBT: ES, 0.66-0.88 ♀; ES, 0.67-1.04 ♂) and specific endurance (ES, 0.05-0.95 ♀; ES, 0.31-0.73 ♂). The present findings underline the importance of certain physical attributes, especially serve velocity and strength- and power-related variables (upper body), and suggest the need to include these parameters in the area of training, physical testing, and talent identification of young tennis players.

  5. Dynamic biomechanics of the human head in lateral impacts.

    Science.gov (United States)

    Zhang, Jiangyue; Yoganandan, Narayan; Pintar, Frank A

    2009-10-01

    The biomechanical responses of human head (translational head CG accelerations, rotational head accelerations, and HIC) under lateral impact to the parietal-temporal region were investigated in the current study. Free drop tests were conducted at impact velocities ranging from 2.44 to 7.70 m/s with a 40 durometer, a 90 durometer flat padding, and a 90 durometer cylinder. Specimens were isolated from PMHS subjects at the level of occipital condyles, and the intracranial substance was replaced with brain simulant (Sylgard 527). Three tri-axial accelerometers were instrumented at the anterior, posterior, and vertex of the specimen, and a pyramid nine accelerometer package (pNAP) was used at the contra-lateral site. Biomechanical responses were computed by transforming accelerations measured at each location to the head CG. The results indicated significant "hoop effect" from skull deformation. Translational head CG accelerations were accurately measured by transforming the pNAP, the vertex accelerations, or the average of anterior/posterior acceleration to the CG. The material stiffness and structural rigidity of the padding changed the biomechanical responses of the head with stiffer padding resulting in higher head accelerations. At the skull fracture, HIC values were more than 2-3x higher than the frontal skull fracture threshold (HIC=1000), emphasizing the differences between frontal and lateral impact. Rotational head accelerations up to 42.1 krad/s(2) were observed before skull fracture, indicating possible severe brain injury without skull fracture in lateral head impact. These data will help to establish injury criteria and threshold in lateral impacts for improved automotive protection and help clinicians understand the biomechanics of lateral head impact from improved diagnosis.

  6. The Effect of the "Zero Tolerance for Head Contact" Rule Change on the Risk of Concussions in Youth Ice Hockey Players.

    Science.gov (United States)

    Krolikowski, Maciej P; Black, Amanda M; Palacios-Derflingher, Luz; Blake, Tracy A; Schneider, Kathryn J; Emery, Carolyn A

    2017-02-01

    Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing "zero tolerance for head contact" was implemented in all leagues in Canada. To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 "zero tolerance for head contact" policy change compared with players in similar divisions before the policy change. Cohort study; Level of evidence, 3. The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis. The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change. The "zero tolerance for head contact" policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and

  7. Head-Neck Biomechanics in Simulated Rear Impact

    OpenAIRE

    Yoganandan, Narayan; Pintar, Frank A.; Cusick, Joseph F.; Kleinberger, Michael

    1998-01-01

    The first objective of this study is to present an overview of the human cadaver studies aimed to determine the biomechanics of the head-neck in a simulated rear crash. The need for kinematic studies to better understand the mechanisms of load transfer to the human head-neck complex is emphasized. Based on this need, a methodology is developed to delineate the dynamic kinematics of the human head-neck complex. Intact human cadaver head-neck complexes were subjected to postero-anterior impact ...

  8. Persistent, Long-term Cerebral White Matter Changes after Sports-Related Repetitive Head Impacts

    Science.gov (United States)

    Bazarian, Jeffrey J.; Zhu, Tong; Zhong, Jianhui; Janigro, Damir; Rozen, Eric; Roberts, Andrew; Javien, Hannah; Merchant-Borna, Kian; Abar, Beau; Blackman, Eric G.

    2014-01-01

    Introduction Repetitive head impacts (RHI) sustained in contact sports are thought to be necessary for the long-term development of chronic traumatic encephalopathy (CTE). Our objectives were to: 1) characterize the magnitude and persistence of RHI-induced white matter (WM) changes; 2) determine their relationship to kinematic measures of RHI; and 3) explore their clinical relevance. Methods Prospective, observational study of 10 Division III college football players and 5 non-athlete controls during the 2011-12 season. All subjects underwent diffusion tensor imaging (DTI), physiologic, cognitive, and balance testing at pre-season (Time 1), post-season (Time 2), and after 6-months of no-contact rest (Time 3). Head impact measures were recorded using helmet-mounted accelerometers. The percentage of whole-brain WM voxels with significant changes in fractional anisotropy (FA) and mean diffusivity (MD) from Time 1 to 2, and Time 1 to 3 was determined for each subject and correlated to head impacts and clinical measures. Results Total head impacts for the season ranged from 431–1,850. No athlete suffered a clinically evident concussion. Compared to controls, athletes experienced greater changes in FA and MD from Time 1 to 2 as well as Time 1 to 3; most differences at Time 2 persisted to Time 3. Among athletes, the percentage of voxels with decreased FA from Time 1 to 2 was positively correlated with several helmet impact measures. The persistence of WM changes from Time 1 to 3 was also associated with changes in serum ApoA1 and S100B autoantibodies. WM changes were not consistently associated with cognition or balance. Conclusions A single football season of RHIs without clinically-evident concussion resulted in WM changes that correlated with multiple helmet impact measures and persisted following 6 months of no-contact rest. This lack of WM recovery could potentially contribute to cumulative WM changes with subsequent RHI exposures. PMID:24740265

  9. On Impact: Students with Head Injuries

    Science.gov (United States)

    Canto, Angela I.; Chesire, David J.; Buckley, Valerie A.

    2011-01-01

    Students with head injuries may not be as "low incidence" as previously believed. Recent efforts from the American Academy of Pediatrics (2010), the National Football League, and other agencies are attempting to raise awareness of traumatic brain injury (TBI) among students. Along with awareness, there has been an increased publicity effort via…

  10. On Impact: Students with Head Injuries

    Science.gov (United States)

    Canto, Angela I.; Chesire, David J.; Buckley, Valerie A.

    2011-01-01

    Students with head injuries may not be as "low incidence" as previously believed. Recent efforts from the American Academy of Pediatrics (2010), the National Football League, and other agencies are attempting to raise awareness of traumatic brain injury (TBI) among students. Along with awareness, there has been an increased publicity effort via…

  11. Head injuries: a study evaluating the impact of the NICE head injury guidelines

    Science.gov (United States)

    Hassan, Z; Smith, M; Littlewood, S; Bouamra, O; Hughes, D; Biggin, C; Amos, K; Mendelow, A; Lecky, F

    2005-01-01

    Background: The NICE head injury guidelines recommend a different approach in the management of head injury patients. It suggests that CT head scan should replace skull x ray (SXR) and observation/admission as the first investigation. We wished to determine the impact of NICE on SXR, CT scan, and admission on all patients with head injury presenting to the ED setting and estimate the cost effectiveness of these guidelines, which has not been quantified to date. Design: Study of head injury patients presenting to two EDs before and after implementation of NICE guidelines Methods: The rate of SXR, CT scan, and admission were determined six months before and one month after NICE implementation in both centres. The before study also looked at predicted rates had NICE been applied. This enabled predicted and actual cost effectiveness to be determined. Result: 1130 patients with head injury were studied in four 1 month periods (two in each centre). At the teaching hospital, the CT head scan rate more than doubled (3% to 7%), the SXR declined (37% to 4%), while the admission rate more than halved (9% to 4%). This represented a saving of £3381 per 100 head injury patients: greater than predicted with no adverse events. At the District General Hospital, the CT head scan rate more than quadrupled (1.4% to 9%), the SXR dropped (19 to 0.57%), while the admission rate declined (7% to 5%). This represented a saving of £290 per 100 head injury patients: less than predicted. Conclusion: The implementation of the NICE guidelines led to a two to fivefold increase in the CT head scan rate depending on the cases and baseline departmental practice. However, the reduction in SXR and admission appears to more than offset these costs without compromising patient outcomes. PMID:16299190

  12. Heading in Soccer: Integral Skill or Grounds for Cognitive Dysfunction?

    Science.gov (United States)

    Kirkendall, Donald T.; Garrett, William E., Jr.

    2001-01-01

    Discusses how purposeful heading of soccer balls and head injuries affect soccer players' cognitive dysfunction. Cognitive deficits may occur for many reasons. Heading cannot be blamed when details of the actual event and impact are unknown. Concussions are the most common head injury in soccer and a factor in cognitive deficits and are probably…

  13. Plume head - trench interaction: impact on subduction dynamics

    Science.gov (United States)

    Betts, P. G.; Moresi, L. N.; Mason, W. G.; Willis, D.

    2013-12-01

    The geologic record provides numerous examples where plumes and their associated buoyancy swell have disrupted convergent plate margins. These interactions have produced a variety of responses in the overriding plate including transient episodes of arc amagmatism, transient episodes of crustal shortening followed by plume-related magmatism in the overriding plate. The latter observation implies the plume must have transitioned from the subducting plate to the overriding plate. We present several 3D Underworld numerical models of plume heads of variable dimension and buoyancy interacting with a subduction trench. The models indicate that plume heads impact enormously on trench geometry. Arcuate trenches are created as the trench retreats around the edges of the plume head, whereas trench advance occurs in front of the plume resulting in transient crustal shortening in the overriding plate. Stalling of subduction when the plume head impacts the trench causes slab windowing. The size of the slab window is dependent on the size and buoyancy of the plume. The creation of the slab window provides a potential conduit for plume migration to the overriding plate. Alternatively, the plume head may be transferred to the overriding plate as subduction is re-established behind the plume. Models with "strong" slabs, characterized by high yield strengths, display different behavior. Plume-heads are entrained in the slab and are subducted without the development of a slab window.

  14. Ice hockey shoulder pad design and the effect on head response during shoulder-to-head impacts.

    Science.gov (United States)

    Richards, Darrin; Ivarsson, B Johan; Scher, Irving; Hoover, Ryan; Rodowicz, Kathleen; Cripton, Peter

    2016-11-01

    Ice hockey body checks involving direct shoulder-to-head contact frequently result in head injury. In the current study, we examined the effect of shoulder pad style on the likelihood of head injury from a shoulder-to-head check. Shoulder-to-head body checks were simulated by swinging a modified Hybrid-III anthropomorphic test device (ATD) with and without shoulder pads into a stationary Hybrid-III ATD at 21 km/h. Tests were conducted with three different styles of shoulder pads (traditional, integrated and tethered) and without shoulder pads for the purpose of control. Head response kinematics for the stationary ATD were measured. Compared to the case of no shoulder pads, the three different pad styles significantly (p shoulder pads reduced linear head accelerations by an additional 18-21% beyond the other two styles of shoulder pads. The data presented here suggest that shoulder pads can be designed to help protect the head of the struck player in a shoulder-to-head check.

  15. Abnormal white matter integrity related to head impact exposure in a season of high school varsity football.

    Science.gov (United States)

    Davenport, Elizabeth M; Whitlow, Christopher T; Urban, Jillian E; Espeland, Mark A; Jung, Youngkyoo; Rosenbaum, Daryl A; Gioia, Gerard A; Powers, Alexander K; Stitzel, Joel D; Maldjian, Joseph A

    2014-10-01

    The aim of this study was to determine whether the cumulative effects of head impacts from a season of high school football produce magnetic resonance imaging (MRI) measureable changes in the brain in the absence of clinically diagnosed concussion. Players from a local high school football team were instrumented with the Head Impact Telemetry System (HITS™) during all practices and games. All players received pre- and postseason MRI, including diffusion tensor imaging (DTI). Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) was also conducted. Total impacts and risk-weighted cumulative exposure (RWE), including linear (RWELinear), rotational (RWERotational), and combined components (RWECP), were computed from the sensor data. Fractional, linear, planar, and spherical anisotropies (FA, CL, CP, and CS, respectively), as well as mean diffusivity (MD), were used to determine total number of abnormal white matter voxels defined as 2 standard deviations above or below the group mean. Delta (post-preseason) ImPACT scores for each individual were computed and compared to the DTI measures using Spearman's rank correlation coefficient. None of the players analyzed experienced clinical concussion (N=24). Regression analysis revealed a statistically significant linear relationship between RWECP and FA. Secondary analyses demonstrated additional statistically significant linear associations between RWE (RWECP and RWELinear) and all DTI measures. There was also a strong correlation between DTI measures and change in Verbal Memory subscore of the ImPACT. We demonstrate that a single season of football can produce brain MRI changes in the absence of clinical concussion. Similar brain MRI changes have been previously associated with mild traumatic brain injury.

  16. The impact of gravity during head-up tilt

    DEFF Research Database (Denmark)

    Olufsen, Mette; Smith, Brittany; Mehlsen, Jesper

    2011-01-01

    The impact of gravity during head-up tilt, a test often used in the clinic to diagnose patients who suffer from dizziness or frequent episodes of syncope, is not well described. This study uses mathematical modeling to analyze experimental blood pressure data measured at the level of the aorta...

  17. Neck forces and moments and head accelerations in side impact

    NARCIS (Netherlands)

    Yoganandan, N.; Pintar, F.A.; Maiman, D.J.; Philippens, M.M.G.M.; Wismans, J.S.H.M.

    2009-01-01

    Objectives: Although side-impact sled studies have investigated chest, abdomen, and pelvic injury mechanics, determination of head accelerations and the associated neck forces and moments is very limited. The purpose of the present study was therefore to determine the temporal forces and moments at

  18. Atlas injury mechanisms during head-first impact.

    Science.gov (United States)

    Ivancic, Paul C

    2012-05-20

    An in vitro biomechanical study. To investigate atlas injury mechanisms due to horizontally aligned head-first impacts of a cadaveric neck model and to document atlas fracture patterns and associated injuries. Experimental atlas injuries have been created by applying compression or radial forces to isolated C1 vertebrae, dropping weight or applying sagittal moments to the upper cervical spine segments, or vertical drop testing of head-neck specimens or whole cadavers. Atlas injuries that commonly occur due to horizontally aligned head-first impacts have not been previously investigated. Horizontally aligned head-first impacts into a padded barrier were simulated at 4.1 m/s, using a human cadaver neck model mounted horizontally to a torso-equivalent mass on a sled and carrying a surrogate head. Atlantal radial force was computed using head and neck load cell data. Postimpact dissection documented atlas and associated injuries. Average atlantal radial force peaks and their occurrence times were statistically compared (P Atlas injuries consisted of either 3- or 4-part burst fractures or incomplete lateral mass fracture unilaterally. Associated injuries included bony avulsion of the transverse ligament unilaterally and fractures of the occipital condyles, superior facets of the axis, or odontoid. The results indicated that the varied atlas fracture patterns were due primarily to radial forces causing outward lateral expansion of its lateral masses. Anterior and posterior arch fracture locations are dependent, in part, upon the cross-sectional arch dimensions. Transverse ligament rupture or bony avulsion is likely associated with real-life atlantal burst fractures.

  19. Multiscale Analysis of Head Impacts in Contact Sports

    Science.gov (United States)

    Guttag, Mark; Sett, Subham; Franck, Jennifer; McNamara, Kyle; Bar-Kochba, Eyal; Crisco, Joseph; Blume, Janet; Franck, Christian

    2012-02-01

    Traumatic brain injury (TBI) is one of the world's major causes of death and disability. To aid companies in designing safer and improved protective gear and to aid the medical community in producing improved quantitative TBI diagnosis and assessment tools, a multiscale finite element model of the human brain, head and neck is being developed. Recorded impact data from football and hockey helmets instrumented with accelerometers are compared to simulated impact data in the laboratory. Using data from these carefully constructed laboratory experiments, we can quantify impact location, magnitude, and linear and angular accelerations of the head. The resultant forces and accelerations are applied to a fully meshed head-form created from MRI data by Simpleware. With appropriate material properties for each region of the head-form, the Abaqus finite element model can determine the stresses, strains, and deformations in the brain. Simultaneously, an in-vitro cellular TBI criterion is being developed to be incorporated into Abaqus models for the brain. The cell-based injury criterion functions the same way that damage criteria for metals and other materials are used to predict failure in structural materials.

  20. Epidemiology and Impact of Knee Injuries in Major and Minor League Baseball Players.

    Science.gov (United States)

    Dahm, Diane L; Curriero, Frank C; Camp, Christopher L; Brophy, Robert H; Leo, Tony; Meister, Keith; Paletta, George A; Steubs, John A; Mandelbaum, Bert R; Pollack, Keshia M

    2016-01-01

    Few studies have explored the frequency and impact of lower extremity injuries, such as those to the knee, among professional baseball players. The purpose of this study was to detail the epidemiology of knee injuries in Major League Baseball (MLB) and Minor League Baseball (MiLB) players during the 2011-2014 seasons. It was hypothesized that knee injuries are a common occurrence in these athletes, and represent a significant source of time away from play. The MLB Health and Injury Tracking System database was searched to identify all patients diagnosed with knee injuries during the 2011-2014 seasons. All injuries that occurred during the preseason, regular season, and postseason that resulted in time away from play were included. Injury data analyzed included total number of knee injuries, specific diagnoses, injury mechanisms, locations, player positions, and time lost. Descriptive statistics were conducted and injury rates per athlete-exposures were calculated. During the 2011-2014 seasons, a total of 2171 knee injuries occurred in MLB and MiLB players, representing 6.5% of all injuries in professional baseball. The knee injury rate across both the MLB and MiLB was 1.2 per 1000 athlete-exposures. The mean number of days missed per injury across both leagues was 16.2 with a total of 30,449 days of missed play amongst all athletes over the 4 seasons. Injuries to the knee were the fifth most common cause of missed time in all of baseball, and the fourth most common reason for missed games in the MLB alone. Approximately 12% of all injuries required surgical intervention. The most common mechanism of injury was noncontact (44%), and base runners were injured more frequently than any other position (24%). The infield (30%) and home plate (23%) were the most common locations in which injuries occurred. These data can be utilized for targeted injury prevention initiatives.

  1. The impact of neuromuscular electrical stimulation on recovery after intensive, muscle damaging, maximal speed training in professional team sports players.

    Science.gov (United States)

    Taylor, Tom; West, Daniel J; Howatson, Glyn; Jones, Chris; Bracken, Richard M; Love, Thomas D; Cook, Christian J; Swift, Eamon; Baker, Julien S; Kilduff, Liam P

    2015-05-01

    During congested fixture periods in team sports, limited recovery time and increased travel hinder the implementation of many recovery strategies; thus alternative methods are required. We examined the impact of a neuromuscular electrical stimulation device on 24-h recovery from an intensive training session in professional players. Twenty-eight professional rugby and football academy players completed this randomised and counter-balanced study, on 2 occasions, separated by 7 days. After baseline perceived soreness, blood (lactate and creatine kinase) and saliva (testosterone and cortisol) samples were collected, players completed a standardised warm-up and baseline countermovement jumps (jump height). Players then completed 60 m × 50 m maximal sprints, with 5 min recovery between efforts. After completing the sprint session, players wore a neuromuscular electrical stimulation device or remained in normal attire (CON) for 8 h. All measures were repeated immediately, 2 and 24-h post-sprint. Player jump height was reduced from baseline at all time points under both conditions; however, at 24-h neuromuscular electrical stimulation was significantly more recovered (mean±SD; neuromuscular electrical stimulation -3.2±3.2 vs. CON -7.2±3.7%; P0.05). Neuromuscular electrical stimulation improves recovery from intensive training in professional team sports players. This strategy offers an easily applied recovery strategy which may have particular application during sleep and travel. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. Finite element modelling of helmeted head impact under frontal loading

    Indian Academy of Sciences (India)

    Praveen Kumar Pinnoji; Puneet Mahajan

    2007-08-01

    Finite element models of the head and helmet were used to study contact forces during frontal impact of the head with a rigid surface. The finite element model of the head consists of skin, skull, cerebro-spinal fluid (CSF), brain, tentorium and falx. The finite element model of the helmet consists of shell and foam liner. The foam is taken as elasto-plastic, the brain is assumed to be viscoelastic and all other components are taken as elastic. The contact forces and coup pressures with helmet on the head are much lower than in the absence of the helmet. A parametric study was performed to investigate the effect of liner thickness and density on the contact forces, pressures and energy absorption during impact. For 4 ms-1 velocity, expanded poly styrene (EPS) foam of density 24 kg m-3 gave the lowest contact forces and for the velocities considered, thickness of the foam did not affect the contact forces.

  3. Does soccer ball heading cause retinal bleeding?

    Science.gov (United States)

    Reed, William F; Feldman, Kenneth W; Weiss, Avery H; Tencer, Alan F

    2002-04-01

    To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage. Regional Children's Hospital, youth soccer camp. Male and female soccer players, 13 to 16 years old, who regularly head soccer balls. Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball. Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7 +/- 1.3g. Rotational accelerations were negligible. Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.

  4. Impact force and time analysis influenced by execution distance in a roundhouse kick to the head in taekwondo.

    Science.gov (United States)

    Estevan, Isaac; Alvarez, Octavio; Falco, Coral; Molina-García, Javier; Castillo, Isabel

    2011-10-01

    The execution distance is a tactic factor that affects mechanical performance and execution technique in taekwondo. This study analyzes the roundhouse kick to the head by comparing the maximum impact force, execution time, and impact time in 3 distances according to the athletes' competition level. It also analyzes the relationship between impact force and weight in each group. It examines whether the execution distance affects the maximum impact force, execution time, and impact time, in each level group or 2 different competition levels. Participants were 27 male taekwondo players (13 medallists and 14 nonmedallists). The medallists executed the roundhouse kick to the head with greater impact force and in a shorter execution time than did the nonmedallists when they kicked from any distance different to their combat distance. However, the results showed that the execution distance is influential in the execution time and impact time in the nonmedallist group. It is considered appropriate to orientate the high-level competitors to train for offensive actions from any distance similar to the long execution distance because it offers equally effectiveness and a greater security against the opponent. Also, practitioners should focus their training to improve time performance because it is more affected by distance than impact force.

  5. Bicycle helmets are highly effective at preventing head injury during head impact: head-form accelerations and injury criteria for helmeted and unhelmeted impacts.

    Science.gov (United States)

    Cripton, Peter A; Dressler, Daniel M; Stuart, Cameron A; Dennison, Christopher R; Richards, Darrin

    2014-09-01

    Cycling is a popular form of recreation and method of commuting with clear health benefits. However, cycling is not without risk. In Canada, cycling injuries are more common than in any other summer sport; and according to the US National Highway and Traffic Safety Administration, 52,000 cyclists were injured in the US in 2010. Head injuries account for approximately two-thirds of hospital admissions and three-quarters of fatal injuries among injured cyclists. In many jurisdictions and across all age levels, helmets have been adopted to mitigate risk of serious head injuries among cyclists and the majority of epidemiological literature suggests that helmets effectively reduce risk of injury. Critics have raised questions over the actual efficacy of helmets by pointing to weaknesses in existing helmet epidemiology including selection bias and lack of appropriate control for the type of impact sustained by the cyclist and the severity of the head impact. These criticisms demonstrate the difficulty in conducting epidemiology studies that will be regarded as definitive and the need for complementary biomechanical studies where confounding factors can be adequately controlled. In the bicycle helmet context, there is a paucity of biomechanical data comparing helmeted to unhelmeted head impacts and, to our knowledge, there is no data of this type available with contemporary helmets. In this research, our objective was to perform biomechanical testing of paired helmeted and unhelmeted head impacts using a validated anthropomorphic test headform and a range of drop heights between 0.5m and 3.0m, while measuring headform acceleration and Head Injury Criterion (HIC). In the 2m (6.3m/s) drops, the middle of our drop height range, the helmet reduced peak accelerations from 824g (unhelmeted) to 181g (helmeted) and HIC was reduced from 9667 (unhelmeted) to 1250 (helmeted). At realistic impact speeds of 5.4m/s (1.5m drop) and 6.3m/s (2.0m drop), bicycle helmets changed the

  6. Neck strength imbalance correlates with increased head acceleration in soccer heading.

    Science.gov (United States)

    Dezman, Zachary D W; Ledet, Eric H; Kerr, Hamish A

    2013-07-01

    Soccer heading is using the head to directly contact the ball, often to advance the ball down the field or score. It is a skill fundamental to the game, yet it has come under scrutiny. Repeated subclinical effects of heading may compound over time, resulting in neurologic deficits. Greater head accelerations are linked to brain injury. Developing an understanding of how the neck muscles help stabilize and reduce head acceleration during impact may help prevent brain injury. Neck strength imbalance correlates to increasing head acceleration during impact while heading a soccer ball. Observational laboratory investigation. Sixteen Division I and II collegiate soccer players headed a ball in a controlled indoor laboratory setting while player motions were recorded by a 14-camera Vicon MX motion capture system. Neck flexor and extensor strength of each player was measured using a spring-type clinical dynamometer. Players were served soccer balls by hand at a mean velocity of 4.29 m/s (±0.74 m/s). Players returned the ball to the server using a heading maneuver at a mean velocity of 5.48 m/s (±1.18 m/s). Mean neck strength difference was positively correlated with angular head acceleration (rho = 0.497; P = 0.05), with a trend toward significance for linear head acceleration (rho = 0.485; P = 0.057). This study suggests that symmetrical strength in neck flexors and extensors reduces head acceleration experienced during low-velocity heading in experienced collegiate players. Balanced neck strength may reduce head acceleration cumulative subclinical injury. Since neck strength is a measureable and amenable strength training intervention, this may represent a modifiable intrinsic risk factor for injury.

  7. Quantification of Accelerometer Derived Impacts Associated With Competitive Games in National Collegiate Athletic Association Division I College Football Players.

    Science.gov (United States)

    Wellman, Aaron D; Coad, Sam C; Goulet, Grant C; McLellan, Christopher P

    2017-02-01

    Wellman, AD, Coad, SC, Goulet, GC, and McLellan, CP. Quantification of accelerometer derived impacts associated with competitive games in National Collegiate Athletic Association division I college football players. J Strength Cond Res 31(2): 330-338, 2017-The aims of the present study were to (a) examine positional impact profiles of National Collegiate Athletic Association (NCAA) division I college football players using global positioning system (GPS) and integrated accelerometry (IA) technology and (b) determine if positional differences in impact profiles during competition exist within offensive and defensive teams. Thirty-three NCAA division I Football Bowl Subdivision players were monitored using GPS and IA (GPSports) during 12 regular season games throughout the 2014 season. Individual player data sets (n = 294) were divided into offensive and defensive teams, and positional subgroups. The intensity, number, and distribution of impact forces experienced by players during competition were recorded. Positional differences were found for the distribution of impacts within offensive and defensive teams. Wide receivers sustained more very light and light to moderate (5-6.5 G force) impacts than other position groups, whereas the running backs were involved in more severe (>10 G force) impacts than all offensive position groups, with the exception of the quarterbacks (p ≤ 0.05). The defensive back and linebacker groups were subject to more very light (5.0-6.0 G force) impacts, and the defensive tackle group sustained more heavy and very heavy (7.1-10 G force) impacts than other defensive positions (p ≤ 0.05). Data from the present study provide novel quantification of positional impact profiles related to the physical demands of college football games and highlight the need for position-specific monitoring and training in the preparation for the impact loads experienced during NCAA division I football competition.

  8. Impact of an Interdisciplinary Food, Nutrition and Health Education Program for adolescent Brazilian volleyball players

    Directory of Open Access Journals (Sweden)

    Natália Vilela Silva DANIEL

    Full Text Available ABSTRACT Objective: To evaluate the impact of an Interdisciplinary Food, Nutrition and Health Education Program on nutrition knowledge, intention to change eating behavior, and body dissatisfaction of adolescent volleyball players. Methods: The sample consisted of 10 female volleyball players from the juvenile category of the city of Santos, São Paulo, Brazil, who participated in a program with eight monthly meetings (one discussion group followed by six educational activities and one final discussion group for evaluation. Results: Nutrition knowledge, body perception, intention to change eating behavior, eating attitudes and practices were investigated using questionnaires and discussion groups before and after the athletes' participation in ludic activities designed to address nutrition strategies for athletic performance and healthy eating, and how to deal with pressure for results and self-image. Nutrition knowledge improved from 57.0%±9.9 to 63.0%±11.8 (p=0.03 of correct answers. The mean body distortion score did not change (70.0±14.9 versus 76.5±22.4, p=0.235. Six athletes advanced in their intention to change eating behavior. Positive food practices were reported during the program and the identified discourses indicated the intention of changing the daily eating habits in the future. Conclusion: The program had a positive impact on nutrition knowledge and intention of changing eating behavior; however, for other issues, especially involving emotional aspects, further interventions should be planned.

  9. Head injuries, heading, and the use of headgear in soccer.

    Science.gov (United States)

    Niedfeldt, Mark W

    2011-01-01

    Soccer has more than 265 million players around the world and is the only contact sport with purposeful use of the head for controlling and advancing the ball. Head contact in soccer has the potential to cause acute traumatic brain injury including concussion or, potentially, a pattern of chronic brain injury. Although early retrospective research on the effects of soccer heading seemed to suggest that purposeful heading may contribute to long-term cognitive impairment, prospective controlled studies do not support this and, in fact, suggest that purposeful heading may not be a risk factor for cognitive impairment. Headgear has not been shown to be effective in reducing ball impact but may be helpful in reducing the force of non-ball-related impacts to the head. There are concerns that universal use of headgear may cause more aggressive heading and head challenges, leading to increased risk of injury.

  10. Impact of Body Composition and Vo2 Max on the Competitive Success in Top-Level Handball Players.

    Science.gov (United States)

    Ilic, Vladimir; Ranisavljev, Igor; Stefanovic, Dorde; Ivanovic, Vuk; Mrdakovic, Vladimir

    2015-09-01

    The purpose of the study was to determine the morphological and functional characteristics of 32 Serbian national U20 handball players (age 20.43 +/- 1.16 y; training experience 8.12 +/- 1.89 y) before European championship in Switzerland (2006) and to determinate their impact on competitive performance and outstanding success achieved. The results show that wing players differ from other players in morphological characteristics. Values for body height, weight, BMI, muscle mass and fat mass were significantly lower compared to the other playing positions. Extremely low values of maximal oxygen uptake (VO2 max) were measured in all players (ranged from 2.68 to 4.66 l x min(-1)). Pivots had the highest VO2 max in absolute values (3.76 l x min(-1)), and wing players in relative terms (40.83 ml x kg(-1) x min(-1)). Handball is characterized by high intensity intermittent play, followed by a number of walking breaks and quick substitutions. This makes possible to retain high playing intensity during whole match, because players can be given rest periods whenever needed. This will result in a high intensity game that does not necessarily require high VO2 max. Competitive success in modern top-level handball might be more reliant on optimal tactical preparation than on the body composition and VO2 max of an individual athlete.

  11. In Vivo Evaluation of Wearable Head Impact Sensors.

    Science.gov (United States)

    Wu, Lyndia C; Nangia, Vaibhav; Bui, Kevin; Hammoor, Bradley; Kurt, Mehmet; Hernandez, Fidel; Kuo, Calvin; Camarillo, David B

    2016-04-01

    Inertial sensors are commonly used to measure human head motion. Some sensors have been tested with dummy or cadaver experiments with mixed results, and methods to evaluate sensors in vivo are lacking. Here we present an in vivo method using high speed video to test teeth-mounted (mouthguard), soft tissue-mounted (skin patch), and headgear-mounted (skull cap) sensors during 6-13 g sagittal soccer head impacts. Sensor coupling to the skull was quantified by displacement from an ear-canal reference. Mouthguard displacements were within video measurement error (sensor error, we found that in-plane skin patch linear acceleration in the anterior-posterior direction could be modeled by an underdamped viscoelastic system. In summary, the mouthguard showed tighter skull coupling than the other sensor mounting approaches. Furthermore, the in vivo methods presented are valuable for investigating skull acceleration sensor technologies.

  12. A Modified Hybrid III 6-Year-Old Dummy Head Model for Lateral Impact Assessment

    Directory of Open Access Journals (Sweden)

    I. A. Rafukka

    2016-01-01

    Full Text Available Hybrid III six-year-old (6YO child dummy head model was developed and validated for frontal impact assessment according to the specifications contained in Code of Federal Regulations, Title 49, Part 572.122, Subpart N by Livermore Software Technology Corporation (LSTC. This work is aimed at improving biofidelity of the head for frontal impact and also extending its application to lateral impact assessment by modifying the head skin viscoelastic properties and validating the head response using the scaled nine-year-old (9YO child cadaver head response recently published in the literature. The modified head model was validated for two drop heights for frontal, right, and left parietal impact locations. Peak resultant acceleration of the modified head model appeared to have good correlation with scaled 9YO child cadaver head response for frontal impact on dropping from 302 mm height and fair correlation with 12.3% difference for 151 mm drop height. Right parietal peak resultant acceleration values correlate well with scaled 9YO head experimental data for 153 mm drop height, while fair correlation with 16.4% difference was noticed for 302 mm drop height. Left parietal, however, shows low biofidelity for the two drop heights as the difference in head acceleration response was within 30%. The modified head model could therefore be used to estimate injuries in vehicle crash for head parietal impact locations which cannot be measured by the current hybrid III dummy head model.

  13. The impact of gravity during head-up tilt

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, Mette; Smith, Brittany

    The impact of gravity during head-up tilt, a test often used in the clinic to diagnose patients who suffer from dizziness or frequent episodes of syncope, is not well described. This study uses mathematical modeling to analyze experimental blood pressure data measured at the level of the aorta...... a model predicting hydrostatic height between the two locations. Results from this model were compared with measurements. Furthermore, we show, using a differential equations model predicting blood pressure, that it is possible to predict blood pressure measured at the level of the carotid sinuses using...

  14. A Review of Instrumented Equipment to Investigate Head Impacts in Sport

    Directory of Open Access Journals (Sweden)

    Declan A. Patton

    2016-01-01

    Full Text Available Contact, collision, and combat sports have more head impacts as compared to noncontact sports; therefore, such sports are uniquely suited to the investigation of head impact biomechanics. Recent advances in technology have enabled the development of instrumented equipment, which can estimate the head impact kinematics of human subjects in vivo. Literature pertaining to head impact measurement devices was reviewed and usage, in terms of validation and field studies, of such devices was discussed. Over the past decade, instrumented equipment has recorded millions of impacts in the laboratory, on the field, in the ring, and on the ice. Instrumented equipment is not without limitations; however, in vivo head impact data is crucial to investigate head injury mechanisms and further the understanding of concussion.

  15. External foam layers to football helmets reduce head impact severity.

    Science.gov (United States)

    Nakatsuka, Austin S; Yamamoto, Loren G

    2014-08-01

    Current American football helmet design has a rigid exterior with a padded interior. Softening the hard external layer of the helmet may reduce the impact potential of the helmet, providing extra head protection and reducing its use as an offensive device. The objective of this study is to measure the impact reduction potential provided by external foam. We obtained a football helmet with built-in accelerometer-based sensors, placed it on a boxing mannequin and struck it with a weighted swinging pendulum helmet to mimic the forces sustained during a helmet-to-helmet strike. We then applied layers of 1.3 cm thick polyolefin foam to the exterior surface of the helmets and repeated the process. All impact severity measures were significantly reduced with the application of the external foam. These results support the hypothesis that adding a soft exterior layer reduces the force of impact which may be applicable to the football field. Redesigning football helmets could reduce the injury potential of the sport.

  16. Interior Head Impact Protective Components and Materials for Use in US Army Vehicles

    Science.gov (United States)

    2015-08-01

    project is to reduce potential head impact related mounted crew injuries and deaths which may occur during underbody blast, crash and rollover events...effort identified solutions which may potentially meet the needs of the Army to reduce head impact related injuries which may occur during crash ...effort centers on reducing potential head impact related injuries and deaths of mounted crew which may occur during blast, crash and rollover events

  17. Comparison of Indiana High School Football Injury Rates by Inclusion of the USA Football “Heads Up Football” Player Safety Coach

    Science.gov (United States)

    Kerr, Zachary Y.; Dalton, Sara L.; Roos, Karen G.; Djoko, Aristarque; Phelps, Jennifer; Dompier, Thomas P.

    2016-01-01

    Background: In Indiana, high school football coaches are required to complete a coaching education course with material related to concussion awareness, equipment fitting, heat emergency preparedness, and proper technique. Some high schools have also opted to implement a player safety coach (PSC). The PSC, an integral component of USA Football’s Heads Up Football (HUF) program, is a coach whose primary responsibility is to ensure that other coaches are implementing proper tackling and blocking techniques alongside other components of the HUF program. Purpose: To compare injury rates in Indiana high school football teams by their usage of a PSC or online coaching education only. Study Design: Cohort study; Level of evidence, 2. Methods: Athletic trainers (ATs) evaluated and tracked injuries at each practice and game during the 2015 high school football season. Players were drawn from 6 teams in Indiana. The PSC group, which used the PSC component, was comprised of 204 players from 3 teams. The “education only” group (EDU), which utilized coaching education only, was composed of 186 players from 3 teams. Injury rates and injury rate ratios (IRRs) were reported with 95% confidence intervals (CIs). Results: During 25,938 athlete-exposures (AEs), a total of 149 injuries were reported, of which 54 (36.2%) and 95 (63.8%) originated from the PSC and EDU groups, respectively. The practice injury rate was lower in the PSC group than the EDU group (2.99 vs 4.83/1000 AEs; IRR, 0.62; 95% CI, 0.40-0.95). The game injury rate was also lower in the PSC group than the EDU group (11.37 vs 26.37/1000 AEs; IRR, 0.43; 95% CI, 0.25-0.74). When restricted to concussions only, the rate was lower in the PSC group (0.09 vs 0.73/1000 AEs; IRR, 0.12; 95% CI, 0.01-0.94), although only 1 concussion was reported in the PSC group. No differences were found in game concussion rates (0.60 vs 4.39/1000 AEs; IRR, 0.14; 95% CI, 0.02-1.11). Conclusion: Findings support the PSC as an effective

  18. METHOD OF MODEL ANALYSIS FOR FLEXIBLE HEAD IMPACTING WITH ELASTIC PLANE

    Institute of Scientific and Technical Information of China (English)

    赵桂范; 谭惠丰; 杜星文

    2003-01-01

    To consider the head is a flexible multi-layer structure and the contact-impact is flexible, the Hertz Contact Law is unsuitable for analyzing the dynamic response of human head impacts elastic plane with initial speed. In this paper, the process of head impacting with elastic plane is modeled as a response of vibrant system, and methods like mechanical network figure and mechanical impedance is taken to resolve this dynamic response problem. Based on the actual head structure, head is modeled as a vibrant model, which concludes the masses of scalp and bone in the impact area, the masses in the other part of the head and the brain, the stiffness of the head, and the damp coefficient of the scalp and brain. At the same time, the elastic plane is simplified as a vibrant model including mass, stiffness and damp. These two vibrant models are linked into one vibrant systematic model. In order to calculate the elastic deformation and the impact acceleration of the head, the models are transformed into mechanical girding figure at violent vibration point. The dynamic impact force of the system, the impact acceleration of the head, the elastic deformation of the plane and the fixed frequency of the system can be worked out by calculating the velocity impedance at the violent vibration point when the initial impact speed is known. The results fit the test data well, which proves that this method is available for the analysis of the dynamic response of the system under impact.

  19. Does Game Playing Experience Have an Impact on the Player-PNPC Relationship?

    Science.gov (United States)

    Daviault, Christine

    2012-01-01

    There are several types of characters in video games: the main protagonist/hero, the countless non-player characters (NPCs), and persistent non-player characters (PNPCs). While there is a substantial body of research about PNPCs from a game design point of view, they have been largely ignored by the academic community from a narrative perspective.…

  20. Evaluating the Impact of Player Experience in the Design of a Serious Game for Upper Extremity Stroke Rehabilitation.

    Science.gov (United States)

    Cordeiro d'Ornellas, Marcos; Cargnin, Diego João; Cervi Prado, Ana Lúcia

    2015-01-01

    Video games have become a major entertainment industry and one of the most popular leisure forms, ranging from laboratory experiments to a mainstream cultural medium. Indeed, current games are multimodal and multidimensional products, relying on sophisticated features including not only a narrative-driven story but also impressive graphics and detailed settings. All of these elements helped to create a seamless and appealing product that have resulted in a growing number of players and in the number of game genres. Although video games have been used in education, simulation, and training, another application that exploits serious gaming is the exploration of player experience in the context of game research. Recent advances in the natural user interfaces and player experience have brought new perspectives on the in-game assessment of serious games. This paper evaluates the impact of player experience in the design of a serious game for upper extremity stroke rehabilitation. The game combines biofeedback and mirror neurons both in single and multiplayer mode. Results have shown that the game is a feasible solution to integrate serious games into the physical therapy routine.

  1. Head Start Impact on Social-Emotional Outcomes for Children with Disabilities

    Science.gov (United States)

    Lee, Kyunghee; Calkins, Andrea; Shin, Tae Seob

    2016-01-01

    Objective: Using the Head Start Impact Study data, this study examines Head Start's impacts on social-emotional outcomes for children with disabilities. Method: Among 4,442 children, 570 children were reported to have disabilities. Ordinary least squares regression was used to determine whether the number of disabilities, having an individualized…

  2. Effects of Soccer Heading on Brain Structure and Function.

    Science.gov (United States)

    Rodrigues, Ana Carolina; Lasmar, Rodrigo Pace; Caramelli, Paulo

    2016-01-01

    Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered as an offensive or defensive move whereby the player's unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of 6-12 incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years, some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the establishment of safety

  3. Biofidelic neck influences head kinematics of parietal and occipital impacts following short falls in infants.

    Science.gov (United States)

    Sullivan, Sarah; Coats, Brittany; Margulies, Susan S

    2015-09-01

    Falls are a major cause of traumatic head injury in children. Understanding head kinematics during low height falls is essential for evaluating injury risk and designing mitigating strategies. Typically, these measurements are made with commercial anthropomorphic infant surrogates, but these surrogates are designed based on adult biomechanical data. In this study, we improve upon the state-of-the-art anthropomorphic testing devices by incorporating new infant cadaver neck bending and tensile data. We then measure head kinematics following head-first falls onto 4 impact surfaces from 3 fall heights with occipital and parietal head impact locations. The biofidelic skull compliance and neck properties of the improved infant surrogate significantly influenced the measured kinematic loads, decreasing the measured impact force and peak angular accelerations, lowering the expected injury risk. Occipital and parietal impacts exhibited distinct kinematic responses in primary head rotation direction and the magnitude of the rotational velocities and accelerations, with larger angular velocities as the head rebounded after occipital impacts. Further evaluations of injury risk due to short falls should take into account the impact surface and head impact location, in addition to the fall height.

  4. SUITABILITY OF FIFA'S "THE 11" TRAINING PROGRAMME FOR YOUNG FOOTBALL PLAYERS - IMPACT ON PHYSICAL PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Dejan Kuzmic

    2008-09-01

    Full Text Available There is a paucity of evidence regarding the use of injury prevention programmes for preadolescents participating in sport. "The 11" injury prevention programme was developed by FIFA's medical research centre (F-MARC to help reduce the risk of injury in football players aged 14 years and over. The aim of this study was to determine the suitability and effectiveness of "The 11" for younger football players. Twenty-four [12 experimental (EXP, 12 control (CON] young football players (age 10.4 ± 1.4 yr participated. The EXP group followed "The 11" training programme 5 days per week, for 6 weeks, completing all but one of the 10 exercises. Prior to, and after the intervention, both EXP and CON groups performed a battery of football-specific physical tests. Changes in performance scores within each group were compared using independent t-tests (p ? 0.05. Feedback was also gathered on the young players' perceptions of "The 11". No injuries occurred during the study in either group. Compliance to the intervention was 72%. Measures of leg power (3 step jump and counter-movement jump increased significantly (3.4 and 6.0% respectively, p < 0.05. Speed over 20 m improved by 2% (p < 0.05. Most players considered "The 11" beneficial but not enjoyable in the prescribed format. Given the observed improvements in the physical abilities and the perceived benefits of "The 11", it would appear that a modified version of the programme is appropriate and should be included in the training of young football players, for both physical development and potential injury prevention purposes, as well as to promote fair play. To further engage young football players in such a programme, some modification to "The 11" should be considered

  5. A head impact detection system using SVM classification and proximity sensing in an instrumented mouthguard.

    Science.gov (United States)

    Wu, Lyndia C; Zarnescu, Livia; Nangia, Vaibhav; Cam, Bruce; Camarillo, David B

    2014-11-01

    Injury from blunt head impacts causes acute neurological deficits and may lead to chronic neurodegeneration. A head impact detection device can serve both as a research tool for studying head injury mechanisms and a clinical tool for real-time trauma screening. The simplest approach is an acceleration thresholding algorithm, which may falsely detect high-acceleration spurious events such as manual manipulation of the device. We designed a head impact detection system that distinguishes head impacts from nonimpacts through two subsystems. First, we use infrared proximity sensing to determine if the mouthguard is worn on the teeth to filter out all off-teeth events. Second, on-teeth, nonimpact events are rejected using a support vector machine classifier trained on frequency domain features of linear acceleration and rotational velocity. The remaining events are classified as head impacts. In a controlled laboratory evaluation, the present system performed substantially better than a 10-g acceleration threshold in head impact detection (98% sensitivity, 99.99% specificity, 99% accuracy, and 99.98% precision, compared to 92% sensitivity, 58% specificity, 65% accuracy, and 37% precision). Once adapted for field deployment by training and validation with field data, this system has the potential to effectively detect head trauma in sports, military service, and other high-risk activities.

  6. The Impact of the FIFA 11+ Training Program on Injury Prevention in Football Players: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Noël C. Barengo

    2014-11-01

    Full Text Available The FIFA 11+ is a simple, and easy to implement, sports injury prevention program comprising a warm up of 10 conditioning exercises. The aim of this systematic review was to evaluate the impact of the FIFA 11+ on injury incidence, compliance and cost effectiveness when implemented among football players. MEDLINE, EMBASE and Scopus databases were searched using the search terms “FIFA 11+”, “football”, “soccer”, “injury prevention”, and “The 11”. The titles and abstracts were screened by two independent reviewers and the data were filtered by one reviewer using a standardized extraction form and thereafter checked by another one. The risk of bias and the methodological quality of the studies were evaluated through the PEDro score and Critical Appraisal Skills Programme (CASP. A total of 911 studies were identified, of which 12 met the inclusion criteria of the review. The FIFA 11+ has demonstrated how a simple exercise program completed as part of warm-up can decrease the incidence of injuries in amateur football players. In general, considerable reductions in the number of injured players, ranging between 30% and 70%, have been observed among the teams that implemented the FIFA 11+. In addition, players with high compliance to the FIFA 11+ program had an estimated risk reduction of all injuries by 35% and show significant improvements in components of neuromuscular and motor performance when participating in structured warm-up sessions at least 1.5 times/week. Most studies had high methodological quality and a low risk of bias. Given the large number of people who play football at amateur level and the detrimental impact of sports injuries on a personal and societal level, the FIFA 11+ can be considered as a fundamental tool to minimize the risks of participation in a sport with substantial health benefits.

  7. Kinetic factors of vertical jumping for heading a ball in flexible flatfooted amateur soccer players with and without insole adoption.

    Science.gov (United States)

    Arastoo, Ali Asghar; Aghdam, Esmaeil Moharrami; Habibi, Abdoul Hamid; Zahednejad, Shahla

    2014-06-01

    According to literature, little is known regarding the effects of orthotic management of flatfoot on kinetics of vertical jump. To compare the kinetic and temporal events of two-legged vertical jumping take-off from a force plate for heading a ball in normal and flexible flatfoot subjects with and without insole. A functional based interventional controlled study. Random sampling method was employed to draw a control group of 15 normal foot subjects to a group of 15 flatfoot subjects. A force platform was used to record kinetics of two-legged vertical jump shots. Results indicate that insole did not lead to a significant effect on kinetics regarding anterior-posterior and mediolateral directions (p > 0.05). Results of kinetics related to vertical direction for maximum force due to take-off and stance duration revealed significant differences between the normal and flexible flatfoot subjects without insole (p 0.05). These results suggest that the use of an insole in the flexible flatfoot subjects led to improved stance time and decrease of magnitude of kinetics regarding vertical direction at take-off as the main feature of two-legged vertical jumping function. Adoption of the insole improved the design of the shoe-foot interface support for the flexible flatfoot athletes, enabling them to develop more effective take-off kinetics for vertical jumping in terms of ground reaction force and stance duration similar to that of normal foot subjects without insole. © The International Society for Prosthetics and Orthotics 2013.

  8. Optimal Impact Isolation for Injury Prevention Evaluated by the Head Injury Criterion

    Directory of Open Access Journals (Sweden)

    D.V. Balandin

    2007-01-01

    Full Text Available The optimal control of the deceleration of a particle moving along a straight line after an impact against an isolated surface is considered. The force applied to the particle by the surface is treated as the control variable. The deceleration distance is minimized subject to a constraint on the Head Injury Criterion functional. This functional is an integral criterion that is utilized in engineering biomechanics to evaluate the expected severity of impact-induced head injury of a human being. The solution obtained provides characteristics of the limiting capabilities for the prevention of head injuries by means of an impact isolator, such as a coating of the surface against which the impacts occur. The head injuries can be due to impact occurrences, including traffic crashes, falling, and contacts with ballistic objects.

  9. The impact of gravity during head-up tilt

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Olufsen, Mette; Smith, Brittany

    and the carotid sinuses in a healthy volunteer. During head-up tilt the head is lifted above the heart stimulating gravitational pooling of blood in the lower extremities. This shift in volume is followed by an increase in blood pressure in the lower body, while the pressure in the head decreases, while...... a model predicting hydrostatic height between the two locations. Results from this model were compared with measurements. Furthermore, we show, using a differential equations model predicting blood pressure, that it is possible to predict blood pressure measured at the level of the carotid sinuses using...

  10. The Impact of 3 Different-Length Between-Matches Microcycles on Training Loads in Professional Rugby League Players.

    Science.gov (United States)

    Moreira, Alexandre; Kempton, Tom; Aoki, Marcelo Saldanha; Sirotic, Anita C; Coutts, Aaron J

    2015-09-01

    To examine the impact of varying between-matches microcycles on training characteristics (ie, intensity, duration, and load) in professional rugby league players and to report on match load related to these between-matches microcycles. Training-load data were collected during a 26-wk competition period of an entire season. Training load was measured using the session rating of perceived exertion (session-RPE) method for every training session and match from 44 professional rugby league players from the same National Rugby League team. Using the category-ratio 10 RPE scale, the training intensity was divided into 3 zones (low 7 AU). Three different-length between-matches recovery microcycles were used for analysis: 5-6 d, 7-8 d, and 9-10 d. A total of 3848 individual sessions were recorded. During the shorter-length between-matches microcycles (5-6 d), significantly lower training load was observed. No significant differences for subsequent match load or intensity were identified between the various match recovery periods. Overall, 16% of the training sessions were completed at the low-intensity zone, 61% at the moderate-intensity zone, and 23% at the high-intensity zone. The findings demonstrate that rugby league players undertake higher training load as the length of between-matches microcycles is increased. The majority of in-season training of professional rugby league players was at moderate intensity, and a polarized approach to training that has been reported in elite endurance athletes does not occur in professional rugby league.

  11. Effects of Soccer Heading on Brain Structure and Function

    OpenAIRE

    Rodrigues, Ana Carolina; Lasmar,Rodrigo Pace; Caramelli,Paulo

    2016-01-01

    Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered as an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of 6–12 incidents o...

  12. Effect of vehicle front end profiles leading to pedestrian secondary head impact to ground.

    Science.gov (United States)

    Gupta, Vishal; Yang, King H

    2013-11-01

    Most studies of pedestrian injuries focus on reducing traumatic injuries due to the primary impact between the vehicle and the pedestrian. However, based on the Pedestrian Crash Data Study (PCDS), some researchers concluded that one of the leading causes of head injury for pedestrian crashes can be attributed to the secondary impact, defined as the impact of the pedestrian with the ground after the primary impact of the pedestrian with the vehicle. The purpose of this study is to understand if different vehicle front-end profiles can affect the risk of pedestrian secondary head impact with the ground and thus help in reducing the risk of head injury during secondary head impact with ground. Pedestrian responses were studied using several front-end profiles based off a mid-size vehicle and a SUV that have been validated previously along with several MADYMO pedestrian models. Mesh morphing is used to explore changes to the bumper height, bonnet leading-edge height, and bonnet rear reference-line height. Simulations leading up to pedestrian secondary impact with ground are conducted at impact speeds of 40 and 30 km/h. In addition, three pedestrian sizes (50th, 5th and 6yr old child) are used to enable us to search for a front-end profile that performs well for multiple sizes of pedestrians, not just one particular size. In most of the simulations, secondary ground impact with pedestrian head/neck/shoulder region occurred. However, there were some front-end profiles that promoted secondary ground impact with pedestrian lower extremities, thus avoiding pedestrian secondary head impact with ground. Previous pedestrian safety research work has suggested the use of active safety methods, such as 'pop up hood', to reduce pedestrian head injury during primary impact. Accordingly, we also conducted simulations using a model with the hood raised to capture the effect of a pop-up hood. These simulations indicated that even though pop-up hood helped reducing the head injury

  13. Sex differences in head acceleration during heading while wearing soccer headgear.

    Science.gov (United States)

    Tierney, Ryan T; Higgins, Michael; Caswell, Shane V; Brady, Jessica; McHardy, Krista; Driban, Jeffrey B; Darvish, Kurosh

    2008-01-01

    Researchers have indicated that female soccer players may be at greater risk of concussion compared with their male counterparts. Soccer headgear is marketed for reducing head acceleration and risk of concussion. To determine the effect of sex and soccer headgear on head impact kinematics and dynamic stabilization during soccer heading. Cross-sectional design. Research laboratory. Forty-four college-aged soccer players (29 women, 15 men). Using a head impact model, participants performed 4 soccer headers under 3 headgear conditions (control, Head Blast Soccer Band, and Full90 Select Performance Headguard). Dependent variables assessed before soccer heading were head-neck anthropometrics and isometric neck muscle strength, and those assessed during soccer headers were resultant linear head acceleration, Head Injury Criteria (HIC(36)), and superficial neck muscle electromyography. Statistical analyses included multivariate and univariate analyses of variance with repeated measures, independent-samples t tests, appropriate follow-up analyses of variance and post hoc t tests, and Pearson product moment correlations (alpha = .05). Head acceleration in women was 32% and 44% greater than in men when wearing the Head Blast (21.5 g versus 16.3 g) and Full90 Select (21.8 g versus 15.2 g), respectively (P head accelerations (20.2 g versus 18.2 g) during the control condition (P = .164). Female soccer players exhibited greater head accelerations than their male counterparts when wearing headgear. Our results are important clinically because they indicate that soccer headgear may not be an appropriate head injury prevention tool for all athletes.

  14. Changes in Parents’ Spanking and Reading as Mechanisms for Head Start Impacts on Children

    OpenAIRE

    Gershoff, Elizabeth T.; Ansari, Arya; Purtell, Kelly M.; Sexton, Holly R.

    2015-01-01

    This study examined whether Head Start, the nation’s main two-generation program for low-income families, benefits children in part through positive changes in parents’ use of spanking and reading to children. Data were drawn from the 3-year-old cohort of the national evaluation of the Head Start program known as the Head Start Impact Study (N = 2,063). Results indicated that Head Start had small indirect effects on children’s spelling ability at age 4 and their aggression at age 4 through an...

  15. Biomechanical head impact characteristics during sparring practice sessions in high school taekwondo athletes.

    Science.gov (United States)

    O'Sullivan, David M; Fife, Gabriel P

    2017-06-01

    OBJECTIVE The purpose of this study was to monitor head impact magnitude and characteristics, such as impact location and frequency, at high school taekwondo sparring sessions. METHODS Eight male high school taekwondo athletes participated in this study. The head impact characteristics were recorded by X-Patch, a wireless accelerometer and gyroscope, during 6 taekwondo sparring sessions. The outcome measures were the peak linear acceleration ( g = 9.81 msec(2)), peak rotational acceleration, rotational velocity, and Head Injury Criterion. RESULTS A total of 689 impacts occurred over 6 sessions involving the 8 athletes. There was an average of 24 impacts per 100 minutes, and there were significant differences in the frequency of impacts among both the sessions and individual athletes. In order of frequency, the most commonly hit locations were the side (38.2%), back (35.7%), and front (23.8%) of the head. CONCLUSIONS The data indicate that there is a relatively high number of head impacts experienced by taekwondo athletes during sparring practice. According to the rotational acceleration predicting impact severity published in previous research, 17.1% of the impacts were deemed to be a moderate and 15.5% were deemed to be severe.

  16. Comparison of Ball-And-Racket Impact Force in Two-Handed Backhand Stroke Stances for Different-Skill-Level Tennis Players.

    Science.gov (United States)

    Lo, Kuo-Cheng; Hsieh, Yung-Chun

    2016-06-01

    This study compared the kinetic roles of the upper extremities in racket impact force generation between the open stance (OS) and square stance (SS) for tennis players with different skill levels in two-handed backhand strokes. Twelve male tennis players were divided into an advanced group (AG) (L3-L2 skill level) and intermediate group (IG) (L7-L6 skill level), and their data were used in a three-dimensional kinetic analysis. Their motions were captured using 21 reflective markers attached to anatomic landmarks for two-handed backhand stroke motion data collection. During the acceleration phase, significant differences were not observed between both stances, but they were observed between the groups with different skill levels for the force of the upper extremities (p = 0.027). The joint forces were significantly lower in the AG than in the IG. Players performing the SS had significantly larger pronation and supination of the wrist joint moment than those in the OS (p = 0.032) during the acceleration phase, irrespective of the playing level. Higher internal rotation moment after impact was observed at each joint, particularly among young intermediate tennis players, regardless of their stance. The AG demonstrated a higher joint force and moment at every joint compared with the IG at impact. Moreover, the AG demonstrated superior stroke efficiency and effectively reduced joint moment after impact and sports injury. Key pointsAdvanced players, regardless of open stance or square stance, have larger joint force and moment at each joint before ball impact resulting in better stroke efficiency and reduced chance of injury.Intermediate players, regardless of stance, have higher internal rotation moment at each joint instead of larger joint force as compared to advanced players before ball impact. The higher internal rotation moment will induce higher joint impact force which makes the player injury-prone.Young intermediate tennis players may want to avoid excessive

  17. The relationship between biomechanical-anthropometrical parameters and the force exerted on the head when heading free kicks in soccer.

    Science.gov (United States)

    Teymouri, Meghdad; Sadeghi, Heydar; Nabaei, Amir; Kasaeian, Amir

    2012-01-01

    Soccer is a contact sport in which the players are frequently faced with the risk of injury. It has been shown that the force exerted on the head during heading can be as much as 500-1200 Newton (N). The main objective of this study was to determine whether there was any relationship between the force exerted on the head and several biomechanical and anthropometrical parameters related to heading free kicks. A total of 16 semi-professional soccer players with at least 5 years experience participated in this study. The mean age, height, and weight of the study participants were 21.36 ± 5.67, 178 ± 5.99 cm, and 70.55 ± 8.55 kg, respectively. To measure the force exerted on the heads of the players, a pressure gauge was installed on their foreheads. Each participant was asked to defend the ball using the heading technique three times. A camera with a sampling frequency of 150 frames per second was used to record the moment of impact between the ball and head during each heading event. For each participant and replicate, the ball and head velocity (m/s) as well as the angular body changes (degrees) were calculated using MATLAB and AutoCAD softwares, respectively. Descriptive statistics, including means and standard deviations were used to describe the data. Pearson correlation coefficient (alpha = 0.05) was used to examine potential relationships between the variables of interest. Significant correlations existed between the force exerted on the head during heading, participant age, body mass, body fat percentage, and head perimeter (P heading, such as age and head perimeter. Therefore, it was concluded that these variables should be considered when teaching and practicing the heading technique with players of different ages and anthropometric sizes.

  18. Impact of Psychological Variables on Playing Ability of University Level Soccer Players

    Directory of Open Access Journals (Sweden)

    Ertan Tufekcioglu

    2014-10-01

    Full Text Available The purpose of the study was to find out the relationship between psychological variables and soccer playing ability among the university level male players. 42 soccer players representing different universities who participated in inter university competitions were selected as the subjects of the study. The dependent variable was soccer playing ability and independent variables were the selected psychological variables. Soccer playing ability was determined through a 10 point scale at the time of competitions. Psychological variables included achievement motivation, anxiety, self-concept and aggression. The data was statistically analyzed using Karl Pearson’s correlation coefficient and multiple regression analysis using SPSS. It was concluded that soccer playing ability has a positive correlation with achievement motivation and self-concept whereas anxiety and aggression have a negative correlation with soccer playing ability.

  19. Effects of soccer heading on brain structure and function

    Directory of Open Access Journals (Sweden)

    Ana Carolina Oliveira Rodrigues

    2016-03-01

    Full Text Available Soccer is the most popular sport in the world, with more than 265 million players worldwide, including professional and amateur ones. Soccer is unique in comparison to other sports, as it is the only sport in which participants purposely use their head to hit the ball. Heading is considered an offensive or defensive move whereby the player’s unprotected head is used to deliberately impact the ball and direct it during play. A soccer player can be subjected to an average of six to twelve incidents of heading the ball per competitive game, where the ball reaches high velocities. Moreover, in practice sessions, heading training, which involves heading the ball repeatedly at low velocities, is common. Although the scientific community, as well as the media, has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The purpose of this study is to review the existing literature regarding the effects of soccer heading on brain structure and function. Only in the last years some investigations have addressed the impact of heading on brain structure, by using neuroimaging techniques. Similarly, there have been some recent studies investigating biochemical markers of brain injury in soccer players. There is evidence of association between heading and abnormal brain structure, but the data are still preliminary. Also, some studies have suggested that subconcussive head impacts, as heading, could cause cognitive impairment, whereas others have not corroborated this finding. Questions persist as to whether or not heading is deleterious to cognitive functioning. Further studies, especially with longitudinal designs, are needed to clarify the clinical significance of heading as a cause of brain injury and to identify risk factors. Such investigations might contribute to the

  20. Impact of a Soccer Game on Cardiac Biomarkers in Adolescent Players.

    Science.gov (United States)

    Hosseini, Seyed Mohsen; Azizi, Mojtaba; Samadi, Ali; Talebi, Nahid; Gatterer, Hannes; Burtscher, Martin

    2017-09-22

    Biochemical markers such as cardiac troponin I (cTnI) and N-terminal pro B-type natriuretic peptide (NT-proBNP) have become indispensable tools for the diagnosis of myocardial injury, providing highly sensitive and specific information about cardiac cell damage and wall stress. The purpose of the present research was to examine the response of cardiac biomarkers to a soccer game in adolescent male soccer players. Twenty-two trained adolescent male soccer players (14-16 y) were selected in a purposive manner. Blood samples were taken before, immediately after, and 2 and 24 hours after the game for the determination of cTnI and NT-proBNP. Serum concentration of cTnI and NT-proBNP increased immediately and 2 hours after the soccer game (P game in adolescent male players. The postgame elevation of cardiac biomarkers and their rapid recovery are indicative of a physiological rather than a pathological response.

  1. Clinical Risk Factors for Head Impact During Falls in Older Adults: A Prospective Cohort Study in Long-Term Care.

    Science.gov (United States)

    Yang, Yijian; Mackey, Dawn C; Liu-Ambrose, Teresa; Leung, Pet-Ming; Feldman, Fabio; Robinovitch, Stephen N

    To examine risk factors associated with head impact during falls in older adults in long-term care (LTC). Two LTC facilities in British Columbia, Canada. 160 LTC residents. Prospective cohort study. Between 2007 and 2014, we video captured 520 falls experienced by participants. Each fall video was analyzed to determine whether impact occurred to the head. Using generalized estimating equation models, we examined how head impact was associated with other fall characteristics and health status prior to the fall. Head impact occurred in 33% of falls. Individuals with mild cognitive impairment were at higher risk for head impact (odds ratio = 2.8; 95% confidence interval, 1.5-5.0) than those with more severe cognitive impairment. Impaired vision was associated with 2.0-fold (1.3-3.0) higher odds of head impact. Women were 2.2 times (1.4-3.3) more likely than men to impact their head during a fall. Head impact is common during falls in LTC, with less cognitively impaired, female residents who suffered from visual impairment, being most likely to impact their head. Future research should focus on improving our ability to detect neural consequences of head impact and evaluating the effect of interventions for reducing the risk for fall-related head injuries in LTC.

  2. On Impact: A Case of a Student with Head Injuries

    Science.gov (United States)

    Buckley, Valerie A.; Chesire, David J.; Canto, Angela I.

    2011-01-01

    This article describes a case of a student with head injuries. While the symptom presentation for students with traumatic brain injury (TBI) can be vastly different, this case represents common symptoms seen in students who are recovering from a concussion. The authors suggest that school psychologists query the teacher and parents about their…

  3. On Impact: A Case of a Student with Head Injuries

    Science.gov (United States)

    Buckley, Valerie A.; Chesire, David J.; Canto, Angela I.

    2011-01-01

    This article describes a case of a student with head injuries. While the symptom presentation for students with traumatic brain injury (TBI) can be vastly different, this case represents common symptoms seen in students who are recovering from a concussion. The authors suggest that school psychologists query the teacher and parents about their…

  4. Measurement of Head Impact Due to Standing Fall in Adults Using Anthropomorphic Test Dummies.

    Science.gov (United States)

    Hajiaghamemar, Marzieh; Seidi, Morteza; Ferguson, James R; Caccese, Vincent

    2015-09-01

    The kinematics and kinetics of head impact due to a standing fall onto a hard surface are summarized. Head injury due to impact from falls represents a significant problem, especially for older individuals. When the head is left unprotected during a fall, the impact severity can be high enough to cause significant injury or even death. To ascertain the range of head impact parameters, the dynamic response was captured for the pedestrian version of the 5th percentile female and 50th percentile male Hybrid III anthropomorphic test dummies as they were dropped from a standing position with different initial postures. Five scenarios of falls were considered including backward falls with/without hip flexion, forward falls with/without knee flexion and lateral falls. The results show that the head impact parameters are dependent on the fall scenario. A wide range of impact parameters was observed in 107 trials. The 95% prediction interval for the peak translational acceleration, peak angular acceleration, peak force, impact translational velocity and peak angular velocity are 146-502 g, 8.8-43.3 krad/s(2), 3.9-24.5 kN, 2.02-7.41 m/s, and 12.9-70.3 rad/s, respectively.

  5. Vertical and Horizontal Impact Force Comparison During Jump Landings With and Without Rotation in NCAA Division I Male Soccer Players.

    Science.gov (United States)

    Harry, John R; Barker, Leland A; Mercer, John A; Dufek, Janet S

    2017-07-01

    Harry, JR, Barker, LA, Mercer, JA, and Dufek, JS. Vertical and horizontal impact force comparison during jump landings with and without rotation in NCAA Division I male soccer players. J Strength Cond Res 31(7): 1780-1786, 2017-There is a wealth of research on impact force characteristics when landing from a jump. However, there are no data on impact forces during landing from a jump with an airborne rotation about the vertical axis. We examined impact force parameters in the vertical and horizontal axes during vertical jump (VJ) landings and VJ landings with a 180° rotation (VJR). Twenty-four Division I male soccer players performed 3 VJ and VJR landings on a dual-force platform system. Paired-samples t-tests (α = 0.05) compared differences in the first (F1) and second (F2) peak vertical ground reaction forces, times to F1 (tF1), F2 (tF2), and the end of the impact phase, vertical impulse, and anterior-posterior and medial-lateral force couples. Effect sizes (ES; large >0.8) were computed to determine the magnitude of the differences. Lower jump height (41.60 ± 4.03 cm, VJ landings; 39.40 ± 4.05 cm, VJR landings; p = 0.002; ES = 0.39), greater F2 (55.71 ± 11.95 N·kg, VJ; 68.16 ± 14.82 N·kg; p < 0.001; ES = 0.94), faster tF2 (0.057 ± 0.012 seconds, VJ; 0.047 ± 0.011 seconds, VJR; p = 0.001; ES = 0.89), greater anterior-posterior (0.06 ± 0.03 N·s·kg, VJ; 0.56 ± 0.15 N·s·kg, VJR; p < 0.001; ES = 1.83) and medial-lateral force couples (0.29 ± 0.11 N·s·kg, VJ; 0.56 ± 0.14 N·s·kg, VJR; p < 0.001; ES = 1.46) occurred during VJR landings. No other differences were identified. This kinetic analysis determined that landing from a jump with 180° airborne rotation is different than landing from a jump without an airborne rotation. Male Division I soccer players could benefit from increasing the volume of VJR landings during training to address the differences in jump height and force parameters compared with VJ landings.

  6. Does aquatic foraging impact head shape evolution in snakes?

    Science.gov (United States)

    Segall, Marion; Cornette, Raphaël; Fabre, Anne-Claire; Godoy-Diana, Ramiro; Herrel, Anthony

    2016-08-31

    Evolutionary trajectories are often biased by developmental and historical factors. However, environmental factors can also impose constraints on the evolutionary trajectories of organisms leading to convergence of morphology in similar ecological contexts. The physical properties of water impose strong constraints on aquatic feeding animals by generating pressure waves that can alert prey and potentially push them away from the mouth. These hydrodynamic constraints have resulted in the independent evolution of suction feeding in most groups of secondarily aquatic tetrapods. Despite the fact that snakes cannot use suction, they have invaded the aquatic milieu many times independently. Here, we test whether the aquatic environment has constrained head shape evolution in snakes and whether shape converges on that predicted by biomechanical models. To do so, we used three-dimensional geometric morphometrics and comparative, phylogenetically informed analyses on a large sample of aquatic snake species. Our results show that aquatic snakes partially conform to our predictions and have a narrower anterior part of the head and dorsally positioned eyes and nostrils. This morphology is observed, irrespective of the phylogenetic relationships among species, suggesting that the aquatic environment does indeed drive the evolution of head shape in snakes, thus biasing the evolutionary trajectory of this group of animals.

  7. The impact of a sports vision training program in youth field hockey players.

    Science.gov (United States)

    Schwab, Sebastian; Memmert, Daniel

    2012-01-01

    The aim of this study was to investigate whether a sports vision training program improves the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training. The choice reaction time task at the D2 board (Learning Task I), the functional field of view task (Learning Task II) and the multiple object tracking (MOT) task (Transfer Task) were assessed before and after the intervention and again six weeks after the second test. Analyzes showed significant differences between the two groups for the choice reaction time task at the D2 board and the functional field of view task, with significant improvements for the intervention group and none for the control group. For the transfer task, we could not find statistically significant improvements for either group. The results of this study are discussed in terms of theoretical and practical implications. Key pointsPerceptual training with youth field hockey playersCan a sports vision training program improve the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training?The intervention was performed in the "VisuLab" as DynamicEye(®) SportsVision Training at the German Sport University Cologne.We ran a series of 3 two-factor univariate analysis of variance (ANOVA) with repeated measures on both within subject independent variables (group; measuring point) to examine the effects on central perception, peripheral perception and choice reaction time.The present study shows an improvement of certain visual abilities with the help of the sports vision training program.

  8. Changes in parents' spanking and reading as mechanisms for Head Start impacts on children.

    Science.gov (United States)

    Gershoff, Elizabeth T; Ansari, Arya; Purtell, Kelly M; Sexton, Holly R

    2016-06-01

    This study examined whether Head Start, the nation's main two-generation program for low-income families, benefits children in part through positive changes in parents' use of spanking and reading to children. Data were drawn from the 3-year-old cohort of the national evaluation of the Head Start program known as the Head Start Impact Study (N = 2,063). Results indicated that Head Start had small, indirect effects on children's spelling ability at Age 4 and their aggression at Age 4 through an increase in parents' reading to their children. Taken together, the results suggest that parents play a role in sustaining positive benefits of the Head Start program for children's behavior and literacy skills, one that could be enhanced with a greater emphasis on parent involvement and education. (PsycINFO Database Record

  9. Head linear and rotational accelerations and craniocervical loads in lateral impact

    NARCIS (Netherlands)

    Yoganandan, N.; Pintar, F.A.; Maiman, D.; Phillippens, M.M.G.M.; Wismans, J.S.H.M.

    2006-01-01

    The objective of the study was to determine lateral impact-induced three-dimensional temporal head center of gravity linear and angular accelerations, and craniocervical forces and moments from post mortem human subject (PMHS) sled tests and compare with the European side impact dummy, ES-II, respon

  10. Selecting team players: Considering the impact of contextual performance and workplace deviance on selection decisions in the National Football League.

    Science.gov (United States)

    Whiting, Steven W; Maynes, Timothy D

    2016-04-01

    Contextual performance and workplace deviance likely influence team functioning and effectiveness and should therefore be considered when evaluating job candidates for team-based roles. However, obtaining this information is difficult given a lack of reliable sources and the desire of job applicants to present themselves in a favorable light. Thus, it is unknown whether those selecting employees for teams incorporate prior contextual performance and workplace deviance into their evaluations, or whether doing so improves the quality of selection decisions. To address these issues, we examined the impact of prior task performance, contextual performance, and workplace deviance on National Football League (NFL) decision maker (organizational insider) and external expert (organizational outsider) evaluations of college football players in the NFL draft, using a content analysis methodology to generate measures of contextual performance and workplace deviance. Our findings indicate that insiders value contextual performance more than outsiders, which is likely because of differing interests and goals that lead to different levels of motivation and/or ability to acquire information about prior contextual performance. We also propose that prior task performance, contextual performance, and workplace deviance will predict player performance in the NFL. Our results support this prediction for task and contextual performance. In addition, we investigated the quality of insider and outsider judgments using Brunswik's (1952) lens model. Implications of our findings for the team selection, contextual performance, and workplace deviance literatures are discussed. (c) 2016 APA, all rights reserved).

  11. Minor head trauma in soccer and serum levels of S100B.

    Science.gov (United States)

    Straume-Naesheim, Truls Martin; Andersen, Thor Einar; Jochum, Marianne; Dvorak, Jiri; Bahr, Roald

    2008-06-01

    To compare the serum levels of S100B after head trauma with the effect of heading, high-intensity exercise, and playing in a league match. Heading and head trauma in soccer have been suspected to cause brain impairment. The protein S100B is a marker of acute neuronal tissue damage. Baseline S100B was measured in 535 Norwegian professional soccer players. Two hundred twenty-eight head impacts were registered from 352 league matches. Three teams (n = 48) performed a high-intensity exercise session without heading and a low-intensity session with heading exercises. A blood sample was drawn from each participant within 1 hour (B1) after the session, and another sample (B12) was drawn after a match or training session. The players were assigned to four groups: Head Impact (n = 65), Match Control (match participants without head impact, n = 49), High-intensity Exercise (n = 35), and Heading (n = 36). Serum S100B increased from baseline to B1 for all groups. The increase for the match groups (Head Impact and Match Control) was significantly higher than for both training groups. However, no significant differences between the Head Impact and Match Control groups or between the two training groups were found. A total of 39 players (33.9%) had elevated B1 values (>/=0.12 ng/ml) after a match, but these findings were equally distributed between the Match Control and Head Impact groups. Both soccer training and soccer matches cause a transient increase in S100B. There is a possible additive effect of activity with high intensity and heading, but minor head impacts do not seem to cause an additional increase.

  12. Neuropsychological consequence of soccer play in adolescent U.K. School team soccer players.

    Science.gov (United States)

    Stephens, Richard; Rutherford, Andrew; Potter, Douglas; Fernie, Gordon

    2010-01-01

    To assess mild head injury effects in adolescent soccer players, neuropsychological performance across school team soccer players, rugby players and noncontact sport players was assessed in a quasi-experimental cross-sectional design. One hundred eighty-five males were tested (ages 13-16; response rate 55%) and 86 contributed data to the analyses after exclusion for recent concussion and overlapping sports participation. Soccer players showed lower premorbid intellectual functioning, but neither soccer players nor rugby players showed neuropsychological decrement compared with noncontact sport players. Cumulative heading did not predict neuropsychological performance. While no specific attribute of soccer was linked with neuropsychological impairment, head injury predicted reduced attention for all participants.

  13. Quantifying Variation in Head Start Effects on Young Children's Cognitive and Socio-Emotional Skills Using Data from the National Head Start Impact Study

    Science.gov (United States)

    Bloom, Howard S.; Weiland, Christina

    2015-01-01

    This paper uses data from the Head Start Impact Study (HSIS), a nationally representative multisite randomized trial, to quantify variation in effects of Head Start during 2002-2003 on children's cognitive and socio-emotional outcomes relative to the effects of other local alternatives, including parent care. We find that (1) treatment and control…

  14. Scaling head-neck response data and derivation of 5th percentile female side-impact dummy head-neck response requirements in NBDL test conditions

    NARCIS (Netherlands)

    Meijer, R.; Wisgerhof, R.P.; Wismans, J.S.H.M.; Been, B.W.

    2009-01-01

    The head-neck biofidelity of side-impact dummies can be assessed according to the response requirements for the head-neck system based on mid-size male human subjects as published in ISO TR9790. These criteria are largely based on volunteer tests performed at the Naval Biodynamics Laboratory (NBDL)

  15. Scaling head-neck response data and derivation of 5th percentile female side-impact dummy head-neck response requirements in NBDL test conditions

    NARCIS (Netherlands)

    Meijer, R.; Wisgerhof, R.P.; Wismans, J.S.H.M.; Been, B.W.

    2009-01-01

    The head-neck biofidelity of side-impact dummies can be assessed according to the response requirements for the head-neck system based on mid-size male human subjects as published in ISO TR9790. These criteria are largely based on volunteer tests performed at the Naval Biodynamics Laboratory (NBDL)

  16. Evaluation of military helmets and roof padding on head injury potential from vertical impacts.

    Science.gov (United States)

    Franklyn, Melanie; Laing, Sheridan

    2016-10-02

    Soldiers in military vehicles subjected to underbelly blasts can sustain traumatic head and neck injuries due to a head impact with the roof. The severity of head and neck trauma can be influenced by the amount of head clearance available to the occupant as well as factors such as wearing a military helmet or the presence of padding on the interior roof. The aim of the current study was to examine the interaction between a Hybrid III headform, the helmet system, and the interior roof of the vehicle under vertical loading. Using a head impact machine and a Hybrid III headform, tests were conducted on a rigid steel plate in a number of different configurations and velocities to assess helmet shell and padding performance, to evaluate different vehicle roof padding materials, and to determine the relative injury mitigating contributions of both the helmet and the roof padding. The resultant translational head acceleration was measured and the head injury criterion (HIC) was calculated for each impact. For impacts with a helmeted headform hitting the steel plate only, which represented a common scenario in an underbelly blast event, velocities of ≤6 m/s resulted in HIC values below the FMVSS 201U threshold of 1,000, and a velocity of 7 m/s resulted in HIC values well over the threshold. Roof padding was found to reduce the peak translational head acceleration and the HIC, with rigid IMPAXX foams performing better than semirigid ethylene vinyl acetate (EVA) foam. However, the head injury potential was reduced considerably more by wearing a helmet than by the addition of roof padding. The results of this study provide initial quantitative findings that provide a better understanding of helmet-roof interactions in vertical impacts and the contributions of the military helmet and roof padding to mitigating head injury potential. Findings from this study will be used to inform further testing with the future aim of developing a new minimum head clearance standard for

  17. Long-Term Cognitive and Neuropsychiatric Consequences of Repetitive Concussion and Head-Impact Exposure.

    Science.gov (United States)

    McAllister, Thomas; McCrea, Michael

    2017-03-01

    Initially, interest in sport-related concussion arose from the premise that the study of athletes engaged in sports associated with high rates of concussion could provide insight into the mechanisms, phenomenology, and recovery from mild traumatic brain injury. Over the last decade, concerns have focused on the possibility that, for some athletes, repetitive concussions may raise the long-term risk for cognitive decline, neurobehavioral changes, and neurodegenerative disease. First conceptualized as a discrete event with variable recovery trajectories, concussion is now viewed by some as a trigger of neurobiological events that may influence neurobehavioral function over the course of the life span. Furthermore, advances in technology now permit us to gain a detailed understanding of the frequency and intensity of repetitive head impacts associated with contact sports (eg, football, ice hockey). Helmet-based sensors can be used to characterize the kinematic features of concussive impacts, as well as the profiles of typical head-impact exposures experienced by athletes in routine sport participation. Many large-magnitude impacts are not associated with diagnosed concussions, whereas many diagnosed concussions are associated with more modest impacts. Therefore, a full understanding of this topic requires attention to not only the effects of repetitive concussions but also overall exposure to repetitive head impacts. This article is a review of the current state of the science on the long-term neurocognitive and neurobehavioral effects of repetitive concussion and head-impact exposure in contact sports.

  18. Effect of clenching with a mouthguard on head acceleration during heading of a soccer ball.

    Science.gov (United States)

    Narimatsu, Keishiro; Takeda, Tomotaka; Nakajima, Kazunori; Konno, Michiyo; Ozawa, Takamitsu; Ishigami, Keiichi

    2015-01-01

    Concussions are acceleration-deceleration injuries that occur when biomechanical forces are transmitted to the cerebral tissues. By limiting acceleration of the head, enhanced cervical muscle activity derived from clenching with a mouthguard (MG) may reduce the incidence or severity of concussions following impact. The purpose of this study was to investigate the effect of voluntary clenching with a proper MG on acceleration of the head during "heading" of a soccer ball. Eleven male high school soccer players (mean age, 16.8 years) participated in the study. Each player was given a customized MG. An automated soccer machine was used to project the ball at the participants at a constant speed. The participants headed the ball under 3 different oral conditions: drill 1, heading freely performed without instruction and without the MG; drill 2, heading performed as the subject was instructed to clench the masseter muscles tightly while not wearing the MG; drill 3, heading performed as the subject was instructed to clench tightly while wearing the MG. Each participant repeated each drill 5 times. Linear acceleration of the head was measured with a 3-axis accelerometer. Activity of the masseter and sternocleidomastoid muscles was measured by wireless electromyography. Weak masseter and sternocleidomastoid muscle activity was observed during drill 1. After the soccer players had been instructed to clench their masseter muscles (drills 2 and 3), statistically significant decreases in head acceleration and increases in masseter and sternocleidomastoid muscle activity were observed (P soccer players to habitually clench while wearing a proper mouthguard to strengthen cervical muscle resistance as a way to mitigate the damage caused by heading.

  19. Concussion in professional football: comparison with boxing head impacts--part 10.

    Science.gov (United States)

    Viano, David C; Casson, Ira R; Pellman, Elliot J; Bir, Cynthia A; Zhang, Liying; Sherman, Donald C; Boitano, Marilyn A

    2005-12-01

    This study addresses impact biomechanics from boxing punches causing translational and rotational head acceleration. Olympic boxers threw four different punches at an instrumented Hybrid III dummy and responses were compared with laboratory-reconstructed NFL concussions. Eleven Olympic boxers weighing 51 to 130 kg (112-285 lb) delivered 78 blows to the head of the Hybrid III dummy, including hooks, uppercuts and straight punches to the forehead and jaw. Instrumentation included translational and rotational head acceleration and neck loads in the dummy. Biaxial acceleration was measured in the boxer's hand to determine punch force. High-speed video recorded each blow. Hybrid III head responses and finite element (FE) brain modeling were compared to similarly determined responses from reconstructed NFL concussions. The hook produced the highest change in hand velocity (11.0 +/- 3.4 m/s) and greatest punch force (4405 +/- 2318 N) with average neck load of 855 +/- 537 N. It caused head translational and rotational accelerations of 71.2 +/- 32.2 g and 9306 +/- 4485 r/s. These levels are consistent with those causing concussion in NFL impacts. However, the head injury criterion (HIC) for boxing punches was lower than for NFL concussions because of shorter duration acceleration. Boxers deliver punches with proportionately more rotational than translational acceleration than in football concussion. Boxing punches have a 65 mm effective radius from the head cg, which is almost double the 34 mm in football. A smaller radius in football prevents the helmets from sliding off each other in a tackle. Olympic boxers deliver punches with high impact velocity but lower HIC and translational acceleration than in football impacts because of a lower effective punch mass. They cause proportionately more rotational acceleration than in football. Modeling shows that the greatest strain is in the midbrain late in the exposure, after the primary impact acceleration in boxing and football.

  20. Concussion in professional football: biomechanics of the struck player--part 14.

    Science.gov (United States)

    Viano, David C; Casson, Ira R; Pellman, Elliot J

    2007-08-01

    Impacts causing concussion in professional football were simulated in laboratory tests to determine collision mechanics. This study focuses on the biomechanics of concussion in the struck player. Twenty-five helmet impacts were reconstructed using Hybrid III dummies. Head impact velocity, direction, and helmet kinematics-matched game video. Translational and rotational accelerations were measured in both players' heads; 6-axis upper neck responses were measured in all striking and five struck players. Head kinematics and biomechanics were determined for concussed players. Head displacement, rotation, and neck loads were determined because finite element analysis showed maximum strains occurring in the midbrain after the high impact forces. A model was developed of the helmet impact to study the influence of neck strength and other parameters on head responses. The impact response of the concussed player's head includes peak accelerations of 94 +/- 28 g and 6432 +/- 1813 r/s2, and velocity changes of 7.2 +/- 1.8 m/s and 34.8 +/- 15.2 r/s. Near the end of impact (10 ms), head movement is only 20.2 +/- 6.8 mm and 6.9 +/- 2.5 degrees. After impact, there is rapid head displacement involving a fourfold increase to 87.6 +/- 21.2 mm and 29.9 +/- 9.5 degrees with neck tension and bending at 20 ms. Impacts to the front of the helmet, the source of the majority of National Football League concussions, cause rotation primarily around the z axis (superior-inferior axis) because the force is forward of the neck centerline. This twists the head to the right or left an average of 17.6 +/- 12.7 degrees, causing a moment of 17.7 +/- 3.3 Nm and neck tension of 1704 +/- 432 N at 20 ms. The head injury criterion correlates with concussion risk and is proportional to deltaV(4)/d(1.5) for half-sine acceleration. Stronger necks reduce head acceleration, deltaV, and displacement. Even relatively small reductions in deltaV have a large effect on head injury criterion that may reduce

  1. Impact of targeting insulin-like growth factor signaling in head and neck cancers.

    Science.gov (United States)

    Limesand, Kirsten H; Chibly, Alejandro Martinez; Fribley, Andrew

    2013-10-01

    The IGF system has been shown to have either negative or negligible impact on clinical outcomes of tumor development depending on specific tumor sites or stages. This review focuses on the clinical impact of IGF signaling in head and neck cancer, the effects of IGF targeted therapies, and the multi-dimensional role of IRS 1/2 signaling as a potential mechanism in resistance to targeted therapies. Similar to other tumor sites, both negative and positive correlations between levels of IGF-1/IGF-1-R and clinical outcomes in head and neck cancer have been reported. In addition, utilization of IGF targeted therapies has not demonstrated significant clinical benefit; therefore the prognostic impact of the IGF system on head and neck cancer remains uncertain.

  2. THE IMPACT OF A SPORTS VISION TRAINING PROGRAM IN YOUTH FIELD HOCKEY PLAYERS

    Directory of Open Access Journals (Sweden)

    Sebastian Schwab

    2012-12-01

    Full Text Available The aim of this study was to investigate whether a sports vision training program improves the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training. The choice reaction time task at the D2 board (Learning Task I, the functional field of view task (Learning Task II and the multiple object tracking (MOT task (Transfer Task were assessed before and after the intervention and again six weeks after the second test. Analyzes showed significant differences between the two groups for the choice reaction time task at the D2 board and the functional field of view task, with significant improvements for the intervention group and none for the control group. For the transfer task, we could not find statistically significant improvements for either group. The results of this study are discussed in terms of theoretical and practical implications

  3. Post-heading heat stress and yield impact in winter wheat of China.

    Science.gov (United States)

    Liu, Bing; Liu, Leilei; Tian, Liying; Cao, Weixing; Zhu, Yan; Asseng, Senthold

    2014-02-01

    Wheat is sensitive to high temperatures, but the spatial and temporal variability of high temperature and its impact on yield are often not known. An analysis of historical climate and yield data was undertaken to characterize the spatial and temporal variability of heat stress between heading and maturity and its impact on wheat grain yield in China. Several heat stress indices were developed to quantify heat intensity, frequency, and duration between heading and maturity based on measured maximum temperature records of the last 50 years from 166 stations in the main wheat-growing region of China. Surprisingly, heat stress between heading and maturity was more severe in the generally cooler northern wheat-growing regions than the generally warmer southern regions of China, because of the delayed time of heading with low temperatures during the earlier growing season and the exposure of the post-heading phase into the warmer part of the year. Heat stress between heading and maturity has increased in the last decades in most of the main winter wheat production areas of China, but the rate was higher in the south than in the north. The correlation between measured grain yields and post-heading heat stress and average temperature were statistically significant in the entire wheat-producing region, and explained about 29% of the observed spatial and temporal yield variability. A heat stress index considering the duration and intensity of heat between heading and maturity was required to describe the correlation of heat stress and yield variability. Because heat stress is a major cause of yield loss and the number of heat events is projected to increase in the future, quantifying the future impact of heat stress on wheat production and developing appropriate adaptation and mitigation strategies are critical for developing food security policies in China and elsewhere.

  4. Comparison of Ball-And-Racket Impact Force in Two-Handed Backhand Stroke Stances for Different-Skill-Level Tennis Players

    Directory of Open Access Journals (Sweden)

    Kuo-Cheng Lo, Yung-Chun Hsieh

    2016-06-01

    Full Text Available This study compared the kinetic roles of the upper extremities in racket impact force generation between the open stance (OS and square stance (SS for tennis players with different skill levels in two-handed backhand strokes. Twelve male tennis players were divided into an advanced group (AG (L3-L2 skill level and intermediate group (IG (L7-L6 skill level, and their data were used in a three-dimensional kinetic analysis. Their motions were captured using 21 reflective markers attached to anatomic landmarks for two-handed backhand stroke motion data collection. During the acceleration phase, significant differences were not observed between both stances, but they were observed between the groups with different skill levels for the force of the upper extremities (p = 0.027. The joint forces were significantly lower in the AG than in the IG. Players performing the SS had significantly larger pronation and supination of the wrist joint moment than those in the OS (p = 0.032 during the acceleration phase, irrespective of the playing level. Higher internal rotation moment after impact was observed at each joint, particularly among young intermediate tennis players, regardless of their stance. The AG demonstrated a higher joint force and moment at every joint compared with the IG at impact. Moreover, the AG demonstrated superior stroke efficiency and effectively reduced joint moment after impact and sports injury.

  5. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  6. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  7. Atlantoaxial instability after a header in an amateur soccer player.

    Science.gov (United States)

    Werle, Stephan; Nahleh, Kais Abu; Boehm, Heinrich

    2015-03-01

    Case report and literature review. To report a unique case of atlantoaxial instability after a header in a 37-year-old amateur soccer player and to discuss the injury pattern in relation to the impact of heading. Although there is potential for cervical spine injuries, the rates in soccer are low compared with other contact or even noncontact sports. No cases of acute post-traumatic atlantoaxial instability after heading have ever been reported in a MEDLINE-listed article. A 37-year-old male soccer player experienced acute upper neck pain and transient quadriplegia after heading a long-distance ball on 2 occasions during a match. Imaging revealed atlantoaxial instability. Persistent neurological symptoms on conservative treatment led to his referral to our department. The considerable instability required surgical intervention. Transarticular C1-C2 fixation and posterior fusion with structural iliac crest grafting were performed. The procedure immediately led to complete relief of the neurological symptoms. After an uneventful postoperative recovery, follow-up at 9 months revealed solid fusion. The patient remained symptom free. Heading the ball in soccer can potentially lead to atlantoaxial instability. Ligamentous damage can theoretically be caused by anteriorly directed and rotational overload. However, the causative mechanism remains unclear. Diagnostic workup should consider dynamic imaging in players with transient neurological symptoms after minor trauma to the cervical spine. N/A.

  8. Cleveland Clinic intelligent mouthguard: a new technology to accurately measure head impact in athletes and soldiers

    Science.gov (United States)

    Bartsch, Adam; Samorezov, Sergey

    2013-05-01

    Nearly 2 million Traumatic Brain Injuries (TBI) occur in the U.S. each year, with societal costs approaching $60 billion. Including mild TBI and concussion, TBI's are prevalent in soldiers returning from Iraq and Afghanistan as well as in domestic athletes. Long-term risks of single and cumulative head impact dosage may present in the form of post traumatic stress disorder (PTSD), depression, suicide, Chronic Traumatic Encephalopathy (CTE), dementia, Alzheimer's and Parkinson's diseases. Quantifying head impact dosage and understanding associated risk factors for the development of long-term sequelae is critical toward developing guidelines for TBI exposure and post-exposure management. The current knowledge gap between head impact exposure and clinical outcomes limits the understanding of underlying TBI mechanisms, including effective treatment protocols and prevention methods for soldiers and athletes. In order to begin addressing this knowledge gap, Cleveland Clinic is developing the "Intelligent Mouthguard" head impact dosimeter. Current testing indicates the Intelligent Mouthguard can quantify linear acceleration with 3% error and angular acceleration with 17% error during impacts ranging from 10g to 174g and 850rad/s2 to 10000rad/s2, respectively. Correlation was high (R2 > 0.99, R2 = 0.98, respectively). Near-term development will be geared towards quantifying head impact dosages in vitro, longitudinally in athletes and to test new sensors for possible improved accuracy and reduced bias. Long-term, the IMG may be useful to soldiers to be paired with neurocognitive clinical data quantifying resultant TBI functional deficits.

  9. Impact of Terrorism on Managerial Efficiency of Heads of Secondary Schools in Khyber Pakhtunkhwa, Pakistan

    Science.gov (United States)

    Khattak, Usman Ghani; Iqba, Javed

    2015-01-01

    Terrorism has adversely affected the educational environment in Khyber Pakhtoon Khwa Province. This study was conducted to know the impact of Terrorism on managerial efficiency of heads of secondary schools in Khyber Pakhtoon Khwa that included Malakand, Mangawara, Dir, Hangu , Bannu and D I Khan which are the highly affected areas of terrorism.…

  10. Impact of Terrorism on Managerial Efficiency of Heads of Secondary Schools in Khyber Pakhtunkhwa, Pakistan

    Science.gov (United States)

    Khattak, Usman Ghani; Iqba, Javed

    2015-01-01

    Terrorism has adversely affected the educational environment in Khyber Pakhtoon Khwa Province. This study was conducted to know the impact of Terrorism on managerial efficiency of heads of secondary schools in Khyber Pakhtoon Khwa that included Malakand, Mangawara, Dir, Hangu , Bannu and D I Khan which are the highly affected areas of terrorism.…

  11. Underbody Blast Models of TBI Caused by Hyper-Acceleration and Secondary Head Impact

    Science.gov (United States)

    2016-02-01

    synaptophysin, and synaptophilin are three proteins crucial for maintaining functional synapses. Immunoblot measurements of these proteins revealed a...energy test- ing of small projectiles, ranging in shape and size, showed the steel sphere produced the highest impact energy and the most consistent...impact characteristics. Additional tests confirmed the steel sphere produced linear and rotational motions on the rat’s head while remaining within a

  12. A transient finite element study reveals the importance of the bycicle helmet material properties on head protection during an impact

    OpenAIRE

    Asiminei, Aida Georgeta; Van der Perre, Georges; Verpoest, Ignace; Goffin, Jan

    2009-01-01

    This paper is focused on understanding the mechanism that gives the bicycle helmet the role of protecting the head during an impact. The finite element method is used here as a first step in the helmet optimisation and improvement process. The relation between different helmet mechanical parameters and the risk of head injury during the impact is described using MSC Marc Mentat finite element software. The reduction in resulting head linear acceleration by more than 80% and in resulting stres...

  13. Real-time head acceleration measurement in girls' youth soccer.

    Science.gov (United States)

    Hanlon, Erin M; Bir, Cynthia A

    2012-06-01

    The purpose of the current study was to collect real-time head acceleration data for soccer impacts during girls' youth (U14) soccer play. Linear and angular head accelerations were collected during girls' youth soccer scrimmages using a wireless head acceleration measurement device (the Head Impact Telemetry System). After field data collection, each individual impact was analyzed. The type of impact, header or nonheader, was determined, and nonheader impacts were further assessed by the category of impact. The head injury criterion and resultant linear and angular accelerations were analyzed and compared with current injury tolerance values for all impacts. A total of 47 header and 20 nonheader impacts were observed during the study. The front of the head experienced more headers than the other locations (n = 17). Header impacts ranged in peak linear acceleration from 4.5 g to 62.9 g and in peak angular head acceleration from 444.8 to 8869.1 rad·s(-2). The majority of the nonheader impacts (40%) were player collisions with other players. Only one goalpost collision occurred, but it resulted in the highest peak angular acceleration (5179.5 rad·s(-2)) and was the only nonheader impact to exceed any of the tolerance levels. Head accelerations were found to exceed the majority of previous laboratory studies. None of the impacts exceeded linear acceleration tolerance values for concussion, but angular accelerations did exceed the suggested limits. Three angular acceleration measurements for heading events (4509.8, 5298.3, and 8869.1 rad·s(-2)) exceeded the concussion tolerance values, but no concussions were diagnosed during the study.

  14. No neurochemical evidence for brain injury caused by heading in soccer.

    Science.gov (United States)

    Zetterberg, Henrik; Jonsson, Michael; Rasulzada, Abdullah; Popa, Cornel; Styrud, Ewa; Hietala, Max Albert; Rosengren, Lars; Wallin, Anders; Blennow, Kaj

    2007-09-01

    The possible injurious effect to the brain of heading in soccer is a matter of discussion. To determine whether standardised headings in soccer are associated with increased levels of biochemical markers for neuronal injury in cerebrospinal fluid (CSF) and serum. 23 male amateur soccer players took part in a heading training session involving heading a ball kicked from a distance of 30 m at least 10 m forward. Ten players performed 10 and 13 players performed 20 approved headings. The players underwent lumbar puncture and serum sampling 7-10 days after the headings. The study also included 10 healthy male non-athletic control subjects. CSF was analysed for neurofilament light protein, total tau, glial fibrillary acidic protein, S-100B and albumin concentrations. Serum was analysed for S-100B and albumin. None of the biomarker levels were abnormal and there were no significant differences between any of the three groups, except for a slightly increased CSF S-100B concentration in controls compared with headers. Biomarker levels did not correlate with the number of headings performed. Repeated low-severity head impacts due to heading in soccer are not associated with any neurochemical signs of injury to the brain.

  15. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks

    Science.gov (United States)

    Kuriyama, Andrew M; Nakatsuka, Austin S

    2017-01-01

    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai‘i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play.

  16. Angular Impact Mitigation system for bicycle helmets to reduce head acceleration and risk of traumatic brain injury.

    Science.gov (United States)

    Hansen, Kirk; Dau, Nathan; Feist, Florian; Deck, Caroline; Willinger, Rémy; Madey, Steven M; Bottlang, Michael

    2013-10-01

    Angular acceleration of the head is a known cause of traumatic brain injury (TBI), but contemporary bicycle helmets lack dedicated mechanisms to mitigate angular acceleration. A novel Angular Impact Mitigation (AIM) system for bicycle helmets has been developed that employs an elastically suspended aluminum honeycomb liner to absorb linear acceleration in normal impacts as well as angular acceleration in oblique impacts. This study tested bicycle helmets with and without AIM technology to comparatively assess impact mitigation. Normal impact tests were performed to measure linear head acceleration. Oblique impact tests were performed to measure angular head acceleration and neck loading. Furthermore, acceleration histories of oblique impacts were analyzed in a computational head model to predict the resulting risk of TBI in the form of concussion and diffuse axonal injury (DAI). Compared to standard helmets, AIM helmets resulted in a 14% reduction in peak linear acceleration (pbicycle helmet, and may enhance prevention of bicycle-related TBI. Further research is required.

  17. Avaliação da retroversão da cabeça do úmero em jogadores de handebol Evaluation of humeral head retroversion in handball players

    Directory of Open Access Journals (Sweden)

    Joel Murachovsky

    2007-01-01

    Full Text Available OBJETIVOS: Avaliar a retroversão da cabeça do úmero em jogadores de handebol e sua relação com a movimentação do ombro. MATERIAIS E MÉTODOS: Foram avaliados 17 jogadores profissionais por meio de exame físico e avaliação radiográfica, para se determinar o ângulo de retroversão e, sua relação com o arco de movimento. O mesmo foi realizado num grupo controle. RESULTADOS: A diferença entre a média do ângulo de retroversão da cabeça do úmero do membro dominante e não dominante foi de 3,06°. Entre eles, aqueles que tiveram um início de treino antes dos 10 anos, apresentaram uma média desse ângulo de 36,29°, enquanto que aqueles que iniciaram acima dessa idade tinham uma média de 26,6° (pOBJECTIVES: To evaluate the humeral head retroversion of handball players and its relationship to shoulder's range of motion. MATERIALS AND METHODS: Seventeen professional players were evaluated by physical examination and X-ray images to determine the humeral head retroversion and its relationship to the range of motion. A control group was also submitted to the same evaluations. RESULTS: The difference between the average of the humeral head retroversion of the dominant and non dominant shoulders was 3.06°. The mean value for this angle between the athletes who had started training as early as 10 years old was 36.29°, compared to those who had started later in life, which was 26.6° (p<0.05. The average of the external rotation of the players whose retroversion angle was bigger than 30° was 112.27°, and for those whose angle was smaller or equal to 30°, it was 95.10° (p<0.05. CONCLUSION: There was a significant difference in the retroversion angle when comparing dominant and non-dominant shoulders. The athletes who started to play before the age of 10 presented, statistically, an increased retroversion. There is a statistical relationship between retroversion increase and shoulder's external rotation gain.

  18. Impact of Type 2 Diabetes Mellitus on Survival in Head and Neck Squamous Cell Carcinoma.

    Science.gov (United States)

    Foreman, Andrew; Lee, Daniel J; McMullen, Caitlin; de Almeida, John; Muhanna, Nidal; Gama, Ricardo Ribeiro; Giuliani, Meredith; Liu, Geoffrey; Bratman, Scott V; Huang, Shao Hui; O'Sullivan, Brian; Song, Yuyao; Xu, Wei; Goldstein, David P

    2017-08-01

    Objective To identify any association between type 2 diabetes mellitus (T2DM) and survival outcomes for mucosal squamous cell carcinoma of the head and neck. An association has been demonstrated between T2DM and cancer outcomes at numerous sites, but data for the head and neck are limited. Improving our understanding of the impact that diabetes has on head and neck cancer survival is relevant for making treatment decisions and counseling patients regarding prognosis. Study Design Retrospective cohort study. Setting Academic tertiary referral head and neck cancer center. Subjects and Methods By accessing data retrospectively from prospectively collected databases at the Princess Margaret Cancer Centre, patients were studied who were treated for mucosal head and neck squamous cell cancer between January 2005 and December 2011. Collection of clinical, pathologic, and survival data was completed with an emphasis on T2DM. Results Of 2498 patients identified in the study period, 319 (12.8%) had T2DM. Five-year overall survival was not different between the diabetic (64%, 95% CI = 58%-71%) and nondiabetic (67%, 95% CI = 65%-69%; P = .078) groups. Furthermore, cause-specific survival did not demonstrate a statistically significant difference between groups (diabetic: 84%, 95% CI = 79%-88%, vs nondiabetic: 84%, 95% CI = 82%-86%; P = .67). Conclusion Despite contradictory evidence at other cancer sites, the presence of T2DM alone does not appear to adversely affect cancer survival outcomes in head and neck squamous cell cancer. This is encouraging for the diabetic patients with head and neck squamous cell cancer, and it provides guidance for the multidisciplinary team that treats them.

  19. Simulative investigation on head injuries of electric self-balancing scooter riders subject to ground impact.

    Science.gov (United States)

    Xu, Jun; Shang, Shi; Qi, Hongsheng; Yu, Guizhen; Wang, Yunpeng; Chen, Peng

    2016-04-01

    The safety performance of an electric self-balancing scooter (ESS) has recently become a main concern in preventing its further wide application as a major candidate for green transportation. Scooter riders may suffer severe brain injuries in possible vehicle crash accidents not only from contact with a windshield or bonnet but also from secondary contact with the ground. In this paper, virtual vehicle-ESS crash scenarios combined with finite element (FE) car models and multi-body scooter/human models are set up. Post-impact kinematic gestures of scooter riders under various contact conditions, such as different vehicle impact speeds, ESS moving speeds, impact angles or positions, and different human sizes, are classified and analyzed. Furthermore, head-ground impact processes are reconstructed using validated FE head models, and important parameters of contusion and laceration (e.g., coup or contrecoup pressures and Von Mises stress and the maximum shear stress) are extracted and analyzed to assess the severity of regional contusion from head-ground contact. Results show that the brain injury risk increases with vehicle speeds and ESS moving speeds and may provide fundamental knowledge to popularize the use of a helmet and the vehicle-fitted safety systems, and lay a strong foundation for the reconstruction of ESS-involved accidents. There is scope to improve safety for the use of ESS in public roads according to the analysis and conclusions.

  20. Does soccer headgear attenuate the impact when heading a soccer ball?

    Science.gov (United States)

    Naunheim, Rosanne S; Ryden, Amanda; Standeven, John; Genin, Guy; Lewis, Larry; Thompson, Paul; Bayly, Phil

    2003-01-01

    There is increasing concern that repetitive blows to the head, such as those from heading a soccer ball, can cause measurable cognitive impairment. Reducing acceleration of impact could reduce neurologic sequelae. To measure the effectiveness of four different types of soccer headgear in reducing the acceleration of impact. A standard magnesium headform was instrumented with a triaxial accelerometer. A soccer ball was propelled at the headform at three different speeds known to occur in soccer play: 9, 12, and 15 m/sec (20, 26, and 34 mph). The main outcome was the peak acceleration of the headform associated with these impacts with and without protective headgear. Peak accelerations were found in a range from 144 m/s(2) to 289 m/s(2) (14.67-29.5 G, G = 9.81 m/s(2)). Using multivariate analysis of variance (MANOVA) methods to compare the headbands and controls, there was no significant difference in the measured accelerations at the center of gravity with or without headgear (p = 0.50). However, the interaction term of headbands, pressure, and speed was significant at F = 5.51 and p = 0.00001. Using contrasts within conditions, some headbands were found to cause a decrease in peak acceleration at the highest speed and pressure. Currently available headgear for soccer heading shows little ability to attenuate impact during simulated soccer heading. However, statistically significant decreases are present at the highest speeds and pressures tested, suggesting the headbands may play a role in decreasing impact for more forceful blows.

  1. Real-time, whole-brain, temporally resolved pressure responses in translational head impact.

    Science.gov (United States)

    Zhao, Wei; Ji, Songbai

    2016-02-01

    Theoretical debate still exists on the role of linear acceleration ( a lin) on the risk of brain injury. Recent injury metrics only consider head rotational acceleration ( a rot) but not a lin, despite that real-world on-field head impacts suggesting a lin significantly improves a concussion risk function. These controversial findings suggest a practical challenge in integrating theory and real-world experiment. Focusing on tissue-level mechanical responses estimated from finite-element (FE) models of the human head, rather than impact kinematics alone, may help address this debate. However, the substantial computational cost incurred (runtime and hardware) poses a significant barrier for their practical use. In this study, we established a real-time technique to estimate whole-brain a lin-induced pressures. Three hydrostatic atlas pressures corresponding to translational impacts (referred to as 'brain print') along the three major axes were pre-computed. For an arbitrary a lin profile at any instance in time, the atlas pressures were linearly scaled and then superimposed to estimate whole-brain responses. Using 12 publically available, independently measured or reconstructed real-world a lin profiles representative of a range of impact/injury scenarios, the technique was successfully validated (except for one case with an extremely short impulse of approx. 1 ms). The computational cost to estimate whole-brain pressure responses for an entire a lin profile was less than 0.1 s on a laptop versus typically hours on a high-end multicore computer. These findings suggest the potential of the simple, yet effective technique to enable future studies to focus on tissue-level brain responses, rather than solely relying on global head impact kinematics that have plagued early and contemporary brain injury research to date.

  2. The effect of motorcycle helmet fit on estimating head impact kinematics from residual liner crush.

    Science.gov (United States)

    Bonin, Stephanie J; Gardiner, John C; Onar-Thomas, Arzu; Asfour, Shihab S; Siegmund, Gunter P

    2017-09-01

    Proper helmet fit is important for optimizing head protection during an impact, yet many motorcyclists wear helmets that do not properly fit their heads. The goals of this study are i) to quantify how a mismatch in headform size and motorcycle helmet size affects headform peak acceleration and head injury criteria (HIC), and ii) to determine if peak acceleration, HIC, and impact speed can be estimated from the foam liner's maximum residual crush depth or residual crush volume. Shorty-style helmets (4 sizes of a single model) were tested on instrumented headforms (4 sizes) during linear impacts between 2.0 and 10.5m/s to the forehead region. Helmets were CT scanned to quantify residual crush depth and volume. Separate linear regression models were used to quantify how the response variables (peak acceleration (g), HIC, and impact speed (m/s)) were related to the predictor variables (maximum crush depth (mm), crush volume (cm(3)), and the difference in circumference between the helmet and headform (cm)). Overall, we found that increasingly oversized helmets reduced peak headform acceleration and HIC for a given impact speed for maximum residual crush depths less than 7.9mm and residual crush volume less than 40cm(3). Below these levels of residual crush, we found that peak headform acceleration, HIC, and impact speed can be estimated from a helmet's residual crush. Above these crush thresholds, large variations in headform kinematics are present, possibly related to densification of the foam liner during the impact. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Development of a Human Head FE Model and Impact Simulation on the Focal Brain Injury

    Science.gov (United States)

    Watanabe, Dai; Yuge, Kohei; Nishimoto, Tetsuya; Murakami, Shigeyuki; Takao, Hiroyuki

    In this paper, a three-dimensional digital human-head model was developed and several dynamic analyses on the head trauma were conducted. This model was built up by the VOXEL approach using 433 slice CT images (512×512 pixels) and made of 1.22 million parallelepiped finite elements with 10 anatomical tissue properties such as scalp, CSF, skull, brain, dura mater and so on. The numerical analyses were conducted using a finite element code the authors have developed. The main features of the code are 1) it is based on the explicit time integration method and 2) it uses the one point integration method to evaluate the equivalent nodal forces with the hourglass control proposed by Flanagan and Belytschko(1) and 3) it utilizes the parallel computation system based on MPI. In order to verify the developed model, the head impact experiment for a cadaver by Nahum et al.(2) was simulated. The calculated results showed good agreement with the experimental ones. A front and rear impact analyses were also performed to discuss on the characteristic measure of the brain injury, in which the von-Mises stress was high in the frontal lobe in both of the analyses because of the large deformations of a frontal cranial base. This result suggests that the von-Mises stress can be a good measure of the brain injury since it is empirically well known that the frontal lobe tends to get injured regardless of the impact positions.

  4. Heading in soccer: dangerous play?

    Science.gov (United States)

    Spiotta, Alejandro M; Bartsch, Adam J; Benzel, Edward C

    2012-01-01

    Soccer is the world's most popular sport and unique in that players use their unprotected heads to intentionally deflect, stop, or redirect the ball for both offensive and defensive strategies. Headed balls travel at high velocity pre- and postimpact. Players, coaches, parents, and physicians are justifiably concerned with soccer heading injury risk. Furthermore, risk of long-term neurocognitive and motor deficits caused by repetitively heading a soccer ball remains unknown. We review the theoretical concerns, the results of biomechanical laboratory experiments, and the available clinical data regarding the effects of chronic, subconcussive head injury during heading in soccer.

  5. The Impact of Reverse Trendelenburg Versus Head-up Position on Intraoperative Bleeding of Elective Rhinoplasty

    Science.gov (United States)

    Nooraei, Navid; Dabbagh, Ali; Niazi, Feizolah; Mohammadi, Siamak; Mohajerani, Seyed Amir; Radmand, Golnar; Hashemian, Seyed Mohammad Reza

    2013-01-01

    Background: In spite of several efforts for decreasing blood loss, our experience sometimes shows that some patients bleed more profusely during rhinoplasty. Patient position could have deep impact on bleeding amount during surgical procedures. Objective: In this study, we aimed to compare reverse trendelenburg position and head-up position on intra-operative bleeding of elective rhinoplasty. This was to check the effects of reverse trendelenburg position and head up position on the intraoperative bleeding of elective rhinoplasty. Methods: In this study, 30 ASA I (American Society of Anesthesiology physical condition classification) patients between 18 and 40 years of age who were candidate to rhinoplasty operations for first time were included. Patients were randomly assigned to reverse trendelenburg or head-up position. Exclusion criteria was any history or lab indicating coagulation problems or using any drug. All gauzes used and the blood that accumulated in the aspirator throughout the operation were calculated. Results: Our results showed that the mean amount of blood loss in reverse trendelenburg was lower (77.00 ± 13.20 ml) than head-up position (83.33 ± 21.18 ml), although, there was no statistical difference between two groups. However, there was no significant differences among two groups in different aspects of hemodynamic determinants and bleeding amount during and after rhinoplasty. Conclusions: Our results showed that patient bleeding is not increased because of positioning per se. In conclusion, perhaps in the future reverse trendelenburg will be given more often during rhinoplasry. PMID:24498500

  6. The impact of reverse trendelenburg versus head-up position on intraoperative bleeding of elective rhinoplasty

    Directory of Open Access Journals (Sweden)

    Navid Nooraei

    2013-01-01

    Full Text Available Background: In spite of several efforts for decreasing blood loss, our experience sometimes shows that some patients bleed more profusely during rhinoplasty. Patient position could have deep impact on bleeding amount during surgical procedures. Objective: In this study, we aimed to compare reverse trendelenburg position and head-up position on intra-operative bleeding of elective rhinoplasty. This was to check the effects of reverse trendelenburg position and head up position on the intraoperative bleeding of elective rhinoplasty. Methods: In this study, 30 ASA I (American Society of Anesthesiology physical condition classification patients between 18 and 40 years of age who were candidate to rhinoplasty operations for first time were included. Patients were randomly assigned to reverse trendelenburg or head-up position. Exclusion criteria was any history or lab indicating coagulation problems or using any drug. All gauzes used and the blood that accumulated in the aspirator throughout the operation were calculated. Results: Our results showed that the mean amount of blood loss in reverse trendelenburg was lower (77.00 ΁ 13.20 ml than head-up position (83.33 ΁ 21.18 ml, although, there was no statistical difference between two groups. However, there was no significant differences among two groups in different aspects of hemodynamic determinants and bleeding amount during and after rhinoplasty. Conclusions: Our results showed that patient bleeding is not increased because of positioning per se. In conclusion, perhaps in the future reverse trendelenburg will be given more often during rhinoplasry.

  7. Altered Neurochemistry in Former Professional Soccer Players without a History of Concussion.

    Science.gov (United States)

    Koerte, Inga K; Lin, Alexander P; Muehlmann, Marc; Merugumala, Sai; Liao, Huijun; Starr, Tyler; Kaufmann, David; Mayinger, Michael; Steffinger, Denise; Fisch, Barbara; Karch, Susanne; Heinen, Florian; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

    2015-09-01

    Soccer is played by more than 250 million people worldwide. Repeatedly heading the ball may place soccer players at high risk for repetitive subconcussive head impacts (RSHI). This study evaluates the long-term effects of RSHI on neurochemistry in athletes without a history of clinically diagnosed concussion, but with a high exposure to RSHI. Eleven former professional soccer players (mean age 52.0±6.8 years) and a comparison cohort of 14 age- and gender-matched, former non-contact sport athletes (mean age 46.9±7.9 years) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation. In the soccer players a significant increase was observed in both choline (Cho), a membrane marker, and myo-inositol (ml), a marker of glial activation, compared with control athletes. Additionally, ml and glutathione (GSH) were significantly correlated with lifetime estimate of RSHI within the soccer group. There was no significant difference in neurocognitive tests between groups. Results of this study suggest an association between RSHI in soccer players and MRS markers of neuroinflammation, suggesting that even subconcussive head impacts affect the neurochemistry of the brain and may precede neurocognitive changes. Future studies will need to determine the role of neuroinflammation in RSHI and the effect on neurocognitive function.

  8. The impact of comorbidity on outcome in 12 623 Danish head and neck cancer patients

    DEFF Research Database (Denmark)

    Bøje, Charlotte Rotbøl; Dalton, Susanne O; Grønborg, Therese K

    2013-01-01

    Head and neck squamous cell carcinoma (HNSCC) is primarily caused by smoking and alcohol. Besides having a carcinogenic effect, smoking also leads to other diseases and thus contributes to a high prevalence of comorbidities among HNSCC patients. Furthermore, the world population is becoming older...... resulting in more elderly patients with HNSCC. The aim of this study was to investigate the prevalence and impact of comorbidity in a retrospective nationwide population-based study of all Danish HNSCC patients diagnosed from 1992 to 2008.......Head and neck squamous cell carcinoma (HNSCC) is primarily caused by smoking and alcohol. Besides having a carcinogenic effect, smoking also leads to other diseases and thus contributes to a high prevalence of comorbidities among HNSCC patients. Furthermore, the world population is becoming older...

  9. Heart rate' based training intensity and its impact on injury incidence amongst elite level professional soccer players.

    Science.gov (United States)

    Owen, Adam L; Forsyth, Jacky J; Wong, Del P; Dellal, Alexandre; Connelly, Sean; Chamari, Karim

    2014-12-24

    Elite level professional soccer players are suggested to have increased physical, technical, tactical and psychological capabilities when compared to their sub-elite counterparts. Ensuring these players remain at the elite level generally involves training many different bodily systems to a high intensity or level within a short duration. This study aimed to examine whether an increase in training volume at high intensity levels were related to injury incidence, or increased the odds of sustaining an injury. Training intensity was monitored through time spent in high- (T-HI) and very high- (T-VHI) intensity zones of 85-level players may be possible if greater focus is placed on the training intensity and volume over a period of time ensuring the potential reduction of fatigue or overuse injuries. In addition, it is important to understand the optimal training load at which adaptation occurs without raising the risk of injury.

  10. Heart rate-based training intensity and its impact on injury incidence among elite-level professional soccer players.

    Science.gov (United States)

    Owen, Adam L; Forsyth, Jacky J; Wong, Del P; Dellal, Alexandre; Connelly, Sean P; Chamari, Karim

    2015-06-01

    Elite-level professional soccer players are suggested to have increased physical, technical, tactical, and psychological capabilities when compared with their subelite counterparts. Ensuring these players remain at the elite level generally involves training many different bodily systems to a high intensity or level within a short duration. This study aimed to examine whether an increase in training volume at high-intensity levels was related to injury incidence, or increased the odds of sustaining an injury. Training intensity was monitored through time spent in high-intensity (T-HI) and very high-intensity (T-VHI) zones of 85-level professional players may be possible if greater focus is placed on the training intensity and volume over a period of time ensuring the potential reduction of fatigue or overuse injuries. In addition, it is important to understand the optimal training load at which adaptation occurs without raising the risk of injury.

  11. Impact of specific training and competition on myocardial structure and function in different age ranges of male handball players.

    Science.gov (United States)

    Agrebi, Brahim; Tkatchuk, Vladimir; Hlila, Nawel; Mouelhi, Emna; Belhani, Ali

    2015-01-01

    Handball activity involves cardiac changes and demands a mixture of both eccentric and concentric remodeling within the heart. This study seeks to explore heart performance and cardiac remodeling likely to define cardiac parameters which influence specific performance in male handball players across different age ranges. Forty three players, with a regular training and competitive background in handball separated into three groups aged on average 11.78 ± 0.41 for youth players aka "schools", "elite juniors" 15.99 ± 0.81 and "elite adults" 24.46 ± 2.63 years, underwent echocardiography and ECG examinations. Incremental ergocycle and specific field (SFT) tests have also been conducted. With age and regular training and competition, myocardial remodeling in different age ranges exhibit significant differences in dilatation's parameters between "schools" and "juniors" players, such as the end-diastolic diameter (LVEDD) and the end-systolic diameter of the left ventricle (LVESD), the root of aorta (Ao) and left atrial (LA), while significant increase is observed between "juniors" and "adults" players in the interventricular septum (IVS), the posterior wall thicknesses (PWT) and LV mass index. ECG changes are also noted but NS differences were observed in studied parameters. For incremental maximal test, players demonstrate a significant increase in duration and total work between "schools" and "juniors" and, in total work only, between "juniors" and "seniors". The SFT shows improvement in performance which ranged between 26.17 ± 1.83 sec to 31.23 ± 2.34 sec respectively from "seniors" to "schools". The cross-sectional approach used to compare groups with prior hypothesis that there would be differences in exercise performance and cardiac parameters depending on duration of prior handball practice, leads to point out the early cardiac remodeling within the heart as adaptive change. Prevalence of cardiac chamber dilation with less hypertrophy remodeling was found

  12. Impact of uncertainty description on assimilating hydraulic head in the MIKE SHE distributed hydrological model

    DEFF Research Database (Denmark)

    Zhang, Donghua; Madsen, Henrik; Ridler, Marc E.

    2015-01-01

    uncertainty. In most hydrological EnKF applications, an ad hoc model uncertainty is defined with the aim of avoiding a collapse of the filter. The present work provides a systematic assessment of model uncertainty in DA applications based on combinations of forcing, model parameters, and state uncertainties....... This is tested in a case where groundwater hydraulic heads are assimilated into a distributed and integrated catchment-scale model of the Karup catchment in Denmark. A series of synthetic data assimilation experiments are carried out to analyse the impact of different model uncertainty assumptions...

  13. Multivariate head injury threshold measures for various sized children seated behind vehicle seats in rear impacts.

    Science.gov (United States)

    Saczalski, Kenneth; Sances, Anthony; Kumaresan, Srirangam; Pozzi, Mark; Saczalski, Todd; Burton, J L; Lewis, P

    2004-01-01

    Government recommendations to place children into the rear areas of motor vehicles to avoid airbag induced injuries have been complicated by the fact that most adult occupied front seats will collapse into the rear area during rear-impacts, and thus pose another potentially serious injury hazard to rear-seated children. Many variables affect whether or not a front seat occupant will collapse into the rear child, and whether that interaction could be injurious to the child. For instance, the severity of rear impact, coupled with front and rear occupant sizes (mass and stature), and the level of front seat strength, all interrelate to influence whether or not a rear seated child is likely to be impacted and possibly injured. The most common types of child injuries in these instances are head and chest injuries. In this study, a "high-low" experimental method was employed with a multi-level "factorial analysis" technique to study "multivariate" biomechanics of child head injury potential determined from rear-seated 3 and 6 year-old child surrogates in different types of vehicle bodies mounted to a sled system. The sled-buck systems were towed rearward into crushable barriers that matched the crash pulses of the vehicle types being tested. Various sizes of adult surrogates (i.e. 50 kg up to 110 kg), seated in both the "typical" low strength "single recliner" collapsing type front seat (i.e. 3.2 kN) and a much stronger "belt-integrated" seat design (i.e. up to 14.5 kN), were tested in the two different "sled body-buck" set-ups at various impact levels (i.e. 22.5 to 50 kph). One set-up used a popular minivan vehicle body with "built-in booster" seats for the 3 year-old. The other used a 4-door family sedan vehicle body with the 6 year-old in a standard rear bench seat. The parameters of the tests enabled the experimental data to be combined into polynomial "head injury" functions of the independent variables so the "likelihood" of rear child head-injury potential could

  14. Quantitative relationship between axonal injury and mechanical response in a rodent head impact acceleration model.

    Science.gov (United States)

    Li, Yan; Zhang, Liying; Kallakuri, Srinivasu; Zhou, Runzhou; Cavanaugh, John M

    2011-09-01

    A modified Marmarou impact acceleration model was developed to study the mechanical responses induced by this model and their correlation to traumatic axonal injury (TAI). Traumatic brain injury (TBI) was induced in 31 anesthetized male Sprague-Dawley rats (392±13 g) by a custom-made 450-g impactor from heights of 1.25 m or 2.25 m. An accelerometer and angular rate sensor measured the linear and angular responses of the head, while the impact event was captured by a high-speed video camera. TAI distribution along the rostro-caudal direction, as well as across the left and right hemispheres, was determined using β-amyloid precursor protein (β-APP) immunocytochemistry, and detailed TAI injury maps were constructed for the entire corpus callosum. Peak linear acceleration 1.25 m and 2.25 m impacts were 666±165 g and 907±501 g, respectively. Peak angular velocities were 95±24 rad/sec and 124±48 rad/sec, respectively. Compared to the 2.25-m group, the observed TAI counts in the 1.25-m impact group were significantly lower. Average linear acceleration, peak angular velocity, average angular acceleration, and surface righting time were also significantly different between the two groups. A positive correlation was observed between normalized total TAI counts and average linear acceleration (R(2)=0.612, plinear and angular acceleration response of the rat head during impact, not necessarily the drop height.

  15. Impact of head modeling and sensor types in localizing human gamma-band oscillations.

    Science.gov (United States)

    Mideksa, K G; Hoogenboom, N; Hellriegel, H; Krause, H; Schnitzler, A; Deuschl, G; Raethjen, J; Heute, U; Muthuraman, M

    2014-01-01

    An effective mechanism in neuronal communication is oscillatory neuronal synchronization. The neuronal gamma-band (30-100 Hz) synchronization is associated with attention which is induced by a certain visual stimuli. Numerous studies have shown that the gamma-band activity is observed in the visual cortex. However, impact of different head modeling techniques and sensor types to localize gamma-band activity have not yet been reported. To do this, the brain activity was recorded using 306 magnetoencephalography (MEG) sensors, consisting of 102 magnetometers and 102 pairs of planar gradiometers (one measuring the derivative of the magnetic field along the latitude and the other along the longitude), and the data were analyzed with respect to time, frequency, and location of the strongest response. The spherical head models with a single-shell and overlapping spheres (local sphere) have been used as a forward model for calculating the external magnetic fields generated from the gamma-band activity. For each sensor type, the subject-specific frequency range of the gamma-band activity was obtained from the spectral analysis. The identified frequency range of interest with the highest gamma-band activity is then localized using a spatial-filtering technique known as dynamic imaging of coherent sources (DICS). The source analysis for all the subjects revealed that the gradiometer sensors which measure the derivative along the longitude, showed sources close to the visual cortex (cuneus) as compared to the other gradiometer sensors which measure the derivative along the latitude. However, using the magnetometer sensors, it was not possible to localize the sources in the region of interest. When comparing the two head models, the local-sphere model helps in localizing the source more focally as compared to the single-shell head model.

  16. Soccer heading frequency predicts neuropsychological deficits.

    Science.gov (United States)

    Witol, Adrienne D; Webbe, Frank M

    2003-05-01

    This study investigated the presence of neuropsychological deficits associated with hitting the ball with one's head (heading) during soccer play. A neuro-cognitive test battery was administered to 60 male soccer players, high school, amateur and professional level, and 12 nonplaying control participants. The effects of currently reported heading behavior as well as that of estimated lifetime heading experience on neuropsychological test performance were examined. Players with the highest lifetime estimates of heading had poorer scores on scales measuring attention, concentration, cognitive flexibility and general intellectual functioning. Players' current level of heading was less predictive of neuro-cognitive level. Comparison of individual scores to age-appropriate norms revealed higher probabilities of clinical levels of impairment in players who reported greater lifetime frequencies of heading. Because of the worldwide popularity of the game, continued research is needed to assess the interaction between heading and soccer experience in the development of neuropsychological deficits associated with soccer play.

  17. Injuries of the head from backface deformation of ballistic protective helmets under ballistic impact.

    Science.gov (United States)

    Rafaels, Karin A; Cutcliffe, Hattie C; Salzar, Robert S; Davis, Martin; Boggess, Brian; Bush, Bryan; Harris, Robert; Rountree, Mark Steve; Sanderson, Ellory; Campman, Steven; Koch, Spencer; Dale Bass, Cameron R

    2015-01-01

    Modern ballistic helmets defeat penetrating bullets by energy transfer from the projectile to the helmet, producing helmet deformation. This deformation may cause severe injuries without completely perforating the helmet, termed "behind armor blunt trauma" (BABT). As helmets become lighter, the likelihood of larger helmet backface deformation under ballistic impact increases. To characterize the potential for BABT, seven postmortem human head/neck specimens wearing a ballistic protective helmet were exposed to nonperforating impact, using a 9 mm, full metal jacket, 124 grain bullet with velocities of 400-460 m/s. An increasing trend of injury severity was observed, ranging from simple linear fractures to combinations of linear and depressed fractures. Overall, the ability to identify skull fractures resulting from BABT can be used in forensic investigations. Our results demonstrate a high risk of skull fracture due to BABT and necessitate the prevention of BABT as a design factor in future generations of protective gear.

  18. Player-character dynamics in multi-player Role Playing Games

    DEFF Research Database (Denmark)

    Tychsen, Anders; McIlwain, Doris; Brolund, Thea

    2007-01-01

    This paper presents the results of a comprehensive empirical study of the impact of integrating complex game characters in multi-player Role Playing Games across tabletop and digital formats. Players were provided with characters that had detailed background history, personality and goals. Player...... and player engagement with their character and no correlation between enjoyment and similarity between player and character personality. © 2007 Authors & Digital Games Research Association (DiGRA)....... and character personality were assessed using the Extended Personal Attributes Questionnaire (EPAQ) and further questionnaires administered to measure player enjoyment and the player-character relationship. Results include a high level of player enjoyment across all formats, a high correlation between enjoyment...

  19. Impact of specific training and competition on myocardial structure and function in different age ranges of male handball players.

    Directory of Open Access Journals (Sweden)

    Brahim Agrebi

    Full Text Available Handball activity involves cardiac changes and demands a mixture of both eccentric and concentric remodeling within the heart. This study seeks to explore heart performance and cardiac remodeling likely to define cardiac parameters which influence specific performance in male handball players across different age ranges. Forty three players, with a regular training and competitive background in handball separated into three groups aged on average 11.78 ± 0.41 for youth players aka "schools", "elite juniors" 15.99 ± 0.81 and "elite adults" 24.46 ± 2.63 years, underwent echocardiography and ECG examinations. Incremental ergocycle and specific field (SFT tests have also been conducted. With age and regular training and competition, myocardial remodeling in different age ranges exhibit significant differences in dilatation's parameters between "schools" and "juniors" players, such as the end-diastolic diameter (LVEDD and the end-systolic diameter of the left ventricle (LVESD, the root of aorta (Ao and left atrial (LA, while significant increase is observed between "juniors" and "adults" players in the interventricular septum (IVS, the posterior wall thicknesses (PWT and LV mass index. ECG changes are also noted but NS differences were observed in studied parameters. For incremental maximal test, players demonstrate a significant increase in duration and total work between "schools" and "juniors" and, in total work only, between "juniors" and "seniors". The SFT shows improvement in performance which ranged between 26.17 ± 1.83 sec to 31.23 ± 2.34 sec respectively from "seniors" to "schools". The cross-sectional approach used to compare groups with prior hypothesis that there would be differences in exercise performance and cardiac parameters depending on duration of prior handball practice, leads to point out the early cardiac remodeling within the heart as adaptive change. Prevalence of cardiac chamber dilation with less hypertrophy remodeling

  20. The rate of change of acceleration: implications to head kinematics during rear-end impacts.

    Science.gov (United States)

    Hynes, Loriann M; Dickey, James P

    2008-05-01

    Whiplash is a mechanism of injury commonly associated with rear-impact vehicle collisions. To date, research has focused primarily on changes in velocity and acceleration as key factors for determining injuries due to whiplash mechanisms, but other characteristics of the acceleration pulse may be important. This study assessed whether the head acceleration response to whiplash-like perturbation profiles were affected by a change in the rate of the applied acceleration, or jerk. Twenty-one subjects were exposed to different low-velocity rear-impact whiplash-like perturbations using a precisely controlled robotic platform. The perturbations were divided into two groupings of peak acceleration (approximately 10 (high) and 5.7 (low) m/s2) and three groupings of jerk (approximately 260, 310, and 360 m/s3). These six profiles were repeated twice. Results demonstrated that the jerk magnitude significantly affected forehead acceleration in the vertical and horizontal directions. Increasing the magnitude of the platform acceleration also differentially affected the horizontal and vertical forehead accelerations. This indicates that the level of jerk influences the resulting head kinematics and should be considered when designing or interpreting experiments that are attempting to predict injury from whiplash-like perturbations.

  1. Revenue Maximizing Head Starts in Contests

    OpenAIRE

    Franke, Jörg; Leininger, Wolfgang; Wasser, Cédric

    2014-01-01

    We characterize revenue maximizing head starts for all-pay auctions and lottery contests with many heterogeneous players. We show that under optimal head starts all-pay auctions revenue-dominate lottery contests for any degree of heterogeneity among players. Moreover, all-pay auctions with optimal head starts induce higher revenue than any multiplicatively biased all-pay auction or lottery contest. While head starts are more effective than multiplicative biases in all-pay auctions, they are l...

  2. IMPACT OF MANAGERIAL SKILLS LEARNT THROUGH MA EDUCATIONAL PLANNING MANAGEMENT PROGRAMME OF AIOU ON THE PERFORMANCE OF INSTITUTIONAL HEADS

    Directory of Open Access Journals (Sweden)

    Muhammad Asif CHUADHRY

    2012-04-01

    Full Text Available Management provides formal coordination in an organization for achieving pre-determined goals. The educational manager particulary performs his duties by using different planning and management techniques. These techniques are equally important for the manager of other sectors. The present study was focused on the impact of managerial skills learnt through MA EPM programme on the performance of the heads. Following were the objectives of the study .to assess the contribution of the programme towards the learning of the heads of educational institutions. Ø To identify the managerial skills and competencies of Educational Managers and heads trained through EPPSL Department of the Allama Iqbal Open University. Ø (ii To evaluate the effectiveness of the programme and its impact on the skills of the MA EPM graduates. Ø (iii To analyze the performance of EPM graduates working as heads in their respective institutions.A questionnaire for graduates was developed for those working as institutional heads in Rawalpindi and Islamabad. There were 58 educational institutionl heads who have their master degree in EPM .The data obtained was organized, tabulated, and analyzed by using descriptive statistics means of percentage method in numbers of tables in order to find out the impact of the skills of the MA EPM programme. The finding and conclusions of the data indicated that the impact of the skills on their performance. Majority of the heads were agreed that the programme was beneficial for them. It was recommended on the basis of the conclusions that the selection of the resource person should be on merit; quality of books might be improved; and there should be a separate course for educational budgeting. It was also recommended that this programme should be compulsory for the institutional heads. There might be upgradation of the course.

  3. The impact of virus in N3 node dissection for head and neck cancer.

    Science.gov (United States)

    Armas, Gian Luca; Su, Chih-Ying; Huang, Chao-Cheng; Fang, Fu-Min; Chen, Ching-Mei; Chien, Chih-Yen

    2008-11-01

    This study is to determine the impact of virus in surgical outcomes among patients of head and neck cancer with N3 lymph node metastasis. A retrospective analysis was conducted for 32 patients with operable N3 neck metastasis undergoing surgical treatment between January 1987 and October 2006. The nuclei of the tumor cells were investigated for the presence of human papillomavirus (HPV) and Epstein-Barr virus (EBV) DNAs and were taken into account as the variable for survival analysis. The primary sites were oropharynx in 11 patients, tongue in 3, buccal mucosa in 1, hypopharynx in 8 and unknown primary in 9. The five-year cumulative overall survival rate was 40.7% and 5-year cumulative regional control rate was 55.8%. The 5-year cumulative overall survival rate of patients with unknown primary site (72.9%) and HPV or EBV positive in the tumor (77.8%) were significantly higher than those patients with known primary site (31.3%) and HPV or EBV negative in the tumor (27.4%), respectively (P = 0.0335 and P = 0.0348, log rank test). In conclusion, surgery with adjuvant therapy offers reasonable outcomes for operable N3 node in head and neck cancer in our cohort. In addition, patients with HPV or EBV positive in the tumor have a better survival.

  4. The impact of instructional and motivational self-talk on cognitive anxiety, somatic anxiety, and learning of soccershoot skill in beginner players

    Directory of Open Access Journals (Sweden)

    Gholamreza Lotfi

    2016-09-01

    Full Text Available This study aimed to investigate the impact of instructional and motivational self-talk on cognitive anxiety, somatic anxiety, and soccershootskill learning in beginner players. For this purpose, 60 non-athlete male students (mean age= 14.9 ± 0.78 years old were voluntarily selected. According to pre-test, they were divided into four groups of fifteen participants: instructional self-talk, positive motivational self-talk, negative motivational self-talk, and control. The anxiety level of participants was measured through Marten's State - Competitive Anxiety Inventory, and shoot performance of participants was measured by Moore-Christian shooting skill test at different stages. The exercise was performed 6 sessions every other day and 24 attempts were conducted in each session. The post-test of anxiety and soccer shoot accuracy was conducted after completing exercises. Immediately after the post-test and two meters higher than the original test, the transmission test was conducted. Then, the retention test was performed after 72 hours of not training. The data were analyzed using descriptive statistics, one way analysis of variance, and repeated measures analysis of variance at significance level of P≤ 0.05. The findings showed that the mean of cognitive anxiety post-test and somatic anxiety post-test in positive motivational self-talk group was significantly better than negative self-talk group; however, there was no significant difference in other groups. The shoot accuracy performance in positive motivational self-talk group and instructional group in post-test was better than negative self-talk group. According to findings, it is recommended that positive motivational self-talk be used to reduce anxiety in beginner players. Also, the negative self-talk should be avoided to improve the performance of these players.

  5. Impact of a competition with two consecutive matches in a day on physical performance in young tennis players.

    Science.gov (United States)

    Gallo-Salazar, Cesar; Del Coso, Juan; Barbado, David; Lopez-Valenciano, Alejandro; Santos-Rosa, Francisco Javier; Sanz-Rivas, David; Moya, Manuel; Fernandez-Fernandez, Jaime

    2017-07-01

    The purpose of this study was to analyze the effects of playing 2 tennis matches on the same day on physical performance in young tennis players. Twelve well-trained young tennis players took part in a simulated tennis competition consisting of 2 tennis matches on the same day (morning and afternoon sessions). Before and the day after the competition, physical performance was measured using a battery of countermovement jumps; a 10 m sprint; the 5-0-5 agility test; hip, grip and shoulder maximal isometric strength; shoulder range of motion; and a serve velocity test. Postcompetition results showed reduced performance in 10 m (-3.3%, effect size (ES) = small), dominant and nondominant 5-0-5 agility test (-4.6%, ES = moderate; -4.2%, ES = moderate, respectively), bilateral (-5.2%, ES = small), and unilateral countermovement jumps (dominant leg: -7.2%, ES = small; non-dominant leg: -9.1%, ES = small). Both dominant and nondominant shoulder external rotation range of motion increased (12.2%, ES = moderate; 5.6%, ES = small), whereas internal rotation decreased (-4.2%, ES = small; -3.3%, ES = small) in the postcompetition tests, together with the dominant shoulder external rotation (-10.7%, ES = moderate) and internal rotation (-9.3%, ES = small) strength. Physical impairments occurred in neuromuscular performance variables involving lower (e.g., jumping, sprinting, and change of direction) and upper (e.g., isometric strength and range of motion) limbs the day after playing a competition with 2 consecutive matches on the same day. These alterations in neuromuscular and sport-specific performance need to be taken into consideration when planning tournament schedules for young tennis players, as well as preparing match and recovery strategies.

  6. Evidence for Acute Electrophysiological and Cognitive Changes Following Routine Soccer Heading.

    Science.gov (United States)

    Di Virgilio, Thomas G; Hunter, Angus; Wilson, Lindsay; Stewart, William; Goodall, Stuart; Howatson, Glyn; Donaldson, David I; Ietswaart, Magdalena

    2016-11-01

    There is growing concern around the effects of concussion and sub-concussive impacts in sport. Routine game-play in soccer involves intentional and repeated head impacts through ball heading. Although heading is frequently cited as a risk to brain health, little data exist regarding the consequences of this activity. This study aims to assess the immediate outcomes of routine football heading using direct and sensitive measures of brain function. Nineteen amateur football players (5 females; age 22±3y) headed machine-projected soccer balls at standardized speeds, modelling routine soccer practice. The primary outcome measure of corticomotor inhibition measured using transcranial magnetic stimulation, was assessed prior to heading and repeated immediately, 24h, 48h and 2weeks post-heading. Secondary outcome measures were cortical excitability, postural control, and cognitive function. Immediately following heading an increase in corticomotor inhibition was detected; further to these electrophysiological alterations, measurable reduction memory function were also found. These acute changes appear transient, with values normalizing 24h post-heading. Sub-concussive head impacts routine in soccer heading are associated with immediate, measurable electrophysiological and cognitive impairments. Although these changes in brain function were transient, these effects may signal direct consequences of routine soccer heading on (long-term) brain health which requires further study. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Survival of patients with head and neck cancer. Impact of physical status and comorbidities.

    Science.gov (United States)

    Sadat, F; Wienke, A; Dunst, J; Kuhnt, T

    2012-01-01

    Prognostic factors (e.g., gender, tumor stage, and hypoxia) have an impact on survival in patients with head and neck cancer. Thus, the impact of physical status and comorbidities on treatment decision and survival were evaluated. A total of 169 primary, inoperable patients with squamous cell cancer of the head and neck were retrospectively investigated. Patients were treated with hyperfractionated accelerated radio(chemo)therapy (HARcT) or hypofractionated radio(chemo)therapy (HypoRcT). Depending on the individual patient's situation (Karnofsky Performance Index, KPI), treatment for patients with a KPI of 80-100% was generally radiochemotherapy and for patients with a KPI ≤ 70% treatment was radiotherapy alone. In addition, all comorbidities were evaluated. Uni- and multivariate proportional hazards model were used, and overall survival (OS) was estimated by the Kaplan-Meier method. Treatment consisted of HARcT for 76 patients (45%), HART for 28 patients (17%), HypoRcT for 14 patients(8%), and HypoRT for 51 patients (30%). Of the patients, 107 patients (63%) presented with a KPI of 80-100%. OS (20%) was significantly better for patients with a KPI of 80-100%, while the OS for patients with a KPI ≤ 70% was 8% (p KPI, total irradiation dose (> 70 Gy), and chemotherapy were significant prognostic factors for better OS. Our retrospective analysis shows that performance status with dependency on comorbidities was an independent risk factor for OS.

  8. The dosimetric impact of dental implants on head-and-neck volumetric modulated arc therapy

    Science.gov (United States)

    Lin, Mu-Han; Li, Jinsheng; Price, Robert A., Jr.; Wang, Lu; Lee, Chung-Chi; Ma, C.-M.

    2013-02-01

    This work aims to investigate the dosimetric impact of dental implants on volumetric modulated arc therapy (VMAT) for head-and-neck patients and to evaluate the effectiveness of using the material's electron-density ratio for the correction. An in-house Monte Carlo (MC) code was utilized for the dose calculation to account for the scattering and attenuation caused by the high-Z implant material. Three different dental implant materials were studied in this work: titanium, Degubond®4 and gold. The dose perturbations caused by the dental implant materials were first investigated in a water phantom with a 1 cm3 insert. The per cent depth dose distributions of a 3 × 3 cm2 photon field were compared with the insert material as water and the three selected dental implant materials. To evaluate the impact of the dental implant on VMAT patient dose calculation, four head-and-neck cases were selected. For each case, the VMAT plan was designed based on the artifact-corrected patient geometry using a treatment planning system (TPS) that was typically utilized for routine patient treatment. The plans were re-calculated using the MC code for five situations: uncorrected geometry, artifact-corrected geometry and artifact-corrected geometry with one of the three different implant materials. The isodose distributions and the dose-volume histograms were cross-compared with each other. To evaluate the effectiveness of using the material's electron-density ratio for dental implant correction, the implant region was set as water with the material's electron-density ratio and the calculated dose was compared with the MC simulation with the real material. The main effect of the dental implant was the severe attenuation in the downstream. The 1 cm3 dental implant can lower the downstream dose by 10% (Ti) to 51% (Au) for a 3 × 3 cm2 field. The TPS failed to account for the dose perturbation if the dental implant material was not precisely defined. For the VMAT patient dose calculation

  9. No impact of early intervention on late outcome after minimal, mild and moderate head injury

    DEFF Research Database (Denmark)

    Heskestad, Ben; Waterloo, Knut; Baardsen, Roald

    2010-01-01

    To evaluate the effect of an educational intervention on outcome after minimal, mild and moderate head injury.......To evaluate the effect of an educational intervention on outcome after minimal, mild and moderate head injury....

  10. Estimating Impacts of Treatment Random Assignment on Classroom Quality in the Head Start Impact Study: The Problem of Missing Data

    Science.gov (United States)

    Friedman-Krauss, Allison H.; Connors, Maia C.; Morris, Pamela A.

    2013-01-01

    As a result of the 1998 reauthorization of Head Start, the Department of Health and Human Services conducted a national evaluation of the Head Start program. The goal of Head Start is to improve the school readiness skills of low-income children in the United States. There is a substantial body of experimental and correlational research that has…

  11. Do crash helmets retain their position on the head in case of an impact ?

    NARCIS (Netherlands)

    Beusenberg, M.C.

    1989-01-01

    This report gives the description and results of three sled tests with each four dummy heads, to record the behaviour of the head and neck of the dummy and the helmet in case of a simulated accident. The simulated accident resulted in a motions of the head, neck and helmet owing to the effects of in

  12. Impact of sentinel node status and other risk factors on the clinical outcome of head and neck melanoma patients

    NARCIS (Netherlands)

    Leong, SPL; Accortt, NA; Essner, R; Ross, M; Gershenwald, JE; Pockaj, B; Hoekstra, HJ; Garberoglio, C; White, RL; Biel, M; Charney, K; Wanebo, H; Avisar, E; Vetto, J; Soong, SJ

    2006-01-01

    Objective: To determine the impact of sentinel lymph node (SLN) status and other risk factors on recurrence and overall survival in head and neck melanoma patients. Design: The SLN Working Group, based in San Francisco, Calif, with its 11 member centers, the John Wayne Cancer Institute, and The Univ

  13. Altered Blood Biomarker Profiles in Athletes with a History of Repetitive Head Impacts.

    Directory of Open Access Journals (Sweden)

    Alex P Di Battista

    Full Text Available The long-term health effects of concussion and sub-concussive impacts in sport are unknown. Growing evidence suggests both inflammation and neurodegeneration are pivotal to secondary injury processes and the etiology of neurodegenerative diseases. In the present study we characterized circulating brain injury and inflammatory mediators in healthy male and female athletes according to concussion history and collision sport participation. Eighty-seven university level athletes (male, n = 60; female, n = 27 were recruited before the start of the competitive season. Athletes were healthy at the time of the study (no medications, illness, concussion or musculoskeletal injuries. Dependent variables included 29 inflammatory and 10 neurological injury analytes assessed in the peripheral blood by immunoassay. Biomarkers were statistically evaluated using partial least squares multivariate analysis to identify possible relationships to self-reported previous concussion history, number of previous concussions and collision sport participation in male and female athletes. Multiple concussions were associated with increases in peripheral MCP-1 in females, and MCP-4 in males. Collision sport participation was associated with increases in tau levels in males. These results are consistent with previous experimental and clinical findings that suggest ongoing inflammatory and cerebral injury processes after repetitive mild head trauma. However, further validation is needed to correlate systemic biomarkers to repetitive brain impacts, as opposed to the extracranial effects common to an athletic population such as exercise and muscle damage.

  14. Head size may modify the impact of white matter lesions on dementia.

    Science.gov (United States)

    Skoog, Ingmar; Olesen, Pernille J; Blennow, Kaj; Palmertz, Bo; Johnson, Sterling C; Bigler, Erin D

    2012-07-01

    We aimed to examine whether total intracranial volume (TICV), a marker of premorbid brain size, modified the impact of the apolipoprotein E (apoE) e4 phenotype and ischemic white matter lesions (WMLs) on odds for dementia. The study comprised a population-based sample of 104 demented and 135 nondemented 85-year-olds, and included physical and neuropsychiatric examinations, and head computerized tomography (CT). Dementia disorders were defined according to standard criteria. TICV and WMLs were rated on computerized tomography. Using the highest group as reference, the risk for dementia, Alzheimer's disease (AD), and vascular dementia (VaD) was increased in those with the smallest half, tertile, and quartile of TICV. Smaller TICV increased the odds of dementia, Alzheimer's disease, and vascular dementia in participants with WMLs. WMLs were not associated with increased odds of dementia in those with the largest TICV. The interaction term WMLs*TICV was also significant. TICV did not modify the odds of dementia in those with the apolipoprotein e4 phenotype. Our results suggest that the impact of brain pathology on the risk of dementia is modified by premorbid brain size. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Neuropsychological development in preschool children born with asymmetrical intrauterine growth restriction and impact of postnatal head growth.

    Science.gov (United States)

    Klaric, Andrea Simić; Galić, Slavka; Kolundzić, Zdravko; Bosnjak, Vlatka Mejaski

    2013-07-01

    Neuropsychological development and the impact of postnatal head growth were studied in preschool children with asymmetrical intrauterine growth restriction. Examinees born at term with a birth weight below the 10th percentile were matched to the control group according to chronological and gestational age, gender, and maternal education. Fifty children were in each group, with a mean age of 6 years, 4 months. The Touwen neurological examination, the Čuturić developmental test, an imitative hand positions test, and a visual attention test were performed. There were significant differences (Pdevelopment. Slow postnatal head growth is correlated with a poorer neuropsychological outcome.

  16. Cervical joint position sense in rugby players versus non-rugby players.

    Science.gov (United States)

    Pinsault, Nicolas; Anxionnaz, Marion; Vuillerme, Nicolas

    2010-05-01

    To determine whether cervical joint position sense is modified by intensive rugby practice. A group-comparison study. University Medical Bioengineering Laboratory. Twenty young elite rugby players (10 forwards and 10 backs) and 10 young non-rugby elite sports players. Participants were asked to perform the cervicocephalic relocation test (CRT) to the neutral head position (NHP) that is, to reposition their head on their trunk, as accurately as possible, after full active left and right cervical rotation. Rugby players were asked to perform the CRT to NHP before and after a training session. Absolute and variable errors were used to assess accuracy and consistency of the repositioning for the three groups of Forwards, Backs and Non-rugby players, respectively. The 2 groups of Forwards and Backs exhibited higher absolute and variable errors than the group of Non-rugby players. No difference was found between the two groups of Forwards and Backs and no difference was found between Before and After the training session. The cervical joint position sense of young elite rugby players is altered compared to that of non-rugby players. Furthermore, Forwards and Backs demonstrated comparable repositioning errors before and after a specific training session, suggesting that cervical proprioceptive alteration is mainly due to tackling and not the scrum.

  17. [A case of vertebral artery occlusion following heading play in soccer].

    Science.gov (United States)

    Motohashi, Osamu; Kameyama, Motonobu; Kon, Hiroyuki; Fujimura, Miki; Onuma, Takehide

    2003-04-01

    A 13-year-old boy suffered from cerebeller infarction due to right vertebral artery occlusion after heading a ball during a rainy soccer game. Dissection of the vertebral artery after trivial head trauma is well known, but heading as the cause has not been reported. We speculated in this present case that excessive impact force to the young boy's neck due to the heavy rain-soaked ball might have caused right vertebral artery dissection and occlusion. High quality balls are recommended for young amateur players on rainy days.

  18. Analysis of finite element models for head injury investigation: reconstruction of four real-world impacts.

    Science.gov (United States)

    Franklyn, Melanie; Fildes, Brian; Zhang, Liying; Yang, King; Sparke, Laurie

    2005-11-01

    Previous studies have shown that both excessive linear and rotational accelerations are the cause of head injuries. Although the head injury criterion has been beneficial as an indicator of head injury risk, it only considers linear acceleration, so there is a need to consider both types of motion in future safety standards. Advanced models of the head/brain complex have recently been developed to gain a better understanding of head injury biomechanics. While these models have been verified against laboratory experimental data, there is a lack of suitable real-world data available for validation. Hence, using two computer models of the head/brain, the objective of the current study was to reconstruct four real-world crashes with known head injury outcomes in a full-vehicle crash laboratory, simulate head/brain responses using kinematics obtained during these reconstructions, and to compare the results predicted by the models against the actual injuries sustained by the occupant. Cases where the occupant sustained no head injuries (AIS 0) and head injuries of severity AIS 4, AIS 5, and multiple head injuries were selected. Data collected from a 9-accelerometer skull were input into the Wayne State University Head Injury Model (WSUHIM) and the NHTSA Simulated Injury Monitor (SIMon). The results demonstrated that both models were able to predict varying injury severities consistent with the difference in AIS injury levels in the real-world cases. The WSUHIM predicted a slightly higher injury threshold than the SIMon, probably due to the finer mesh and different software used for the simulations, and could also determine regions of the brain which had been injured. With further validation, finite element models can be used to establish an injury criterion for each type of brain injury in the future.

  19. Impact of uncertainty description on assimilating hydraulic head in the MIKE SHE distributed hydrological model

    Science.gov (United States)

    Zhang, Donghua; Madsen, Henrik; Ridler, Marc E.; Refsgaard, Jens C.; Jensen, Karsten H.

    2015-12-01

    The ensemble Kalman filter (EnKF) is a popular data assimilation (DA) technique that has been extensively used in environmental sciences for combining complementary information from model predictions and observations. One of the major challenges in EnKF applications is the description of model uncertainty. In most hydrological EnKF applications, an ad hoc model uncertainty is defined with the aim of avoiding a collapse of the filter. The present work provides a systematic assessment of model uncertainty in DA applications based on combinations of forcing, model parameters, and state uncertainties. This is tested in a case where groundwater hydraulic heads are assimilated into a distributed and integrated catchment-scale model of the Karup catchment in Denmark. A series of synthetic data assimilation experiments are carried out to analyse the impact of different model uncertainty assumptions on the feasibility and efficiency of the assimilation. The synthetic data used in the assimilation study makes it possible to diagnose model uncertainty assumptions statistically. Besides the model uncertainty, other factors such as observation error, observation locations, and ensemble size are also analysed with respect to performance and sensitivity. Results show that inappropriate definition of model uncertainty can greatly degrade the assimilation performance, and an appropriate combination of different model uncertainty sources is advised.

  20. Through the Google Glass: The impact of heads-up displays on visual attention.

    Science.gov (United States)

    Lewis, Joanna E; Neider, Mark B

    2016-01-01

    In five experiments, we evaluated how secondary information presented on a heads-up display (HUD) impacts performance of a concurrent visual attention task. To do so, we had participants complete a primary visual search task under a variety of secondary load conditions (a single word presented on Google Glass during each search trial). Processing of secondary information was measured through a recognition memory task. Other manipulations included relevance (Experiments 1-4) and temporal onset of secondary information relative to the primary task (Experiment 3). Secondary information was always disruptive to the visual search, regardless of temporal onset and even when participants were instructed to ignore it. These patterns were evident in search tasks reflective of both selective (Experiments 1-3) and preattentive (Experiment 4) attentional mechanisms, and were not a result of onset-offset attentional capture (Experiment 5). Recognition memory for secondary information was always above chance. Our findings suggest that HUD-based visual information is profoundly disruptive to attentional processes and largely immune to user-centric prioritization.

  1. Tauopathy PET and amyloid PET in the diagnosis of chronic traumatic encephalopathies: studies of a retired NFL player and of a man with FTD and a severe head injury.

    Science.gov (United States)

    Mitsis, E M; Riggio, S; Kostakoglu, L; Dickstein, D L; Machac, J; Delman, B; Goldstein, M; Jennings, D; D'Antonio, E; Martin, J; Naidich, T P; Aloysi, A; Fernandez, C; Seibyl, J; DeKosky, S T; Elder, G A; Marek, K; Gordon, W; Hof, P R; Sano, M; Gandy, S

    2014-09-16

    Single, severe traumatic brain injury (TBI) which elevates CNS amyloid, increases the risk of Alzheimer's disease (AD); while repetitive concussive and subconcussive events as observed in athletes and military personnel, may increase the risk of chronic traumatic encephalopathy (CTE). We describe two clinical cases, one with a history of multiple concussions during a career in the National Football League (NFL) and the second with frontotemporal dementia and a single, severe TBI. Both patients presented with cognitive decline and underwent [(18)F]-Florbetapir positron emission tomography (PET) imaging for amyloid plaques; the retired NFL player also underwent [(18)F]-T807 PET imaging, a new ligand binding to tau, the main constituent of neurofibrillary tangles (NFT). Case 1, the former NFL player, was 71 years old when he presented with memory impairment and a clinical profile highly similar to AD. [(18)F]-Florbetapir PET imaging was negative, essentially excluding AD as a diagnosis. CTE was suspected clinically, and [(18)F]-T807 PET imaging revealed striatal and nigral [(18)F]-T807 retention consistent with the presence of tauopathy. Case 2 was a 56-year-old man with personality changes and cognitive decline who had sustained a fall complicated by a subdural hematoma. At 1 year post injury, [(18)F]-Florbetapir PET imaging was negative for an AD pattern of amyloid accumulation in this subject. Focal [(18)F]-Florbetapir retention was noted at the site of impact. In case 1, amyloid imaging provided improved diagnostic accuracy where standard clinical and laboratory criteria were inadequate. In that same case, tau imaging with [(18)F]-T807 revealed a subcortical tauopathy that we interpret as a novel form of CTE with a distribution of tauopathy that mimics, to some extent, that of progressive supranuclear palsy (PSP), despite a clinical presentation of amnesia without any movement disorder complaints or signs. A key distinguishing feature is that our patient presented

  2. Cold-Water Corals and Anthropogenic Impacts in La Fonera Submarine Canyon Head, Northwestern Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Galderic Lastras

    Full Text Available We assess the occurrence and extent of cold-water coral (CWC species Madrepora oculata and Dendrophyllia cornigera, as well as gorgonian red coral Corallium rubrum, in La Fonera canyon head (Northwestern Mediterranean Sea, as well as human impacts taking place in their habitats. Occurrence is assessed based on Remotely Operated Vehicle (ROV video imaging. Terrain classification techniques are applied to high-resolution swath bathymetric data to obtain semi-automatic interpretative maps to identify the relationship between coral distribution patterns and canyon environments. A total of 21 ROV immersions were carried out in different canyon environments at depths ranging between 79 and 401 m. Large, healthy colonies of M. oculata occur on abrupt, protected, often overhanging, rocky sections of the canyon walls, especially in Illa Negra branch. D. cornigera is sparser and evenly distributed at depth, on relatively low sloping areas, in rocky but also partially sedimented areas. C. rubrum is most frequent between 100 and 160 m on highly sloping rocky areas. The probable extent of CWC habitats is quantified by applying a maximum entropy model to predict habitat suitability: 0.36 km2 yield M. oculata occurrence probabilities over 70%. Similar predictive models have been produced for D. cornigera and C. rubrum. All ROV transects document either the presence of litter on the seafloor or pervasive trawling marks. Nets and longlines are imaged entangled on coral colonies. Coral rubble is observed at the foot of impacted colonies. Some colonies are partially covered by sediment that could be the result of the resuspension generated by bottom trawling on neighbouring fishing grounds, which has been demonstrated to be responsible of daily increases in sediment fluxes within the canyon. The characteristics of the CWC community in La Fonera canyon are indicative that it withstands high environmental stress of both natural and human origin.

  3. The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hun; Jeong, Ho Gul; Hwang, Jae Joon; Lee, Jung Hee; Han, Sang Sun [Dept. of Oral and Maxillofacial Radiology, Yonsei University, College of Dentistry, Seoul (Korea, Republic of)

    2016-06-15

    The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions.

  4. The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

    Science.gov (United States)

    Kim, Jae Hun; Hwang, Jae Joon; Lee, Jung-Hee

    2016-01-01

    Purpose The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. Materials and Methods CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. Results In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. Conclusion The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions. PMID:27358821

  5. Demographics, Velocity Distributions, and Impact Type as Predictors of AIS 4+ Head Injuries in Motor Vehicle Crashes

    Science.gov (United States)

    Yoganandan, Narayan; Fitzharris, Michael; Pintar, Frank A.; Stemper, Brian D.; Rinaldi, James; Maiman, Dennis J.; Fildes, Brian N.

    2011-01-01

    The objective of the study was to determine differences between the United States-based NASS and CIREN and Australia-based ANCIS databases in occupant-, crash-, and vehicle-related parameters for AIS 4+ head injuries in motor vehicle crashes. Logistic regression analysis was performed to examine roles of the change in velocity (DV), crash type (frontal, far-side, nearside, rear impact), seatbelt use, and occupant position, gender, age, stature, and body mass in cranial traumas. Belted and unbelted non-ejected occupant (age >16 years) data from 1997–2006 were used for the NASS and CIREN datasets, and 2000–2010 for ANCIS. Vehicle model year, and occupant position and demographics including body mass index (BMI) data were obtained. Injuries were coded using AIS 1990–1998 update. Similarities were apparent across all databases: mean demographics were close to the mid-size anthropometry, mean BMI was in the normal to overweight range, and representations of extreme variations were uncommon. Side impacts contributed to over one-half of the ensemble, implying susceptibility to head trauma in this mode. Odds of sustaining head injury increased by 4% per unit increase in DV (OR: 1.04, 95% CI: 1.03–1.04, pcrash- and occupant-related outcomes from the two continents indicate a worldwide need to revise the translation acceleration-based head injury criterion to include the angular component in an appropriate format for improved injury assessment and mitigation. PMID:22105402

  6. Impact of chemotherapy on the outcome of osteosarcoma of the head and neck in adults

    Science.gov (United States)

    Boon, Eline; van der Graaf, Winette T. A.; Gelderblom, Hans; Tesselaar, Margot E. T.; van Es, Robert J. J.; Oosting, Sjoukje F.; de Bree, Remco; van Meerten, Esther; Hoeben, Ann; Smeele, Ludi E.; Willems, Stefan M.; Witjes, Max J. H.; Buter, Jan; Baatenburg de Jong, Robert J.; Flucke, Uta E.; Peer, Petronella G. M.; Bovée, Judith V. M. G.

    2016-01-01

    Abstract Background There is an ongoing debate about the value of (neo‐)adjuvant chemotherapy in high‐ and intermediate‐grade osteosarcoma of the head and neck. Methods All records of patients older than 16 years diagnosed with osteosarcoma of the head and neck in the Netherlands between 1993 and 2013 were reviewed. Results We identified a total of 77 patients with an osteosarcoma of the head and neck; the 5‐year overall survival (OS) was 55%. In 50 patients with surgically resected high‐ or intermediate‐grade osteosarcoma of the head and neck younger than 75 years, univariate and multivariable analysis, adjusting for age and resection margins, showed that patients who had not received chemotherapy had a significantly higher risk of local recurrence (hazard ratio [HR] = 3.78 and 3.66, respectively). Conclusion In patients younger than 75 years of age with surgically resected high‐ and intermediate‐grade osteosarcoma of the head and neck, treatment with (neo‐)adjuvant chemotherapy resulted in a significantly smaller risk of local recurrence. Therefore, we suggest (neo‐)adjuvant chemotherapy in patients amenable to chemotherapy. © 2016 The Authors Head & Neck Published by Wiley Periodicals, Inc. Head Neck 39: 140–146, 2017 PMID:27507299

  7. Cavum Septi Pellucidi in Symptomatic Former Professional Football Players.

    Science.gov (United States)

    Koerte, Inga K; Hufschmidt, Jakob; Muehlmann, Marc; Tripodis, Yorghos; Stamm, Julie M; Pasternak, Ofer; Giwerc, Michelle Y; Coleman, Michael J; Baugh, Christine M; Fritts, Nathan G; Heinen, Florian; Lin, Alexander; Stern, Robert A; Shenton, Martha E

    2016-02-15

    Post-mortem studies reveal a high rate of cavum septi pellucidi (CSP) in chronic traumatic encephalopathy (CTE). It remains, however, to be determined whether or not the presence of CSP may be a potential in vivo imaging marker in populations at high risk to develop CTE. The aim of this study was to evaluate CSP in former professional American football players presenting with cognitive and behavioral symptoms compared with noncontact sports athletes. Seventy-two symptomatic former professional football players (mean age 54.53 years, standard deviation [SD] 7.97) as well as 14 former professional noncontact sports athletes (mean age 57.14 years, SD 7.35) underwent high-resolution structural 3T magnetic resonance imaging. Two raters independently evaluated the CSP, and interrater reliability was calculated. Within National Football League players, an association of CSP measures with cognitive and behavioral functioning was evaluated using a multivariate mixed effects model. The measurements of the two raters were highly correlated (CSP length: rho = 0.98; Intraclass Correlation Coefficient [ICC] 0.99; p football players compared with athlete controls. In addition, a greater length of CSP was associated with decreased performance on a list learning task (Neuropsychological Assessment Battery List A Immediate Recall, p = 0.04) and decreased test scores on a measure of estimate verbal intelligence (Wide Range Achievement Test Fourth Edition Reading Test, p = 0.02). Given the high prevalence of CSP in neuropathologically confirmed CTE in addition to the results of this study, CSP may serve as a potential early in vivo imaging marker to identify those at high risk for CTE. Future research is needed to investigate the pathomechanism underlying the development of CSP after repetitive head impacts, and its potential association with neuropathologically confirmed CTE.

  8. Rotational Acceleration during Head Impact Resulting from Different Judo Throwing Techniques

    Science.gov (United States)

    MURAYAMA, Haruo; HITOSUGI, Masahito; MOTOZAWA, Yasuki; OGINO, Masahiro; KOYAMA, Katsuhiro

    2014-01-01

    Most severe head injuries in judo are reported as acute subdural hematoma. It is thus necessary to examine the rotational acceleration of the head to clarify the mechanism of head injuries. We determined the rotational acceleration of the head when the subject is thrown by judo techniques. One Japanese male judo expert threw an anthropomorphic test device using two throwing techniques, Osoto-gari and Ouchigari. Rotational and translational head accelerations were measured with and without an under-mat. For Osoto-gari, peak resultant rotational acceleration ranged from 4,284.2 rad/s2 to 5,525.9 rad/s2 and peak resultant translational acceleration ranged from 64.3 g to 87.2 g; for Ouchi-gari, the accelerations respectively ranged from 1,708.0 rad/s2 to 2,104.1 rad/s2 and from 120.2 g to 149.4 g. The resultant rotational acceleration did not decrease with installation of an under-mat for both Ouchi-gari and Osoto-gari. We found that head contact with the tatami could result in the peak values of translational and rotational accelerations, respectively. In general, because kinematics of the body strongly affects translational and rotational accelerations of the head, both accelerations should be measured to analyze the underlying mechanism of head injury. As a primary preventative measure, throwing techniques should be restricted to participants demonstrating ability in ukemi techniques to avoid head contact with the tatami. PMID:24477065

  9. Impact of head immobilization position on dose distribution in patients of brainstem glioma

    Directory of Open Access Journals (Sweden)

    Seema Sharma

    2015-03-01

    Full Text Available Purpose: The purpose of this study is to investigate the impact of patient position (supine and prone on conventional bilateral field, three dimensional conformal radiotherapy (3DCRT and intensity modulated radiotherapy (IMRT treatment plans in patients of brainstem glioma with a view to exploring the possibility of avoiding beam entry through immobilization accessories. Methods: Five patients of brainstem glioma were immobilized and scanned in supine and prone positions with a combination of head rest and thermoplastic cast. Each patient was planned with three techniques: (i 2-fields bilateral (ii 3-fields 3DCRT, and (iii 5-fields IMRT. Plan quality was analyzed in terms of planning target volume (PTV coverage and dose to various critical organs at risk (OAR for both the supine and prone treatment positions. Results: In case of bilateral fields (parallel opposed planning, the PTV coverage and dose to the OAR were almost similar for both the supine and prone positions. In 3DCRT plan, although the PTV coverage and dose to critical structures were comparable for both the supine and prone position, dose to cochlea was lower for the prone position plan. A modest decrease in maximum dose to optic nerves and mean dose to temporal lobes were also observed for the prone position plan. In IMRT plans, the PTV coverage and homogeneity were comparable in both the supine and prone positions. Reduction in average maximum and mean doses to all OARs with functional subunit (FSU in series and parallel respectively was observed in the IMRT plan for prone position when compared to the supine position.Conclusion: Supine and prone positions resulted in almost similar dose distribution in all the three techniques applied. At some instances, the prone position showed better normal tissues sparing when compared to supine. Moreover, prone position is more likely to avoid attenuation due to immobilization devices and uncertainty in dose calculation under large

  10. Capabilities of Helmets for Preventing Head Injuries Induced by Ballistic Impacts

    Directory of Open Access Journals (Sweden)

    D.V. Balandin

    2004-01-01

    Full Text Available The limiting performance of ballistically loaded helmets designed to reduce head injuries is studied analytically. The projectile does not penetrate the helmet. This analysis evaluates the absolute minimum of the peak displacement of the helmet shell relative to the head, provided that criteria measuring the severity of head injuries lie within prescribed limits. Rather than optimize a specific design configuration, e.g. a viscoelastic foam liner, characteristics of a time-dependent force representing the helmet liner are calculated. The formulation reduces the limiting performance analysis to an optimal control problem.

  11. Oncogenic impact of human papilloma virus in head and neck cancer.

    LENUS (Irish Health Repository)

    Heffernan, C B

    2012-02-01

    There is considerable debate within the literature about the significance of human papilloma virus in head and neck squamous cell carcinoma, and its potential influence on the prevention, diagnosis, grading, treatment and prognosis of these cancers. Cigarette smoking and alcohol consumption have traditionally been cited as the main risk factors for head and neck cancers. However, human papilloma virus, normally associated with cervical and other genital carcinomas, has emerged as a possible key aetiological factor in head and neck squamous cell carcinoma, especially oropharyngeal cancers. These cancers pose a significant financial burden on health resources and are increasing in incidence. The recent introduction of vaccines targeted against human papilloma virus types 16 and 18, to prevent cervical cancer, has highlighted the need for ongoing research into the importance of human papilloma virus in head and neck squamous cell carcinoma.

  12. The relation between mechanical impact parameters and most frequent bicycle related head injuries

    NARCIS (Netherlands)

    Monea, A.G.; Perre, G. van der; Baeck, K.; Delye, H.H.; Verschueren, P.; Forausebergher, E.; Lierde, C. van; Verpoest, I.; Sloten, J. van der; Goffin, J.; Depreitere, B.

    2014-01-01

    The most frequent head injuries resulting from bicycle accidents include skull fracture acute subdural hematoma (ASDH), cerebral contusions, and diffuse axonal injury (DAI). This review includes epidemiological studies, cadaver experiments, in vivo imaging, image processing techniques, and computer

  13. Impacts of Social-Emotional Curricula on Three-Year-Olds: Exploratory Findings from the Head Start CARES Demonstration. Research Snapshot. OPRE Report 2014-78

    Science.gov (United States)

    Hsueh, JoAnn; Lowenstein, Amy E.; Morris, Pamela; Mattera, Shira K.; Bangser, Michael

    2014-01-01

    This report presents exploratory impact findings for 3-year-olds from the Head Start CARES demonstration, a large-scale randomized controlled trial implemented in Head Start centers for one academic year across the country. The study was designed primarily to test the effects of the enhancements on 4-year-olds, but it also provides an opportunity…

  14. Does superior caval vein pressure impact head growth in Fontan circulation?

    Science.gov (United States)

    Trachsel, Tina; Balmer, Christian; Wåhlander, Håkan; Weber, Roland; Dave, Hitendu; Poretti, Andrea; Kretschmar, Oliver; Cavigelli-Brunner, Anna

    2016-10-01

    Patients with bidirectional cavopulmonary anastomosis have unphysiologically high superior caval vein pressure as it equals pulmonary artery pressure. Elevated superior caval vein pressure may cause communicating hydrocephalus and macrocephaly. This study analysed whether there exists an association between head circumference and superior caval vein pressure in patients with single ventricle physiology. We carried out a retrospective analysis of infants undergoing Fontan completion at our institution from 2007 to 2013. Superior caval vein pressures were measured during routine catheterisation before bidirectional cavopulmonary anastomosis and Fontan completion as well as head circumference, adjusted to longitudinal age-dependent percentiles. We included 74 infants in our study. Median ages at bidirectional cavopulmonary anastomosis and Fontan were 4.8 (1.6-12) and 27.9 (7-40.6) months, respectively. Head circumference showed significant growth from bidirectional cavopulmonary anastomosis until Fontan completion (7th (0-100th) versus 20th (0-100th) percentile). There was no correlation between superior caval vein pressure and head circumference before Fontan (R2=0.001). Children with lower differences in superior caval vein pressures between pre-bidirectional cavopulmonary anastomosis and pre-Fontan catheterisations showed increased growth of head circumference (R2=0.19). Patients with moderately elevated superior caval vein pressure associated with single ventricle physiology did not have a tendency to develop macrocephaly. There is no correlation between superior caval vein pressure before Fontan and head circumference, but between bidirectional cavopulmonary anastomosis and Fontan head circumference increases significantly. This may be explained by catch-up growth of head circumference in patients with more favourable haemodynamics and concomitant venous pressures in the lower range. Further studies with focus on high superior caval vein pressures are needed to

  15. Evidence of cognitive dysfunction after soccer playing with ball heading using a novel tablet-based approach.

    Directory of Open Access Journals (Sweden)

    Marsha R Zhang

    Full Text Available Does frequent head-to-ball contact cause cognitive dysfunctions and brain injury to soccer players? An iPad-based experiment was designed to examine the impact of ball-heading among high school female soccer players. We examined both direct, stimulus-driven, or reflexive point responses (Pro-Point as well as indirect, goal-driven, or voluntary point responses (Anti-Point, thought to require cognitive functions in the frontal lobe. The results show that soccer players were significantly slower than controls in the Anti-Point task but displayed no difference in Pro-Point latencies, indicating a disruption specific to voluntary responses. These findings suggest that even subconcussive blows in soccer can result in cognitive function changes that are consistent with mild traumatic brain injury of the frontal lobes. There is great clinical and practical potential of a tablet-based application for quick detection and monitoring of cognitive dysfunction.

  16. Evidence of cognitive dysfunction after soccer playing with ball heading using a novel tablet-based approach.

    Science.gov (United States)

    Zhang, Marsha R; Red, Stuart D; Lin, Angela H; Patel, Saumil S; Sereno, Anne B

    2013-01-01

    Does frequent head-to-ball contact cause cognitive dysfunctions and brain injury to soccer players? An iPad-based experiment was designed to examine the impact of ball-heading among high school female soccer players. We examined both direct, stimulus-driven, or reflexive point responses (Pro-Point) as well as indirect, goal-driven, or voluntary point responses (Anti-Point), thought to require cognitive functions in the frontal lobe. The results show that soccer players were significantly slower than controls in the Anti-Point task but displayed no difference in Pro-Point latencies, indicating a disruption specific to voluntary responses. These findings suggest that even subconcussive blows in soccer can result in cognitive function changes that are consistent with mild traumatic brain injury of the frontal lobes. There is great clinical and practical potential of a tablet-based application for quick detection and monitoring of cognitive dysfunction.

  17. The independent influence of concussive and sub-concussive impacts on soccer players' neurophysiological and neuropsychological function.

    Science.gov (United States)

    Moore, R Davis; Lepine, Julien; Ellemberg, Dave

    2017-02-01

    Accumulating research demonstrates that repetitive sub-concussive impacts can alter the structure, function and connectivity of the brain. However, the functional significance of these alterations as well as the independent contribution of concussive and sub-concussive impacts to neurophysiological and neuropsychological health are unclear. Accordingly, we compared the neurophysiological and neuropsychological function of contact athletes with (concussion group) and without (sub-concussion group) a history of concussion, to non-contact athletes. We evaluated event-related brain potentials (ERPs) elicited during an oddball task and performance on a targeted battery of neuropsychological tasks. Athletes in the sub-concussion and concussion groups exhibited similar amplitude reductions in the ERP indices of attentional resource allocation (P3b) and attentional orienting (P3a) relative to non-contact athletes. However, only athletes in the concussion group exhibited reduced amplitude in the ERP index of perceptual attention (N1). Athletes in the sub-concussion and concussion groups also exhibited deficits in memory recall relative to non-contact athletes, but athletes in the concussion group also exhibited significantly more recall errors than athletes in the sub-concussion group. Additionally, only athletes in the concussion group exhibited response delays during the oddball task. The current findings suggest that sub-concussive impacts are associated with alterations in the neurophysiological and neuropsychological indices of essential cognitive functions, albeit to a lesser degree than the combination of sub-concussive and concussive impacts.

  18. Impact test comparisons of 20th and 21st century American football helmets.

    Science.gov (United States)

    Bartsch, Adam; Benzel, Edward; Miele, Vincent; Prakash, Vikas

    2012-01-01

    Concussion is the signature American football injury of the 21st century. Modern varsity helmets, as compared with vintage leather helmets, or "leatherheads," are widely believed to universally improve protection by reducing head impact doses and head injury risk for the 3 million young football players in the US. The object of this study was to compare the head impact doses and injury risks with 11 widely used 21st century varsity helmets and 2 early 20th century leatherheads and to hypothesize what the results might mean for children wearing similar varsity helmets. In an injury biomechanics laboratory, the authors conducted front, oblique front, lateral, oblique rear, and rear head impact tests at 5.0 m/second using helmeted headforms, inducing near- and subconcussive head impact doses on par with approximately the 95th percentile of on-field collision severity. They also calculated impact dose injury risk parameters common to laboratory and on-field traumatic neuromechanics: linear acceleration, angular acceleration, angular velocity, Gadd Severity Index, diffuse axonal injury, acute subdural hematoma, and brain contusion. In many instances the head impact doses and head injury risks while wearing vintage leatherheads were comparable to or better than those while wearing several widely used 21st century varsity helmets. The authors do not advocate reverting to leather headgear, but they do strongly recommend, especially for young players, instituting helmet safety designs and testing standards, which encourage the minimization of linear and angular impact doses and injury risks in near- and subconcussive head impacts.

  19. The impact of head movements on EEG and contact impedance: an adaptive filtering solution for motion artifact reduction.

    Science.gov (United States)

    Mihajlovic, Vojkan; Patki, Shrishail; Grundlehner, Bernard

    2014-01-01

    Designing and developing a comfortable and convenient EEG system for daily usage that can provide reliable and robust EEG signal, encompasses a number of challenges. Among them, the most ambitious is the reduction of artifacts due to body movements. This paper studies the effect of head movement artifacts on the EEG signal and on the dry electrode-tissue impedance (ETI), monitored continuously using the imec's wireless EEG headset. We have shown that motion artifacts have huge impact on the EEG spectral content in the frequency range lower than 20 Hz. Coherence and spectral analysis revealed that ETI is not capable of describing disturbances at very low frequencies (below 2 Hz). Therefore, we devised a motion artifact reduction (MAR) method that uses a combination of a band-pass filtering and multi-channel adaptive filtering (AF), suitable for real-time MAR. This method was capable of substantially reducing artifacts produced by head movements.

  20. Measurement of Hybrid III Head Impact Kinematics Using an Accelerometer and Gyroscope System in Ice Hockey Helmets.

    Science.gov (United States)

    Allison, Mari A; Kang, Yun Seok; Maltese, Matthew R; Bolte, John H; Arbogast, Kristy B

    2015-08-01

    Helmet-based instrumentation is used to study the biomechanics of concussion. The most extensively used systems estimate rotational acceleration from linear acceleration, but new instrumentation measures rotational velocity using gyroscopes, potentially reducing error. This study compared kinematics from an accelerometer and gyroscope-containing system to reference measures. A Hybrid III (HIII) adult male anthropometric test device head and neck was fit with two helmet brands, each instrumented with gForce Tracker (GFT) sensor systems in four locations. Helmets were impacted at various speeds and directions. Regression relationships between GFT-measured and reference peak kinematics were quantified, and influence of impact direction, sensor location, and helmet brand was evaluated. The relationship between the sensor output and the reference acceleration/velocity experienced by the head was strong. Coefficients of determination for data stratified by individual impact directions ranged from 0.77 to 0.99 for peak linear acceleration and from 0.78 to 1.0 for peak rotational velocity. For the data from all impact directions combined, coefficients of determination ranged from 0.60 to 0.80 for peak resultant linear acceleration and 0.83 to 0.91 for peak resultant rotational velocity. As expected, raw peak resultant linear acceleration measures exhibited large percent differences from reference measures. Adjustment using regressions resulted in average absolute errors of 10-15% if regression adjustments were done by impact direction or 25-40% if regressions incorporating data from all impact directions were used. Average absolute percent differences in raw peak resultant rotational velocity were much lower, around 10-15%. It is important to define system accuracy for a particular helmet brand, sensor location, and impact direction in order to interpret real-world data.

  1. Head impact accelerations for brain strain-related responses in contact sports: a model-based investigation.

    Science.gov (United States)

    Ji, Songbai; Zhao, Wei; Li, Zhigang; McAllister, Thomas W

    2014-10-01

    Both linear [Formula: see text] and rotational [Formula: see text] accelerations contribute to head impacts on the field in contact sports; however, they are often isolated in injury studies. It is critical to evaluate the feasibility of estimating brain responses using isolated instead of full degrees-of-freedom (DOFs) accelerations. In this study, we investigated the sensitivities of regional brain strain-related responses to resultant [Formula: see text] and [Formula: see text] as well as the relative contributions of these acceleration components to the responses via random sampling and linear regression using parameterized, triangulated head impacts with kinematic variable values based on on-field measurements. Two independently established and validated finite element models of the human head were employed to evaluate model-consistency and dependency in results: the Dartmouth Head Injury Model and Simulated Injury Monitor. For the majority of the brain, volume-weighted regional peak strain, strain rate, and von Mises stress accumulated from the simulation significantly correlated with the product of the magnitude and duration of [Formula: see text], or effectively, the rotational velocity, but not to [Formula: see text]. Responses from [Formula: see text]-only were comparable to the full-DOF counterparts especially when normalized by injury-causing thresholds (e.g., volume fractions of large differences virtually diminished (i.e., [Formula: see text]1 %) at typical difference percentage levels of 1-4 % on average). These model-consistent results support the inclusion of both rotational acceleration magnitude and duration into kinematics-based injury metrics and demonstrate the feasibility of estimating strain-related responses from isolated [Formula: see text] for analyses of strain-induced injury relevant to contact sports without significant loss of accuracy, especially for the cerebrum.

  2. The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia.

    Science.gov (United States)

    Walter, Scott R; Olivier, Jake; Churches, Tim; Grzebieta, Raphael

    2011-11-01

    The study aimed to assess the effect of compulsory cycle helmet legislation on cyclist head injuries given the ongoing debate in Australia as to the efficacy of this measure at a population level. We used hospital admissions data from New South Wales, Australia, from a 36 month period centred at the time legislation came into effect. Negative binomial regression of hospital admission counts of head and limb injuries to cyclists were performed to identify differential changes in head and limb injury rates at the time of legislation. Interaction terms were included to allow different trends between injury types and pre- and post-law time periods. To avoid the issue of lack of cyclist exposure data, we assumed equal exposures between head and limb injuries which allowed an arbitrary proxy exposure to be used in the model. As a comparison, analyses were also performed for pedestrian data to identify which of the observed effects were specific to cyclists. In general, the models identified a decreasing trend in injury rates prior to legislation, an increasing trend thereafter and a drop in rates at the time legislation was enacted, all of which were thought to represent background effects in transport safety. Head injury rates decreased significantly more than limb injury rates at the time of legislation among cyclists but not among pedestrians. This additional benefit was attributed to compulsory helmet legislation. Despite numerous data limitations, we identified evidence of a positive effect of compulsory cycle helmet legislation on cyclist head injuries at a population level such that repealing the law cannot be justified.

  3. Evaluating the Impact of Head Rotation Amplification on Virtual Reality Training Effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Ragan, Eric D [ORNL; Bowman, Doug A [Virginia Polytechnic Institute and State University; Scerbo, Siroberto [Virginia Polytechnic Institute and State University; Bacim, Felipe [Virginia Polytechnic Institute and State University

    2013-01-01

    Virtual reality (VR) systems have been proposed for use in numerous training scenarios, such as room clearing, which require the trainee to maintain spatial awareness. But many VR training systems lack a fully surrounding display, requiring trainees to use a combination of physical and virtual turns to view the environment, thus decreasing spatial awareness. One solution to this problem is to amplify head rotations, such that smaller physical turns are mapped to larger virtual turns, allowing trainees to view the surrounding environment with head movements alone. For example, in a multi-monitor system covering only a 90-degree field of regard, head rotations could be amplified four times to allow the user to see the entire 360-degree surrounding environment. This solution is attractive because it can be used with lower-cost VR systems and does not require virtual turning. However, the effects of amplified head rotations on spatial awareness and training transfer are not well understood. We hypothesized that small amounts of amplification might be tolerable, but that larger amplifications might cause trainees to become disoriented and to have decreased task performance and training transfer. In this paper, we will present our findings from an experiment designed to investigate these hypotheses. The experiment placed users in a virtual warehouse and asked them to move from room to room, counting objects placed around them in space. We varied the amount of amplification applied during these trials, and also varied the type of display used (head-mounted display or CAVE). We measured task performance and spatial awareness. We then assessed training transfer in an assessment environment with a fully surrounding display and no amplification. The results of this study will inform VR training system developers about the potential negative effects of using head rotation amplification and contribute to more effective VR training system design.

  4. Utility of providing a concussion definition in the assessment of concussion history in former NFL players.

    Science.gov (United States)

    Alosco, Michael L; Jarnagin, Johnny; Tripodis, Yorghos; Martin, Brett; Chaisson, Christine; Baugh, Christine M; Torres, Alcy; Nowinski, Christopher J; Cantu, Robert C; Stern, Robert A

    2017-01-01

    Former National Football League (NFL) players' working knowledge of concussion has not yet been evaluated, despite this population being a major clinical research target due to the association between repetitive head impacts (RHI) and long-term clinical impairments. This study examined former NFL players' understanding of the current concussion definition, and the association between number of concussions with clinical function. 95 former NFL players (mean age = 55.29; mean NFL year = 8.10) self-reported number of concussions before being provided with a concussion definition and after being read a modern definition of concussion. Subjects reported number of concussions with loss of consciousness (LOC). Principal Component Analysis of a battery of tests generated behaviour/mood, psychomotor speed/executive function, and verbal and visual memory factor scores. Post-definition number of concussions (median = 50) was five times the pre-definition (median = 10; p < 0.001). Greater pre- (p = 0.019) and post-definition concussions (p = 0.036) correlated with worse behaviour/mood scores, after controlling for years of football played, with specific effects for depressive symptoms and impulsivity. LOC did not account for variance beyond number of concussions. Practitioners and clinical researchers should provide a definition of concussion in the assessment of concussion history in former football players to facilitate accuracy and standardization.

  5. The Impact of Gross Anatomy on the Future Head and Neck Surgeon

    Science.gov (United States)

    Archibald, David J.; Carlson, Matthew L.

    2009-01-01

    Gross anatomy is not only a rite of passage for medical students as they enter the world of practicing medicine but may also be an unrecognized fork in the road in their pursuit of choosing a medical specialty. Otolaryngology: head and neck surgery tends to be poorly represented in medical school curriculum, often only offered as an elective…

  6. Supporting Head Start Parents: Impact of a Text Message Intervention on Parent-Child Activity Engagement

    Science.gov (United States)

    Hurwitz, Lisa B.; Lauricella, Alexis R.; Hanson, Ann; Raden, Anthony; Wartella, Ellen

    2015-01-01

    Head Start emphasises parent engagement as a critical strategy in promoting children's long-term learning. Parents can support children's positive development by engaging them in stimulating activities. The following study assessed whether a service that delivered parenting tips via text message could prompt parents of children enrolled in Head…

  7. Sex Differences in Anthropometrics and Heading Kinematics Among Division I Soccer Athletes.

    Science.gov (United States)

    Bretzin, Abigail C; Mansell, Jamie L; Tierney, Ryan T; McDevitt, Jane K

    Soccer players head the ball repetitively throughout their careers; this is also a potential mechanism for a concussion. Although not all soccer headers result in a concussion, these subconcussive impacts may impart acceleration, deceleration, and rotational forces on the brain, leaving structural and functional deficits. Stronger neck musculature may reduce head-neck segment kinematics. The relationship between anthropometrics and soccer heading kinematics will not differ between sexes. The relationship between anthropometrics and soccer heading kinematics will not differ between ball speeds. Pilot, cross-sectional design. Level 3. Division I soccer athletes (5 male, 8 female) were assessed for head-neck anthropometric and neck strength measurements in 6 directions (ie, flexion, extension, right and left lateral flexions and rotations). Participants headed the ball 10 times (25 or 40 mph) while wearing an accelerometer secured to their head. Kinematic measurements (ie, linear acceleration and rotational velocity) were recorded at 2 ball speeds. Sex differences were observed in neck girth ( t = 5.09, P soccer heading kinematics for sex and ball speeds. Neck girth and neck strength are factors that may limit head impact kinematics.

  8. Effect of the Head Restraint Properties on Head-neck Kinematics in Low Speed Rear-end Impacts%汽车低速追尾碰撞中人体颈部伤害及保护系统研究

    Institute of Scientific and Technical Information of China (English)

    乔维高; 商博

    2011-01-01

    在MADYMO软件中使用BioRID Ⅱ后碰撞假人建立追尾碰撞模型,分析了头枕位置和倾角参数对汽车发生追尾碰撞时头颈部动力学的影响,并使用颈部损伤准则值NIC和Nkm来评估颈部损伤的风险.仿真结果表明这些因素对颈部的动力学响应有着重要影响,高而且靠近头部,并且有适当增大倾角的头枕,有助于减小颈部的损伤.%Head restraint plays a very important part in protecting the occupants during the rear impact. The present study investigated the effects of the position, tilt angle of the head restraint on the biomechanical responses and related injury measures of the neck in a rear-end impact. A series of simulated rear-end impacts were conducted by applying a rear-end impact model, which is developed in the MADYMO package by using the BioRID II dummy. Then, the neck injury criterion (NIC) and JV\\-km were utilized to assess the likelihood of injury. The results show that modifying the head restraint may influence the head-neck kinematics to a great extent. It is possible to reduce the neck injury risk by positioning the head restraint higher and closer to the head, and with a proper larger tilt angle.

  9. Postradiation trismus and its impact on quality of life in patients with head and neck cancer.

    Science.gov (United States)

    Lee, Li-Yun; Chen, Shu-Ching; Chen, Wen-Cheng; Huang, Bing-Shen; Lin, Chien-Yu

    2015-02-01

    The aims of this study were to investigate the following in patients with head and neck cancer (HNC): (1) factors related to trismus that predict the development of trismus, (2) factors affecting quality of life and measurements of these factors, and (3) comparison of these findings in patients with and without trismus to evaluate the effects of trismus on quality of life. This cross-sectional study included the questionnaires: the Hospital Anxiety and Depression Scale (HADS) - Depression Subscale, the Chewing Function Questionnaire (CFQ), and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Head and Neck Cancer Module (EORTC QLQ-HN35). A scaled ruler was used to measure maximal intercisal opening (MIO). Of the 104 patients in the study, 8.7% had clinical depression. The average MIO was 35.81 mm, and 47.1% of patients had trismus. Moderate levels of chewing dysfunction with regard to different types of food were noted. Lower body mass index, chemoradiotherapy treatment, longer time since treatment completion, and higher radiation dose were significantly associated with trismus. Such patients had significantly lower head and neck-specific quality of life in terms of social contact, sexuality, teeth, mouth opening, dry mouth, feeling ill, nutritional supplement, and weight loss. Patients with trismus should be provided mouth opening exercises after treatment and programs to improve trismus and quality of life. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Impact of genetic targets on therapy in head and neck squamous cell carcinoma.

    Science.gov (United States)

    Chaikhoutdinov, Irina; Goldenberg, David

    2013-01-01

    Despite advances in surgical technique, radiation therapy and chemotherapy, the mortality from head and neck squamous cell carcinoma (HNSCC) has not improved significantly. Squamous cell carcinoma is caused by tobacco use, alcohol consumption and infection with high-risk types of human papillomavirus. It is the 6th most common cancer in the world, with upwards of 45,000 new cases reported yearly in the United States alone.In recent years, there has been a significant increase in the understanding of the molecular and genetic pathogenesis of head and neck cancer, shedding light on the unexpected heterogeneity of the disease. Genetic analysis has led to new classification schemes for HNSCC, with different subgroups exhibiting different prognoses. In addition, multiple targets in aberrant signaling pathways have been identified using increasingly sophisticated bio-informatics tools. Advances in technology have allowed for novel delivery mechanisms to introduce genetic material into cells to produce a therapeutic effect by targeting cancer cells via a number of different approaches.A pressing need to develop novel therapies to augment current treatment modalities has led to a number of translational studies involving gene therapy in the treatment of HNSCC. This article will focus on a review of the most recent developments in molecular biology of head and neck squamous cell carcinoma in regards to possible targets for gene therapy, as well as the array of novel therapeutic strategies directed at these targets.

  11. The biomechanics of concussion in unhelmeted football players in Australia: a case–control study

    Science.gov (United States)

    McIntosh, Andrew S; Patton, Declan A; Fréchède, Bertrand; Pierré, Paul-André; Ferry, Edouard; Barthels, Tobias

    2014-01-01

    Objective Concussion is a prevalent brain injury in sport and the wider community. Despite this, little research has been conducted investigating the dynamics of impacts to the unprotected human head and injury causation in vivo, in particular the roles of linear and angular head acceleration. Setting Professional contact football in Australia. Participants Adult male professional Australian rules football players participating in 30 games randomly selected from 103 games. Cases selected based on an observable head impact, no observable symptoms (eg, loss-of-consciousness and convulsions), no on-field medical management and no injury recorded at the time. Primary and secondary outcome measures A data set for no-injury head impact cases comprising head impact locations and head impact dynamic parameters estimated through rigid body simulations using the MAthematical DYnamic MOdels (MADYMO) human facet model. This data set was compared to previously reported concussion case data. Results Qualitative analysis showed that the head was more vulnerable to lateral impacts. Logistic regression analyses of head acceleration and velocity components revealed that angular acceleration of the head in the coronal plane had the strongest association with concussion; tentative tolerance levels of 1747 rad/s2 and 2296 rad/s2 were reported for a 50% and 75% likelihood of concussion, respectively. The mean maximum resultant angular accelerations for the concussion and no-injury cases were 7951 rad/s2 (SD 3562 rad/s2) and 4300 rad/s2 (SD 3657 rad/s2), respectively. Linear acceleration is currently used in the assessment of helmets and padded headgear. The 50% and 75% likelihood of concussion values for resultant linear head acceleration in this study were 65.1 and 88.5 g, respectively. Conclusions As hypothesised by Holbourn over 70 years ago, angular acceleration plays an important role in the pathomechanics of concussion, which has major ramifications in terms of

  12. The biomechanics of concussion in unhelmeted football players in Australia: a case-control study.

    Science.gov (United States)

    McIntosh, Andrew S; Patton, Declan A; Fréchède, Bertrand; Pierré, Paul-André; Ferry, Edouard; Barthels, Tobias

    2014-05-20

    Concussion is a prevalent brain injury in sport and the wider community. Despite this, little research has been conducted investigating the dynamics of impacts to the unprotected human head and injury causation in vivo, in particular the roles of linear and angular head acceleration. Professional contact football in Australia. Adult male professional Australian rules football players participating in 30 games randomly selected from 103 games. Cases selected based on an observable head impact, no observable symptoms (eg, loss-of-consciousness and convulsions), no on-field medical management and no injury recorded at the time. A data set for no-injury head impact cases comprising head impact locations and head impact dynamic parameters estimated through rigid body simulations using the MAthematical DYnamic MOdels (MADYMO) human facet model. This data set was compared to previously reported concussion case data. Qualitative analysis showed that the head was more vulnerable to lateral impacts. Logistic regression analyses of head acceleration and velocity components revealed that angular acceleration of the head in the coronal plane had the strongest association with concussion; tentative tolerance levels of 1747 rad/s(2) and 2296 rad/s(2) were reported for a 50% and 75% likelihood of concussion, respectively. The mean maximum resultant angular accelerations for the concussion and no-injury cases were 7951 rad/s(2) (SD 3562 rad/s(2)) and 4300 rad/s(2) (SD 3657 rad/s(2)), respectively. Linear acceleration is currently used in the assessment of helmets and padded headgear. The 50% and 75% likelihood of concussion values for resultant linear head acceleration in this study were 65.1 and 88.5 g, respectively. As hypothesised by Holbourn over 70 years ago, angular acceleration plays an important role in the pathomechanics of concussion, which has major ramifications in terms of helmet design and other efforts to prevent and manage concussion. Published by

  13. Do anthropogenic or coastal aerosol sources impact on a clean marine aerosol signature at Mace Head?

    Directory of Open Access Journals (Sweden)

    C. O'Dowd

    2013-03-01

    Full Text Available Atmospheric aerosols have been sampled and characterised at the Mace Head North East (N.E. Atlantic atmospheric research station since 1958, with many interesting phenomena being discovered. However, with the range of new discoveries and scientific advances, there has been a range of concomitant criticisms challenging the representativeness of aerosol sampled at the station to that of aerosol over the open ocean. Two recurring criticisms relate to the lack of representativeness due to enhanced coastal sources, thereby leading to artificially high values to aerosol parameters, and to the influence of long-range transport of anthropogenic aerosol and its potential dominance over, or drowning-out of, a natural marine aerosol signal. Here we review the results of previous experimental studies into marine aerosols over the N.E. Atlantic and at Mace Head with the aim of evaluating their representativeness relative to that of an open ocean aerosol with negligible anthropogenic influence. Particular focus is given to organic matter (OM aerosol. In summary, no correlation was found between OM and black carbon (BC either at BC levels of 0–15 or 15–50 ng m−3, suggesting that OM concentrations up to peak values of 3.8 μg m−3 are predominantly natural in origin. Sophisticated carbon isotope analysis and aerosol mass spectral finger printing corroborate the natural source of OM with 80% biogenic source apportionment being observed for general clean air conditions, rising to 98% during specific primary marine organic plumes when peak concentrations >3 μg m−3 are observed. A range of other experiments are discussed which corroborate the dominance of a marine signal under Mace Head clean air criteria along. Further, analysis of a series of experiments conducted at Mace Head conclude that negligible coastal, surf zone, or tidal effects are discernible in the submicron size range for sampling heights of 7 m and above. The Mace Head clean air criteria

  14. Is Heading in Youth Soccer Dangerous Play?

    Science.gov (United States)

    O'Kane, John W

    2016-01-01

    Soccer is among the most popular youth sports with over 3 million youth players registered in the U.S. Soccer is unique in that players intentionally use their head to strike the ball, leading to concerns that heading could cause acute or chronic brain injury, especially in the immature brains of children. Pub Med search without date restriction was conducted in November 2014 and August 2015 using the terms soccer and concussion, heading and concussion, and youth soccer and concussion. 310 articles were identified and reviewed for applicable content specifically relating to youth athletes, heading, and/or acute or chronic brain injury from soccer. Soccer is a low-risk sport for catastrophic head injury, but concussions are relatively common and heading often plays a role. At all levels of play, concussions are more likely to occur in the act of heading than with other facets of the game. While concussion from heading the ball without other contact to the head appears rare in adult players, some data suggests children are more susceptible to concussion from heading primarily in game situations. Contributing factors include biomechanical forces, less developed technique, and the immature brain's susceptibility to injury. There is no evidence that heading in youth soccer causes any permanent brain injury and there is limited evidence that heading in youth soccer can cause concussion. A reasonable approach based on U.S. Youth Soccer recommendations is to teach heading after age 10 in controlled settings, and heading in games should be delayed until skill acquisition and physical maturity allow the youth player to head correctly with confidence.

  15. Mechanisms for Triceps Surae Injury in High Performance Front Row Rugby Union Players: A Kinematic Analysis of Scrummaging Drills

    OpenAIRE

    Flavell, Carol A.; Sayers, Mark G.L.; Gordon, Susan J; Lee, James B.

    2013-01-01

    The front row of a rugby union scrum consists of three players. The loose head prop, hooker and tight head prop. The objective of this study was to determine if known biomechanical risk factors for triceps surae muscle injury are exhibited in the lower limb of front row players during contested scrummaging. Eleven high performance front row rugby union players were landmarked bilaterally at the posterior superior iliac spine (PSIS), greater trochanter, lateral femoral epicondyle, midline of t...

  16. Measurement of six degrees of freedom head kinematics in impact conditions employing six accelerometers and three angular rate sensors (6aω configuration).

    Science.gov (United States)

    Kang, Yun-Seok; Moorhouse, Kevin; Bolte, John H

    2011-11-01

    The ability to measure six degrees of freedom (6 DOF) head kinematics in motor vehicle crash conditions is important for assessing head-neck loads as well as brain injuries. A method for obtaining accurate 6 DOF head kinematics in short duration impact conditions is proposed and validated in this study. The proposed methodology utilizes six accelerometers and three angular rate sensors (6aω configuration) such that an algebraic equation is used to determine angular acceleration with respect to the body-fixed coordinate system, and angular velocity is measured directly rather than numerically integrating the angular acceleration. Head impact tests to validate the method were conducted using the internal nine accelerometer head of the Hybrid III dummy and the proposed 6aω scheme in both low (2.3 m/s) and high (4.0 m/s) speed impact conditions. The 6aω method was compared with a nine accelerometer array sensor package (NAP) as well as a configuration of three accelerometers and three angular rate sensors (3aω), both of which have been commonly used to measure 6 DOF kinematics of the head for assessment of brain and neck injuries. The ability of each of the three methods (6aω, 3aω, and NAP) to accurately measure 6 DOF head kinematics was quantified by calculating the normalized root mean squared deviation (NRMSD), which provides an average percent error over time. Results from the head impact tests indicate that the proposed 6aω scheme is capable of producing angular accelerations and linear accelerations transformed to a remote location that are comparable to that determined from the NAP scheme in both low and high speed impact conditions. The 3aω scheme was found to be unable to provide accurate angular accelerations or linear accelerations transformed to a remote location in the high speed head impact condition due to the required numerical differentiation. Both the 6aω and 3aω schemes were capable of measuring accurate angular displacement while the

  17. RETIRED MATCHES AMONG MALE PROFESSIONAL TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Kristijan Breznik

    2012-06-01

    Full Text Available The aim of this study was to explore the effect of characteristics of various games and players on the proportion of retired tennis matches in the Open Era of tennis. The data included over 420,000 matches played among 17,553 tennis players in the period from 1968 to the end of 2010. The influence of the surface type was clearly confirmed, with the proportion of retired matches being higher on hard and clay courts compared to grass and carpet surfaces. Similarly, more retired matches were observed in outdoor venues than in indoor ones. The impact of other variables, tournament types, rounds at which the game was played and both players' ranks, is more ambiguous. Our interpretation of the obtained results is presented in the paper. Network analytic methods were applied to extract players with the most retired matches in their careers. Eventually, we defined a group of top tennis players and gave a more precise insight into retired matches in that group. Correspondence analysis was used to visually display the two-mode network of top players and the proportion of retired matches by surface type

  18. Impact resistance and hardness modelling of Aluminium alloy welds using square-headed friction-stir welding tool

    Science.gov (United States)

    Sudhakar, U.; Srinivas, J., Dr.

    2016-02-01

    This paper proposes modelling and optimization issues relating to friction-stir welding process of aluminium alloys. A specially prepared SS tool of square headed pin profile with cylindrical shoulder is used with a vertical milling machine. Effects of process variables including tool rotation and tool velocity on the weld performance are studied in terms of impact strength and hardness. Three different rotational motions and three welding speeds (feeds) of tool are considered at constant axial load (depth of cut) condition and altogether nine experiments are conducted on a vertical milling machine with specially prepared fixture. Each weld sample is then tested for its impact strength (IS) and hardness independently. A model is developed to correlate the relations between the hardness/impact strength with tool rotation and weld speed using neural networks. The optimized process conditions are predicted to improvise the impact strength and hardness of the weld. Further, the morphology of the weld is studied using SEM to know the material flow characteristics.

  19. Interaction of Blast and Head Impact in the Generation of Brain Injuries

    Science.gov (United States)

    2009-08-01

    supported during the acceleration phase in order to eliminate the neck flexion /extension prior to impact. The NDTs were implanted into two columns...al. (1999). Relationship Between Localized Spine Deformation and Cervical Vertebral Motions for Low Speed Rear Impacts Using Human Volunteers. In: Ir

  20. Age of first exposure to football and later-life cognitive impairment in former NFL players.

    Science.gov (United States)

    Stamm, Julie M; Bourlas, Alexandra P; Baugh, Christine M; Fritts, Nathan G; Daneshvar, Daniel H; Martin, Brett M; McClean, Michael D; Tripodis, Yorghos; Stern, Robert A

    2015-03-17

    To determine the relationship between exposure to repeated head impacts through tackle football prior to age 12, during a key period of brain development, and later-life executive function, memory, and estimated verbal IQ. Forty-two former National Football League (NFL) players ages 40-69 from the Diagnosing and Evaluating Traumatic Encephalopathy using Clinical Tests (DETECT) study were matched by age and divided into 2 groups based on their age of first exposure (AFE) to tackle football: AFE NFL players in the AFE <12 group performed significantly worse than the AFE ≥12 group on all measures of the WCST, NAB-LL, and WRAT-4 Reading tests after controlling for total number of years of football played and age at the time of evaluation, indicating executive dysfunction, memory impairment, and lower estimated verbal IQ. There is an association between participation in tackle football prior to age 12 and greater later-life cognitive impairment measured using objective neuropsychological tests. These findings suggest that incurring repeated head impacts during a critical neurodevelopmental period may increase the risk of later-life cognitive impairment. If replicated with larger samples and longitudinal designs, these findings may have implications for safety recommendations for youth sports. © 2015 American Academy of Neurology.

  1. The impact of pediatric-specific dose modulation curves on radiation dose and image quality in head computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Joana; Paulo, Graciano [Instituto Politecnico de Coimbra, ESTESC, DMIR, Coimbra (Portugal); Foley, Shane; Rainford, Louise [University College Dublin, School of Medicine and Medical Science, Health Science Centre, Dublin 4 (Ireland); McEntee, Mark F. [The University of Sydney, Faculty of Health Sciences, Cumberland Campus, Sydney (Australia)

    2015-11-15

    The volume of CT examinations has increased with resultant increases in collective dose values over the last decade. To analyze the impact of the tube current and voltage modulation for dose values and image quality of pediatric head CT examinations. Head CT examinations were performed on anthropomorphic phantoms and four pediatric age categories before and after the introduction of dedicated pediatric curves for tube voltage and current modulation. Local diagnostic reference levels were calculated. Visual grading characteristic image quality evaluation was performed by four pediatric neuroradiologists and image noise comparisons were performed. Pediatric-specific modulation curves demonstrated a 49% decrease in mean radiation dose for phantom examinations. The local diagnostic reference levels (CTDIvol) for clinical examinations decreased by 52%, 41%, 46% and 40% for newborn, 5-, 10- and 15-year-old patients, respectively. Visual grading characteristic image quality was maintained for the majority of age categorizations (area under the curve = 0.5) and image noise measurements did not change (P = 0.693). Pediatric-specific dose modulation curves resulted in an overall mean dose reduction of 45% with no significant differences in subjective or objective image quality findings. (orig.)

  2. Impact of MLC leaf position errors on simple and complex IMRT plans for head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mu, G; Ludlum, E; Xia, P [Department of Radiation Oncology, University of California, San Francisco, CA (United States)

    2008-01-07

    The dosimetric impact of random and systematic multi-leaf collimator (MLC) leaf position errors is relatively unknown for head and neck intensity-modulated radiotherapy (IMRT) patients. In this report we studied 17 head and neck IMRT patients, including 12 treated with simple plans (<50 segments) and 5 treated with complex plans (>100 segments). Random errors (-2 to +2 mm) and systematic errors ({+-}0.5 mm and {+-}1 mm) in MLC leaf positions were introduced into the clinical plans and the resultant dose distributions were analyzed based on defined endpoint doses. The dosimetric effect was insignificant for random MLC leaf position errors up to 2 mm for both simple and complex plans. However, for systematic MLC leaf position errors, we found significant dosimetric differences between the simple and complex IMRT plans. For 1 mm systematic error, the average changes in D{sub 95%} were 4% in simple plans versus 8% in complex plans. The average changes in D{sub 0.1cc} of the spinal cord and brain stem were 4% in simple plans versus 12% in complex plans. The average changes in parotid glands were 9% in simple plans versus 13% for the complex plans. Overall, simple IMRT plans are less sensitive to leaf position errors than complex IMRT plans.

  3. Impact of head models in N170 component source imaging: results in control subjects and ADHD patients

    Science.gov (United States)

    Beltrachini, L.; Blenkmann, A.; von Ellenrieder, N.; Petroni, A.; Urquina, H.; Manes, F.; Ibáñez, A.; Muravchik, C. H.

    2011-12-01

    The major goal of evoked related potential studies arise in source localization techniques to identify the loci of neural activity that give rise to a particular voltage distribution measured on the surface of the scalp. In this paper we evaluate the effect of the head model adopted in order to estimate the N170 component source in attention deficit hyperactivity disorder (ADHD) patients and control subjects, considering faces and words stimuli. The standardized low resolution brain electromagnetic tomography algorithm (sLORETA) is used to compare between the three shell spherical head model and a fully realistic model based on the ICBM-152 atlas. We compare their variance on source estimation and analyze the impact on the N170 source localization. Results show that the often used three shell spherical model may lead to erroneous solutions, specially on ADHD patients, so its use is not recommended. Our results also suggest that N170 sources are mainly located in the right occipital fusiform gyrus for faces stimuli and in the left occipital fusiform gyrus for words stimuli, for both control subjects and ADHD patients. We also found a notable decrease on the N170 estimated source amplitude on ADHD patients, resulting in a plausible marker of the disease.

  4. The impacts of climate change on a Norwegian high-head hydropower plant

    Energy Technology Data Exchange (ETDEWEB)

    Chernet, Haregewoin Haile; Alfredsen, Knut; Killintveit, Aanund

    2010-07-01

    Full text: Norway relies on hydropower for 99 percent of the electricity production and thus Hydropower is important for Norway today and in the future energy system. The work presented in this paper shows how a high-head hydropower system in Norway will be affected in the future climate. The Aurland Hydropower system, operated by E-Co Vannkraft, Norway is the test case for the study. The Aurland hydropower system has many reservoirs and transfer systems and is considered to be one of the complex systems in Norway, but also a typical example of a Norwegian high head system. The nMAG Hydropower simulation model, which has been developed at the Norwegian Hydro technical Laboratory, is used to simulate the hydropower system. Historical and future inflow series were transposed from the neighbouring catchment Flaamselvi using scaling based on area and specific runoff, as there is no discharge station in Aurland catchment with long unregulated inflow series to set up the model and to be used for developing future climate scenarios. To generate the future inflow series for the analysis, the HBV hydrological model is calibrated for the Flaamselvi catchment. The model is then used to generate future inflow series of using the Hadley GCM (HADAm3) and A2, B2 climate scenarios. The operation of the hydropower system is then simulated for the period 2071 -2100 to see how future power production is affected by the change in the inflow conditions. The HBV model is also used to see how snow accumulation will be affected in the future as snow melt is important for Norwegian reservoir and hydropower systems. The Hydrologic scenarios under climate change imply an average increase in runoff for the system. Snow accumulation will decrease with sooner snow melt and more winter precipitation as rain. The hydropower simulation results show that associated with the increase in runoff there is an increase in energy generation with 10-20% under the current reservoir operation strategies

  5. Dysphagia. Impact on quality of life after radio(chemo)therapy of head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, Julia; Hipp, Matthias; Koelbl, Oliver [Regensburg Univ. Medical Center (Germany). Dept. of Radiotherapy; Schaefer, Christof [Hospital St. Elisabeth Straubing (Germany). Dept. of Radiotherapy

    2011-11-15

    In the past, xerostomia was considered one of the most important determining factors of quality of life (QoL) after radiotherapy (RT) of the head and neck region. In addition, more recent studies have shown that RT-induced dysphagia has an essential influence on the QoL. Between September 2005 and August 2007, 35 patients with locally advanced squamous cell carcinoma of the head and neck region were included in the prospective study. Patients were treated by IMAT (intensity-modulated arc therapy) or IMRT (intensity-modulated radiotherapy) planned on 3D imaging. A total of 28 patients (80%) received concomitant chemotherapy. The evaluation of QoL (EORTC QLQ - C30, H and N C-35) and toxicities (CTC 2.0) were assessed at the beginning of, during, and after RT as well as up to 12 months after the end of therapy. At the end of therapy, 86% of the patients experienced difficulties in swallowing (62% CTC II-III ). Twelve months after the end of treatment, 15% still suffered from dysphagia CTC II-III . Concomitant chemotherapy exacerbated the incidence and gravity of dysphagia, resulting in increasing dietary problems. QoL (EORTC) was significantly affected by dysphagia. In particular, the global state of health and QoL were influenced at the end of treatment (p = 0.033) and at a later stage (p = 0.050). The findings of this study suggest that more emphasis should be placed on structured clinical diagnostics, therapy, and rehabilitation of deglutition problems. This means in particular to not only spare the parotids while planning the irradiation, but also to take into consideration the important structures for deglutition, like the retropharyngeal muscles. (orig.)

  6. The Player Engagement Process

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik

    2011-01-01

    Engagement is an essential element of the player experience, and the concept is described in various ways in the literature. To gain a more detailed comprehension of this multifaceted concept, and in order to better understand what aspects can be used to evaluate engaging game play and to design...... engaging user experiences, this study investigates one dimension of player engagement by empirically identifying the components associated with the desire to continue playing. Based on a description of the characteristics of player engagement, a series of surveys were developed to discover the components......, categories and triggers involved in this process. By applying grounded theory to the analysis of the responses, a process-oriented player engagement framework was developed and four main components consisting of objectives, activities, accomplishments and affects as well as the corresponding categories...

  7. Investigating the impact of performance management on human resource performance across head offices of Agricultural bank branches in Tehran

    Directory of Open Access Journals (Sweden)

    Mir Hamid Reza Torabi Shahidi

    2013-08-01

    Full Text Available Human resource is one of the most precious assets across contemporary organizations and companies. For this reason, enterprises have to invest on them to promote and improve their employees’ performance. An effective mechanism to develop corporate and human performance is to design and establish a system of performance management so that it improves employees’ performance by determining explicit organizational objectives and coordinating them with individual goals.Current work aims to determine the impact of performance management on human resource performance across head offices of Agricultural Bank branches in Tehran (the main goal and prioritize among performance management components and human resource performance components and also present some procedures to improve human performance using performance management components (sub-goals.

  8. The impact of compulsory helmet legislation on cyclist head injuries in New South Wales, Australia: a response.

    Science.gov (United States)

    Walter, Scott R; Olivier, Jake; Churches, Tim; Grzebieta, Raphael

    2013-03-01

    This article responds to criticisms made in a rejoinder (Accident Analysis and Prevention 2012, 45: 107-109) questioning the validity of a study on the impact of mandatory helmet legislation (MHL) for cyclists in New South Wales, Australia. We systematically address the criticisms through clarification of our methods, extension of the original analysis and discussion of new evidence on the population-level effects of MHL. Extensions of our analysis confirm the original conclusions that MHL had a beneficial effect on head injury rates over and above background trends and changes in cycling participation. The ongoing debate around MHL draws attention away from important ways in which both safety and participation can be improved through investment in well-connected cycling infrastructure, fostering consideration between road users, and adequate legal protection for vulnerable road users. These are the essential elements for providing a cycling environment that encourages participation, with all its health, economic and environmental benefits, while maximising safety.

  9. How do clarinet players adjust the resonances of their vocal tracts for different playing effects?

    Science.gov (United States)

    Fritz, Claudia; Wolfe, Joe

    2005-11-01

    In a simple model, the reed of the clarinet is mechanically loaded by the series combination of the acoustical impedances of the instrument itself and of the player's airway. Here we measure the complex impedance spectrum of players' airways using an impedance head adapted to fit inside a clarinet mouthpiece. A direct current shunt with high acoustical resistance allows players to blow normally, so the players can simulate the tract condition under playing conditions. The reproducibility of the results suggest that the players' ``muscle memory'' is reliable for this task. Most players use a single, highly stable vocal tract configuration over most of the playing range, except for the altissimo register. However, this ``normal'' configuration varies substantially among musicians. All musicians change the configuration, often drastically for ``special effects'' such as glissandi and slurs: the tongue is lowered and the impedance magnitude reduced when the player intends to lower the pitch or to slur downwards, and vice versa.

  10. How do clarinet players adjust the resonances of their vocal tracts for different playing effects

    CERN Document Server

    Fritz, C; Fritz, Claudia; Wolfe, Joe

    2005-01-01

    In a simple model, the reed of the clarinet is mechanically loaded by the series combination of the acoustical impedances of the instrument itself and of the player's vocal tract. Here we measure the complex impedance spectrum of players' tracts using an impedance head adapted to fit inside a clarinet mouthpiece. A direct current shunt with high acoustical resistance allows players to blow normally, so the players can simulate the tract condition under playing conditions. The reproducibility of the results suggest that the players' "muscle memory" is reliable for this task. Most players use a single, highly stable vocal tract configuration over most of the playing range, except for the altissimo register. However, this 'normal' configuration varies substantially among musicians. All musicians change the configuration, often drastically for "special effects'' such as glissandi and slurs: the tongue is lowered and the impedance magnitude reduced when the player intends to lower the pitch or to slur downwards, a...

  11. An evaluation of the cumulative concussive effect of soccer heading in the youth population.

    Science.gov (United States)

    Janda, David H; Bir, Cynthia A; Cheney, Angela L

    2002-03-01

    Soccer is the most popular team sport in the world, with 120 million individuals participating and 16 million of these individuals being based in the United States. In addition, soccer has become the fastest growing team sport in the United States over the past 10 years. Head impact injuries have been cited as comprising 15% of all injuries related to soccer. Previous studies have identified the technique of heading as being a significant factor in head impact injuries. In fact, 85% of various subgroups of participants, 19 years of age and older, have had a diminution in cognitive function abilities on a permanent basis. It was the purpose of this study to evaluate the effect of repetitive head impacts due to heading in 57 youth soccer players with a mean age of 11.5 years. The data were collected over three seasons during the first year, which correlated to approximately 60 games and/or practices. One team of 18 boys was followed for an additional year. The data collected included a cognitive function test, as well as documentation of concussive symptoms. These cognitive evaluations, conducted at both periods of time, revealed that statistically significant differences were not evident when compared to standardized norms with the exception of verbal learning. There was an inverse relationship between the number of ball impacts and verbal learning. Of note, however, is that 49% of the year-one study group did complain of headaches after heading the ball.

  12. EXPERIMENTAL AND MICRO-IMPACT MECHANISM OF GRINDING HEAD IN POLISHING MACHINE%抛光机磨头微观冲击机理与实验

    Institute of Scientific and Technical Information of China (English)

    邵俊鹏; 徐斌

    2012-01-01

    In order to investigate the microcosmic polishing mechanism ot grlnclmg neaa. Micro impact Mechanism of low/ high speed grinding head were derived. Mathematical modeling of microimpact and amplitude is established. It is concluded that the process of forming ceramic tile defects, by a series of SEM experiments of ceramic tiles. It is concluded that the micro-impact mechanism theory agreement with ceramic tile surface topography is obtained. A series of vibration experiments of grinding head is performed, low speed grinding head can help ceramic tile defects and it can considerably reduce the impact vibration of grinding head at the rough polishing; high speed grinding head so as to effectively enhance the tile surface smoothness at the finish polishing.%为了研究磨头微观加工机理,提出低、高速磨头微观冲击机理。建立微观冲击速度和振幅模型。通过SEM实验得出瓷砖微观缺陷形成过程,并验证了冲击机理理论符合瓷砖表面形貌。通过振动实验得出:粗抛阶段,低速磨头可以减少瓷砖缺陷,降低冲击振动;精抛阶段,高转速磨头可以提高瓷砖的表面质量。

  13. Mixed pathologies including chronic traumatic encephalopathy account for dementia in retired association football (soccer) players.

    Science.gov (United States)

    Ling, Helen; Morris, Huw R; Neal, James W; Lees, Andrew J; Hardy, John; Holton, Janice L; Revesz, Tamas; Williams, David D R

    2017-03-01

    In retired professional association football (soccer) players with a past history of repetitive head impacts, chronic traumatic encephalopathy (CTE) is a potential neurodegenerative cause of dementia and motor impairments. From 1980 to 2010, 14 retired footballers with dementia were followed up regularly until death. Their clinical data, playing career, and concussion history were prospectively collected. Next-of-kin provided consent for six to have post-mortem brain examination. Of the 14 male participants, 13 were professional and 1 was a committed amateur. All were skilled headers of the ball and had played football for an average of 26 years. Concussion rate was limited in six cases to one episode each during their careers. All cases developed progressive cognitive impairment with an average age at onset of 63.6 years and disease duration of 10 years. Neuropathological examination revealed septal abnormalities in all six post-mortem cases, supportive of a history of chronic repetitive head impacts. Four cases had pathologically confirmed CTE; concomitant pathologies included Alzheimer's disease (N = 6), TDP-43 (N = 6), cerebral amyloid angiopathy (N = 5), hippocampal sclerosis (N = 2), corticobasal degeneration (N = 1), dementia with Lewy bodies (N = 1), and vascular pathology (N = 1); and all would have contributed synergistically to the clinical manifestations. The pathological diagnosis of CTE was established in four individuals according to the latest consensus diagnostic criteria. This finding is probably related to their past prolonged exposure to repetitive head impacts from head-to-player collisions and heading the ball thousands of time throughout their careers. Alzheimer's disease and TDP-43 pathologies are common concomitant findings in CTE, both of which are increasingly considered as part of the CTE pathological entity in older individuals. Association football is the most popular sport in the world and the potential link between

  14. Impact of copper toxicity on stone-head cabbage (Brassica oleracea var. capitata) in hydroponics.

    Science.gov (United States)

    Ali, Sajid; Shahbaz, Muhammad; Shahzad, Ahmad Naeem; Khan, Hafiz Azhar Ali; Anees, Moazzam; Haider, Muhammad Saleem; Fatima, Ammara

    2015-01-01

    Arable soils are frequently subjected to contamination with copper as the consequence of imbalanced fertilization with manure and organic fertilizers and/or extensive use of copper-containing fungicides. In the present study, the exposure of stone-head cabbage (Brassica oleracea var. capitata) to elevated Cu(2+) levels resulted in leaf chlorosis and lesser biomass yield at ≥2 µ M. Root nitrate content was not statistically affected by Cu(2+) levels, although it was substantially decreased at ≥5 µ M Cu(2+) in the shoot. The decrease in nitrate contents can be related to lower nitrate uptake rates because of growth inhibition by Cu-toxicity. Shoot sulfate content increased strongly at ≥2 µ M Cu(2+) indicating an increase in demand for sulfur under Cu stress. Furthermore, at ≥2 µM concentration, concentration of water-soluble non-protein thiol increased markedly in the roots and to a smaller level in the shoot. When exposed to elevated concentrations of Cu(2+) the improved sulfate and water-soluble non-protein thiols need further studies for the evaluation of their direct relation with the synthesis of metal-chelating compounds (i.e., phytochelatins).

  15. Impact of copper toxicity on stone-head cabbage (Brassica oleracea var. capitata in hydroponics

    Directory of Open Access Journals (Sweden)

    Sajid Ali

    2015-08-01

    Full Text Available Arable soils are frequently subjected to contamination with copper as the consequence of imbalanced fertilization with manure and organic fertilizers and/or extensive use of copper-containing fungicides. In the present study, the exposure of stone-head cabbage (Brassica oleracea var. capitata to elevated Cu2+ levels resulted in leaf chlorosis and lesser biomass yield at ≥2 µ M. Root nitrate content was not statistically affected by Cu2+ levels, although it was substantially decreased at ≥5 µ M Cu2+ in the shoot. The decrease in nitrate contents can be related to lower nitrate uptake rates because of growth inhibition by Cu-toxicity. Shoot sulfate content increased strongly at ≥2 µ M Cu2+ indicating an increase in demand for sulfur under Cu stress. Furthermore, at ≥2 µM concentration, concentration of water-soluble non-protein thiol increased markedly in the roots and to a smaller level in the shoot. When exposed to elevated concentrations of Cu2+ the improved sulfate and water-soluble non-protein thiols need further studies for the evaluation of their direct relation with the synthesis of metal-chelating compounds (i.e., phytochelatins.

  16. The Impact of Ocular Pressures, Material Properties and Geometry on Optic Nerve Head Deformation

    Science.gov (United States)

    Feola, Andrew J.; Myers, Jerry G.; Raykin, Julia; Nelson, Emily S.; Samuels, Brian C.; Ethier C. Ross

    2017-01-01

    Alteration in intracranial pressure (ICP) has been associated with various diseases that cause visual impairment, including glaucoma, idiopathic intracranial hypertension and Visual Impairment and Intracranial Pressure (VIIP) syndrome. However, how changes in ICP lead to vision loss is unclear, although it is hypothesized to involve deformations of the tissues in the optic nerve head (ONH). Recently, understanding the effect of ICP alterations on ocular tissues has become a major concern for NASA, where 42 of astronauts that partake in long duration space missions suffer from VIIP syndrome. Astronauts with VIIP syndrome suffer from visual impairment and changes in ocular anatomy that persist after returning to earth (1). It is hypothesized that the cephalad fluid shift that occurs upon entering microgravity increases ICP, which leads to an altered biomechanical environment in the posterior globe and optic nerve sheath, and subsequently VIIP syndrome. Our goal was to develop a finite element (FE) model to simulate the acute effects of elevated ICP on the posterior eye. Here, we simulated how inter-individual differences affect the deformation of ONH tissues. Further, we examined how several different geometries influenced deformations when exposed to elevated ICP.

  17. Shoulder injuries in rugby players: mechanisms, examination, and rehabilitation.

    Science.gov (United States)

    Helgeson, Kevin; Stoneman, Paul

    2014-11-01

    The sport of rugby is growing in popularity for players at the high school and collegiate levels. This article will provided the sports therapist with an introduction to the management of shoulder injuries in rugby players. Rugby matches results in frequent impacts and leveraging forces to the shoulder region during the tackling, scrums, rucks and maul components of the game. Rugby players frequently sustain contusion and impact injuries to the shoulder region, including injuries to the sternoclavicular, acromioclavicular (AC), and glenohumeral (GH) joints. Players assessed during practices and matches should be screened for signs of fracture, cervical spine and brachial plexus injuries. A three phase program will be proposed to rehabilitate players with shoulder instabilities using rugby specific stabilization, proprioception, and strengthening exercises. A plan for return to play will be addressed including position-specific activities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Human head-neck response during low-speed rear end impacts

    NARCIS (Netherlands)

    Kroonenberg, A.J. van den; Philippens, M.M.G.M.; Cappon, H.J.; Wismans, J.S.H.M.; Hell, W.; Langwieder, K.

    1998-01-01

    Neck injuries resulting from rear-end collisions rank among the top car safety problems and have serious implications for society. Many rear impact sled experiments with volunteers and PMHSs have been performed in the past. However, in most of these studies, T1 kinematics were not obtained so that t

  19. The impact of single nucleotide polymorphisms on patterns of non-contact musculoskeletal soft tissue injuries in a football player population according to ethnicity.

    Science.gov (United States)

    Pruna, Ricard; Ribas, Jordi; Montoro, Jose Bruno; Artells, Rosa

    2015-02-02

    The prevention, diagnosis, and management of non-contact musculoskeletal soft tissue injuries (NCMSTIs) related to participation in sports are key components of sport and exercise medicine. Epidemiological data have demonstrated the existence of interindividual differences in the severity of NCMSTIs, indicating that these injuries occur as a consequence of both extrinsic and intrinsic factors, including genetic variations. We have collected data on NCMSTIs suffered by 73 elite players of White, black African and Hispanic ethnicity of European football over the course of three consecutive seasons. We have also examined eight single nucleotide polymorphisms (SNPs) in genes related to tissue recovery and tissue repair in blood drawn from the players and correlated our findings with type and severity of injuries in each ethnic group. The frequency of the SNPs varied among the three ethnic sub-groups (p<0.0001). Among Whites, a significant relationship was observed between ligament injuries and ELN (p=0.001) and between tendinous injuries and ELN (p=0.05) and IGF2 (p=0.05). Among Hispanics, there was a significant relation between muscle injuries and ELN (p=0.032) and IGF2 (p=0.016). Interracial genotypic differences may be important in the study of NCMSTIs. A genetic profile based on SNPs may be useful tool to describe each individual's injuribility risk and provide specific treatment and preventive care for football players. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  20. Hypoconnectivity and Hyperfrontality in Retired American Football Players

    Science.gov (United States)

    Hampshire, Adam; MacDonald, Alex; Owen, Adrian M.

    2013-10-01

    Recent research has raised concerns about the long-term neurological consequences of repetitive concussive and sub-concussive injuries in professional players of American Football. Despite this interest, the neural and psychological status of retired players remains unknown. Here, we evaluated the performances and brain activation patterns of retired National Football League players (NFL alumni) relative to controls using an fMRI-optimised neuropsychological test of executive function. Behaviourally, the NFL alumni showed only modest performance deficits on the executive task. By contrast, they showed pronounced hyperactivation and hypoconnectivity of the dorsolateral frontal and frontopolar cortices. Critically, abnormal frontal-lobe function was correlated with the number of times that NFL alumni reported having been removed from play after head injury and was evident in individual players. These results support the hypothesis that NFL alumni have a heightened probability of developing executive dysfunction and suggest that fMRI provides the most sensitive biomarker of the underlying neural abnormality.

  1. Unpacking the Treatment Contrast in the Head Start Impact Study: To What Extent Does Assignment to Treatment Affect Quality of Care?

    Science.gov (United States)

    Friedman-Krauss, Allison H.; Connors, Maia C.; Morris, Pamela A.

    2017-01-01

    Attending high-quality early childhood care and education (ECCE) is associated with higher cognitive and social-emotional skills, especially for children growing up in poverty, but access to high-quality ECCE is limited. This study capitalizes on the random assignment design of the Head Start Impact Study to better understand whether the…

  2. Strengthening Families in Head Start: The Impact of a Parent Education Programme on the Emotional Well-Being of Latino Families

    Science.gov (United States)

    Duch, Helena; Rodriguez, Carmen

    2011-01-01

    This study explores the impact of a Head Start add-on programme, a matrix of services for parents which provides educational and vocational supports, on maternal depression and children's behaviour in Latino families. We hypothesise that after having completed training, parents who participated in the add-on programme would have lower levels of…

  3. An examination of the impact of participation in a conversation group for individuals with a closed head injury.

    Science.gov (United States)

    Goldblum, G; Mulder, M; von Gruenewaldt, A

    2001-01-01

    This study describes the impact of participation in a conversational group for individuals with chronic closed head injury in the Department of Communication Pathology at the University of Pretoria over the period 1995-2000. The information was obtained through a combination of clinical observations by the writers; the examination of data from Pragmatic measures; and a Quality of Life Scale that was compiled and administered (to both the subjects and their significant others) examining the perceived effects of group therapy over time. The results showed that despite the plateauing of pragmatic competence over time, the impact of group therapy appeared to reveal itself in perceived improvements in social-communicative competence and quality of life by the subjects. Recommendation and suggestions were made for the refinement of the QOL Scale to more reliably measure the subjective perceptions of group members regarding the perceived value of group therapy. In addition to addressing future implications to move the conversation group forward, the results of the current study lead the authors to advocate the establishment of conversation groups for individuals with CHI who are suitable candidates.

  4. Growth hormone deficiency and central hypogonadism in retired professional football players

    Directory of Open Access Journals (Sweden)

    Gábor László Kovács

    2016-12-01

    Full Text Available Purpose: The aim of this cross-sectional study was to evaluate the possible impact of multiple mild head traumas sustained during a long-term football career on the presence of central hypogonadism and growth hormone (GH deficiency. Methods: Twenty-seven retired, former professional male football players were investigated. All subjects were assessed for serum levels of insulin-like growth factor (IGF-1, luteinizing hormone (LH and total testosterone (TT. Quality of life was quantified using the Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA questionnaire. Results: Subjects had a median age of 48.0 (42.0 – 53.0 years and a median football career of 29.0 years (22.0 – 32.0. One subject had central hypogonadism and none had growth hormone deficiency. Nine subjects reported sport-related head injuries. We found a negative correlation between sport-related head injuries and serum LH (p = -0.459, P = 0.016. Subjects with a history of sport-related head injury had a median LH of 3.3 U/L (2.7 – 3.6, while those without a history of sport-related head injury had a median LH of 4.1 (U/L (3.6 – 5.7, P = 0.017. However, there were no differences in other hormones between the two groups. Moreover, we did not find any correlation between the duration of the player’s career nor their field position with hormone profiles or QoL-AGHDA. Conclusion: Although retired footfall players with a history of sport-related head injury had lower LH levels, we did not find strong evidence of an increased prevalence of central hypogonadism or GH deficiency in these patients. Our results suggest that a long-term football career, which includes headings and repetitive mild head traumas, does not damage the most vulnerable anterior pituitary cells.

  5. Assessment of shoulder position variation and its impact on IMRT and VMAT doses for head and neck cancer

    Directory of Open Access Journals (Sweden)

    Neubauer Emily

    2012-02-01

    Full Text Available Abstract Background For radiotherapy of the head and neck, 5-point mask immobilization is used to stabilize the shoulders. Still, the daily position of the shoulders during treatment may be different from the position in the treatment plan despite correct isocenter setup. The purpose of this study was to determine the interfractional displacement of the shoulders relative to isocenter over the course of treatment and the associated dosimetric effect of this displacement. Methods The extent of shoulder displacements relative to isocenter was assessed for 10 patients in 5-point thermoplastic masks using image registration and daily CT-on-rails scans. Dosimetric effects on IMRT and VMAT plans were evaluated in Pinnacle based on simulation CTs modified to represent shoulder shifts between 3 and 15 mm in the superior-inferior, anterior-posterior, and right-left directions. The impact of clinically observed shoulder shifts on the low-neck dose distributions was examined. Results Shoulder motion was 2-5 mm in each direction on average but reached 20 mm. Superior shifts resulted in coverage loss, whereas inferior shifts increased the dose to the brachial plexus. These findings were generally consistent for both IMRT and VMAT plans. Over a course of observed shifts, the dose to 99% of the CTV decreased by up to 101 cGy, and the brachial plexus dose increased by up to 72 cGy. Conclusions he position of the shoulder affects target coverage and critical structure dose, and may therefore be a concern during the setup of head and neck patients, particularly those with low neck primary disease.

  6. Assessment of shoulder position variation and its impact on IMRT and VMAT doses for head and neck cancer

    Science.gov (United States)

    2012-01-01

    Background For radiotherapy of the head and neck, 5-point mask immobilization is used to stabilize the shoulders. Still, the daily position of the shoulders during treatment may be different from the position in the treatment plan despite correct isocenter setup. The purpose of this study was to determine the interfractional displacement of the shoulders relative to isocenter over the course of treatment and the associated dosimetric effect of this displacement. Methods The extent of shoulder displacements relative to isocenter was assessed for 10 patients in 5-point thermoplastic masks using image registration and daily CT-on-rails scans. Dosimetric effects on IMRT and VMAT plans were evaluated in Pinnacle based on simulation CTs modified to represent shoulder shifts between 3 and 15 mm in the superior-inferior, anterior-posterior, and right-left directions. The impact of clinically observed shoulder shifts on the low-neck dose distributions was examined. Results Shoulder motion was 2-5 mm in each direction on average but reached 20 mm. Superior shifts resulted in coverage loss, whereas inferior shifts increased the dose to the brachial plexus. These findings were generally consistent for both IMRT and VMAT plans. Over a course of observed shifts, the dose to 99% of the CTV decreased by up to 101 cGy, and the brachial plexus dose increased by up to 72 cGy. Conclusions he position of the shoulder affects target coverage and critical structure dose, and may therefore be a concern during the setup of head and neck patients, particularly those with low neck primary disease. PMID:22316381

  7. Direct comparison of the impact of head tracking, reverberation, and individualized head-related transfer functions on the spatial perception of a virtual speech source

    Science.gov (United States)

    Begault, D. R.; Wenzel, E. M.; Anderson, M. R.

    2001-01-01

    A study of sound localization performance was conducted using headphone-delivered virtual speech stimuli, rendered via HRTF-based acoustic auralization software and hardware, and blocked-meatus HRTF measurements. The independent variables were chosen to evaluate commonly held assumptions in the literature regarding improved localization: inclusion of head tracking, individualized HRTFs, and early and diffuse reflections. Significant effects were found for azimuth and elevation error, reversal rates, and externalization.

  8. Impact of repeat computerized tomography replans in the radiation therapy of head and neck cancers

    Directory of Open Access Journals (Sweden)

    Virendra Bhandari

    2014-01-01

    Full Text Available Anatomical changes can occur during course of head-and-neck (H and N radiotherapy like tumor shrinkage, decreased edema and/or weight loss. This can lead to discrepancies in planned and delivered dose increasing the dose to organs at risk. A study was conducted to determine the volumetric and dosimetric changes with the help of repeat computed tomography (CT and replanning for selected H and N cancer patients treated with IMRT plans to see for these effects. In 15 patients with primary H and N cancer, a repeat CT scan after 3 rd week of radiotherapy was done when it was clinically indicated and then two plans were generated on repeat CT scan, actual plan (AP planned on repeat CT scan, and hybrid plan (HP, which was generated by applying the first intensity-modulated radiation therapy (IMRT plan (including monitoring units to the images of second CT scan. Both plans (AP and HP on repeat CT scan were compared for volumetric and dosimetric parameter. The mean variation in volumes between CT and repeat CT were 44.32 cc, 82.2 cc, and 149.83 cc for gross tumor volume (GTV, clinical target volumes (CTV, and planning target volume (PTV, respectively. Mean conformity index and homogeneity index was 0.68 and 1.07, respectively for AP and 0.5 and 1.16, respectively for HP. Mean D 95 and D 99 of PTV was 97.92% (standard deviation, SD 2.32 and 93.4% (SD 3.75, respectively for AP and 92.8% (SD 3.83 and 82.8% (SD 8.0, respectively for HP. Increase in mean doses to right parotid, left parotid, spine, and brainstem were 5.56 Gy (D mean , 3.28 Gy (D mean , 1.25 Gy (D max , and 3.88 Gy (D max , respectively in HP compared to AP. Repeat CT and replanning reduces the chance of discrepancies in delivered dose due to volume changes and also improves coverage to target volume and further reduces dose to organ at risk.

  9. RELATIONS BETWEEN MORPHOLOGICAL CHARACTERISTICS AND ACCURACY OF KICKING A BALL BY YOUNG FOOTBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Slobodan Andrašić

    2015-05-01

    Full Text Available Kicking a ball with foot or head are the basic elements of football, which can raise the efficiency of the game in terms of speed of action in terms of scoring goals. This is also the reason why the shot needs to be performed in a timely manner, usefully, and also quickly. The most commonly used kick in football is a inner-side instep kick, which is also the most accurate and the most used among the players (Cabri, De Prof, Dufour, & Clarys, 1998. Success in performing precise actions largely depends on the precision of locating targets in space, and therefore the role of our receptors is crucial for a successful precision (Szekeres, Santrač, Radosav, Toplak, Miljanić, 1994. The research problem was establishing the predictive impacts of morphological characteristics on the elevation accuracy of hitting the ball in young players. The subjects of the study were morphological characteristics and accuracy of the players. Aim of the paper was to determine the relation between morphological characteristics and precision of players aged 13-14 years from the Municipality of Loznica. Method: 50 players of the FK “Kabel” from Novi Sad, aged 13-14 years, were subjected to testing. Measurement of morphological characteristics was conducted. Specific (elevation accuracy of hitting the ball towards the vertical and horizontal objective was also tested. By using the statistical analysis firstly the basic descriptive statistics of variables were determine. In order to determine the size of the impact of anthropometric characteristics on motor skills – precision, linear regression analysis was used. Results: Regression analysis showed that there was no statistically significant effect of the predictor system of morphological variables on the criterion variables tested: Precision of kicking the ball towards a horizontal target and Precision of kicking the ball towards a vertical target. The results pointed to the fact that some other characteristics and

  10. Safer Heads Prevail with New High School Football Rule

    Science.gov (United States)

    ... html Safer Heads Prevail With New High School Football Rule When full-contact practices were limited, blows ... Concussions are a major risk for high school football players, but new research found that limiting tackling ...

  11. The prevalence and impact of Fusarium head blight pathogens and mycotoxins on malting barley quality in UK

    Science.gov (United States)

    Nielsen, L.K.; Cook, D.J.; Edwards, S.G.; Ray, R.V.

    2014-01-01

    Fusarium head blight (FHB) caused by Fusarium and Microdochium species can significantly affect the yield of barley grain as well as the quality and safety of malt and beer. The present study provides new knowledge on the impacts of the FHB pathogen complex on the malting and brewing quality parameters of naturally infected barley. Quantitative real-time PCR and liquid chromatography double mass spectrometry were used to quantify the predominant FHB pathogens and Fusarium mycotoxins, respectively, in commercially grown UK malting barley samples collected between 2007 and 2011. The predominant Fusarium species identified across the years were F. poae, F. tricinctum and F. avenaceum. Microdochium majus was the predominant Microdochium species in 2007, 2008, 2010 and 2011 whilst Microdochium nivale predominated in 2009. Deoxynivalenol and zearalenone quantified in samples collected between 2007 and 2009 were associated with F. graminearum and F. culmorum, whilst HT-2 and T-2, and nivalenol in samples collected between 2010 and 2011 correlated positively with F. langsethiae and F. poae, respectively. Analysis of the regional distribution and yearly variation in samples from 2010 to 2011 showed significant differences in the composition of the FHB species complex. In most regions (Scotland, the South and North of England) the harvest in 2010 had higher concentrations of Fusarium spp. than in 2011, although no significant difference was observed in the Midlands between the two years. Microdochium DNA was significantly higher in 2011 and in the North of England and Scotland compared to the South or Midlands regions. Pathogens of the FHB complex impacted negatively on grain yield and quality parameters. Thousand grain weight of malting barley was affected significantly by M. nivale and M. majus whilst specific weight correlated negatively with F. avenaceum and F. graminearum. To determine the impact of sub-acute infections of the identified Fusarium and Microdochium

  12. The prevalence and impact of Fusarium head blight pathogens and mycotoxins on malting barley quality in UK.

    Science.gov (United States)

    Nielsen, L K; Cook, D J; Edwards, S G; Ray, R V

    2014-06-02

    Fusarium head blight (FHB) caused by Fusarium and Microdochium species can significantly affect the yield of barley grain as well as the quality and safety of malt and beer. The present study provides new knowledge on the impacts of the FHB pathogen complex on the malting and brewing quality parameters of naturally infected barley. Quantitative real-time PCR and liquid chromatography double mass spectrometry were used to quantify the predominant FHB pathogens and Fusarium mycotoxins, respectively, in commercially grown UK malting barley samples collected between 2007 and 2011. The predominant Fusarium species identified across the years were F. poae, F. tricinctum and F. avenaceum. Microdochium majus was the predominant Microdochium species in 2007, 2008, 2010 and 2011 whilst Microdochium nivale predominated in 2009. Deoxynivalenol and zearalenone quantified in samples collected between 2007 and 2009 were associated with F. graminearum and F. culmorum, whilst HT-2 and T-2, and nivalenol in samples collected between 2010 and 2011 correlated positively with F. langsethiae and F. poae, respectively. Analysis of the regional distribution and yearly variation in samples from 2010 to 2011 showed significant differences in the composition of the FHB species complex. In most regions (Scotland, the South and North of England) the harvest in 2010 had higher concentrations of Fusarium spp. than in 2011, although no significant difference was observed in the Midlands between the two years. Microdochium DNA was significantly higher in 2011 and in the North of England and Scotland compared to the South or Midlands regions. Pathogens of the FHB complex impacted negatively on grain yield and quality parameters. Thousand grain weight of malting barley was affected significantly by M. nivale and M. majus whilst specific weight correlated negatively with F. avenaceum and F. graminearum. To determine the impact of sub-acute infections of the identified Fusarium and Microdochium

  13. Impact of in-scanner head motion on multiple measures of functional connectivity: relevance for studies of neurodevelopment in youth.

    Science.gov (United States)

    Satterthwaite, Theodore D; Wolf, Daniel H; Loughead, James; Ruparel, Kosha; Elliott, Mark A; Hakonarson, Hakon; Gur, Ruben C; Gur, Raquel E

    2012-03-01

    It has recently been reported (Van Dijk et al., 2011) that in-scanner head motion can have a substantial impact on MRI measurements of resting-state functional connectivity. This finding may be of particular relevance for studies of neurodevelopment in youth, confounding analyses to the extent that motion and subject age are related. Furthermore, while Van Dijk et al. demonstrated the effect of motion on seed-based connectivity analyses, it is not known how motion impacts other common measures of connectivity. Here we expand on the findings of Van Dijk et al. by examining the effect of motion on multiple types of resting-state connectivity analyses in a large sample of children and adolescents (n=456). Following replication of the effect of motion on seed-based analyses, we examine the influence of motion on graphical measures of network modularity, dual-regression of independent component analysis, as well as the amplitude and fractional amplitude of low frequency fluctuation. In the entire sample, subject age was highly related to motion. Using a subsample where age and motion were unrelated, we demonstrate that motion has marked effects on connectivity in every analysis examined. While subject age was associated with increased within-network connectivity even when motion was accounted for, controlling for motion substantially attenuated the strength of this relationship. The results demonstrate the pervasive influence of motion on multiple types functional connectivity analysis, and underline the importance of accounting for motion in studies of neurodevelopment. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. CoolSim: using industrial modeling techniques to examine the impact of selective head cooling in a model of perinatal regionalization.

    Science.gov (United States)

    Gray, James; Geva, Alon; Zheng, Zheng; Zupancic, John A F

    2008-01-01

    A selective head-cooling device for the treatment of moderate to severe hypoxic-ischemic encephalopathy has been approved by the Food and Drug Administration for use in the United States. To reflect the complexity of health care delivery at the systems level, we used the industrial modeling technique of discrete event simulation to analyze the impact of various deployment strategies for selective head cooling and its partner technology, amplitude-integrated electroencephalography. We modeled the course through the perinatal system of all births in Massachusetts over a 1-year period. Cohort and care characteristics were drawn from existing databases. Results of a recently published trial were used to estimate the effects of selective head cooling. One thousand cohort replications were conducted to assess uncertainty. Several policy alternatives were examined, including no use of selective head cooling and scenarios that altered the number and placement of selective head-cooling and amplitude-integrated electroencephalography units throughout the state. Patient-level outcome and cost data were assessed. For all scenarios tested, the use of amplitude-integrated electroencephalography/selective head cooling resulted in better outcomes at lower cost. However, substantial differences in transfer rates, failure-to-cool rates, and total costs were seen across scenarios. Optimal decision-making regarding the number and placement of devices led to a 16% improvement in cost savings and a 10-fold decrease in failure-to-cool rates, compared with other deployment scenarios. These results were insensitive to significant changes in model inputs. On the basis of currently available data, the package of amplitude-integrated electroencephalography and selective head cooling seems to be an economically desirable intervention. Quantifiable techniques to assess system-wide technology performance provide a powerful approach to informing decisions regarding the structure and function of

  15. The impact of physical activity on health-related fitness and quality of life for patients with head and neck cancer: a systematic review.

    Science.gov (United States)

    Capozzi, Lauren C; Nishimura, Kathryn C; McNeely, Margaret L; Lau, Harold; Culos-Reed, S Nicole

    2016-03-01

    Patients with head and neck cancer often face a plethora of cancer and treatment-related side effects, negatively impacting their lean body mass, physical functioning, quality of life and fatigue management. Physical activity is a potential mediator of many of these side effects. This is the first systematic review reporting on head and neck cancer and physical activity literature. A literature search was conducted up to January 2015. Two reviewers independently identified articles using the outlined inclusion criteria, assessing the study methodology, risk of bias and extracting the necessary data from studies evaluating the impact of full-body physical activity on patients with head and neck cancer. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement was used to guide this review. We identified 16 articles published from 2003 to 2014, the majority of which were published within the past 5 years. Physical activity interventions were feasible, safe and beneficial in mediating cancer and treatment-related side effects. Specifically, patients experienced improvements in lean body mass, muscular strength, physical functioning, quality of life and fatigue management. Owing to significant study heterogeneity, data were not pooled. Reflecting the early state of the literature, included studies were found to vary greatly in design, quality and reporting characteristics. There is early evidence that supports the benefit of physical activity interventions for patients with head and neck cancer, both during and following treatment. Future research is necessary to determine the benefits of different physical activity interventions, and their impact on patients with different head and neck cancers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  16. Cavum Septum Pellucidum in Retired American Pro-Football Players.

    Science.gov (United States)

    Gardner, Raquel C; Hess, Christopher P; Brus-Ramer, Marcel; Possin, Katherine L; Cohn-Sheehy, Brendan I; Kramer, Joel H; Berger, Mitchel S; Yaffe, Kristine; Miller, Bruce; Rabinovici, Gil D

    2016-01-01

    Previous studies report that cavum septum pellucidum (CSP) is frequent among athletes with a history of repeated traumatic brain injury (TBI), such as boxers. Few studies of CSP in athletes, however, have assessed detailed features of the septum pellucidum in a case-control fashion. This is important because prevalence of CSP in the general population varies widely (2% to 85%) between studies. Further, rates of CSP among American pro-football players have not been described previously. We sought to characterize MRI features of the septum pellucidum in a series of retired pro-football players with a history of repeated concussive/subconcussive head traumas compared with controls. We retrospectively assessed retired American pro-football players presenting to our memory clinic with cognitive/behavioral symptoms in whom structural MRI was available with slice thickness ≤2 mm (n=17). Each player was matched to a memory clinic control patient with no history of TBI. Scans were interpreted by raters blinded to clinical information and TBI/football history, who measured CSP grade (0-absent, 1-equivocal, 2-mild, 3-moderate, 4-severe) and length according to a standard protocol. Sixteen of 17 (94%) players had a CSP graded ≥2 compared with 3 of 17 (18%) controls. CSP was significantly higher grade (pfootball players compared with patients without a history of TBI.

  17. "Heading" and neck injuries in soccer: a review of biomechanics and potential long-term effects.

    Science.gov (United States)

    Mehnert, Michael J; Agesen, Thomas; Malanga, Gerard A

    2005-10-01

    Although soccer has a lower injury rate than does American football, injuries to the head and neck do occur. Indeed, soccer is classified as a contact sport. The potential for cervical injuries from the maneuver known as "heading" are of particular concern. This review provides a synopsis of soccer-related head and neck injuries, an overview of the biomechanics of trauma, and a rational approach to evaluating patients. This review was conducted to assess and evaluate existing literature on the biomechanics of the act of heading in soccer and the potential for acute and long-term injury to the head and neck. The resulting work is based on literature searches of the PubMed and Medline databases, textbook reviews, and bibliographies of articles and textbooks obtained during the search. Findings from several studies were summarized and critiqued. Biomechanics, anatomy, pathophysiology, and their relation to the act of heading in soccer were also synthesized into the discussion. Relevant studies of athletes in other sports where activity can affect the neck and head in a manner similar to heading were also considered. The act of heading in soccer involves the athlete's entire body, and studies have used electromyography to define the activity of neck musculature during heading. The majority of head and neck injuries in soccer occur secondary to impacts other than those that occur during heading, however, rare case reports of serious injury exist. Degenerative bony changes in the cervical spine of soccer players have been noted in a few studies, but the connection with heading is not well established. Data from research in other sports, particularly American football and rugby, suggest a predisposition to degenerative disease of the neck secondary to axial loading mechanisms; the exact relevance of these studies to heading and soccer is unclear. The complex biomechanics of heading in soccer are not completely defined, especially with regard to long-term effects on the

  18. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    Science.gov (United States)

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  19. Impact of head and neck radiotherapy on the mechanical behavior of composite resins and adhesive systems: A systematic review.

    Science.gov (United States)

    Madrid Troconis, Cristhian Camilo; Santos-Silva, Alan Roger; Brandão, Thaís Bianca; Lopes, Marcio Ajudarte; de Goes, Mario Fernando

    2017-08-08

    To analyze the evidence regarding the impact of head and neck radiotherapy (HNRT) on the mechanical behavior of composite resins and adhesive systems. Searches were conducted on PubMed, Embase, Scopus and ISI Web of Science databases using "Radiotherapy", "Composite resins" and "Adhesive systems" as keywords. Selected studies were written in English and assessed the mechanical behavior of composite resins and/or adhesive systems when bonding procedure was conducted before and/or after a maximum radiation dose ≥50Gy, applied under in vitro or in vivo conditions. In total, 115 studies were found but only 16 were included, from which five evaluated the effect of in vitro HNRT on microhardness, wear resistance, diametral tensile and flexural strength of composite resins, showing no significant negative effect in most of reports. Regarding bond strength of adhesive systems, 11 studies were included from which five reported no meaningful negative effect when bonding procedure was conducted before simulated HNRT. Conversely, five studies showed that bond strength diminished when adhesive procedure was done after in vitro radiation therapy. Only two studies about dental adhesion were conducted after in vivo radiotherapy but the results were not conclusive. The mechanical behavior of composite resins and adhesive systems seems not to be affected when in vitro HNRT is applied after bonding procedure. However, bond strength of adhesive systems tends to decrease when simulated radiotherapy is used immediately before bonding procedure. Studies assessing dentin bond strength after in-vivo HNRT were limited and controversial. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  20. Basosquamous Carcinoma of the Head and Neck: Clinical and Histologic Characteristics and Their Impact on Disease Progression

    Directory of Open Access Journals (Sweden)

    Kai Wermker

    2015-03-01

    Full Text Available OBJECTIVES: Basosquamous carcinoma (BSC is a rare tumor entity, and the most common onset is in the head and neck region (BSC-HN. The data on diagnosis, treatment, and especially risk assessment concerning disease course and outcome are deficient or inconsistent. This study aimed to evaluate risk factors for local relapse (LR and lymph node metastasis (LNM and their impact on progression-free survival (PFS. MATERIALS AND METHODS: In a retrospective monocentric study, patients with BSC-HN treated between 1999 and 2011 were analyzed regarding clinical and histologic characteristics. Prognostic parameters for LR, LNM, and PFS were evaluated. In total, 89 patients (55 male, 34 female, mean age of 71.8 years with a mean follow-up time of 47.7 months (range 12-112 were included. RESULTS: LR occurred in four patients (4.5%, LNM occurred in five patients (5.6%. Patients with LNM had a significantly shorter PFS time (16.1 months compared with patients without LNM (154.2 months; P < .001. Tumor depth and size (T classification, incomplete resection, localization at the ear, deep maximal vertical infiltration, muscle and vessel invasion all showed significant (P < .05 associations with LR, LNM, and shorter PFS time. BSC showed more histologic features of basal cell carcinoma (BCC, especially with regard to BerEP4 expression. CONCLUSION: While histology shows some typical characteristics of BCC, the biologic behavior and aggressiveness of BSC are similar to those of cutaneous squamous cell carcinoma. This is the first study to show that LR and, especially, LNM indicate a higher risk of an unfavorable outcome.

  1. What is the Safest Sprint Starting Position for American Football Players?

    Directory of Open Access Journals (Sweden)

    Bruno Bonnechere, Benoit Beyer, Marcel Rooze, Jan Serge Van Sint

    2014-06-01

    Full Text Available The main objective of this study was to perform a biomechanical analysis of three different sprint start patterns to determine the safest position in term of neck injury and Sport-Related Concussion (SRC. The second objective was to collect data on the learning process effect between football players and non-players. Three different sprint initial positions adopted by football players were studied (i.e., 4-, 3- and 2-point positions. Twenty five young healthy males, including 12 football players, participated to this study. A stereophotogrammetric system (i.e., Vicon was used to record motion patterns and body segments positions. Various measurements related to head and trunk orientation, and player field-of-view were obtained (e.g., head height, trunk bending, time to reach upright position, head speed (vertical direction and body speed (horizontal direction. Learning process was found to have no influence on studied parameters. Head redress is also delayed when adopting a 4-point position leading to a reduce field-of-view during the start and increasing therefore the probability of collision. Concerning the three different positions, the 4-point position seems to be the more dangerous because leading to higher kinetic energy than the 2- and 3-point start positions. This study proposes a first biomechanical approach to understand risk/benefit balance for athletes for those three different start positions. Results suggested that the 4-point position is the most risky for football players.

  2. The Impact of Secondary Lymphedema after Head and Neck Cancer Treatment on Symptoms, Functional Status, and Quality Of Life

    Science.gov (United States)

    Deng, Jie; Murphy, Barbara A.; Dietrich, Mary S.; Wells, Nancy; Wallston, Kenneth A.; Sinard, Robert J.; Cmelak, Anthony J.; Gilbert, Jill; Ridner, Sheila H.

    2014-01-01

    Background Lymphedema may disrupt local function and affect quality of life (QOL) in patients with head and neck cancer. The study aim was to examine the associations among severity of internal and external lymphedema, symptoms, functional status, and QOL in patients with head and neck cancer. Methods The sample included 103 patients who were ≥3 months post head and neck cancer treatment. Variables assessed included severity of internal and external lymphedema, physical/psychological symptoms, functional status, and QOL. Results Severity of internal and external lymphedema was associated with physical symptoms and psychological symptoms. Patients with more severe external lymphedema were more likely to have a decrease in neck left/right rotation. The combined effects of external and internal lymphedema severity were associated with hearing impairment and decreased QOL. Conclusions Lymphedema severity correlates with symptom burden, functional status, and QOL in patients post head and neck cancer treatment. PMID:22791550

  3. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  4. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  5. Age at First Exposure to Football Is Associated with Altered Corpus Callosum White Matter Microstructure in Former Professional Football Players.

    Science.gov (United States)

    Stamm, Julie M; Koerte, Inga K; Muehlmann, Marc; Pasternak, Ofer; Bourlas, Alexandra P; Baugh, Christine M; Giwerc, Michelle Y; Zhu, Anni; Coleman, Michael J; Bouix, Sylvain; Fritts, Nathan G; Martin, Brett M; Chaisson, Christine; McClean, Michael D; Lin, Alexander P; Cantu, Robert C; Tripodis, Yorghos; Stern, Robert A; Shenton, Martha E

    2015-11-15

    Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40-65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure.

  6. Anthropometric Characteristics of Spanish Professional Basketball Players

    Directory of Open Access Journals (Sweden)

    Vaquera Alejandro

    2015-06-01

    Full Text Available The study of elite basketball players’ anthropometric characteristics alongside those of body composition contributes significantly to their profiling as professional athletes and plays an important role in the selection process, as these characteristics can have a significant impact on performance. In the current study, 110 professional basketball players from a series of Spanish professional Leagues (ACB, LEB and EBA and youth level National Teams (U20 and U18 had their anthropometric profiles measured and compared to determine differences between them. Furthermore, all 110 players were divided into three different categories according to their playing position: guards, forwards and centres. The results obtained show no significant differences between players in different competitions in weight, height and the sum of skinfolds. Nonetheless, there were several differences related to body fat content (13.03% in ACB players and 10.52% in the lower categories and National Teams. There were also several differences found between the different playing positions amongst all playing levels in body mass (79.56 ± 2.41, 91.04 ± 1.51 and 104.56 ± 1.73 kg, height (182.28 ± 0.96, 195.65 ± 1.00 and 204.08 ± 0.67 cm, skinfold distribution and perimeters. However, there were no significant differences in body fat content between the different playing positions. The conclusions obtained from this study provide a better understanding to basketball specialists regarding the selection process of players at the elite level, especially on the transition from youth elite programs to men’s elite leagues.

  7. Concussion among female middle-school soccer players.

    Science.gov (United States)

    O'Kane, John W; Spieker, Amy; Levy, Marni R; Neradilek, Moni; Polissar, Nayak L; Schiff, Melissa A

    2014-03-01

    Despite recent increased awareness about sports concussions, little research has evaluated concussions among middle-school athletes. To evaluate the frequency and duration of concussions in female youth soccer players and to determine if concussions result in stopping play and seeking medical care. Prospective cohort study from March 2008 through May 2012 among 4 soccer clubs from the Puget Sound region of Washington State, involving 351 elite female soccer players, aged 11 to 14 years, from 33 randomly selected youth soccer teams. Of the players contacted, 83.1% participated and 92.4% completed the study. Concussion cumulative incidence, incidence rate, and description of the number, type, and duration of symptoms. We inquired weekly about concussion symptoms and, if present, the symptom type and duration, the event resulting in symptom onset, and whether the player sought medical attention or played while symptomatic. Among the 351 soccer players, there were 59 concussions with 43 742 athletic exposure hours. Cumulative concussion incidence was 13.0% per season, and the incidence rate was 1.2 per 1000 athletic exposure hours (95% CI, 0.9-1.6). Symptoms lasted a median of 4.0 days (mean, 9.4 days). Heading the ball accounted for 30.5% of concussions. Players with the following symptoms had a longer recover time than players without these symptoms: light sensitivity (16.0 vs 3.0 days, P = .001), emotional lability (15.0 vs 3.5 days, P = .002), noise sensitivity (12.0 vs 3.0 days, P = .004), memory loss (9.0 vs 4.0 days, P = .04), nausea (9.0 vs 3.0 days, P = .02), and concentration problems (7.0 vs 2.0 days, P = .02). Most players (58.6%) continued to play with symptoms, with almost half (44.1%) seeking medical attention. Concussion rates in young female soccer players are greater than those reported in older age groups, and most of those concussed report playing with symptoms. Heading the ball is a frequent precipitating event. Awareness

  8. Biological impact of superparamagnetic iron oxide nanoparticles for magnetic particle imaging of head and neck cancer cells

    Directory of Open Access Journals (Sweden)

    Lindemann A

    2014-10-01

    Full Text Available Antje Lindemann,1 Kerstin Lüdtke-Buzug,2 Bianca M Fräderich,1 Ksenija Gräfe,2 Ralph Pries,1 Barbara Wollenberg11Department of Otorhinolaryngology, University Hospital of Schleswig-Holstein, Luebeck, Germany; 2Institute of Medical Engineering, University of Luebeck, Luebeck, GermanyBackground: As a tomographic imaging technology, magnetic particle imaging (MPI allows high spatial resolution and sensitivity, and the possibility to create real-time images by determining the spatial distribution of magnetic particles. To ensure a prospective biosafe application of UL-D (University of Luebeck-Dextran coated superparamagnetic nanoparticles, we evaluated the biocompatibility of superparamagnetic iron oxide nanoparticles (SPIONs, their impact on biological properties, and their cellular uptake using head and neck squamous cancer cells (HNSCCs.Methods: SPIONs that met specific MPI requirements were synthesized as tracers. Labeling and uptake efficiency were analyzed by hematoxylin and eosin staining and magnetic particle spectrometry. Flow cytometry, 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT assays, and real-time cell analyzer assays were used to investigate apoptosis, proliferation, and the cytokine response of SPION-labeled cells. The production of reactive oxygen species (ROS was determined using a fluorescent dye. Experimental results were compared to the contrast agent Resovist®, a standard agent used in MPI.Results: UL-D nanoparticles and Resovist particles were taken up in vitro by HNSCCs via unspecific phagocytosis followed by cytosolic accumulation. To evaluate toxicity, flow cytometry analysis was performed; results showed that dose- and time-dependent administration of Resovist induced apoptosis whereas cell viability of UL-D-labeled cells was not altered. We observed decreased cell proliferation in response to increased SPION concentrations. An intracellular production of ROS could not be detected, suggesting that

  9. Chronic spinal cord injury in the cervical spine of a young soccer player.

    Science.gov (United States)

    Kato, Yoshihiko; Koga, Michiaki; Taguchi, Toshihiko

    2010-05-12

    A 17-year-old male soccer player presented with numbness in the upper- and lower-left extremities of 6 months' duration. He had no apparent history of trauma but experienced neck pain during heading of the ball 5 years prior. A high-signal intensity area was seen on T2-weighted magnetic resonance imaging (MRI) of the cervical spine. No muscle weakness was observed. Hypoesthesia was observed in bilateral forearms, hands, and extremities below the inguinal region. Plain radiographs in the neutral position showed local kyphosis at C3/4. A small protrusion of the C3/4 disk was observed on T1-weighted MRI. A high-signal area in the spinal cord at the C3/4 level was observed on T2-weighted MRI, but this was not enhanced by gadolinium. Multiple sclerosis, intramedullary spinal cord tumor, sarcoidosis and malignant lymphoma, and spinal cord injury were all considered in the differential diagnosis. However, in view of the clinical, laboratory, and radiological investigations, we concluded that repeated impacts to the neck caused by heading of the ball during soccer induced a chronic, minor spinal cord injury. This contributed to the high-signal intensity change of the spinal cord in T2-weighted MRI. The present case demonstrates that repeated impact may cause chronic spinal cord injury. Soccer, American football, or rugby players presenting with neck or extremity symptoms should not be overlooked for the possibility of latent spinal cord injury, as this could present later development of more severe or unrecoverable spinal cord injuries. Copyright 2010, SLACK Incorporated.

  10. Performance following a first professional concussion among National Basketball Association players.

    Science.gov (United States)

    Yengo-Kahn, Aaron M; Zuckerman, Scott L; Stotts, Jeff; Zalneraitis, Brian H; Gardner, Ryan M; Kerr, Zachary Y; Solomon, Gary S

    2016-09-01

    Basketball is a physical game played on a hardwood floor among high-jumping athletes at risk for injury. It is currently unknown how sport-related concussion (SRC) affects player performance after injury among professional basketball players. The objective of this study was to explore the impact of SRC on basketball performance among National Basketball Association (NBA) players. A retrospective, archival cohort study was performed that compared NBA player performance following concussion to pre-concussive performance. A comprehensive NBA injury database, compiled from publically available sources, was queried for NBA players who suffered concussion from 2005-06 to 2014-15 (10 seasons). Intra-and inter-player analyses were performed against a matched control group of players who missed playing time for personal reasons. Following application of inclusion/exclusion criteria and a matching process, 51 concussed players and 51 control players were included in analysis. There were no statistically significant decrements in baseline to post-concussion performance metrics in intra-player or player vs. controls after 5 return games. Our findings suggest that at the NBA level, an athlete's performance in the initial 5 games following injury does not suffer from the after-effects of concussive injury. These results may be useful in counseling professional athletes following a concussion.

  11. Smoking has a negative impact upon health related quality of life after treatment for head and neck cancer

    DEFF Research Database (Denmark)

    Jensen, Kenneth; Jensen, Anders Bonde; Grau, Cai

    2006-01-01

    To examine the influence of smoking on observer based morbidity scores and patient assessed health related quality of life after treatment for head and neck cancer. The results of EORTC C30 and H&N35 questionnaires and DAHANCA morbidity scores were studied according to smoking status in 114...... recurrence free head and neck cancer patients. In contrast to observer based toxicity scoring, smoking had a significantly negative influence on 20 of the 33 quality of life scales. Previous smokers had quality of life scores in between never smokers and continuous smokers. Smoking after treatment of head...... and neck cancer adversely influenced a wide range of quality of life endpoints. Quitters had better quality of life than patients who continued to smoke after treatment, suggesting that smoking cessation may improve quality of life in addition to reducing the risk of new cancer. Udgivelsesdato: 2007-Feb...

  12. How Big of an Effect Do Small Dams Have? Using Geomorphological Footprints to Quantify Spatial Impact of Low-Head Dams and Identify Patterns of Across-Dam Variation.

    Science.gov (United States)

    Fencl, Jane S; Mather, Martha E; Costigan, Katie H; Daniels, Melinda D

    2015-01-01

    Longitudinal connectivity is a fundamental characteristic of rivers that can be disrupted by natural and anthropogenic processes. Dams are significant disruptions to streams. Over 2,000,000 low-head dams (dams on geomorphology and ecology are largely untested. Progress for research and conservation is impaired by not knowing the magnitude of low-head dam impacts. Based on the geomorphic literature, we refined a methodology that allowed us to quantify the spatial extent of low-head dam impacts (herein dam footprint), assessed variation in dam footprints across low-head dams within a river network, and identified select aspects of the context of this variation. Wetted width, depth, and substrate size distributions upstream and downstream of six low-head dams within the Upper Neosho River, Kansas, United States of America were measured. Total dam footprints averaged 7.9 km (3.0-15.3 km) or 287 wetted widths (136-437 wetted widths). Estimates included both upstream (mean: 6.7 km or 243 wetted widths) and downstream footprints (mean: 1.2 km or 44 wetted widths). Altogether the six low-head dams impacted 47.3 km (about 17%) of the mainstem in the river network. Despite differences in age, size, location, and primary function, the sizes of geomorphic footprints of individual low-head dams in the Upper Neosho river network were relatively similar. The number of upstream dams and distance to upstream dams, but not dam height, affected the spatial extent of dam footprints. In summary, ubiquitous low-head dams individually and cumulatively altered lotic ecosystems. Both characteristics of individual dams and the context of neighboring dams affected low-head dam impacts within the river network. For these reasons, low-head dams require a different, more integrative, approach for research and management than the individualistic approach that has been applied to larger dams.

  13. MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players

    OpenAIRE

    Mendez-Villanueva, Alberto; Suarez-Arrones, Luis; Rodas, Gil; Fernandez-Gonzalo, Rodrigo; Tesch, Per; Linnehan, Richard; Kreider, Richard; Di Salvo, Valter

    2016-01-01

    The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semi...

  14. Recency and frequency of soccer heading interact to decrease neurocognitive performance.

    Science.gov (United States)

    Webbe, Frank M; Ochs, Shelley R

    2003-01-01

    This study investigated the role of heading recency interacting with heading frequency in determining neuropsychological deficits associated with heading the ball during soccer play. Sixty-four high-ability male soccer players ages 16 to 34 completed the California Verbal Learning Test (CVLT), the Trailmaking Test, the Paced Auditory Serial Addition Test (PASAT), the Facial Recognition Test, the Rey-Osterrieth Complex Figure, and the Shipley Scales. Heading recency interacted with heading frequency, such that players with the highest self-reported estimates of heading who also experienced heading within the previous 7 days scored significantly lower on CVLT, Shipley, Trailmaking, and PASAT than other combinations of heading and recency. Although strict ball-to-head contacts could not be isolated as sufficient to cause this interaction, these results increase the weight of evidence that heading behavior is problematic for causing at least transient cognitive impairment.

  15. Cervical range of motion and proprioception in rugby players versus non-rugby players.

    Science.gov (United States)

    Lark, Sally D; McCarthy, Peter W

    2007-06-01

    In this study, we examined the effects of number of years of playing rugby on neck function. Active cervical spine range of motion and proprioception were assessed in 14 non-rugby-playing but trained sportsmen (mean age 28 years, s = 7) and 46 rugby players (26 rugby forwards: mean age 26 years, s = 5; mean years played 14 years; 20 backs: mean age 24 years, s = 5; mean years played 14 years). Active cervical range of motion in flexion, extension, left and right lateral flexion, plus left and right rotation were measured using a cervical range of motion device. The ability to reposition the head in a central position with eyes closed was taken as a measure of proprioception. Results show that rugby forwards generally had the least active cervical range of motion, particularly neck extension (forwards, 43 degrees ; backs, 55 degrees ; controls, 58 degrees ), with the decrement correlating with the number of years played. In addition, repositioning was significantly worse in rugby players after neck extension than non-rugby players (6 degrees vs. 3 degrees ). The active cervical range of motion of rugby forwards is similar to that of whiplash patients, suggesting that participation in rugby can have an effect on neck range of motion that is equivalent to chronic disability. Reduced active cervical range of motion could also increase the likelihood of injury and exacerbate age-related neck problems.

  16. Examining Neurocognitive Function in Previously Concussed Interscholastic Female Soccer Players.

    Science.gov (United States)

    Forbes, Cameron R; Glutting, Joseph J; Kaminski, Thomas W

    2016-01-01

    Awareness of sport-related concussions in soccer has gained recent attention in the medical community. Interestingly, purposeful heading-a unique yet strategic and inherent part of soccer-involves repeated subconcussive blows to the head. We divided 210 female interscholastic soccer players into control (CON [never concussed]) and experimental (EXP [previously concussed]) groups. We assessed neurocognitive performance using the Automated Neuropsychological Assessment Metrics computer program before and after the players' competitive season. Headers were recorded at all sanctioned matches. Data were analyzed using a series of one-way analyses of covariance and t tests. Both groups essentially played in the same number of games (EXP = 16.1 vs. CON = 16.1) and had an equal number of total headers (EXP = 24.9 vs. CON = 24.3). Additionally, headers per game were surprisingly low in both groups (1.4 in EXP vs. 1.3 in CON). Unexpectedly, there were no significant differences between the EXP and CON groups across all dependent variables measured (p > .05). This study suggests that although previously concussed players involve themselves in purposeful heading (i.e., subconcussive insults) throughout a competitive season, there appear to be no negative consequences on neuropsychological test performance or concussion-related symptoms. Additional research is needed to determine what may result during the course of a playing career.

  17. Keeping Kids on Track: Impacts of a Parenting-Focused Early Head Start Program on Attachment Security and Cognitive Development

    Science.gov (United States)

    Roggman, Lori A.; Boyce, Lisa K.; Cook, Gina A.

    2009-01-01

    Research Findings: The home-based Early Head Start program in this local study aimed to promote children's early attachment and cognitive development by establishing supportive relationships with parents and guiding responsive parenting and positive parent-child play interactions. To test the effectiveness of this approach, we studied the…

  18. The Impact of the Chile Intervention on the Food Served in Head Start Centers in Rural New Mexico

    Science.gov (United States)

    Morshed, Alexandra B.; Davis, Sally M.; Keane, Patricia C.; Myers, Orrin B.; Mishra, Shiraz I.

    2016-01-01

    Background: The Child Health Initiative for Lifelong Eating and Exercise is a multicomponent obesity-prevention intervention, which was evaluated among Head Start (HS) centers in American Indian and predominantly Hispanic communities in rural New Mexico. This study examines the intervention's foodservice outcomes: fruits, vegetables, whole grains,…

  19. The Impact of the Chile Intervention on the Food Served in Head Start Centers in Rural New Mexico

    Science.gov (United States)

    Morshed, Alexandra B.; Davis, Sally M.; Keane, Patricia C.; Myers, Orrin B.; Mishra, Shiraz I.

    2016-01-01

    Background: The Child Health Initiative for Lifelong Eating and Exercise is a multicomponent obesity-prevention intervention, which was evaluated among Head Start (HS) centers in American Indian and predominantly Hispanic communities in rural New Mexico. This study examines the intervention's foodservice outcomes: fruits, vegetables, whole grains,…

  20. Multi-Player Quantum Games

    CERN Document Server

    Benjamin, S C; Benjamin, Simon C.; Hayden, Patrick M.

    2001-01-01

    Game theory is a mature field of applied mathematics. It formalizes the conflict between competing agents, and has found applications ranging from economics through to biology. Recently the first efforts have been made to introduce quantum information into game theory. For two-player games, it has been found that when the allowed `moves' are extended to include everything quantum mechanically possible, then the predominant strategies in the game can disappear, and only reappear if the players degrade the quantum coherence. Here we present the first study of quantum games with more than two players. We demonstrate that such games can exhibit `coherent' equilibrium strategies which have no analogue in classical games, or even in two-player quantum games. These equilibria are generally of a cooperative nature: quantum players can exploit their environment highly efficiently through the use of collaborative strategies.

  1. A Prediction of Response of the Head and Neck of the U.S. Adult Military Population to Dynamic Impact Acceleration from Selected Dynamic Test Subjects.

    Science.gov (United States)

    1976-05-01

    concussion in whiplash . However, Hodgson (13), Gurdjian (12) and others contend that other factors such as resultant intracranial pressure gradients may...degree of head-neck hyperextension. This disagreement among researchers as to the mecha- nisms of injury in hdad impact and whiplash is also seen in...results were obtained after some 62 42 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ > _ _ _ _ _ fi 4 ae I4 *0 &AeJ s- C9. d -- q a 3 1 8 £ 3 36 3’ U) L) 4’ U- 4-) i d

  2. Impact of low-level laser therapy on hyposalivation, salivary pH, and quality of life in head and neck cancer patients post-radiotherapy.

    Science.gov (United States)

    Palma, Luiz Felipe; Gonnelli, Fernanda Aurora Stabile; Marcucci, Marcelo; Dias, Rodrigo Souza; Giordani, Adelmo José; Segreto, Roberto Araújo; Segreto, Helena Regina Comodo

    2017-03-03

    Late effects of radiotherapy for head and neck cancer treatment have been increasingly investigated due to its impact on patients' quality of life. The purpose of this study was to evaluate the effect of low-level laser therapy on hyposalivation, low salivary pH, and quality of life in head and neck cancer patients post-radiotherapy. Twenty-nine patients with radiation-induced xerostomia received laser sessions twice a week, during 3 months (24 sessions). For this, a continuous wave Indium-Gallium-Aluminium-Phosphorus diode laser device was used punctually on the major salivary glands (808 nm, 0.75 W/cm(2), 30 mW, illuminated area 0.04 cm(2), 7.5 J/cm(2), 10 s, 0.3 J). Six extraoral points were illuminated on each parotid gland and three on each submandibular gland, as well as two intraoral points on each sublingual gland. Stimulated and unstimulated salivary flow rate, pH (two scales with different gradations), and quality of life (University Of Washington Quality of Life Questionnaire for Patients with Head and Neck Cancer) were assessed at baseline and at the end of the treatment. There were significant increases in both mean salivary flow rates (unstimulated: p = 0.0012; stimulated: p < 0.0001), mean pH values (p = 0.0002 and p = 0.0004), and mean score from the quality of life questionnaire (p < 0.0001). Low-level laser therapy seems to be effective to mitigate salivary hypofunction and increase salivary pH of patients submitted to radiotherapy for head and neck cancer, thereby leading to an improvement in quality of life.

  3. Tibia and fibula fractures in soccer players.

    Science.gov (United States)

    Boden, B P; Lohnes, J H; Nunley, J A; Garrett, W E

    1999-01-01

    We performed a retrospective review of 31 athletes who sustained a fracture of the lower leg from a direct blow while playing soccer. Fifteen fractures involved both the tibia and fibula 11 only the tibia, and 5 only the fibula. Information was collected using a standardized questionnaire. The mean follow-up from the time of injury was 30 months. Injuries typically occurred in young, competitive athletes during game situations. The mechanisms were broadly classified into several categories: contact during a slide tackle (13, 42%), a collision with the goalkeeper (8, 26%), two opposing players colliding while swinging for a loose ball (7, 23%), or a player being kicked by a standing opponent (3, 10%). The majority of fractures (26, 90%) occurred while the athletes were wearing shin guards. The point of impact was with the shin guard prior to the fracture in 16 cases (62%). Return to competitive soccer averaged 40 weeks for combined tibia and fibula fractures, 35 weeks for isolated tibia fractures, and 18 weeks for isolated fibula fractures. Injuries were associated with a high incidence of major complications (12 out of 31, 39%), especially in concurrent tibia and fibula fractures (8 out of 15, 50%). These findings suggest that lower leg fractures in soccer players are serious injuries, often necessitating a prolonged recovery time. In addition, this study questions the ability of shin guards to protect against fractures.

  4. Scatter radiation breast exposure during head CT: impact of scanning conditions and anthropometric parameters on shielded and unshielded breast dose

    Energy Technology Data Exchange (ETDEWEB)

    Klasic, B. [Hospital for pulmonary diseases, Zagreb (Croatia); Knezevic, Z.; Vekic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Brnic, Z.; Novacic, K. [Merkur Univ. Hospital, Zagreb (Croatia)

    2006-07-01

    Constantly increasing clinical requests for CT scanning of the head on our facility continue to raise concern regarding radiation exposure of patients, especially radiosensitive tissues positioned close to the scanning plane. The aim of our prospective study was to estimate scatter radiation doses to the breast from routine head CT scans, both with and without use of lead shielding, and to establish influence of various technical and anthropometric factors on doses using statistical data analysis. In 85 patient referred to head CT for objective medical reasons, one breast was covered with lead apron during CT scanning. Radiation doses were measured at skin of both breasts and over the apron simultaneously, by the use of thermo luminescent dosimeters. The doses showed a mean reduction by 37% due to lead shielding. After we statistically analyzed our data, we observed significant correlation between under-the-shield dose and values of technical parameters. We used multiple linear regression model to describe the relationships of doses to unshielded and shielded breast respectively, with anthropometric and technical factors. Our study proved lead shielding of the breast to be effective, easy to use and leading to a significant reduction in scatter dose. (author)

  5. Upper extremity sensorimotor control among collegiate football players.

    Science.gov (United States)

    Laudner, Kevin G

    2012-03-01

    Injuries stemming from shoulder instability are very common among athletes participating in contact sports, such as football. Previous research has shown that increased laxity negatively affects the function of the sensorimotor system potentially leading to a pathological cycle of shoulder dysfunction. Currently, there are no data detailing such effects among football players. Therefore, the purpose of this study was to examine the differences in upper extremity sensorimotor control among football players compared with that of a control group. Forty-five collegiate football players and 70 male control subjects with no previous experience in contact sports participated. All the subjects had no recent history of upper extremity injury. Each subject performed three 30-second upper extremity balance trials on each arm. The balance trials were conducted in a single-arm push-up position with the test arm in the center of a force platform and the subjects' feet on a labile device. The trials were averaged, and the differences in radial area deviation between groups were analyzed using separate 1-way analyses of variance (p football players showed significantly more radial area deviation of the dominant (0.41 ± 1.23 cm2, p = 0.02) and nondominant arms (0.47 ± 1.63 cm2, p = 0.03) when compared with the control group. These results suggest that football players may have decreased sensorimotor control of the upper extremity compared with individuals with no contact sport experience. The decreased upper extremity sensorimotor control among the football players may be because of the frequent impacts accumulated during football participation. Football players may benefit from exercises that target the sensorimotor system. These findings may also be beneficial in the evaluation and treatment of various upper extremity injuries among football players.

  6. Perfusion Neuroimaging Abnormalities Alone Distinguish National Football League Players from a Healthy Population.

    Science.gov (United States)

    Amen, Daniel G; Willeumier, Kristen; Omalu, Bennet; Newberg, Andrew; Raghavendra, Cauligi; Raji, Cyrus A

    2016-04-25

    National Football League (NFL) players are exposed to multiple head collisions during their careers. Increasing awareness of the adverse long-term effects of repetitive head trauma has raised substantial concern among players, medical professionals, and the general public. To determine whether low perfusion in specific brain regions on neuroimaging can accurately separate professional football players from healthy controls. A cohort of retired and current NFL players (n = 161) were recruited in a longitudinal study starting in 2009 with ongoing interval follow up. A healthy control group (n = 124) was separately recruited for comparison. Assessments included medical examinations, neuropsychological tests, and perfusion neuroimaging with single photon emission computed tomography (SPECT). Perfusion estimates of each scan were quantified using a standard atlas. We hypothesized that hypoperfusion particularly in the orbital frontal, anterior cingulate, anterior temporal, hippocampal, amygdala, insular, caudate, superior/mid occipital, and cerebellar sub-regions alone would reliably separate controls from NFL players. Cerebral perfusion differences were calculated using a one-way ANOVA and diagnostic separation was determined with discriminant and automatic linear regression predictive models. NFL players showed lower cerebral perfusion on average (p NFL players from controls with 90% sensitivity, 86% specificity, and 94% accuracy (95% CI 95-99). Automatic linear modeling achieved similar results. Inclusion of age and clinical co-morbidities did not improve diagnostic classification. Specific brain regions commonly damaged in traumatic brain injury show abnormally low perfusion on SPECT in professional NFL players. These same regions alone can distinguish this group from healthy subjects with high diagnostic accuracy. This study carries implications for the neurological safety of NFL players.

  7. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  8. The Astro Learning Design Player

    NARCIS (Netherlands)

    Sharples, Paul; Wilson, Scott; Popat, Kris; Griffiths, David; Beauvoir, Phillip

    2010-01-01

    Sharples, Paul Wilson, S., Popat, K., Griffiths, D., Beauvoir, P. (2009) The Astro Learning Design Player. This software is distributed under the three clause BSD license, copyright TENCompetence Foundation

  9. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  10. Blunt force impact to the head using a teeball bat: systematic comparison of physical and finite element modeling.

    Science.gov (United States)

    Kettner, Mattias; Ramsthaler, Frank; Potente, Stefan; Bockenheimer, Alexander; Schmidt, Peter H; Schrodt, Michael

    2014-12-01

    Blunt head trauma secondary to violent actions with various weapons is frequently a cause of injury in forensic casework; differing striking tools have varying degrees of injury capacity. The systematic approach used to examine a 19-year-old student who was beaten with a wooden teeball bat will be described. The assailant stopped beating the student when the teeball bat broke into two pieces. The surviving victim sustained bruises and a forehead laceration. The State's Attorney assigned a forensic expert to examine whether the forces exerted on the victim's head (leading to the fracture of the bat) were potentially life threatening (e.g. causing cranial bone fractures). Physical modeling was conducted using a pigskin-covered polyethylene end cap cushioned by cellulose that was connected to a piezoelectric force gauge. Experiments with teeball bats weighing 295-485 g demonstrated that 12-20 kN forces were necessary to cause a comparable bat fracture. In addition to physical testing, a computer-aided simulation was conducted, utilizing a finite-element (FE) method. In the FE approach, after selecting for wood properties, a virtual bat was swung against a hemisphere comprising two layers that represented bone and soft tissue. Employing this model, a 17.6 kN force was calculated, with the highest fracture probability points resembling the fracture patterns of the physically tested bats.

  11. No acute changes in postural control after soccer heading.

    Science.gov (United States)

    Broglio, S P; Guskiewicz, K M; Sell, T C; Lephart, S M

    2004-10-01

    Soccer heading has been proposed as a potential cause of cerebral dysfunction. To examine the acute effects of two types of soccer heading on postural control. Collegiate soccer players were randomly assigned to one of four groups: control, linear heading, simulated rotational heading, or rotational heading. Each subject completed a baseline postural stability assessment on day 1. On day 2 the same assessment was completed for the control subjects. The simulated rotational heading group completed a simulated heading drill before postural stability testing. The linear and rotational heading groups performed a heading drill with 20 balls at 88.71 km/h (55 mph), before postural stability testing. Separate one between (group), three within (surface, eyes, and day), mixed model, repeated measures analyses of variance were conducted on values for total sway and mean centre of pressure. The mixed model analysis of variance of results showed no significant differences (p>0.05) for the interactions of interest for either variable. Results suggest no acute changes in measures of postural control in soccer players completing either a linear or rotational soccer heading drill of 20 balls at a fixed speed. Non-significant interactions between surface, eyes, day, and group indicate that sensory interaction of the balance mechanism components are not be compromised by the heading drill. This research supports previous studies suggesting that there are no acute risks associated with routine soccer heading. A direct comparison between these findings and those suggesting long term chronic deficits, however, cannot be made. Other studies that report chronic cerebral deficits in soccer players may have resulted from factors other than soccer heading and warrant further examination.

  12. Investigation of Sub-Assembly of Product for Environment Impact Assessment: Quantitative Evaluation of Shroud Fan Cover assembly and Cylinder Head Cover assembly

    Directory of Open Access Journals (Sweden)

    Ms. SUMAN SHARMA

    2011-09-01

    Full Text Available We live in a changing world. In many countries the systems are under change. The changes are largely driven by environmental considerations and one driving force is the threat of global climate change. When making new strategic decisions related to manufacturing any product it becomes important to consider the environmentalimplications. The total consumption of materials and energy during the Life cycle of product is greatly affecting the environment. The proper selection of engineering materials for manufacturing of a product can minimize the environmental impact. The environmental impact of products and processes has become a key issue that has led companies to investigate ways to minimize their effects on the environment. LCA is a means of deriving a quantitative evaluation of environmental impact of product design and thereby refining product quality and characteristics. The overall aim of the present work is to evaluate the environmental impact of some important sub-assembliesof a two wheeler for main stages of life cycle i.e. manufacturing stages of raw material and part manufacturing. An investigation has been done on two sub-assemblies of engine group of Activa i.e. shroud fan cover and cylinder head cover. It has been presented using EDIP (Environmental Design of Industrial Product as LCA method as per ISO 14040. The study reveals that the environmental impact is more in the case of manufacturing of steel and rubber parts as compared to plastic and aluminium parts of selected subassemblies and eco-toxicityand human toxicity is more as compared to other impact categories.

  13. The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia: a rejoinder.

    Science.gov (United States)

    Rissel, Chris

    2012-03-01

    This paper challenges the conclusion of a recent paper by Walter et al. (Accident Analysis and Prevention 2011, doi:10.1016/j.aap.2011.05.029) reporting that despite numerous data limitations repealing the helmet legislation in Australia could not be justified. This conclusion is not warranted because of the limited time period used in their analysis and the lack of data beyond a few years before the introduction of legislation, the failure to adequately account for the effect of the phasing in of the legislation, the effect of the marked reduction in child cyclists, and the non-comparability of the pedestrian and cycling injuries and related lack of consideration of the severity of head injuries. The extent to which helmet legislation deters people from cycling is discussed.

  14. Head position and impact direction in whiplash injuries: associations with MRI-verified lesions of ligaments and membranes in the upper cervical spine.

    Science.gov (United States)

    Kaale, Bertel Rune; Krakenes, Jostein; Albrektsen, Grethe; Wester, Knut

    2005-11-01

    In the present study, we compared magnetic resonance imaging (MRI) findings of soft tissue structures in the upper cervical spine between whiplash-associated disorder (WAD) patients and population-based control persons, and examined whether MRI-verified abnormalities in WAD patients were related to accident-related factors hypothesized to be of importance for severity of injury. A total of 92 whiplash patients and 30 control persons, randomly drawn, were included. Information on the accident-related factors (i.e., head position and impact direction) was obtained by a questionnaire that was answered within 1 week after the accident. The MRI examination was performed 2-9 (mean 6) years after the accident. Focus was on MRI abnormalities of the alar and the transverse ligaments, and the tectorial and posterior atlanto-occipital membranes, graded 0-3. For all neck structures, the whiplash patients had more high-grade lesions (grade 2 or 3) than the control persons (Chi-square test, p Whiplash patients who had been sitting with their head/neck turned to one side at the moment of collision more often had high-grade lesions of the alar and transverse ligaments (p whiplash trauma.

  15. Impact of organ-specific dose reduction on the image quality of head and neck CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Schimmoeller, L.; Lanzman, R.S.; Heusch, P.; Dietrich, S.; Miese, F.; Aissa, J.; Heusner, T.A.; Antoch, G.; Kroepil, P. [University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany)

    2013-06-15

    Organ-specific dose reduction (OSDR) algorithms can reduce radiation on radiosensitive organs up to 59 %. This study evaluates the influence of a new OSDR algorithm on image quality of head and neck computed tomographic angiography (CTA) in clinical routine. Sixty-two consecutive patients (68 {+-} 13 years) were randomised into two groups and imaged using 128-row multidetector CT. Group A (n = 31) underwent conventional CTA and group B (n = 31) CTA with a novel OSDR algorithm. Subjective and objective image quality were statistically compared. Subjective image quality was rated on a five-point scale. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated with region-of-interest measurements. The SNR of the common carotid artery and middle cerebral artery was 53.6 {+-} 22.7 and 43.3 {+-} 15.3 (group A) versus 54.1 {+-} 20.5 and 46.2 {+-} 14.6 (group B). The CNR was 40.0 {+-} 19.3 and 29.7 {+-} 12.0 (group A) compared with 40.7 {+-} 16.8 and 32.9 {+-} 10.9 (group B), respectively. Subjective image quality was excellent in both groups (mean score 4.4 {+-} 0.7 versus 4.4 {+-} 0.6). Differences between the two groups were not significant. The novel OSDR algorithm does not compromise image quality of head and neck CTA. Its application can be recommended for CTA in clinical routine to protect the thyroid gland and ocular lenses from unnecessary high radiation. (orig.)

  16. Frontal Lobe Function in Chess Players

    Directory of Open Access Journals (Sweden)

    Vahid Nejati

    2012-05-01

    Full Text Available Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players dont have any preference in any stage of Stroop test. Chess players dont have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  17. Impact of Brunswick River Mouth Training Walls on Adjacent Beaches,Brunswick Heads, New South Wales, Australia

    Institute of Scientific and Technical Information of China (English)

    HUANG Hai-jun (黄海军); Andrew D. SHORT; Thomas ZENG; David HANSLOW

    2004-01-01

    River training walls have been built at scores of locations along the NSW coast and their impacts on shoreline change are still not fully understood. In this study, the Bnmswick River entrance and adjacent beaches are selected for examination of the impact of the construction of major training walls. Thirteen sets of aerial photographs taken between 1947 and 1994 are used in a GIS approach to accurately determine the shoreline position, beach contours and sand volumes, and their changes in both time and space, and then to assess the contribution of both the structures and natural hydrodynamic conditions to large scale (years-decades and kilometres) beach changes. The impact of the training walls can be divided into four stages: natural conditions prior to their construction (pre 1959), major downdrift erosion and updrift accretion during and following the construction of the walls in 1959 ~ 1962 and 1966, diminishing impact of the walls between 1966and 1987, and finally no apparent impact between 1987 ~ 1994. The impact extends horizontally about 8 km updrift and 17 km downdrift, and temporally up to 25 years.

  18. Head Injuries

    Science.gov (United States)

    ... object that's stuck in the wound. previous continue Concussions Concussions — the temporary loss of normal brain function due ... also a type of internal head injury. Repeated concussions can permanently damage the brain. In many cases, ...

  19. Head Tilt

    Science.gov (United States)

    ... Healthy Living Healthy Living Healthy Living Nutrition Fitness Sports Oral Health Emotional Wellness Growing Healthy Sleep Safety & ... When this happens, the neck muscles go into spasm, causing the head to tilt to one side. ...

  20. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay Safe: Baseball Concussions Concussions: Getting Better Sports and Concussions Dealing ...

  1. Head MRI

    Science.gov (United States)

    ... heart valves Heart defibrillator or pacemaker Inner ear (cochlear) implants Kidney disease or dialysis (you may not ... to: Abnormal blood vessels in the brain ( arteriovenous malformations of the head ) Tumor of the nerve that ...

  2. Survivorship Analysis of Eighty Revised Hip Arthroplasties With the Impaction Grafting Technique Using Whole Femoral Head Allografts With the Articular Cartilage.

    Science.gov (United States)

    Fadulelmola, Ahmed; Drampalos, Efstathios; Hodgkinson, John; Hemmady, Mukesh

    2017-06-01

    Acetabular impaction bone grafting aims to restore anatomy in hip revision surgery. This is an effective but expensive and time-consuming technique. Usually, the articular cartilage is removed from the femoral head allograft. We aimed to reproduce the same results retaining the cartilage of the allograft. Eighty acetabular revisions using impacted morselized bone graft retaining the articular cartilage and a cemented cup were studied retrospectively. Six were lost during follow-up. The mean follow-up was 6.5 years (range 1-13). Clinical and radiological assessment was made using the Oxford Hip Score, Hodgkinson's criteria for socket loosening, and the Gie classification for evaluation of allograft incorporation. Sixty-three sockets (85.1%) were considered radiologically stable (type 0, 1, and 2 demarcations), 8 (10.8%) were radiologically loose (type 3), and 3 (4.1%) presented with migration. Fifty-one (68.9%) cases showed good trabecular remodeling (grade 3), 20 (27%) showed trabecular incorporation (grade 2), and 3 (4.1%) showed poor allograft incorporation. Mean preoperative hip score was 43 and postoperative score was 28. Six (8.1%) cases presented heterotopic ossification around the revised implants, 2 patients (2.7%) had periprosthetic fractures, and 4 (5.4%) had dislocations. The Kaplan-Meier survivorship at a mean of 6.5 years with revision of the cup for any reason was 95.9% (95% confidence interval 5.6-7.5). The mid-term results of our technique are promising. Particularly when the supply of fresh-frozen allografts and surgical time is limited, using whole femoral head with articular cartilage is both safe and effective. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Significance of ubiquitin carboxy-terminal hydrolase L1 elevations in athletes after sub-concussive head hits.

    Directory of Open Access Journals (Sweden)

    Vikram Puvenna

    Full Text Available The impact of sub-concussive head hits (sub-CHIs has been recently investigated in American football players, a population at risk for varying degrees of post-traumatic sequelae. Results show how sub-CHIs in athletes translate in serum as the appearance of reporters of blood-brain barrier disruption (BBBD, how the number and severity of sub-CHIs correlate with elevations of putative markers of brain injury is unknown. Serum brain injury markers such as UCH-L1 depend on BBBD. We investigated the effects of sub-CHIs in collegiate football players on markers of BBBD, markers of cerebrospinal fluid leakage (serum beta 2-transferrin and markers of brain damage. Emergency room patients admitted for a clinically-diagnosed mild traumatic brain injury (mTBI were used as positive controls. Healthy volunteers were used as negative controls. Specifically this study was designed to determine the use of UCH-L1 as an aid in the diagnosis of sub-concussive head injury in athletes. The extent and intensity of head impacts and serum values of S100B, UCH-L1, and beta-2 transferrin were measured pre- and post-game from 15 college football players who did not experience a concussion after a game. S100B was elevated in players experiencing the most sub-CHIs; UCH-L1 levels were also elevated but did not correlate with S100B or sub-CHIs. Beta-2 transferrin levels remained unchanged. No correlation between UCH-L1 levels and mTBI were measured in patients. Low levels of S100B were able to rule out mTBI and high S100B levels correlated with TBI severity. UCH-L1 did not display any interpretable change in football players or in individuals with mild TBI. The significance of UCH-L1 changes in sub-concussions or mTBI needs to be further elucidated.

  4. Effect of Putting Grip on Eye and Head Movements During the Golf Putting Stroke

    Directory of Open Access Journals (Sweden)

    George K. Hung

    2003-01-01

    Full Text Available The objective of this article is to determine the effect of three different putting grips (conventional, cross-hand, and one-handed on variations in eye and head movements during the putting stroke. Seven volunteer novice players, ranging in age from 21 to 22 years, participated in the study. During each experimental session, the subject stood on a specially designed platform covered with artificial turf and putted golf balls towards a standard golf hole. The three different types of grips were tested at two distances: 3 and 9 ft. For each condition, 20 putts were attempted. For each putt, data were recorded over a 3-s interval at a sampling rate of 100 Hz. Eye movements were recorded using a helmet-mounted eye movement monitor. Head rotation about an imaginary axis through the top of the head and its center-of-rotation was measured by means of a potentiometer mounted on a fixed frame and coupled to the helmet. Putter-head motion was measured using a linear array of infrared phototransistors embedded in the platform. The standard deviation (STD, relative to the initial level was calculated for eye and head movements over the duration of the putt (i.e., from the beginning of the backstroke, through the forward stroke, to impact. The averaged STD for the attempted putts was calculated for each subject. Then, the averaged STDs and other data for the seven subjects were statistically compared across the three grip conditions. The STD of eye movements were greater (p < 0.1 for conventional than cross-hand (9 ft and one-handed (3 and 9 ft grips. Also, the STD of head movements were greater (p < 0.1; 3 ft for conventional than cross-hand and one-handed grips. Vestibulo-ocular responses associated with head rotations could be observed in many 9 ft and some 3 ft putts. The duration of the putt was significantly longer (p < 0.05; 3 and 9 ft for the one-handed than conventional and cross-hand grips. Finally, performance, or percentage putts made, was

  5. Repeatedly Heading a Soccer Ball Does Not Increase Serum Levels of S-100B, a Biochemical Marker of Brain Tissue Damage: an Experimental Study.

    Science.gov (United States)

    Stålnacke, Britt-Marie; Sojka, Peter

    2008-02-29

    OBJECTIVES: The aim of the study was to analyse whether the controlled heading of soccer balls elicits increased serum concentrations of a biochemical marker of brain tissue damage S-100B. METHODS: Nineteen male soccer players were randomly divided into two groups, A and B. Group A headed a soccer ball falling from 18 m five times, while group B served as controls (no heading). Blood samples were taken before and 0.5 h, 2 h and 4 h after the heading for analysis of S-100B. RESULTS: No statistically significant (p > 0.05) increases in serum concentrations of S-100B were encountered in group A at 0.5 h (0.109 +/-0.024 mug/L), 2 h (0.098 +/- 0.026 mug/L), and 4 h (0.113 +/- 0.035 mug/L) when the blood samples obtained before and after the heading were compared (0.157 +/- 0.134 mug/L). No statistically significant difference was found when the serum concentrations of S-100B were compared between groups A and B either before or after heading. CONCLUSIONS: Heading a soccer ball dropped from a height of 18 m five times was not found to cause an increase in serum concentrations of S-100B, indicating that the impact was not sufficient to cause biochemically discernible damage of brain tissue.

  6. Repeatedly Heading a Soccer Ball Does Not Increase Serum Levels of S-100B, a Biochemical Marker of Brain Tissue Damage: an Experimental Study

    Directory of Open Access Journals (Sweden)

    Peter Sojka

    2008-01-01

    Full Text Available Objectives: The aim of the study was to analyse whether the controlled heading of soccer balls elicits increased serum concentrations of a biochemical marker of brain tissue damage S-100B.Methods: Nineteen male soccer players were randomly divided into two groups, A and B. Group A headed a soccer ball falling from 18 m five times, while group B served as controls (no heading. Blood samples were taken before and 0.5 h, 2 h and 4 h after the heading for analysis of S-100B.Results: No statistically significant (p > 0.05 increases in serum concentrations of S-100B were encountered in group A at 0.5 h (0.109 ± 0.024 μg/L, 2 h (0.098 ± 0.026 μg/L, and 4 h (0.113 ± 0.035 μg/L when the blood samples obtained before and after the heading were compared (0.157 ± 0.134 μg/L. No statistically significant difference was found when the serum concentrations of S-100B were compared between groups A and B either before or after heading.Conclusions: Heading a soccer ball dropped from a height of 18 m five times was not found to cause an increase in serum concentrations of S-100B, indicating that the impact was not sufficient to cause biochemically discernible damage of brain tissue.

  7. Consequences of repeated blood-brain barrier disruption in football players.

    Directory of Open Access Journals (Sweden)

    Nicola Marchi

    Full Text Available The acknowledgement of risks for traumatic brain injury in American football players has prompted studies for sideline concussion diagnosis and testing for neurological deficits. While concussions are recognized etiological factors for a spectrum of neurological sequelae, the consequences of sub-concussive events are unclear. We tested the hypothesis that blood-brain barrier disruption (BBBD and the accompanying surge of the astrocytic protein S100B in blood may cause an immune response associated with production of auto-antibodies. We also wished to determine whether these events result in disrupted white matter on diffusion tensor imaging (DT scans. Players from three college football teams were enrolled (total of 67 volunteers. None of the players experienced a concussion. Blood samples were collected before and after games (n = 57; the number of head hits in all players was monitored by movie review and post-game interviews. S100B serum levels and auto-antibodies against S100B were measured and correlated by direct and reverse immunoassays (n = 15 players; 5 games. A subset of players underwent DTI scans pre- and post-season and after a 6-month interval (n = 10. Cognitive and functional assessments were also performed. After a game, transient BBB damage measured by serum S100B was detected only in players experiencing the greatest number of sub-concussive head hits. Elevated levels of auto-antibodies against S100B were elevated only after repeated sub-concussive events characterized by BBBD. Serum levels of S100B auto-antibodies also predicted persistence of MRI-DTI abnormalities which in turn correlated with cognitive changes. Even in the absence of concussion, football players may experience repeated BBBD and serum surges of the potential auto-antigen S100B. The correlation of serum S100B, auto-antibodies and DTI changes support a link between repeated BBBD and future risk for cognitive changes.

  8. Consequences of Repeated Blood-Brain Barrier Disruption in Football Players

    Science.gov (United States)

    Puvenna, Vikram; Janigro, Mattia; Ghosh, Chaitali; Zhong, Jianhui; Zhu, Tong; Blackman, Eric; Stewart, Desiree; Ellis, Jasmina; Butler, Robert; Janigro, Damir

    2013-01-01

    The acknowledgement of risks for traumatic brain injury in American football players has prompted studies for sideline concussion diagnosis and testing for neurological deficits. While concussions are recognized etiological factors for a spectrum of neurological sequelae, the consequences of sub-concussive events are unclear. We tested the hypothesis that blood-brain barrier disruption (BBBD) and the accompanying surge of the astrocytic protein S100B in blood may cause an immune response associated with production of auto-antibodies. We also wished to determine whether these events result in disrupted white matter on diffusion tensor imaging (DT) scans. Players from three college football teams were enrolled (total of 67 volunteers). None of the players experienced a concussion. Blood samples were collected before and after games (n = 57); the number of head hits in all players was monitored by movie review and post-game interviews. S100B serum levels and auto-antibodies against S100B were measured and correlated by direct and reverse immunoassays (n = 15 players; 5 games). A subset of players underwent DTI scans pre- and post-season and after a 6-month interval (n = 10). Cognitive and functional assessments were also performed. After a game, transient BBB damage measured by serum S100B was detected only in players experiencing the greatest number of sub-concussive head hits. Elevated levels of auto-antibodies against S100B were elevated only after repeated sub-concussive events characterized by BBBD. Serum levels of S100B auto-antibodies also predicted persistence of MRI-DTI abnormalities which in turn correlated with cognitive changes. Even in the absence of concussion, football players may experience repeated BBBD and serum surges of the potential auto-antigen S100B. The correlation of serum S100B, auto-antibodies and DTI changes support a link between repeated BBBD and future risk for cognitive changes. PMID:23483891

  9. The impact of direct aperture optimization on plan quality and efficiency in complex head and neck IMRT

    Directory of Open Access Journals (Sweden)

    Sabatino Marcello

    2012-01-01

    Full Text Available Abstract Background Conventional step&shoot intensity modulated radio therapy (IMRT approaches potentially lead to treatment plans with high numbers of segments and monitor units (MU and, therefore, could be time consuming at the linear accelerator. Direct optimization methods are able to reduce the complexity without degrading the quality of the plan. The aim of this study is the evaluation of different IMRT approaches at standardized conditions for head and neck tumors. Method For 27 patients with carcinomas in the head and neck region a planning study with a 2-step-IMRT system (KonRad, a direct optimization system (Panther DAO and a mixture of both approaches (MasterPlan DSS was created. In order to avoid different prescription doses for boost volumes a simple standardization was realized. The dose was downscaled to 50 Gy to the planning target volume (PTV which included the primary tumor as well as the bilateral lymphatic drainage (cervical and supraclavicular. Dose restrictions for the organs at risk (OAR were downscaled to this prescription from high dose concepts up to 72 Gy. Those limits were defined as planning objectives while reaching definable PTV coverage with a standardized field setup. The parameters were evaluated from the corresponding dose volume histogram (DVH. Special attention was paid to the efficiency of the method, measured by means of calculated MU and required segments. Statistical tests of significance were applied to quantify the differences between the evaluated systems. Results PTV coverage for all systems in terms of V90% and V95% fell short of the requested 100% and 95%, respectively, but were still acceptable (range: 98.7% to 99.1% and 94.2% to 94.7%. Overall for OAR sparing and the burden of healthy tissue with low doses no technique was superior for all evaluated parameters. Differences were found for the number of segments where the direct optimization systems generated less segments. Lowest average numbers of

  10. Impact of the health services utilization and improvement model (HUIM) on self efficacy and satisfaction among a head start population.

    Science.gov (United States)

    Tataw, David B; Bazargan-Hejazi, Shahrzad

    2010-01-01

    The aim of this paper is to evaluate and report the impact of the Health Services Utilization Improvement Model (HUIM) on utilization and satisfaction with care, as well as knowledge regarding prevention, detection, and treatment of asthma, diabetes, tuberculosis, and child injury among low income health services consumers. HUIM outcomes data shows that the coupling of parental education and ecological factors (service linkage and provider orientation) impacts the health services utilization experience of low income consumers evidenced by improved self-efficacy (knowledge and voice), and satisfaction with care from a child's regular provider. Participation in HUIM activities also improved the low income consumer's knowledge of disease identification, self-care and prevention.

  11. Impact of concomitant chemoradiation on survival for patients with T1-2N1 head and neck cancer.

    Science.gov (United States)

    Zumsteg, Zachary S; Kim, Sungjin; David, John M; Yoshida, Emi J; Tighiouart, Mourad; Shiao, Stephen L; Scher, Kevin; Mita, Alain; Sherman, Eric J; Lee, Nancy Y; Ho, Allen S

    2017-05-01

    Single-modality radiotherapy is considered a standard-of-care option for certain stage III, T1-2N1 head and neck squamous cell carcinomas (HNSCCs). The role of concomitant chemoradiation is not well established because there have been no studies comparing chemoradiation with radiation alone in this population. This study analyzed patients in the National Cancer Data Base with cT1-2N1M0 invasive squamous cell carcinomas of the oropharynx, larynx, and hypopharynx who were diagnosed between 2004 and 2012 and were undergoing definitive radiation. Patients who were undergoing surgery before radiation with unknown follow-up or for whom either the receipt or timing of chemotherapy was unknown were excluded. In all, 5030 patients with T1-2N1 oropharyngeal, laryngeal, or hypopharyngeal cancer were included. The median follow-up was 56.8 months (95% confidence interval [CI], 55.7-58.6 months). Overall, 68% of the patients received concomitant chemoradiation (CCRT). The use of CCRT significantly increased during the time period of this study from 53% in 2004 to 78% in 2012 (P cancer (HR, 0.74; 95% CI, 0.65-0.85; P Cancer 2017;123:1555-1565. © 2017 American Cancer Society. © 2016 American Cancer Society.

  12. Impact of Early Head Start in North Carolina on Dental Care Use Among Children Younger Than 3 Years.

    Science.gov (United States)

    Burgette, Jacqueline M; Preisser, John S; Weinberger, Morris; King, Rebecca S; Lee, Jessica Y; Rozier, R Gary

    2017-04-01

    To examine the effects of North Carolina Early Head Start (EHS), an early education program for low-income children younger than 3 years and their families, on dental care use among children. We performed a quasi-experimental study in which we interviewed 479 EHS and 699 non-EHS parent-child dyads at baseline (2010-2012) and at a 24-month follow-up (2012-2014). We estimated the effects of EHS participation on the probability of having a dental care visit after controlling for baseline dental care need and use and a propensity score covariate; we included random effects to account for EHS program clustering. The odds of having a dental care visit of any type (adjusted odds ratio [OR] = 2.5; 95% confidence interval [CI] = 1.74, 3.48) and having a preventive dental visit (adjusted OR = 2.6; 95% CI = 1.84, 3.63) were higher among EHS children than among non-EHS children. In addition, the adjusted mean number of dental care visits among EHS children was 1.3 times (95% CI = 1.17, 1.55) the mean number among non-EHS children. This study is the first, to our knowledge, to demonstrate that EHS participation increases dental care use among disadvantaged young children.

  13. Evaluation of the impact of water harvesting techniques on the evolution of piezometric head of Ain El Bidha groundwater in Kairouan at the Central part of Tunisia

    Science.gov (United States)

    Mechergui, M. Mohamed; Henda Saoudi, Mme

    2016-04-01

    This study aims to assess the impact of water harvesting constructed hydraulic structures (big and small dams, terraces, seuils for recharge…) on the evolution of piezometric head of Ain El Beidha groundwater table. The measurements of depth of water table, taken at the end of rain season and at the end of irrigation season, in many piezometers and monitoring wells, for a long period of observation before and after implementation of all the hydraulic structures, were used with the cumulative rain to the highest water table to diagnostic the effect of natural recharge and constructed hydraulic structures. According to the analysis of curves illustrating the evolution of piezometric head and rainfall over time, it was shown that despite the fact that the same amount of rain fall on the total area in the limits of Ain El Beidha groundwater table, the piezometers respond differently. This is because there are many sources of recharge and many factors affecting the recharge. First of all, the aquifer is divided in four compartments (the calcareous formation of Djebel El Houyareb, the plio-quaternary formation, the Miocene formation: Baglia and Saouaf). All those respond differently to the recharge by their capacity of infiltration and their hydrodynamic characteristics. The recharge of the groundwater table was increased by the implementation of small soil and water conservation structures, artificial lakes, El Haouareb Dam, run off in the natural Oued bads and seuils for recharge installed in the bads of oueds. The different piezometric drown maps were used to determine the flow direction and hydraulic gradient in order to identify the recharge areas, while tracking maps for three equal piezometric heads 210 m 300 m and 370 m established over different years made it possible to assess the impact of hydraulic structures, namely the effect of SWC and Ben Zitoun Lake. To illustrate the impact of El Houareb dam on the groundwater, the piezometric maps and local values

  14. Impact of Managerial Skills Learnt through MA Educational Planning Management Programme of AIOU on the Performance of Institutional Heads

    Science.gov (United States)

    Chuadhry, Muhammad Asif; Shah, Syed Manzoor Hussain

    2012-01-01

    Management provides formal coordination in an organization for achieving pre-determined goals. The educational manager particulary performs his duties by using different planning and management techniques. These techniques are equally important for the manager of other sectors. The present study was focused on the impact of managerial skills…

  15. Pediatric head injury.

    Science.gov (United States)

    Tulipan, N

    1998-01-01

    Pediatric head injury is a public health problem that exacts a high price from patients, their families and society alike. While much of the brain damage in head-injured patients occurs at the moment of impact, secondary injuries can be prevented by aggressive medical and surgical intervention. Modern imaging devices have simplified the task of diagnosing intracranial injuries. Recent advances in monitoring technology have made it easier to assess the effectiveness of medical therapy. These include intracranial pressure monitoring devices that are accurate and safe, and jugular bulb monitoring which provides a continuous, qualitative measure of cerebral blood flow. The cornerstones of treatment remain hyperventilation and osmotherapy. Despite maximal treatment, however, the mortality and morbidity associated with pediatric head injury remains high. Reduction of this mortality and morbidity will likely depend upon prevention rather than treatment.

  16. Effect of high-intensity interval training on body composition and bioenergetic indices in boys - futsal players

    OpenAIRE

    Fatemeh Balbasi; Ramin Shabani; Marzieh Nazari

    2016-01-01

    Background: High-intensity interval trainings (HIIT) can result in the best improvement of body fitness among athletes in the shortest possible time. The impact of HIIT on bioenergetic factors of futsal players has not been studied extensively. The objective of the present study was to investigate the effect of 3-week HIIT on body composition indices, maximum aerobic power, and maximum anaerobic power, anaerobic power among boys - futsal players. Material: 30 boys - futsal players (mean± SD a...

  17. Estimate of the impact of FDG-avidity on the dose required for head and neck radiotherapy local control

    Science.gov (United States)

    Jeong, Jeho; Setton, Jeremy S.; Lee, Nancy Y.; Oh, Jung Hun; Deasy, Joseph O.

    2016-01-01

    Background and purpose Although FDG-avid tumors are recognized as a potential target for dose escalation, there is no clear basis for selecting a boost dose to counter this apparent radioresistance. Using a novel analysis method, based on the new concept of an outcome-equivalent dose, we estimate the extra dose required to equalize local control between FDG-avid and non-avid head and neck tumors. Materials and methods Based on a literature review, five reports of head and neck cancer (423 patients in total), along with an internal validation dataset from our institution (135 oropharynx patients), were used in this analysis. To compensate for the heterogeneity among multi-institutional patient cohorts and corresponding treatment techniques, local control data of the cohorts were fit to a single dose–response curve with a clinically representative steepness (γ50 = 2), thereby defining an ‘outcome-equivalent dose’ (OED) for each institutional cohort. Separate dose–response curves were then determined for the FDG-avid and FDG-non-avid patient cohorts, and the ratio of TD50 (tumor dose required for 50% of control) values between the high- and low-FDG-uptake groups (TD50,high/TD50,low) was estimated, resulting in an estimated metabolic dose-modifying factor (mDMF) due to FDG-avidity. Results For individual datasets, the estimated mDMFs were found to be in the range of 1.07–1.62, decreasing if the assumed slope (γ50) increased. Weighted logistic regression for the six datasets resulted in a mDMF of 1.19 [95% CI: 1.04–1.34] for a γ50 value of 2, which translates to a needed dose increase of about 1.5 Gy per unit increase in the maximum standardized uptake value (SUVm) of FDG-PET [95% CI: 0.3–2.7]. Assumptions of lower or higher γ50 values (1.5 or 2.5) resulted in slightly different mDMFs: 1.26 or 1.15, respectively. A validation analysis with seven additional datasets, based on relaxed criteria, was consistent with the estimated mDMF. Conclusions We

  18. Linear and angular head accelerations during heading of a soccer ball.

    Science.gov (United States)

    Naunheim, Rosanne S; Bayly, Philip V; Standeven, John; Neubauer, Jeremy S; Lewis, Larry M; Genin, Guy M

    2003-08-01

    Cognitive deficits observed in professional soccer players may be related to heading of a soccer ball. To assess the severity of a single instance of heading a soccer ball, this study experimentally and theoretically evaluated the linear and angular accelerations experienced by the human head during a frontal heading maneuver. Accelerations were measured using a set of three triaxial accelerometers mounted to the head of each of four adult male subjects. These measurements (nine signals) were used to estimate the linear acceleration of the mass center and the angular acceleration of the head. Results were obtained for ball speeds of 9 and 12 m.s(-1) (approximately 20 and 26 mph). A simple mathematical model was derived for comparison. At 9 m.s(-1), peak linear acceleration of the head was 158 +/- 19 m.s(-2) (mean +/- standard deviation) and peak angular acceleration was 1302 +/- 324 rad.s(-2); at 12 m.s(-1), the values were 199 +/- 27 m.s-2 and 1457 +/- 297 rad.s-2, respectively. The initial acceleration pulses lasted approximately 25 ms. Measured head accelerations confirmed laboratory headform measurements reported in the literature and fell within the ranges predicted by the theoretical model. Linear and angular acceleration levels for a single heading maneuver were well below those thought to be associated with traumatic brain injury, as were computed values of the Gadd Severity Index and the Head Injury Criterion. However, the effect of repeated acceleration at this relatively low level is unknown.

  19. Neuropsychological functioning and recovery after mild head injury in collegiate athletes.

    Science.gov (United States)

    Macciocchi, S N; Barth, J T; Alves, W; Rimel, R W; Jane, J A

    1996-09-01

    This study prospectively examined neuropsychological functioning in 2300 collegiate football players from 10 National Collegiate Athletic Association Division A universities. The study was designed to determine the presence and duration of neuropsychological symptoms after mild head injury. A nonequivalent repeated measures control group design was used to compare the neuropsychological test scores and symptoms of injured players (n = 183) with those of gender, age, and education matched controls. A number of neuropsychological tests, including the Paced Auditory Serial Addition Test, the Digit Symbol Test, and the Trail Making Test, as well as a symptom checklist were used. Players and controls were assessed before engaging in game activity and 24 hours, 5 days, and 10 days after injury, using the standardized test battery and symptom checklist. Players with head injuries displayed impaired performance and increased symptoms in comparison to controls, but this impairment resolved within 5 days in most players. Players with head injuries showed significant improvement between 24 hours and 5 days, as well as between 5 and 10 days. Although single, uncomplicated mild head injuries do cause limited neuropsychological impairment, injured players generally experience rapid resolution of symptoms with minimal prolonged sequelae.

  20. Neuropsychological impairment as a consequence of football (soccer) play and football heading: a preliminary analysis and report on school students (13-16 years).

    Science.gov (United States)

    Stephens, Richard; Rutherford, Andrew; Potter, Douglas; Fernie, Gordon

    2005-12-01

    Footballers run the risk of incurring mild head injury from a variety of sources, including the intentional use of the head to play the ball, known as heading. This paper presents a preliminary exploratory analysis of data collected to examine whether cumulative incidence of mild head injury, or cumulative heading frequency, are related to neuropsychological functioning in male adolescent footballers. In a quasi-experimental cross-sectional design, neuropsychological test scores of school team footballers were compared with those of similarly aged rugby players and noncontact sport players. Cumulative mild head injury incidence was estimated using self-reports, and cumulative heading was estimated using a combination of observation and self-reports. No participants had sustained a head injury within 3 months of testing. There was no relationship between head injury and neuropsychological performance, and there were no decrements in either the footballers or the rugby players in comparison with the noncontact sport players. Within the footballers, cumulative heading did not predict any of the neuropsychological test scores. These findings indicate the absence of neuropsychological impairment arising due to cumulative mild head injury incidence, or cumulative heading. Although these null findings may be reassuring to players, parents, and football organizers, we stress that they are preliminary. Further data is being collected from the same populations to provide more reliable effect estimates.

  1. Single, Divorced, or Separated? Factors That Impact the Lives of Women Who Are Heads of Household in Lima, Peru

    OpenAIRE

    2015-01-01

    The rupture of a conjugal relationship has both a positive and negative impact on the lives of immediate family members. Although for many women terminating marriage may signal freedom from an oppressive, even violent conjugal relationship, it is undeniable that this separation also results in strong social pressure and discrimination in certain contexts, a situation which limits the woman’s freedom of action in and ou...

  2. The Effectiveness Evaluation among Different Player-Matching Mechanisms in a Multi-Player Quiz Game

    Science.gov (United States)

    Tsai, Fu-Hsing

    2016-01-01

    This study aims to investigate whether different player-matching mechanisms in educational multi-player online games (MOGs) can affect students' learning performance, enjoyment perception and gaming behaviors. Based on the multi-player quiz game, TRIS-Q, developed by Tsai, Tsai and Lin (2015) using a free player-matching (FPM) mechanism, the same…

  3. Does trust promote more teamwork? Modeling online game players' teamwork using team experience as a moderator.

    Science.gov (United States)

    Lee, Chun-Chia; Chang, Jen-Wei

    2013-11-01

    The need for teamwork has grown significantly in today's organizations. Especially for online game communities, teamwork is an important means of online game players' engagement. This study aims to investigate the impacts of trust on players' teamwork with affective commitment and normative commitment as mediators. Furthermore, this research includes team experience as a moderator to compare the difference between different player groups. A model was proposed and tested on 296 online game players' data using structural equation modeling. Findings revealed that team experience moderated the relationship between trust and teamwork. The results indicated that trust promotes more teamwork only for players with high experience through affective commitment than those who with low experience. Implications of the findings are discussed.

  4. Nutrient consumption pattern of male soccer players in Shiraz/Iran

    Directory of Open Access Journals (Sweden)

    Saeed Najafpour Bushehry

    2003-09-01

    Full Text Available Exercise and nutrition have a significant impact on health. To evaluate nutrient consumption pattern of soccer players in city of Shiraz, 323 players were selected by proportional multi-stage cluster random sampling from 11 clubs in Shiraz. Anthropometric indices, socioeconomic status, 24 hours dietary recall and food frequency data were collected. Protein, carbohydrate and fat intake of the players were 73.73 gr (10.8%, 493.3 gr (72.4% and 50.8 gr (16.7%, respectively. Calcium (689.6 mg, phosphorus (734.4 mg, iron (20.3 mg, vitamin B1 (2 mg, vitamin B2 (1.6 mg, vitamin C (107.5 mg and vitamin A (962.4 mcg RE intake were lower than the desirable levels. The mean energy consumption of the players was 2723 Kcal per day. In conclusion, protein and micronutrients intakes are not desirable in Iranian soccer players in Shiraz.

  5. The NBA’s Maximum Player Salary and the Distribution of Player Rents

    Directory of Open Access Journals (Sweden)

    Kelly M. Hastings

    2015-03-01

    Full Text Available The NBA’s 1999 Collective Bargaining Agreement (CBA included provisions capping individual player pay in addition to team payrolls. This study examines the effect the NBA’s maximum player salary on player rents by comparing player pay from the 1997–1998 and 2003–2004 seasons while controlling for player productivity and other factors related to player pay. The results indicate a large increase in the pay received by teams’ second highest and, to a lesser extent, third highest paid players. We interpret this result as evidence that the adoption of the maximum player salary shifted rents from stars to complementary players. We also show that the 1999 CBA’s rookie contract provisions reduced salaries of early career players.

  6. The impact of taste and smell alterations on quality of life in head and neck cancer patients.

    Science.gov (United States)

    Alvarez-Camacho, M; Gonella, S; Ghosh, S; Kubrak, C; Scrimger, R A; Chu, K P; Wismer, W V

    2016-06-01

    Taste and smell alterations (TSAs) are among the most frequent and troublesome symptoms reported by head and neck cancer (HNC) patients after treatment. Little is known about the relationship between TSAs and quality of life (QoL) among HNC patients. The aim of this study was to determine the effect of TSAs on overall QoL among tube-fed and orally fed HNC patients before treatment, at end of treatment and at 2.5-month follow-up. Data were collected in a longitudinal study prior to treatment (n = 126), at end of treatment (n = 100) and at 2.5-month follow-up (n = 85). Chemosensory Complaint Score (CCS) and the University of Washington Quality of Life Questionnaire version 3 were used to assess TSAs and QoL, respectively. Generalized estimated equation modeling was used to estimate the effect of CCS on QoL. At end of treatment, QoL and CCS had declined for both tube-fed and orally fed patients and thereafter improved, but not to pre-treatment levels. Neither QoL nor CCS mean scores were different between the two groups at any time point. CCS was a significant predictor of overall QoL (β = -1.82, p < 0.0001), social-emotional (β = -1.76, p < 0.0001), physical (β = -1.12, p < 0.0001) and overall functions (β = -1.15, p < 0.0001) at a multivariate level. Taste was reported as an important symptom for both tube-fed and orally fed groups at end of treatment and follow-up. TSAs are an important symptom and an independent predictor of QoL for both tube-fed and orally fed HNC patients. HNC patients need support to manage TSAs, regardless of the method of nutritional intake.

  7. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  8. Single, Divorced, or Separated? Factors That Impact the Lives of Women Who Are Heads of Household in Lima, Peru

    Directory of Open Access Journals (Sweden)

    Beatriz Alvarado

    2015-10-01

    Full Text Available The rupture of a conjugal relationship has both a positive and negative impact on the lives of immediate family members. Although for many women terminating marriage may signal freedom from an oppressive, even violent conjugal relationship, it is undeniable that this separation also results in strong social pressure and discrimination in certain contexts, a situation which limits the woman’s freedom of action in and outside of the home. The purpose of this descriptive, phenomenological study is to explore the experiences of 15 Peruvian, urban-based mothers, all of whom made the decision to exchange marriage for single parenthood within the confines of a strong patriarchal system. The study follows the actions of the women as they seek to overcome obstacles related to parenting and the management of their respective households. Three emerging themes are identified in this study: (a the development of the woman’s relationship as wife and mother, (b impact of the separation/divorce on the maternal role, and (c experiences in the single parent household. Implications for social research studies and practice are discussed.

  9. Is There Chronic Brain Damage in Retired NFL Players? Neuroradiology, Neuropsychology, and Neurology Examinations of 45 Retired Players.

    Science.gov (United States)

    Casson, Ira R; Viano, David C; Haacke, E Mark; Kou, Zhifeng; LeStrange, Danielle G

    2014-09-01

    Neuropathology and surveys of retired National Football League (NFL) players suggest that chronic brain damage is a frequent result of a career in football. There is limited information on the neurological statuses of living retired players. This study aimed to fill the gap in knowledge by conducting in-depth neurological examinations of 30- to 60-year-old retired NFL players. In-depth neurological examinations of 30- to 60-year-old retired players are unlikely to detect objective clinical abnormalities in the majority of subjects. A day-long medical examination was conducted on 45 retired NFL players, including state-of-the-art magnetic resonance imaging (MRI; susceptibility weighted imaging [SWI], diffusion tensor imaging [DTI]), comprehensive neuropsychological and neurological examinations, interviews, blood tests, and APOE (apolipoprotein E) genotyping. Level 3. Participants' histories focused on neurological and depression symptoms, exposure to football, and other factors that could affect brain function. The neurological examination included Mini-Mental State Examination (MMSE) evaluation of cognitive function and a comprehensive search for signs of dysarthria, pyramidal system dysfunction, extrapyramidal system dysfunction, and cerebellar dysfunction. The Beck Depression Inventory (BDI) and Patient Health Questionnaire (PHQ) measured depression. Neuropsychological tests included pen-and-paper and ImPACT evaluation of cognitive function. Anatomical examination SWI and DTI MRI searched for brain injuries. The results were statistically analyzed for associations with markers of exposure to football and related factors, such as body mass index (BMI), ethanol use, and APOE4 status. The retired players' ages averaged 45.6 ± 8.9 years (range, 30-60 years), and they had 6.8 ± 3.2 years (maximum, 14 years) of NFL play. They reported 6.9 ± 6.2 concussions (maximum, 25) in the NFL. The majority of retired players had normal clinical mental status and central

  10. Anterior Hip Dislocation in a Football Player: A Case Report

    Directory of Open Access Journals (Sweden)

    Alexander Schuh

    2009-01-01

    Full Text Available Hip dislocations during sporting activities represent only 2%–5% of all hip dislocations. Most hip dislocations in sports can be categorised as “less complicated traumatic hip dislocations” by the Stewart-Milford classification due to the fact that minimal force is involved. The incidence of avascular necrosis of the femoral head greatly increases if the time to reduction is more than six hours. We report the case of a 38-year-old football player who suffered hip dislocation while kicking the ball with the medial aspect of the right foot in an external rotated manner of the right hip. Closed reduction was performed within 2 hours; postoperative follow-up was uneventful. Six months later the patient is out of any complaints; there is no sign of AVN of the femoral head.

  11. The Very Low Head Turbine enters into industrial phase and confirms its Extremely Low Environmental Impact; Le turbo generateur pour tres basses chutes VLH entre en phase industrielle et confirme son tres faible impact environnemental

    Energy Technology Data Exchange (ETDEWEB)

    Leclerc, Marc [MJ2 Technologies, Route De Millau, ZA Millau Larzac, 12230 La Cavalerie (France)

    2012-01-15

    From their respective experience in the small hydro field the three members of the team separately came to the same conclusion regarding renewable energy and particularly small hydro development in developed countries and in the world. The only big potential still unused is the enormous quantity of very low head sites abandoned all along the course of the main rivers. Thousands of sites in the developed countries are left because no manufacturer has been able to design a turbo generator group that optimizes the overall investment and makes the cost per installed kW profitable. The aim of the VLH project is to design, scientifically test and manufacture a compact Turbo Generator set which will allow harnessing very low head hydroelectric sites with a competitive rate of return on investment. Furthermore, the exceptionally low environmental impact of the VLH has been confirmed by scientific tests of live eels and smolts downstream passage tests through the VLH. The VLH concept has now reached the industrial stage. The first series have been manufactured. 22 machines have been commissioned, 4 of them in foreign countries. (author)

  12. Psychosocial Factors Involved in Transitions from College to Postcollege Careers for Male NCAA Division-1 Basketball Players

    Science.gov (United States)

    Cummins, Paul; O'Boyle, Ian

    2015-01-01

    This article investigated the key psychosocial factors that impact upon National Collegiate Athletic Association (NCAA) Division-1 male basketball players, as they transition from college to postcollege athletic or nonathletic careers. Participants (N = 9) were current/former NCAA Division-1 basketball players. Four participants were selected…

  13. A comparison of the injuries sustained by female basketball and netball players.

    Science.gov (United States)

    McKay, G D; Payne, W R; Goldie, P A; Oakes, B W; Stanley, J J

    1996-03-01

    A prospective and reliable method of injury surveillance was implemented to document a comprehensive injury profile in female basketball and netball. The study further aimed to compare the injury profiles of the two sports. Trained observers viewed basketball and netball games, noting the occurrence of injuries. Injuries were confirmed by questioning all players on site after the game. Injured players completed a questionnaire and the progress of their injury was monitored by telephone interview. A total of 16,162 player participations were observed; 6,972 for basketball and 9,190 for netball. Comparable injury rates were observed for female basketball and netball players; 18.22 and 17.30 injuries per 1,000 participations, respectively. The ankle, hand and knee were the body parts injured most frequently in both sports, whilst head and neck injuries were prevalent in basketball only. Netball players sustained severe injuries at a rate 3.3 times that of female basketball players. The major and severe injuries occurred at an average of one injury in 625 games in female basketball and one in 250 games in netball. The ankle, knee and calf/shin were the body parts most frequently involved in the more serious injuries.

  14. Radiographic knee osteoarthritis in ex-elite table tennis players

    Directory of Open Access Journals (Sweden)

    Rajabi Reza

    2012-02-01

    levels of radiological signs of OA in the knee joint though this did not transpire through to altered levels of physical disability or knee stiffness in these players when compared with subjects from the general population suggesting that function in these players is not severely impacted upon.

  15. Influence of Pokémon Go on physical activity levels of university players: a cross-sectional study.

    Science.gov (United States)

    Wong, Fiona Y

    2017-02-22

    The prevalence of overweight is increasing and the effectiveness of various weight management and exercise programs varied. An augmented reality smartphone game, Pokémon Go, appears to increase activity levels of players. This study assessed the players and ex-players' frequencies and durations of staying outdoors, and walking/jogging before and during the time they played Pokémon Go, evaluated the physical activity levels of players, ex-players and non-players, and investigated the potential factors which determined their play statuses. Students in a university answered an online-questionnaire survey. The IPAQ-short form was incorporated to measure vigorous-intensity activities, moderate-intensity activities and walking. Chi square tests were used to compare frequencies and durations of staying outdoors and walking/jogging, health discomforts and physical activity levels between players, ex-players and non-players. Wilcoxon signed ranks tests were performed to assess the changes prior to and during the time when the players and ex-players played Pokémon Go. Logistic regression analyses were performed to assess factors contributing to playing, quitting or not playing Pokémon Go. 644 university students answered the questionnaire. Compared with the ex-players, the players were significantly more frequent to stay outdoors when playing Pokémon Go (P Go. The game can be used as a starting point for sedentary people to begin an active lifestyle. The impact of Pokémon Go on physical activity can provide insights to public health workers in using novel strategies in health promotion.

  16. Impact of the Low Head Dam/Barrage on Fisheries – A Case Study of Giri River of Yamuna Basin (India

    Directory of Open Access Journals (Sweden)

    Rumana Harcharan Singh

    2015-12-01

    Full Text Available Shannon’s diversity index H’ = pi log2 pi was calculated for 16 fish species. The index was resolved into its components, species richness and relative abundance, to determine which components played a larger role in the determination of diversity pattern. Changes in diversity were correlated with species richness (r, habitat heterogeneity, and hydrological regimes in a longitudinal stretch of 35 km along the river Giri, a major tributary of the Yamuna River system, in Western Himalayas. Abundance differs with change in habitat structures, habitat preference of fish species and water regimes. The decrease in diversity in the lower stretch of about 3-4 km upstream of the barrage was found to be associated with habitat fragmentation and as well as d/s with loss of biotic integrity of aquatic ecosystem due to water scarcity. Species richness was found to be maximum at upper and middle reaches (elevation 650-800 m, msl of the river, whereas it was low in lower reaches. Change in water chemistry was also noticed at Jatan barrage-low head dam due to impoundment of river water. It is inferred that the regulation of water has an impact on species richness and relative abundance, and on habitat heterogeneity which has decreased due to the change in environmental condition.

  17. Water pressure head and temperature impact on isoxaflutole degradation in crop residues and loamy surface soil under conventional and conservation tillage management.

    Science.gov (United States)

    Alletto, Lionel; Coquet, Yves; Bergheaud, Valérie; Benoit, Pierre

    2012-08-01

    Laboratory incubations were performed in order to evaluate the dissipation of the proherbicide isoxaflutole in seedbed layer soil samples from conventional and conservation tillage systems and in maize and oat residues left at the soil surface under conservation tillage. The effects of temperature and water pressure head on radiolabelled isoxaflutole degradation were studied for each sample for 21d. Mineralisation of isoxaflutole was low for all samples and ranged from 0.0% to 0.9% of applied (14)C in soil samples and from 0.0% to 2.4% of applied (14)C in residue samples. In soil samples, degradation half-life of isoxaflutole ranged from 9 to 26h, with significantly higher values under conservation tillage. In residue samples, degradation half-life ranged from 3 to 31h, with significantly higher values in maize residues, despite a higher mineralisation and bound residue formation than in oat residues. Whatever the sample, most of the applied (14)C remained extractable during the experiment and, after 21d, less than 15% of applied (14)C were unextractable. This extractable fraction was composed of diketonitrile, benzoic acid derivative and several unidentified metabolites, with one of them accounting for more than 17% of applied (14)C. This study showed that tillage system design, including crop residues management, could help reducing the environmental impacts of isoxaflutole.

  18. Adapting playware to multiple players

    DEFF Research Database (Denmark)

    Þorsteinsson, Arnar Tumi; Lund, Henrik Hautop; Mastorakis, Nikos

    2011-01-01

    With the creation of playware as intelligent hardware and software that creates play, it is possible to adapt the play tool to the individual user, and even to multiple users playing at the same time with the play tool. In this paper, we show how it is possible to implement adaptivity in modular...... to such differences, and argues that adaptivity is needed to make games fit to the individual users in both single-player games and multi-player games. As a case study, we implemented such adaptivity on modular interactive tiles for the single-user game ColorTimer, and for the multiple-user games PingPong, in which...

  19. Psychological games of entangled players

    CERN Document Server

    Zak, Michail

    2012-01-01

    The paper introduces a new approach to theory of differential games in which entangled players try to predict and influence actions of their adversaries. The entanglement is generated be a joint probability density known by the players. Incase of complex density, its imaginary part represents a measure of uncertainty of the density distribution. The novelty of the approach is in non-Newtonian mathematical formalism thatis based upon a behavioral model of Livings. The model is quantum-inspired: it represented by a modified Madelung equation which the quantum potential is replaced by different, specially chosen "computational" potential. It consists of motor dynamics simulating actual behavior of the object, and mental dynamics representing evolution of the corresponding knowledge-based and incorporating this knowledge in the for m of information flows into the motor dynamics. Due to feedback from mental dynamics, motor dynamics attains quantum-like properties: its trajectory splits into a family of different t...

  20. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  1. Reciprocity on the hardwood: passing patterns among professional basketball players.

    Science.gov (United States)

    Willer, Robb; Sharkey, Amanda; Frey, Seth

    2012-01-01

    Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA) games of the 2008-9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had "received" assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity - a tendency to "pay forward" assists - and only very limited evidence for indirect reciprocity - a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition.

  2. Reciprocity on the hardwood: passing patterns among professional basketball players.

    Directory of Open Access Journals (Sweden)

    Robb Willer

    Full Text Available Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA games of the 2008-9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had "received" assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity - a tendency to "pay forward" assists - and only very limited evidence for indirect reciprocity - a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition.

  3. Wireless nanosensors for monitoring concussion of football players

    Science.gov (United States)

    Ramasamy, Mouli; Harbaugh, Robert E.; Varadan, Vijay K.

    2015-04-01

    Football players are more to violent impacts and injuries more than any athlete in any other sport. Concussion or mild traumatic brain injuries were one of the lesser known sports injuries until the last decade. With the advent of modern technologies in medical and engineering disciplines, people are now more aware of concussion detection and prevention. These concussions are often overlooked by football players themselves. The cumulative effect of these mild traumatic brain injuries can cause long-term residual brain dysfunctions. The principle of concussion is based the movement of the brain in the neurocranium and viscerocranium. The brain is encapsulated by the cerebrospinal fluid which acts as a protective layer for the brain. This fluid can protect the brain against minor movements, however, any rapid movements of the brain may mitigate the protective capability of the cerebrospinal fluid. In this paper, we propose a wireless health monitoring helmet that addresses the concerns of the current monitoring methods - it is non-invasive for a football player as helmet is not an additional gear, it is efficient in performance as it is equipped with EEG nanosensors and 3D accelerometer, it does not restrict the movement of the user as it wirelessly communicates to the remote monitoring station, requirement of individual monitoring stations are not required for each player as the ZigBee protocol can couple multiple transmitters with one receiver. A helmet was developed and validated according to the above mentioned parameters.

  4. Increasing mouthguards usage among junior rugby and basketball players.

    Science.gov (United States)

    Jalleh, G; Donovan, R J; Clarkson, J; March, K; Foster, M; Giles-Corti, B

    2001-06-01

    To evaluate a Western Australian mouthguard promotion campaign, launched at the start of the 1997/98 junior rugby union and junior basketball seasons, aimed at increasing mouthguard usage at competition and training. A quasi-experimental field design was used to assess the impact of the mouthguard campaign on behavioural change. Observational data were collected pre- and post-campaign on mouthguard usage by players present at a rugby and basketball competition event and at a training session. Junior Australian Rules Football players were used as a control group. Pre-post observational surveys showed a significantly greater increase in mouthguard usage in competition games among rugby union (77% to 84%) and basketball players (23% to 43%) compared with the control group (72% to 73%). All codes showed a post-campaign increase in mouthguard usage at training, but the intervention codes' increases were greater than the control's increase (rugby union: 29% to 40%; basketball: 11% to 36%; football: 34% to 40%). The campaign had a significant and substantial effect on behaviour and provides evidence of the benefits of leveraging a sponsorship to modify the behaviour of the target group. This campaign provides a model for promoting mouthguard usage in other sports among junior players.

  5. Radiographic findings of femoroacetabular impingement in capoeira players.

    Science.gov (United States)

    Mariconda, Massimo; Cozzolino, Andrea; Di Pietto, Francesco; Ribas, Manuel; Bellotti, Vittorio; Soldati, Alessandra

    2014-04-01

    Capoeira is a Brazilian martial art that requires extreme movements of the hip to perform jumps and kicks. This study evaluated a group of capoeira players to assess the prevalence of femoroacetabular impingement (FAI) in athletes practicing this martial art. Twenty-four experienced capoeira players (14 men, 10 women) underwent a diagnostic assessment, including clinical examination and standard radiographs of the pelvis and hips. The α-angle, head-neck offset, crossover sign, acetabular index, lateral centre-edge angle, and the Tönnis grade were assessed using the radiographs. Clinical relationships for any radiographic abnormalities indicating FAI were also evaluated. Four subjects (17 %) reported pain in their hips. Forty-four hips (91.7 %) had at least one radiographic sign of CAM impingement, and 22 (45.8 %) had an α-angle of more than 60°. Eighteen hips (37.5 %) had at least one sign of pincer impingement and 16 (33.3 %) a positive crossover sign. Sixteen hips (33.3 %) had mixed impingement. There was a significant positive association between having an α-angle of more than 60° and the presence of groin pain (P = 0.002). A reduced femoral head-neck offset (P < 0.001) and an increased α-angle on the anteroposterior radiograph (P = 0.008) were independently associated with a higher Tönnis grade. High prevalence of radiographic CAM-type FAI among these skilled capoeira players was found. In these subjects, a negative clinical correlation for an increased α-angle was also detected. Additional caution should be exercised whenever subjects with past or present hip pain engage in capoeira.

  6. Two-Player Graph Pebbling

    Science.gov (United States)

    Prudente, Matthew James

    Given a graph G with pebbles on the vertices, we define a pebbling move as removing two pebbles from a vertex u, placing one pebble on a neighbor v, and discarding the other pebble, like a toll. The pebbling number pi( G) is the least number of pebbles needed so that every arrangement of pi(G) pebbles can place a pebble on any vertex through a sequence of pebbling moves. We introduce a new variation on graph pebbling called two-player pebbling. In this, players called the mover and the defender alternate moves, with the stipulation that the defender cannot reverse the previous move. The mover wins only if they can place a pebble on a specified vertex and the defender wins if the mover cannot. We define η(G), analogously, as the minimum number of pebbles such that given every configuration of the η( G) pebbles and every specified vertex r, the mover has a winning strategy. First, we will investigate upper bounds for η( G) on various classes of graphs and find a certain structure for which the defender has a winning strategy, no matter how many pebbles are in a configuration. Then, we characterize winning configurations for both players on a special class of diameter 2 graphs. Finally, we show winning configurations for the mover on paths using a recursive argument.

  7. Motivational profile quality players handball

    Directory of Open Access Journals (Sweden)

    Alfonso Martínez Moreno

    2017-06-01

    Full Text Available In the sport context, elite category, it is necessary to know all the factors, which in one way or another, affect the athletes throughout the different competitions. The object of study is to know the motivational profile of elite handball players. The sample consisted of 495 players, of whom 47.8% were boys and 52.2% girls, their ages ranged from 12 to 16 years, with an average of 13.8 years (dt = 1.0. Descriptive statistical analyzes of the sample, absolute and relative frequencies were performed for the qualitative variables and for the quantitative values minimum, maximum, mean, standard deviation, Cronbach's alpha. Correlation between variables, with the Pearson correlation coefficient. The MANCOVA test was performed to determine if there were differences between the dimensions of the questionnaire, according to age and years of practice. The results reveal that handball players elite category of the sample object of study have mainly intrinsic motivation, achieving high scores on general motivation, motivation achievement and motivation stimulation. In addition to moderately high values in introjected regulation and very low values in demotivation.

  8. Nutrient intake and food habits of soccer players: Analyzing the correlates of eating practice

    OpenAIRE

    García-Rovés, Pablo M.; Pedro García-Zapico; Ángeles M. Patterson; Eduardo Iglesias-Gutiérrez

    2014-01-01

    Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of thes...

  9. Analytical modelling of soccer heading

    Indian Academy of Sciences (India)

    Zahari Taha; Mohd Hasnun Arif Hassan; Iskandar Hasanuddin

    2015-08-01

    Heading occur frequently in soccer games and studies have shown that repetitive heading of the soccer ball could result in degeneration of brain cells and lead to mild traumatic brain injury. This study proposes a two degree-of-freedom linear mathematical model to study the impact of the soccer ball on the brain. The model consists of a mass–spring–damper system, in which the skull, the brain and the soccer ball are modelled as a mass and the neck modelled as a spring–damper system. The proposed model was compared with previous dynamic model for soccer ball-to-head impact. Moreover, it was also validated against drop ball experiment on an instrumented dummy skull and also compared with head acceleration data from previous studies. Comparison shows that our proposed model is capable of describing both the skull and brain accelerations qualitatively and quantitatively. This study shows that a simple linear mathematical model can be useful in giving a preliminary insight on the kinematics of human skull and brain during a ball-to-head impact. The model can be used to investigate the important parameters during soccer heading that affect the brain displacement and acceleration, thus providing better understanding of the mechanics behind it.

  10. [Dietary behaviours of volleyball and basketball players].

    Science.gov (United States)

    Szczepańska, Elzbieta; Spałkowska, Agnieszka

    2012-01-01

    In sports, such as basketball and volleyball, players must demonstrate the speed, strength, stamina and concentration. Correct nutrition affects the strength of the muscles and the extension of capacity. It is also necessary for the proper functioning of the nervous system and determines the rate of regeneration after physical effort. The aim of this study was to assess dietary behaviours of professional volleyball and basketball players and compare the prevalence of correct behaviours in both groups. 209 professional volleyball and basketball players from sports clubs localized in six Silesian cities were survived with the mean of author questionnaire. The chi-square test was used to examine differences in the prevalence of the correct behaviours among players. Analysis of the results obtained showed that 52% of the players had 4-5 meals a day. 35% of respondents had wholemeal bread and/or groats daily. Milk and dairy products daily ate 71% of surveyed players, meat and sausages 70% respectively. 41% of respondents had cottage cheese and 28% had fish several times a week. Vegetables and fruit were eaten by 21% and respectively 23% of respondents. Sweets were eaten daily by 40% of surveyed, while fast-food were eaten several times a week by 17% of players. Nutrients for athletes were used by 32%, and vitamin supplementation by 48% of respondents. Prevalence of correct dietary behaviour in the group of professional volleyball and basketball players differed. Basketball players statistically more frequently than volleyball players had 4-5 meals a day, had wholemeal bread and/or thick groats, milk and dairy products, meat and sausages, especially poultry. They had raw vegetables and fruit several times a day. They drank more than 2.5 liters of fluids per day. They also significantly more frequently than volleyball players consumed the fast-food occasionally or never. Dietary behaviours of surveyed players were incorrect. Comparison of prevalence of proper behaviours

  11. Dynamic Contrast-Enhanced MRI in Head-and-Neck Cancer: The Impact of Region of Interest Selection on the Intra- and Interpatient Variability of Pharmacokinetic Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Craciunescu, Oana I., E-mail: oana.craciunescu@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Yoo, David S. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Cleland, Esi [GECAD Ghana Ltd., Acra (Ghana); Muradyan, Naira [iCAD Inc., Nashua, NH (United States); Carroll, Madeline D. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); MacFall, James R.; Barboriak, Daniel P. [Department of Radiology, Duke University Medical Center, Durham, NC (United States); Brizel, David M. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Department of Surgery, Duke University Medical Center, Durham, NC (United States)

    2012-03-01

    Purpose: Dynamic contrast-enhanced (DCE) MRI-extracted parameters measure tumor microvascular physiology and are usually calculated from an intratumor region of interest (ROI). Optimal ROI delineation is not established. The valid clinical use of DCE-MRI requires that the variation for any given parameter measured within a tumor be less than that observed between tumors in different patients. This work evaluates the impact of tumor ROI selection on the assessment of intra- and interpatient variability. Method and Materials: Head and neck cancer patients received initial targeted therapy (TT) treatment with erlotinib and/or bevacizumab, followed by radiotherapy and concurrent cisplatin with synchronous TT. DCE-MRI data from Baseline and the end of the TT regimen (Lead-In) were analyzed to generate the vascular transfer function (K{sup trans}), the extracellular volume fraction (v{sub e}), and the initial area under the concentration time curve (iAUC{sub 1min}). Four ROI sampling strategies were used: whole tumor or lymph node (Whole), the slice containing the most enhancing voxels (SliceMax), three slices centered in SliceMax (Partial), and the 5% most enhancing contiguous voxels within SliceMax (95Max). The average coefficient of variation (aCV) was calculated to establish intrapatient variability among ROI sets and interpatient variability for each ROI type. The average ratio between each intrapatient CV and the interpatient CV was calculated (aRCV). Results: Baseline primary/nodes aRCVs for different ROIs not including 95Max were, for all three MR parameters, in the range of 0.14-0.24, with Lead-In values between 0.09 and 0.2, meaning a low intrapatient vs. interpatient variation. For 95Max, intrapatient CVs approximated interpatient CVs, meaning similar data dispersion and higher aRCVs (0.6-1.27 for baseline) and 0.54-0.95 for Lead-In. Conclusion: Distinction between different patient's primary tumors and/or nodes cannot be made using 95Max ROIs. The other

  12. MECHANISMS FOR TRICEPS SURAE INJURY IN HIGH PERFORMANCE FRONT ROW RUGBY UNION PLAYERS: A KINEMATIC ANALYSIS OF SCRUMMAGING DRILLS

    Directory of Open Access Journals (Sweden)

    Carol A. Flavell

    2013-03-01

    Full Text Available The front row of a rugby union scrum consists of three players. The loose head prop, hooker and tight head prop. The objective of this study was to determine if known biomechanical risk factors for triceps surae muscle injury are exhibited in the lower limb of front row players during contested scrummaging. Eleven high performance front row rugby union players were landmarked bilaterally at the posterior superior iliac spine (PSIS, greater trochanter, lateral femoral epicondyle, midline of the calcaneus above the plantar aspect of the heel, midline lower leg 5cm and 20cm proximal to the lateral malleolus, at the axis of subtalar joint, lateral malleolus, and head of the fifth metatarsal. Players were video recorded during a series of 2 on 1 live scrummaging drills. Biomechanical three dimensional analysis identified large angular displacements, and increased peak velocities and accelerations at the ankle joint during attacking scrummaging drill techniques when in the stance phase of gait. This places the triceps surae as increased risk of injury and provides valuable information for training staff regarding injury prevention and scrum training practices for front row players

  13. Vitamin D Deficiency Among Professional Basketball Players.

    Science.gov (United States)

    Fishman, Matthew P; Lombardo, Stephen J; Kharrazi, F Daniel

    2016-07-01

    Vitamin D plays an important role in several systems of the human body. Various studies have linked vitamin D deficiency to stress and insufficiency fractures, muscle recovery and function, and athletic performance. The prevalence of vitamin D deficiency in the elite athletic population has not been extensively studied, and very few reports exist among professional athletes. There is a high prevalence of vitamin D deficiency or insufficiency among players attending the National Basketball Association (NBA) Combine. Cross-sectional study; Level of evidence, 3. This is a retrospective review of data previously collected as part of the routine medical evaluation of players in the NBA Combines from 2009 through 2013. Player parameters evaluated were height, weight, body mass index (BMI), and vitamin D level. Statistical analysis using t tests and analysis of variance was used to detect any correlation between the player parameters and vitamin D level. Vitamin D levels were categorized as deficient (32 ng/mL). After institutional review board approval was submitted to the NBA, the NBA released deidentified data on 279 players who participated in the combines from 2009 through 2013. There were 90 players (32.3%) who were deficient, 131 players (47.0%) who were insufficient, and 58 players (20.8%) who were sufficient. A total of 221 players (79.3%) were either vitamin D deficient or insufficient. Among all players included, the average vitamin D level was 25.6 ± 10.2 ng/mL. Among the players who were deficient, insufficient, and sufficient, the average vitamin D levels were 16.1 ± 2.1 ng/mL, 25.0 ± 3.4 ng/mL, and 41.6 ± 8.6 ng/mL, respectively. Player height and weight were significantly increased in vitamin D-sufficient players compared with players who were not sufficient (P = .0008 and .009, respectively). Player age and BMI did not significantly differ depending on vitamin D status (P = .15 and .77, respectively). There is a high prevalence of vitamin D deficiency

  14. Is heading a soccer ball injurious to brain function?

    Science.gov (United States)

    Baroff, G S

    1998-04-01

    With the growing popularity of soccer both in the United States and worldwide, reports of adverse effects of 'heading' on brain function are a source of concern. This article reviews the related research literature on neurologic and neuropsychological findings. Neurologic and neuropsychological abnormalities have been reported in a significant minority of older former professional players in Norway. Purportedly unrelated to age, the most prominent findings were cerebral atrophy and impairment on intelligence test abilities that are particularly vulnerable to brain damage. Also noteworthy in these retired players were persistent physical, cognitive, and emotional complaints consistent with a postconcussive syndrome. Younger amateur players appear to be free of major abnormalities, although some report persistent difficulties with memory and concentration. The severity of these complaints may be related to a history of soccer-related head injuries and not necessarily specific to heading. Research findings specific to heading are not more than suggestive at best, and clarification of the risks of heading a soccer ball awaits more definitive studies.

  15. Head Position and Internally Headed Relative Clauses.

    Science.gov (United States)

    Basilico, David

    1996-01-01

    Examines "Head Movement" in internally headed relative clauses (IHRCs). The article shows that in some cases, head movement to an external position need not take place and demonstrates that this movement of the head to a sentence-internal position results from the quantificational nature of IHRCs and Diesing's mapping hypothesis (1990, 1992). (56…

  16. An investigation of player to player character identification via personal pronouns

    DEFF Research Database (Denmark)

    Hichens, Michael; Drachen, Anders; Richards, Deborah

    2012-01-01

    The player character is an important feature of many games, where it is through the character that the player interacts with game world. There has been considerable interest in the relationship between the player and the player character. Much of this work has examined the identification of players...... in playing video games, did have a statistically significant affect, indicating that different levels of identification are more dependent on the player than on the game. This indicates that players are not a homogeneous group with respect to player character identification and is an important consideration...... with their characters, generally taking either a textual analysis approach, or has been empirical work that has explicitly identified the idea of identification through survey instruments, etc. The work presented here takes a different empirical approach, focusing on the use of various pronoun forms (first, second...

  17. Comparison of posture among adolescent male volleyball players and non-athletes

    Science.gov (United States)

    2014-01-01

    Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified. PMID:25729154

  18. Causal Attributions of Success and Failure and Mood States in Football Players

    Directory of Open Access Journals (Sweden)

    Szczepaniak Joanna

    2016-12-01

    Full Text Available Introduction. The aim of the study was to determine the causal attributions of success and failure in a football match in a group of football players, as well as to investigate the association of the players’ attributions with their level of achievement and the relationships between their causal attributions and affective states. Material and methods. The study involved 75 football players, including 44 players from the first league and 31 players from the third league. The research was carried out using the Profile of Mood States (POMS by D.M. McNair, M. Lorr, and L.F. Droppleman and a specially designed questionnaire concerning the causal attributions of success and failure. Results. It was found that the football players who participated in the study tended to attribute success to internal causes and failure to external causes. More frequent use of external attributions most likely had an adverse impact on the mood state of the players. Conclusion. Information concerning the attributions that a given player makes can be useful for coaches, as it can help them develop the athlete’s mental abilities more effectively. Beliefs related to attributions can be modified. It is worth considering the benefits of encouraging internal attributions in the case of success and external attributions in situations of failure.

  19. Comparison of posture among adolescent male volleyball players and non-athlete

    Directory of Open Access Journals (Sweden)

    Małgorzata Grabara

    2014-10-01

    Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

  20. Comparison of posture among adolescent male volleyball players and non-athletes

    Directory of Open Access Journals (Sweden)

    Małgorzata Grabara

    2014-11-01

    Full Text Available Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified.

  1. Serious eye injury in badminton players.

    Science.gov (United States)

    Kelly, S P

    1987-10-01

    Serious eye injury can occur in badminton players and may become more frequent. The causes and nature of such injuries in this sport in six patients are discussed. All were playing competitive doubles matches. Penetrating eye injury due to a shattered glass spectacle lens occurred. Players should be advised not to wear spectacles with glass lenses. Ocular protection in this sport is desirable, and the forward player should hold the racket in front of the face.

  2. The Prevalence of Injuries in Professional Turkish Soccer Players

    Science.gov (United States)

    Yamaner, Faruk; Gumusdag, Hayrettin; Kartal, Alparslan; Gumus, M.; Gullu, A.; Imamoglu, O.

    2011-01-01

    Study aim: To assess the prevalence and anatomical sites of injuries in professional soccer players in one game season. Material and methods: A cohort of 510 professional male soccer players consisting of 48 goalkeepers, 194 defence players, 189 mid-field players and 79 forward players of the 1st and 2nd Turkish Professional Soccer Leagues in…

  3. Premier League academy soccer players' experiences of competing in a tournament bio-banded for biological maturation.

    Science.gov (United States)

    Cumming, Sean P; Brown, Daniel J; Mitchell, Siobhan; Bunce, James; Hunt, Dan; Hedges, Chris; Crane, Gregory; Gross, Aleks; Scott, Sam; Franklin, Ed; Breakspear, Dave; Dennison, Luke; White, Paul; Cain, Andrew; Eisenmann, Joey C; Malina, Robert M

    2017-06-19

    Individual differences in the growth and maturation have been shown to impact player performance and development in youth soccer. This study investigated Premier League academy players' experiences of participating in a tournament bio-banded for biological maturation. Players (N = 66) from four professional soccer clubs aged 11 and 14 years and between 85-90% of adult stature participated in a tournament. Players competed in three 11 vs 11 games on a full size pitch with 25-min halves. Sixteen players participated in four 15-min focus groups and were asked to describe their experiences of participating in the bio-banded tournament in comparison to age group competition. All players described their experience as positive and recommended the Premier League integrate bio-banding into the existing games programme. In comparison to age-group competitions, early maturing players described the bio-banded games more physically challenging, and found that they had to adapt their style of play placing a greater emphasis on technique and tactics. Late maturing players considered the games to be less physically challenging, yet appreciated the having more opportunity to use, develop and demonstrate their technical, physical, and psychological competencies. Bio-banding strategies appear to contribute positively towards the holistic development of young soccer players.

  4. Effects of two training-learning methodologies on the individual technique of players from 6 to 10 years old

    Directory of Open Access Journals (Sweden)

    Molinero, Olga

    2012-07-01

    Full Text Available The study aims to compare the effect of technical and tactical training in technical skills of the players (running with the ball, dribbling, heading the ball and shooting with the ball. The study included a sample of 76 players aged between 6 and 10 years, from different clubs of the province of Salamanca. The results indicate that all players have improved running with the ball and dribbling; while hitting the ball with the head and hitting the ball with the non-dominant foot only improved in the participants of the technical training. For these reasons, the training of the player’s individual technique could be a combination of closed skills strategies with other games based on tactical application.

  5. Chess players' fame versus their merit

    CERN Document Server

    Simkin, M V

    2015-01-01

    We investigate a pool of international chess title holders born between 1901 and 1943. Using Elo ratings we compute for every player his expected score in a game with a randomly selected player from the pool. We use this figure as player's merit. We measure players' fame as the number of Google hits. The correlation between fame and merit is 0.38. At the same time the correlation between the logarithm of fame and merit is 0.61. This suggests that fame grows exponentially with merit.

  6. Physiological characteristics of international female soccer players.

    Science.gov (United States)

    Manson, Sarah A; Brughelli, Matt; Harris, Nigel K

    2014-02-01

    The purpose of this study was to investigate the physiological characteristics of Fédération Internationale de Football Association (FIFA) eligible international female soccer players aged 14-36 years and to determine if measures were significantly different for players selected (i.e., starters) to the starting line up for an FIFA tournament as compared with those not selected (i.e., nonstarters). Fifty-one (N = 18 Under 17; N = 18 Under 20; N = 15 Senior) international female soccer players participated in this study. The subjects underwent measurements of anthropometry (height and body mass), lower body strength (isokinetic testing), sprint kinetics and kinematics (nonmotorized treadmill), leg power (unilateral jumping), and maximal aerobic velocity (30:15 intermittent fitness test) during the final preparatory stage for an FIFA event. Outcomes of the age group data indicate that differences in physiological capacities are evident for the Under 17 players as compared with those for the Under 20 and Senior capped international players, suggesting a plateau in the acquisition of physical qualities as players mature. Starters tended to be faster (effect size [ES] = 0.55-1.0, p velocity (ES = 0.78-2.45, p velocity (ES = 0.87, p players, where maximal aerobic velocity was the primary difference between starters and nonstarters (ES = 0.83-2.45, p players. Coaches should emphasize the development of speed, maximal aerobic velocity, and leg strength in developing female soccer players.

  7. The incidence of trismus and long-term impact on health-related quality of life in patients with head and neck cancer.

    Science.gov (United States)

    Pauli, Nina; Johnson, Joakim; Finizia, Caterina; Andréll, Paulin

    2013-08-01

    Trismus is a common symptom related to the treatment of head and neck (H&N) cancer. To date there are few prospective studies regarding the incidence of trismus and the patients' experience of trismus in daily life activities. The aim of the study was to assess the incidence of trismus in H&N cancer patients and the impact on health-related quality of life (HRQL), by evaluating the patients before and after oncological treatment. We used the criteria for trismus of maximum interincisal opening (MIO) ≤ 35 mm and measured the patients at several occasions before and after treatment during one year. The patients answered the HRQL questionnaires EORTC QLQ C30, EORTC QLQ H&N 35, Gothenburg Trismus Questionnaire (GTQ) and the Hospital Anxiety and Depression Scale (HADS). The incidence of trismus was 9% pre-treatment and 28% at the one-year follow-up post-treatment. The highest incidence, 38%, was found six months post-treatment. Patients with tumours of the tonsils were most prone to develop trismus. Patients with trismus reported greater HRQL impairments with regard to the GTQ domains; mouth opening (p trismus, 6-12 months post-treatment. Furthermore, all patients reported pain, anxiety and depression pre- and post-treatment. The incidence of trismus in patients with H&N cancer is non-negligible. Trismus severely impairs HRQL and negatively affects daily life activities in patients with H&N cancer. Further studies regarding symptomatic treatment of patients with trismus are highly warranted. The symptom-specific questionnaire GTQ is useful to identify the problems in this group of patients given it is responsive to showing change over time.

  8. Protection of the side of the head.

    Science.gov (United States)

    Gilchrist, A; Mills, N J

    1996-07-01

    The side of the head is a frequent impact site for pedal cyclists, motorcyclists, and industrial workers. It is vulnerable to impact, yet many helmet standards do not have impact tests at the side of the helmet. Laboratory impact tests should reproduce the phenomena in real impacts, but usually they do not allow the headform to rotate, or ignore the effect of the neck on the motion of the head. The authors designed a linkage, simulating the flexibility of the neck, for use with anthropomorphic dummies in helmet testing. Impacts at the side of the helmet, normal to the helmet surface, were made with flat and hemispherical strikers. Head rotation during impacts caused the impact site to move, in some cases to below the level protected by the helmet. The peak angular head acceleration correlated with the peak linear accelerations. Neck flexibility means that helmets can protect the head from higher kinetic energy impacts than those specified in standards using immovable headforms or impact anvils. The load spreading efficiency of polypropylene foam, used in soft shell bicycle helmets, is better than that of polystyrene foam. The authors conclude that the side of the head can be protected by a suitable helmet design.

  9. Women's football: Player characteristics and demands of the game

    Directory of Open Access Journals (Sweden)

    Vanessa Martínez-Lagunas

    2014-12-01

    Full Text Available The number of scientific investigations on women's football specific to the topics of player characteristics and demands of the game has considerably increased in recent years due to the increased popularity of the women's game worldwide, although they are not yet as numerous as in the case of men's football. To date, only two scientific publications have attempted to review the main findings of studies published in this area. However, one of them was published about 20 years ago, when women's football was still in its infancy and there were only a few studies to report on. The other review was more recent. Nonetheless, its main focus was on the game and training demands of senior elite female players. Thus, information on female footballers of lower competitive levels and younger age groups was not included. Consequently, an updated review is needed in this area. The present article therefore aims to provide an overview of a series of studies that have been published so far on the specific characteristics of female football players and the demands of match-play. Mean values reported in the literature for age (12–27 years, body height (155–174 cm, body mass (48–72 kg, percent body fat (13%–29%, maximal oxygen uptake (45.1–55.5 mL/kg/min, Yo-Yo Intermittent Recovery Test Level 1 (780–1379 m, maximum heart rate (189–202 bpm, 30 m sprint times (4.34–4.96 s, and counter-movement jump or vertical jump (28–50 cm vary mostly according to the players' competitive level and positional role. There are also some special considerations that coaches and other practitioners should be aware of when working with female athletes such as the menstrual cycle, potential pregnancy and lactation, common injury risks (particularly knee and head injuries and health concerns (e.g., female athlete triad, iron deficiency, and anemia that may affect players' football performance, health or return to play. Reported mean values for total distance

  10. Gamification in Fostering Creativity: Player Type Approach

    Directory of Open Access Journals (Sweden)

    Marius Kalinauskas

    2015-02-01

    personality model for game and non-game contexts is purely theoretical and would require empirical evidence in the future research.Practical implications – Knowing how to apply game mechanics elements for specific groups of creative workers may increase their engagement and performance rates in collective and individual creativity.Value – The article emphasizes theoretical analysis of gamification and its applicability in promoting individual and collective creativity based on player/personality types. This area of research is rather new and there are very few attempts to create a unified personality and gamer type model. Gamification is working by providing different experiences to players and stimulating their intrinsic and extrinsic motivation to perform their activities with greater engagement. However, not all elements of game mechanics have the same impact towards the players since their gaming approach may vary. Knowing what triggers to pull for certain personality type may increase their engagement into creative activities, thus providing better chances of being more productive at problem solving in various domains.Research type – general review, viewpoint.

  11. Do UK university football club players suffer neuropsychological impairment as a consequence of their football (soccer) play?

    Science.gov (United States)

    Rutherford, Andrew; Stephens, Richard; Fernie, Gordon; Potter, Douglas

    2009-08-01

    Male players from football and rugby clubs and sportsmen from a variety of noncontact sports clubs at a UK university were compared on biographical and neuropsychological test measures. A data analysis paradigm was developed and employed to control the inflation of Type 1 error rate due to multiple hypotheses testing. Rugby players sustained most head injuries in their chosen sport, but neuropsychological tests of attention, memory, and executive function provided no evidence of performance impairment attributable to the number of head injuries sustained or the football, rugby, or noncontact sport groups. Footballers' heading frequency was related to the number of football head injuries sustained, but no relationship was detected between footballers' heading frequency and their neuropsychological test performance. Following discussion of pertinent methodological limitations it is concluded that there was no evidence in this dataset of neuropsychological impairment consistent with either mild head injury incidence or football heading frequency. However, a need for further research examining the long-term neuropsychological consequences of such head injuries was identified.

  12. Post-concussive syndrome in a female basketball player: a case study

    OpenAIRE

    2013-01-01

    Sarah L StrandDepartment of Health and Human Sciences, Loyola Marymount University, Los Angeles, CA, USAAbstract: The objective of this case study was to identify the signs and symptoms of concussion and post-concussive syndrome in a collegiate, female basketball player, as well as her progress to becoming symptom free. The patient, a previously healthy, 21-year-old with no previous head injuries, experienced a concussion and continued to participate in her sport. Even though the athlete knew...

  13. Impact of communicative head movements on the quality of functional near-infrared spectroscopy signals: negligible effects for affirmative and negative gestures and consistent artifacts related to raising eyebrows

    Science.gov (United States)

    Balardin, Joana Bisol; Morais, Guilherme Augusto Zimeo; Furucho, Rogério Akira; Trambaiolli, Lucas Romualdo; Sato, João Ricardo

    2017-04-01

    Functional near-infrared spectroscopy (fNIRS) is currently one of the most promising tools in the neuroscientific research to study brain hemodynamics during naturalistic social communication. The application of fNIRS by studies in this field of knowledge has been widely justified by its strong resilience to motion artifacts, including those that might be generated by communicative head and facial movements. Previous studies have focused on the identification and correction of these artifacts, but a quantification of the differential contribution of common communicative movements on the quality of fNIRS signals is still missing. We assessed the impact of four movements (nodding head up and down, reading aloud, nodding head sideways, and raising eyebrows) performed during rest and task conditions on two metrics of signal quality control: an estimative of signal-to-noise performance and the negative correlation between oxygenated and deoxygenated hemoglobin (oxy-Hb and deoxy-Hb). Channel-wise group analysis confirmed the robustness of the fNIRS technique to head nodding movements but showed a large effect of raising eyebrows in both signal quality control metrics, both during task and rest conditions. Reading aloud did not disrupt the expected anticorrelation between oxy-Hb and deoxy-Hb but had a relatively large effect on signal-to-noise performance. These findings may have implications to the interpretation of fNIRS studies examining communicative processes.

  14. Cooperation: New Players in Africa

    Directory of Open Access Journals (Sweden)

    Philippe Hugon

    2010-03-01

    Full Text Available In the context of globalisation and the current global financial crisis, new players are emerging in cooperation in Africa. These partners loosen financial constraints and conditionalities, increase the room for manoeuvre and stimulate commodity markets. On the other hand, they also increase the risks of renewed indebtedness and potentially weaken the coordination of aid policies. Do these partnerships call the new cooperation practices of OECD countries into question? Do they justify the return to a realpolitik or are they repeating the earlier mistakes of industrial powers? Can these mistakes be corrected? The question also arises as to whether the global crisis, which has a profound effect on Africa, will lead to a withdrawal or to a passing of the baton on to new, emerging powers. This article highlights the new geopolitical issues concerning Africa in a multipolar world, then discusses the new players involved in cooperation in Africa, before going on to explore the horizons that are opening up for cooperation in Africa, in particular with regard to the global crisis.

  15. 活血补肾中药联合植骨支撑治疗非创伤性股骨头坏死%Combined treatment of HUOXUEBUSHEN Decoction and bone impaction grafting for nontraumatic osteonecrosis of the femoral head

    Institute of Scientific and Technical Information of China (English)

    韦标方; 孙丙银

    2014-01-01

      结果与结论:治疗组患者Harris总分、疼痛程度、关节活动范围分值均显著高于对照组(P 0.05);治疗组患者疗效优良率显著高于对照组(88%,74%,χ2=4.54, P OBJECTIVE:To investigate clinical efficacy of combined treatment of HUOXUEBUSHEN decoction and bone impaction grafting through a femoral neck window at high location for non-traumatic osteoporosis of the femoral head. METHODS:This study is a prospective control ed trial. The patients with non-traumatic osteoporosis of the femoral head were divided into two groups:treatment group (n=52, 60 hips) and control group (n=51, 60 hips). The treatment group was given a combined treatment of HUOXUEBUSHEN decoction and bone impaction grafting through a femoral neck window (the decoction was prepared in People’s Hospital of Linyi, China). The control group underwent simple bone impaction grafting through a femoral neck window. Al the involved patients were fol owed up for 12 months, Harris hip score and the excellent-good rate at the last fol ow-up were used to evaluate clinical efficacy. RESULTS AND CONCLUSION:The Harris score, pain degree, and joint range of motion scores in the treatment group were higher than that in control group (P0.05). The excellent-good rate in the treatment group was significantly higher than that in control group (88%, 75%;χ2=4.91, P<0.05). The combined treatment of HUOXUEBUSHEN decoction and bone impaction grafting through a femoral neck window at high location is effective in the treatment of non-traumatic osteonecrosis of the femoral head, and is better than simple bone impaction grafting at al eviating pain and improving joint range of motion.

  16. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems, such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  17. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems,such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  18. Who Are the Players in Canadian Curriculum?

    Science.gov (United States)

    Milburn, Geoffrey

    1987-01-01

    Labels range of persons advocating different theoretical positions of Canadian curriculum as "players." Describes players as "managers,""predictors,""transformers,""sleuths,""analysts." Values varied viewpoints for attention to language regarding curriculum, critical review of ideas/concepts, examination of current policies, awareness of history…

  19. QuizUp Single Player Web

    OpenAIRE

    Gunnar Marteinsson 1983; Kristinn Júlíusson 1993; Sonja Jónsdóttir 1992; Steinar Þór Árnason 1993

    2016-01-01

    In this report we discuss the B.Sc. project named QuizUp Single Player Web. The project was developed at Reykjavik University in the spring of 2016 in collaboration with Plain Vanilla Games, the makers of the world famous QuizUp app. We developed a Single Player Web application based on the original multiplayer game.

  20. Inferring Player Experiences Using Facial Expressions Analysis

    NARCIS (Netherlands)

    Tan, C.T.; Bakkes, S.; Pisan, Y.; Blackmore, K.; Nesbitt, K.; Smith, S.P.

    2014-01-01

    Understanding player experiences is central to game design. Video captures of players is a common practice for obtaining rich reviewable data for analysing these experiences. However, not enough has been done in investigating ways of preprocessing the video for a more efficient analysis process. Thi

  1. Clinicopathological Evaluation of Chronic Traumatic Encephalopathy in Players of American Football.

    Science.gov (United States)

    Mez, Jesse; Daneshvar, Daniel H; Kiernan, Patrick T; Abdolmohammadi, Bobak; Alvarez, Victor E; Huber, Bertrand R; Alosco, Michael L; Solomon, Todd M; Nowinski, Christopher J; McHale, Lisa; Cormier, Kerry A; Kubilus, Caroline A; Martin, Brett M; Murphy, Lauren; Baugh, Christine M; Montenigro, Phillip H; Chaisson, Christine E; Tripodis, Yorghos; Kowall, Neil W; Weuve, Jennifer; McClean, Michael D; Cantu, Robert C; Goldstein, Lee E; Katz, Douglas I; Stern, Robert A; Stein, Thor D; McKee, Ann C

    2017-07-25

    Players of American football may be at increased risk of long-term neurological conditions, particularly chronic traumatic encephalopathy (CTE). To determine the neuropathological and clinical features of deceased football players with CTE. Case series of 202 football players whose brains were donated for research. Neuropathological evaluations and retrospective telephone clinical assessments (including head trauma history) with informants were performed blinded. Online questionnaires ascertained athletic and military history. Participation in American football at any level of play. Neuropathological diagnoses of neurodegenerative diseases, including CTE, based on defined diagnostic criteria; CTE neuropathological severity (stages I to IV or dichotomized into mild [stages I and II] and severe [stages III and IV]); informant-reported athletic history and, for players who died in 2014 or later, clinical presentation, including behavior, mood, and cognitive symptoms and dementia. Among 202 deceased former football players (median age at death, 66 years [interquartile range, 47-76 years]), CTE was neuropathologically diagnosed in 177 players (87%; median age at death, 67 years [interquartile range, 52-77 years]; mean years of football participation, 15.1 [SD, 5.2]), including 0 of 2 pre-high school, 3 of 14 high school (21%), 48 of 53 college (91%), 9 of 14 semiprofessional (64%), 7 of 8 Canadian Football League (88%), and 110 of 111 National Football League (99%) players. Neuropathological severity of CTE was distributed across the highest level of play, with all 3 former high school players having mild pathology and the majority of former college (27 [56%]), semiprofessional (5 [56%]), and professional (101 [86%]) players having severe pathology. Among 27 participants with mild CTE pathology, 26 (96%) had behavioral or mood symptoms or both, 23 (85%) had cognitive symptoms, and 9 (33%) had signs of dementia. Among 84 participants with severe CTE pathology, 75 (89

  2. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    BACKGROUND: Outpatient clinic visits are a window of opportunity to address health risk behaviors and promote a healthier lifestyle among young people. The HEADS (Home, Education, Eating, Activities, Drugs [i.e. substance use including tobacco, alcohol, and illegal drugs], Sexuality [including...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...... patients. Young patients reported that smoking, alcohol, illegal drugs, sexuality, and contraception were addressed significantly more at adult clinics in comparison to pediatric clinics. After controlling for age, gender and duration of illness, according to young patients, adjusted odds ratios...

  3. Finite stage asymmetric repeated games: Both players' viewpoints

    KAUST Repository

    Li, Lichun

    2017-01-05

    In asymmetric zero-sum games, one player has superior information about the game over the other. It is known that the informed players (maximizer) face the tradeoff of exploiting its superior information at the cost of revealing its superior information, but the basic point of the uninformed player (minimizer)\\'s decision making remains unknown. This paper studies the finite stage asymmetric repeated games from both players\\' viewpoints, and derives that not only security strategies but also the opponents\\' corresponding best responses depends only on the informed player\\'s history action sequences. Moreover, efficient LP formulations to compute both player\\'s security strategies are provided.

  4. Injuries in racket sports among Slovenian players.

    Science.gov (United States)

    Kondric, Miran; Matković, Branka R; Furjan-Mandić, Gordana; Hadzić, Vedran; Dervisević, Edvin

    2011-06-01

    On the sample of 83 top Slovenian athletes we have studied the frequency of injuries among table tennis, tennis and badminton players, types of injuries and severity of injuries--the latter based on data of players absences from training and/or competition processes. The most liable parts to injuries are shoulder girdle (17.27%), spine (16.55%) and ankle (15.83%), while foot (10.07%) and wrist (12.23%) are slightly less liable to injuries. The most frequent injuries in racket sports pertain to muscle tissues. According to this data, the majority of injuries occur halfway through a training session or a competition event, mostly during a competition season. The injuries primarily pertain to muscle tissues; these are followed by joint and tendon injuries. There are no differences between male and female players. Compared to other racket sports players, table tennis players suffer from fewer injuries.

  5. Decreased Nerve Conduction Velocity in Football Players

    Directory of Open Access Journals (Sweden)

    Daryoush Didehdar

    2014-06-01

    Full Text Available Background: Lower limbs nerves are exposed to mechanical injuries in the football players and the purpose of this study is to evaluate the influence of football on the lower leg nerves. Materials and Methods: Nerve conduction studies were done on 35 male college students (20 football players, 15 non active during 2006 to 2007 in the Shiraz rehabilitation faculty. Standard nerve conduction techniques using to evaluate dominant and non dominant lower limb nerves. Results: The motor latency of deep peroneal and tibial nerves of dominant leg of football players and sensory latency of superficial peroneal, tibial and compound nerve action potential of tibial nerve of both leg in football players were significantly prolonged (p<0.05. Motor and sensory nerve conduction velocity of tibial and common peroneal in football players were significant delayed (p<0.05. Conclusion: It is concluded that football is sport with high contact and it causes sub-clinical neuropathies due to nerve entrapment.

  6. Outcomes of microfracture in professional basketball players.

    Science.gov (United States)

    Cerynik, Douglas L; Lewullis, Gabriel E; Joves, Brian C; Palmer, Michael P; Tom, James A

    2009-09-01

    Surgical treatment for chondral defects of the knee in competitive running and jumping athletes remains controversial. This study evaluated the performance outcomes of professional basketball players in the National Basketball Association (NBA) who underwent microfracture. Data from 24 professional basketball players from 1997 to 2006 was obtained and analyzed. NBA player efficiency ratings (PER) were calculated for two seasons before and after injury. A control group of 24 players was used for comparison. Study group and control group demographics including age, NBA experience, and minutes per game demonstrated no statistical difference. Mean time to return to an NBA game was 30.0 weeks from the time of surgery. The first season after returning to competition PER and minutes per game decreased by 3.5 (P 0.05) and 3.0 min (P NBA game. On return to competition player performance and minutes per game are diminished.

  7. Executive functioning in highly talented soccer players.

    Science.gov (United States)

    Verburgh, Lot; Scherder, Erik J A; van Lange, Paul A M; Oosterlaan, Jaap

    2014-01-01

    Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer.

  8. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  10. Incidence of Stingers in Young Rugby Players.

    Science.gov (United States)

    Kawasaki, Takayuki; Ota, Chihiro; Yoneda, Takeshi; Maki, Nobukazu; Urayama, Shingo; Nagao, Masashi; Nagayama, Masataka; Kaketa, Takefumi; Takazawa, Yuji; Kaneko, Kazuo

    2015-11-01

    A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated. To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players. Descriptive epidemiology study. A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires. The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury. Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for

  11. Growth and maturity status of elite British junior tennis players.

    Science.gov (United States)

    Myburgh, Gillian K; Cumming, Sean P; Coelho E Silva, Manuel; Cooke, Karl; Malina, Robert M

    2016-10-01

    Growth and maturation impact the selection, development and progression of youth athletes. Individual differences in the growth and maturity may afford a performance advantage, clouding coaches and practitioners' perceptions regarding current ability and future potential. This may result in the exclusion of talented, yet less physically gifted athletes. Participants were 91 male (n = 47) and female (n = 44) elite British Junior tennis players, 8-17 years of age (12.5 ± 1.9 years). Height and body mass were measured and compared to growth charts; hand-wrist radiographs were taken. Skeletal age (SA) was estimated with the Fels method and contrasted to chronological age (CA). Mean height and body mass of individual players ranged between the 50th and 90th centiles for age and sex. Females were advanced in SA relative to CA (0.3-0.89 years.) from 8 years. Males were average to delayed in maturation from 8 to 12 years, but advanced in SA from 14 to 16 years (0.75-1.23 years). Individual differences in growth and maturation appear to contribute towards the selection of elite junior tennis players, with a bias towards males and females who are advanced in maturation and comparatively tall and heavy for their age. This has important implications for talent identification and development.

  12. Examining Player Anger in World of Warcraft

    Science.gov (United States)

    Barnett, Jane; Coulson, Mark; Foreman, Nigel

    This questionnaire study of the sources of anger in World of Warcraft applies classical quantitative measurement scale construction to a new problem, generating a host of questionnaire items that could find use in future studies, and identifying four major categories of events that cause negative effect among players. First, 33 players provided examples of in-game scenarios that had made them angry, and their responses were culled to create a 93-item battery rated by hundreds of player respondents in terms of anger intensity and anger frequency. An iterative process of factor analysis and scale reliability assessment led to a 28-item instrument measuring four anger-provoking factors: Raids/Instances, Griefers, Perceived Time Wasting, and Anti-social Players. These anger-causing scenarios were then illustrated by concrete examples from player and researcher experiences in World of Warcraft. One striking finding is that players become angry at other players' negative behavior, regardless of whether that behavior was intended to harm.

  13. Applied physiology of female soccer players.

    Science.gov (United States)

    Davis, J A; Brewer, J

    1993-09-01

    Women's soccer is in its infancy as a sport and research into its physiological demands and the physical characteristics of players is somewhat limited. There is now an increasing demand for scientific investigation of the female game and of the players, match analysis and role variations requiring particular attention. Current research suggests that the demands of the game for women are similar to those placed on male players. Women are reported to cover a similar distance (mean 8471m) to their male counterparts during a game and much the same proportions of the game appear to be devoted to exercise of varying intensities. Furthermore, female and male players appear to tax the aerobic and anaerobic energy systems to a similar level. The physical and physiological characteristics of female soccer players are comparable with those of other female games players and are more favourable than average for the population. Mean body fat percentages of between 19.7 and 22.0% and VO2max values of between 47.1 and 57.6 ml/kg/min have been reported for elite female players, while faster than average sprint times are also characteristic of them.

  14. Nutrient intake and food habits of soccer players: analyzing the correlates of eating practice.

    Science.gov (United States)

    García-Rovés, Pablo M; García-Zapico, Pedro; Patterson, Angeles M; Iglesias-Gutiérrez, Eduardo

    2014-07-18

    Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player's career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.

  15. Concussion history and reporting rates in elite Irish rugby union players.

    Science.gov (United States)

    Fraas, Michael R; Coughlan, Garrett F; Hart, Emily C; McCarthy, Conor

    2014-08-01

    To determine the self-reported, seasonal rates of concussion and the reporting practices among Irish rugby union players. Descriptive epidemiology study. The study was conducted at the training grounds of four professional Irish rugby union clubs. One hundred seventy-two players (24.97 ± 4.11 years of age, 13.49 ± 5.79 years playing experience) gave consent to participate. Number of concussions reported during the 2010-2011 season, reasons for not reporting, and positions of concussed players. Forty-five percent of players reported at least one concussion during the 2010-2011 season, but only 46.6% of these presented to medical staff. The reasons for not reporting their concussions included, not thinking the injury was serious enough, and not wanting to be removed from the game. The relative proportion of concussions was higher for backs than forwards; however, the severity of injury was greater for forwards. Scrum-halves (12.0%) and flankers (10.9%) accounted for the majority of concussions reported. The self-reported rate of concussion in elite rugby union players in Ireland is higher than reported in other countries or other sports. Many concussions remain unreported and, therefore, unmanaged. However, recent changes in concussion management guidelines by the International Rugby Board may impact future reporting practices of players. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Multiple Past Concussions in High School Football Players

    Science.gov (United States)

    Brooks, Brian L.; Mannix, Rebekah; Maxwell, Bruce; Zafonte, Ross; Berkner, Paul D.; Iverson, Grant L.

    2017-01-01

    Background There is increasing concern about the possible long-term effects of multiple concussions, particularly on the developing adolescent brain. Whether the effect of multiple concussions is detectable in high school football players has not been well studied, although the public health implications are great in this population. Purpose To determine if there are measureable differences in cognitive functioning or symptom reporting in high school football players with a history of multiple concussions. Study Design Cross-sectional study; Level of evidence, 3. Methods Participants included 5232 male adolescent football players (mean [±SD] age, 15.5 ± 1.2 years) who completed baseline testing between 2009 and 2014. On the basis of injury history, athletes were grouped into 0 (n = 4183), 1 (n = 733), 2 (n = 216), 3 (n = 67), or ≥4 (n = 33) prior concussions. Cognitive functioning was measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery, and symptom ratings were obtained from the Post-Concussion Symptom Scale. Results There were no statistically significant differences between groups (based on the number of reported concussions) regarding cognitive functioning. Athletes with ≥3 prior concussions reported more symptoms than did athletes with 0 or 1 prior injury. In multivariate analyses, concussion history was independently related to symptom reporting but less so than developmental problems (eg, attention or learning problems) or other health problems (eg, past treatment for psychiatric problems, headaches, or migraines). Conclusion In the largest study to date, high school football players with multiple past concussions performed the same on cognitive testing as those with no prior concussions. Concussion history was one of several factors that were independently related to symptom reporting. PMID:27474382

  17. Computing Decoupled Residuals for Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2006-01-01

    In order to improve Compact Disc Players playability regarding playing Compact Discs with surface faults, like scratches and fingerprints etc, the attention has been put on fault tolerant control schemes. Almost every of those methods are based on fault detection. The standard approach is to use...... a pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  18. Towards Player-Driven Procedural Content Generation

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Togelius, Julian

    2012-01-01

    Generating immersive game content is one of the ultimate goals for a game designer. This goal can be achieved by realizing the fact that players’ perception of the same game differ according to a number of factors including: players’ personality, playing styles, expertise and culture background....... While one player might find the game immersive, others may quit playing as a result of encountering a seemingly insoluble problem. One promising avenue towards optimizing the gameplay experience for individual game players is to tailor player experience in real-time via automatic game content generation......-driven content generation....

  19. Climate change impacts on the ecology of Fusarium graminearum species complex and susceptibility of wheat to Fusarium head blight: a review

    Science.gov (United States)

    Fusarium head blight (FHB) of wheat caused mainly by members of the Fusarium graminearum species complex (FGSC) is a major threat to agricultural grain production, food safety, and animal health. The severity of disease epidemics and accumulation of associated trichothecene mycotoxins in wheat kerne...

  20. Maturation of glutamatergic transmission in the vestibulo-olivary pathway impacts on the registration of head rotational signals in the brainstem of rats.

    Science.gov (United States)

    Lai, Chun-Hong; Ma, Chun-Wai; Lai, Suk-King; Han, Lei; Wong, Hoi-Man; Yeung, Kelvin Wai-Kwok; Shum, Daisy Kwok-Yan; Chan, Ying-Shing

    2016-01-01

    The recognition of head orientation in the adult involves multi-level integration of inputs within the central vestibular circuitry. How the different inputs are recruited during postnatal development remains unclear. We hypothesize that glutamatergic transmission at the vestibular nucleus contributes to developmental registration of head orientations along the vestibulo-olivary pathway. To investigate the maturation profile by which head rotational signals are registered in the brainstem, we used sinusoidal rotations on the orthogonal planes of the three pairs of semicircular canals. Fos expression was used as readout of neurons responsive to the rotational stimulus. Neurons in the vestibular nucleus and prepositus hypoglossal nucleus responded to all rotations as early as P4 and reached adult numbers by P21. In the reticular formation and inferior olive, neurons also responded to horizontal rotations as early as P4 but to vertical rotations not until P21 and P25, respectively. Neuronal subpopulations that distinguish between rotations activating the orthogonally oriented vertical canals were identifiable in the medial and spinal vestibular nuclei by P14 and in the inferior olivary subnuclei IOβ and IOK by P25. Neonatal perturbation of glutamate transmission in the vestibular nucleus was sufficient to derange formation of this distribution in the inferior olive. This is the first demonstration that developmental refinement of glutamatergic synapses in the central vestibular circuitry is essential for developmental registration of head rotational signals in the brainstem.

  1. Could the biological robustness of low level laser therapy (Photobiomodulation) impact its use in the management of mucositis in head and neck cancer patients

    NARCIS (Netherlands)

    Sonis, S.T.; Hashemi, S.; Epstein, J.B.; Nair, R.G.; Raber-Durlacher, J.E.

    2016-01-01

    Low level laser therapy (LLLT) has been noted to be effective in mitigating the development of oral mucositis among patients being treated with chemoradiation for cancers of the head and neck. To explain the biological basis for this observation we performed a comprehensive literature search. Our in

  2. Impact Findings from the Head Start CARES Demonstration: National Evaluation of Three Approaches to Improving Preschoolers' Social and Emotional Competence. Executive Summary. OPRE Report 2014-44

    Science.gov (United States)

    Morris, Pamela; Mattera, Shira K.; Castells, Nina; Bangser, Michael; Bierman, Karen; Raver, Cybele

    2014-01-01

    Low-income preschool children face risks to their social-emotional development that can affect them later on. Although there are promising approaches to promoting preschoolers' social-emotional skills, the evidence base is limited, particularly on their effectiveness when implemented at scale. The Head Start CARES demonstration evaluated the…

  3. The impact of oral rehabilitation on oral health-related quality of life in patients receiving radiotherapy for the treatment of head and neck cancer.

    Science.gov (United States)

    Schweyen, Ramona; Kuhnt, Thomas; Wienke, Andreas; Eckert, Alexander; Hey, Jeremias

    2017-05-01

    To analyze the influence of dental treatment on oral health-related quality of life (OHRQoL) in head and neck cancer patients. This study included the data of 116 patients who underwent radiotherapy (RT) because of head and neck cancer. For each patient, the variables age, sex, tumor site, irradiation technique, dose on the spared parotid gland, concomitant chemotherapy, and denture status were documented. OHRQoL was determined using the OHIP-G14 questionnaire. Patients were divided into subgroups according to denture status: none or fixed partial dentures (none/FPD), removable partial dentures (RPD), and full dentures (CD). OHIP summary scores were determined and tested for clinical relevant differences with respect to the different variables. The association between OHRQol and the variables was assessed using linear regression. No clinically relevant influence on OHRQoL was found for gender, irradiation technique, and chemotherapy. Patients with tumors located in the oral cavity had a significantly higher OHIP score than patients with other tumor sites (p denture seem to have a limited effect on OHRQoL in head and neck cancer patients. Prosthetic treatment in head and neck cancer patients do not lead to the same improvement in OHRQoL as found in the normal population. This might be taken into account especially if extensive dental treatment is intended.

  4. The impact of Chinese cultural values on Taiwan nursing leadership styles: comparing the self-assessments of staff nurses and head nurses.

    Science.gov (United States)

    Chang, Yuanmay

    2008-06-01

    The purpose of this study was to investigate the influence of Chinese culture on nursing leadership behavior in Taiwan nurses. A descriptive study compared staff nurses' assessment of Chinese value in the leadership behavior of their head nurses. Data analysis was made on a convenience sample in Taiwan of 214 head nurses and 2,127 staff nurses who had worked with their head nurse for at least one year. Six medical centers and regional hospitals in northern (Taipei), central (Taichung) and southern (Kaohsiung) Taiwan were recruited for this study. Instruments included the demographic questionnaire, Chinese Value Survey, and Kang's Chinese Leadership Behaviors Module Scale. Results indicated that head nurses scored significantly higher than staff nurses in terms of all cultural values and leadership behaviors. Both staff nurses and head nurses scored the highest mean scores in personal integrity (Yi) and human connectedness (Ren) and the lowest in moral discipline (Li). Staff nurse perceptions of leadership behavior indicated the role of parent to be higher than either the role of director or mentor. Head nurses perceptions of leadership behavior emphasized the role of the director more than either parent or mentor. There were no significant differences between the staff nurses and head nurses in terms of expectative leadership behavior, which gave the role of director higher mean scores than those of either the parent or mentor. Positive and significant associations (r = .266 to r = .334) were found between cultural values and perceptions of leadership behavior. Cultural values predicted 10.6% of leadership behavior variance. The three demographic characteristics of location in northern Taiwan (beta = .09), intention to leave (beta = -.14), and general unit (beta = .10) and the two cultural values of human connectedness (Ren) (beta = .16) and personal integrity (Yi) (beta = .16) together reported a cumulative R2 of 14.6% to explain variance in leadership behavior

  5. The impact of use of Glutamine on patients with head and neck tumors in radiotherapy and chemotherapy treatment; O Impacto do uso de Glutamina em pacientes com tumores de cabeca e pescoco em tratamento radioterapico e quimioterapico

    Energy Technology Data Exchange (ETDEWEB)

    Boligon, Caroline Schardong, E-mail: caronut@bol.com.b [Hospital de Caridade de Ijui, RS (Brazil); Huth, Adriane, E-mail: adriane.huth@unijui.edu.b [UNIJUI, RS (Brazil). Dept. Ciencias da Saude

    2011-07-01

    Introduction: patients with head and neck neoplasia usually show malnutrition or a nutritional risk, because of common symptoms like: dysphagia, odynophagia and xerostomia. Objective: this study aimed to verify the impact of using amino glutamine in patients with head and neck neoplasia and under radiotherapy and chemotherapy treatment concomitantly. Methods: the research was quantitative, cross-sectional, descriptive and exploratory. The data was collected from nutritional evaluation, and patients chart consultation. The patients were divided in a control group (without use of glutamine) and a test group (with use of glutamine). 16 patients, 13 of which were men and three were women, participated in the research. Results: The control group presented mucositis grades I to IV while patients who used the amino glutamine showed mucositis grades I to II only. It could be observed that the Nutritional Risk Index decreased, which represents higher nutritional risk in patients from the control group only. In patients who used glutamine, this decrease was not significant. Conclusion: these results suggest that the use of glutamine in patients with head and neck tumors and under antineoplastic therapy helps to maintain their nutritional stage and to prevent mucositis throughout their treatment, mainly grades III and IV, which prevents adequate and regular eating and nourishment. (author)

  6. The impact of 8 weeks selected corrective exercises on neck pain, range of motion in the shoulder and neck of lifesaver women who suffering from forward head posture and myofascial pain syndrome

    Directory of Open Access Journals (Sweden)

    Melody Tabatabaei

    2017-06-01

    Full Text Available Background: The purpose of this research was studying the impact of 8 weeks selected corrective exercises on neck pain, range of motion in the shoulder and neck of lifesaver women who suffering from forward head posture and myofascial pain syndrome. Methods: The method of research is semi-experimental. The population consists of 30 lifesaver women who suffering from forward head posture and myofascial pain syndrome who they placed randomly in two groups of experimental (33±2.2 and control (33±2.5. Research plan was as the pre-test and post-test with control group. The exercise protocol was carried out by experimental groups for 8 weeks, 3 sessions per week, each session lasting 45 minutes. Studied variables include myofascial pain in the neck, shoulder and neck range of motion. The mean and standard deviation were used as descriptive statistics and in the section of inferential statistics analysis of covariance was used. Results: Results of research indicated that, the protocol on the reform exercise of neck pain (P=0.001, range of motion of shoulder joint (P=0.001 and neck range of motion (P=0.001 has significant difference. Conclusion: Therefore, lifesavers women can benefit from it as a training program to improve and prevent damage caused by head forward and myofascial pain syndrome.

  7. Technical player profiles related to the physical fitness of young female volleyball players predict team performance.

    Science.gov (United States)

    Dávila-Romero, C; Hernández-Mocholí, M A; García-Hermoso, A

    2015-03-01

    This study is divided into three sequential stages: identification of fitness and game performance profiles (individual player performance), an assessment of the relationship between these profiles, and an assessment of the relationship between individual player profiles and team performance during play (in championship performance). The overall study sample comprised 525 (19 teams) female volleyball players aged 12-16 years and a subsample (N.=43) used to examine study aims one and two was selected from overall sample. Anthropometric, fitness and individual player performance (actual game) data were collected in the subsample. These data were analyzed through clustering methods, ANOVA and independence chi-square test. Then, we investigated whether the proportion of players with the highest individual player performance profile might predict a team's results in the championship. Cluster analysis identified three volleyball fitness profiles (high, medium, and low) and two individual player performance profiles (high and low). The results showed a relationship between both types of profile (fitness and individual player performance). Then, linear regression revealed a moderate relationship between the number of players with a high volleyball fitness profile and a team's results in the championship (R2=0.23). The current study findings may enable coaches and trainers to manage training programs more efficiently in order to obtain tailor-made training, identify volleyball-specific physical fitness training requirements and reach better results during competitions.

  8. The Cheerleader and the Football Player.

    Science.gov (United States)

    Patil, Malati

    2001-01-01

    Describes an activity in physics using a narrative about a bet between a cheerleader who claims she can lift a 300-pound football player off the ground. Includes questions, teaching notes, and solutions. (MM)

  9. Menstrual cycle disorders in female volleyball players.

    Science.gov (United States)

    Wodarska, M; Witkoś, J; Drosdzol-Cop, A; Dąbrowska, J; Dąbrowska-Galas, M; Hartman, M; Plinta, R; Skrzypulec-Plinta, V

    2013-07-01

    The aim of this study was to examine the relation between increased physical activity and menstrual disorders in adolescent female volleyball players. The study was conducted on 210 Polish female volleyball players, aged 13-17 years, the authorship questionnaire was used. The results of the study showed that irregular menstruation occurred in 19% of girls, spotting between menstrual periods in 27% and heavy menstruation was reported in 33% of girls. Out of all volleyball female players participating in the study, 94 girls (45%) declared absence of menstrual periods after regular cycles. Statistical analysis showed that the more training hours per week, the bigger probability of the occurrence of irregular menstruation. It was concluded that the number of hours of volleyball training per week affects regularity of menstrual cycles in female volleyball players. The absence of menstruation might be caused by the duration of training per week or years of training.

  10. Towards Generic Models of Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Shaker, Mohammad; Abou-Zleikha, Mohamed

    2015-01-01

    further examine whether generic features of player be- haviour can be defined and used to boost the modelling per- formance. The accuracies obtained in both experiments in- dicate a promise for the proposed approach and suggest that game-independent player experience models can be built.......-dependent and their applicability is usually limited to the system and the data used for model construction. Establishing models of user experience that are highly scalable while maintaing the performance constitutes an important research direction. In this paper, we propose generic models of user experience in the computer games...... domain. We employ two datasets collected from players in- teractions with two games from different genres where accu- rate models of players experience were previously built. We take the approach one step further by investigating the mod- elling mechanism ability to generalise over the two datasets. We...

  11. Video Player Keyboard Shortcuts: MedlinePlus

    Science.gov (United States)

    ... page: https://medlineplus.gov/hotkeys.html Video Player Keyboard Shortcuts To use the sharing features on this ... enable JavaScript. MedlinePlus offers a set of accessible keyboard shortcuts for our latest Health videos on the ...

  12. Scouting the Elite, Unbreakable Football Player.

    Science.gov (United States)

    Moore, M

    1981-02-01

    Some NFL football teams see physiological profiling as a means to protect and enhance their competitive and business success. Whether football players will benefit by increased performance and fewer injuries remains to be seen.

  13. Minimizing Head Acceleration in Soccer: A Review of the Literature.

    Science.gov (United States)

    Caccese, Jaclyn B; Kaminski, Thomas W

    2016-11-01

    Physicians and healthcare professionals are often asked for recommendations on how to keep athletes safe during contact sports such as soccer. With an increase in concussion awareness and concern about repetitive subconcussion, many parents and athletes are interested in mitigating head acceleration in soccer, so we conducted a literature review on factors that affect head acceleration in soccer. We searched electronic databases and reference lists to find studies using the keywords 'soccer' OR 'football' AND 'head acceleration'. Because of a lack of current research in soccer heading biomechanics, this review was limited to 18 original research studies. Low head-neck segment mass predisposes athletes to high head acceleration, but head-neck-torso alignment during heading and follow-through after contact can be used to decrease head acceleration. Additionally, improvements in symmetric neck flexor and extensor strength and neuromuscular neck stiffness can decrease head acceleration. Head-to-head impacts and unanticipated ball contacts result in the highest head acceleration. Ball contacts at high velocity may also be dangerous. The risk of concussive impacts may be lessened through the use of headgear, but headgear may also cause athletes to play more recklessly because they feel a sense of increased security. Young, but physically capable, athletes should be taught proper heading technique in a controlled setting, using a carefully planned progression of the skill.

  14. Does the Quantum Player Always Win the Classical One?

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-Jun; FANG Xi-Ming

    2004-01-01

    @@ We study quantum games in which the players have different strategic spaces. We find that the player who can use a quantum strategic space does not always possess more payoffs than the player who is restricted to apply only classical strategies. We find the condition of the classical player getting more payoffs than the quantum player. We also find that the game exhibits intriguing structures.

  15. University of Virginia prospective study of football-induced minor head injury: status report.

    Science.gov (United States)

    Alves, W M; Rimel, R W; Nelson, W E

    1987-01-01

    We have recently completed the field work phase of a 4-year prospective study of football-induced minor head injuries. Players from 10 University football teams were monitored up to 4 years, and a brief neuropsychological and psychosocial assessment battery was administered to them up to five times before and after injury. Objectives of this project focus on the frequency of head injuries in college football, the impairments that might result from such injury, the duration of impairments, the time course of their recovery, and the possibility of cumulative effects of multiple injuries during the player's college career. Approximately 2500 players were monitored during the study, and nearly 200 players were restudied following minor head injuries. A series of nearly 60 players with orthopedic injuries were tested using the same protocol, and a college student control series of 50 patients were similarly studied. Data analyses are currently underway, and the first report of the findings of this study will be available soon. This article has described the objectives and design of this study, outlined the neuropsychological and psychosocial assessment protocol, and discussed some of the issues related to project implementation. Current data analyses focus on the size of the effects of minor head injury on cognitive and psychosocial performance observed following minor head injury. Upon completion of the initial data analyses, our analysis plan includes having at least two neuropsychologists make independent assessments of the clinical significance of the findings. Similar assessments will be made of the neurophysical symptoms and complaints and psychosocial performance of players after injury.

  16. Incidence of Concussion During Practice and Games in Youth, High School, and Collegiate American Football Players.

    Science.gov (United States)

    Dompier, Thomas P; Kerr, Zachary Y; Marshall, Stephen W; Hainline, Brian; Snook, Erin M; Hayden, Ross; Simon, Janet E

    2015-07-01

    .80; 95% CI, 0.67-0.96). Youth football had the lowest 1-season concussion risks in 2012 (3.53%) and 2013 (3.13%). The 1-season concussion risk was highest in high school (9.98%) and college (5.54%) in 2012. Football practices were a major source of concussion at all 3 levels of competition. Concussions during practice might be mitigated and should prompt an evaluation of technique and head impact exposure. Although it is more difficult to change the intensity or conditions of a game, many strategies can be used during practice to limit player-to-player contact and other potentially injurious behaviors.

  17. 能力本位教育对提高护士长评判性思维能力的影响%Impact of competence-based education on upgrading critical thinking ability of head nurses

    Institute of Scientific and Technical Information of China (English)

    华亚芳; 金学勤; 张桂珍; 潘胜桂; 盛祺

    2012-01-01

    目的:探讨实施能力本位教育对临床护士长评判性思维能力的影响,为临床培训提供依据.方法:对45名护士长进行基于能力本位为主岗位培训模式体系的培训,培训前后采用评判性思维能力量表(CTDI-CV)评估培训效果.结果:实施能力本位教育后45名护士长分析能力、系统化能力、批判性思维的自信心及求知欲维度的评分均高于实施能力本位教育前(P<0.05).结论:能力本位教育可提高临床护士长评判性思维能力.%To explore the impact of competence ?based education on upgrading critical thinking ability of head nurses. Methods:45 head nurses received competence 梑ased training and the training effect was assessed by the critical thinking disposition inventory ( CTDI- CV } before and after training. Results:The scores of the ability of analysis and systematic thinking,critical thinking confidence and the scores of curiosity dimensions of 45 head nurses were higher after training than that before training( P <0. 05 }. Conclusion: The competence- based education can improve the critical thinking ability of clinical head nurses.

  18. Head kinematics during shaking associated with abusive head trauma.

    Science.gov (United States)

    Lintern, T O; Puhulwelle Gamage, N T; Bloomfield, F H; Kelly, P; Finch, M C; Taberner, A J; Nash, M P; Nielsen, P M F

    2015-09-18

    Abusive head trauma (AHT) is a potentially fatal result of child abuse but the mechanisms of injury are controversial. To address the hypothesis that shaking alone is sufficient to elicit the injuries observed, effective computational and experimental models are necessary. This paper investigates the use of a coupled rigid-body computational modelling framework to reproduce in vivo shaking kinematics in AHT. A sagittal plane OpenSim computational model of a lamb was developed and used to interpret biomechanical data from in vivo shaking experiments. The acceleration of the head during shaking was used to provide in vivo validation of the associated computational model. Results of this study demonstrated that peak accelerations occurred when the head impacted the torso and produced acceleration magnitudes exceeding 200ms(-)(2). The computational model demonstrated good agreement with the experimental measurements and was shown to be able to reproduce the high accelerations that occur during impact. The biomechanical results obtained with the computational model demonstrate the utility of using a coupled rigid-body modelling framework to describe infant head kinematics in AHT.

  19. Electromyographic Study of Neck Muscle Activity According to Head Position in Rugby Tackles

    Science.gov (United States)

    Morimoto, Koji; Sakamoto, Masaaki; Fukuhara, Takashi; Kato, Kazuo

    2013-01-01

    [Purpose] This study examined differences in neck muscle activity in two different head positions during tackles with the aim of contributing to the prevention of sports injuries. [Subjects] The subjects were 28 male high-school rugby players. [Methods] Two tackle positions were considered: a head-up position and a head-down position. Muscle activities of the sternocleidomastoid muscles and the upper, middle, and lower parts of the trapezius muscles were measured. [Results] Muscle activities of the sternocleidomastoid muscles and the right upper trapezius muscle were significantly increased in the head-up position, and the activity of the lower trapezius was significantly increased in the head-down position. [Conclusion] Tackling with the head-up position increases neck muscle activity and stability of the head and the neck. PMID:24259802

  20. Who Is Whistling Vivaldi? How Black Football Players Engage with Stereotype Threats in College

    Science.gov (United States)

    Griffin, Whitney

    2017-01-01

    In light of the impact of negative stereotypes on student-athlete academic performance, the purpose of this paper was to conduct a qualitative study that examined how Black American male football players engage and cope with negative stereotypes at a predominantly White institution. Data were collected and analyzed from semi-structured interviews…

  1. Who Is Whistling Vivaldi? How Black Football Players Engage with Stereotype Threats in College

    Science.gov (United States)

    Griffin, Whitney

    2017-01-01

    In light of the impact of negative stereotypes on student-athlete academic performance, the purpose of this paper was to conduct a qualitative study that examined how Black American male football players engage and cope with negative stereotypes at a predominantly White institution. Data were collected and analyzed from semi-structured interviews…

  2. Perceived Musculoskeletal Discomfort among Elementary, Middle, and High School String Players

    Science.gov (United States)

    Russell, Joshua A.; Benedetto, Rachel L.

    2014-01-01

    The purposes of this study were to identify the body regions where young string players report experiencing musculoskeletal discomfort and explore factors that may impact their perceived discomfort. A purposive yet nonprobability sample of elementary (n = 101), middle school (n = 97), and high school (n = 159) students participated in the study by…

  3. Limiting Performance of Helmets for the Prevention of Head Injury

    Directory of Open Access Journals (Sweden)

    Z.Q. Cheng

    1999-01-01

    Full Text Available This is a study of the theoretical optimal (limiting performance of helmets for the prevention of head injury. A rigid head injury model and a two-mass translational head injury model are employed. Several head injury criteria are utilized, including head acceleration, the head injury criterion (HIC, the energy imparted to the brain which is related to brain injury, and the power developed in the skull that is associated with skull fracture. A helmeted head hitting a rigid surface and a helmeted head hit by a moving object such as a ball are considered. The optimal characteristics of helmets and the impact responses of the helmeted head are investigated computationally. An experiment is conducted on an ensemble of bicycle helmets. Computational results are compared with the experimental results.

  4. Chryse 'Alien Head'

    Science.gov (United States)

    2005-01-01

    26 January 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an impact crater in Chryse Planitia, not too far from the Viking 1 lander site, that to seems to resemble a bug-eyed head. The two odd depressions at the north end of the crater (the 'eyes') may have formed by wind or water erosion. This region has been modified by both processes, with water action occurring in the distant past via floods that poured across western Chryse Planitia from Maja Valles, and wind action common occurrence in more recent history. This crater is located near 22.5oN, 47.9oW. The 150 meter scale bar is about 164 yards long. Sunlight illuminates the scene from the left/lower left.

  5. Concussions and Head Injuries in English Community Rugby Union Match Play.

    Science.gov (United States)

    Roberts, Simon P; Trewartha, Grant; England, Michael; Goodison, William; Stokes, Keith A

    2017-02-01

    Previous research has described general injury patterns in community-level rugby union, but specific information on time-loss head injuries has not been reported. To establish the incidence and nature of significant time-loss head injuries in English community rugby match play, and to identify the injury risk for specific contact events. Descriptive epidemiology study. Over 6 seasons, injury information was collected from 46 (2009-2010), 67 (2010-2011), 76 (2011-2012), 50 (2012-2013), 67 (2013-2014), and 58 (2014-2015) English community rugby clubs (Rugby Football Union levels 3-9) over a total of 175,940 hours of player match exposure. Club injury management staff reported information for all head injuries sustained during match play whereby the player was absent for 8 days or greater. Clubs were subdivided into semiprofessional (mean player age, 24.6 ± 4.7 years), amateur (24.9 ± 5.1 years), and recreational (25.6 ± 6.1 years) playing levels. Contact events from a sample of 30 matches filmed over seasons 2009-2010, 2010-2011, and 2011-2012 provided mean values for the frequency of contact events. The overall incidence for time-loss head injuries was 2.43 injuries per 1000 player match hours, with a higher incidence for the amateur (2.78; 95% CI, 2.37-3.20) compared with recreational (2.20; 95% CI, 1.86-2.53) ( P = .032) playing level but not different to the semiprofessional (2.31; 95% CI, 1.83-2.79) playing level. Concussion was the most common time-loss head injury, with 1.46 per 1000 player match hours. The tackle event was associated with 64% of all head injuries and 74% of all concussions. There was also a higher risk of injuries per tackle (0.33 per 1000 events; 95% CI, 0.30-0.37) compared with all other contact events. Concussion was the most common head injury diagnosis, although it is likely that this injury was underreported. Continuing education programs for medical staff and players are essential for the improved identification and management of

  6. Morphology of young handball players

    Directory of Open Access Journals (Sweden)

    Adair da Silva Lopes

    2007-06-01

    Full Text Available The purpose of this study was to compare anthropometric and body composition variables from the best male handball athletes competing in the Santa Catarina state youth competition to variables from the other athletes in the same competition, by game position. Seven of the twelve coaches participating in the Santa Catarina Open Youth Games 2004 (up to 18 years freely consented to select the seven best athletes in the competition (one goalkeeper, one pivot, two wingers and three backcourt players. In addition to these seven players, there were a further 79 team members taking part, bringing the total sample size to 86 athletes. The following variables were analyzed: body weight (MC, height (ES, arm span (ENV, hand breadth (DPA, wrist breadth (DRU, forearm circumference (PA, percentage fat (%G, fat mass (MG and lean body mass (MCM. Descriptive statistics (means and standard deviations were employed to classify the athletes according to court position. The chosen athletes were compared with the others using the single-sample t test (p RESUMO Este estudo objetivou comparar variáveis antropométricas e da composição corporal dos melhores atletas de uma competição juvenil (até 18 anos de handebol masculino de Santa Catarina, em relação aos demais atletas da competição por posição de jogo. Sete dentre os doze técnicos participantes dos Joguinhos Abertos de Santa Catarina 2004 aceitaram, voluntariamente, realizar a escolha da seleção dos sete melhores atletas da competição (um goleiro, um pivô, dois extremas e três armadores. Contabilizou-se, além dos sete atletas da seleção, mais 79 atletas titulares de suas equipes, totalizando na amostra, 86 atletas. Foram analisadas as variáveis: massa corporal (MC, estatura (ES, percentual de gordura (%G, massa de gordura (MG, massa corporal magra (MCM, envergadura (ENV, diâmetro palmar (DPA, diâmetro biestilóide rádio-ulnar (DRU e perímetro do antebraço (PA. Utilizou-se a estat

  7. Sports injuries in Plus League volleyball players.

    Science.gov (United States)

    Cieśla, E; Dutkiewicz, R; Mgłosiek, M; Nowak-Starz, G; Markowska, M; Jasiński, P; Dudek, J

    2015-06-01

    Although physical activity brings a range of lifelong health benefits, it may also lead to injuries that pose a significant threat to health. It is particularly noticeable in people involved in professional sports where sport-related injuries commonly occur and are associated with intense exercise which aims to improve physical fitness. The article attempts to determine incidence of sports injuries reported by Plus League volleyball players, as well as to identify their most common types and causes. The research project involved 90 Plus League volleyball players aged 18-37 with the average age of 25.11 (SD±5.378). A method of diagnostic survey was applied to collect empirical data by means of questionnaire developed by the authors (researchers). The results were statistically analysed and verified with the analysis of variance (ANOVA) and χ2 test at the significance level (or critical P-value) of P≤0.05. Over 87% of the respondents suffered from at least one sport-related injury. In total, 362 injuries occurred, on average 4.02 injuries per one volleyball player. The most common sports injuries involved ankle or talocrural joint (46 injuries), knee and lower leg muscles (30), interphalangeal articulations of fingers (30) as well as shoulder joint. More than half of the injuries (57%) occurred twice or three times. Volleyball players commonly sustain injuries through contact with an opposing player in competition. Sport-specific injuries may also occur due to exhaustion, lack of rest and undertreated injuries. The most common volleyball-related injuries are primarily talocrural joint, hand and shoulder injuries. Common types of injuries that can affect volleyball players include muscles, joints and ligaments injuries, sprains and strains as well as bruises. Most of these injuries are caused by exhaustion, contact with an opposing player during competition and fatigue. The incidence of sport-related injuries seems to be influenced by such factors as somatic

  8. Strength of the Shoulder Rotators in Second-League Volleyball Players

    Directory of Open Access Journals (Sweden)

    Popieluch Aneta

    2015-12-01

    Full Text Available Introduction. The main aim of the study was to assess the strength of the shoulder rotator muscles of a group of second-league volleyball players. These muscles are assumed to have a crucial impact on attack effectiveness in volleyball. Strength was assessed based on peak torque values obtained for the rotator muscles measured using the maximal voluntary contraction (MVC method. Torque was measured in both limbs and the differences between the two limbs were examined. The torque values obtained for the volleyball players were also compared against those measured in a group of students who had never trained any sports.

  9. Comparison of posture among adolescent male volleyball players and non-athletes

    OpenAIRE

    Grabara, M

    2014-01-01

    Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. T...

  10. Bone properties in child and adolescent male hockey and soccer players.

    Science.gov (United States)

    Falk, Bareket; Braid, Sarah; Moore, Michael; Yao, Matthew; Sullivan, Phil; Klentrou, Nota

    2010-07-01

    Children and adolescents who train extensively in high-impact, weight-bearing activities have enhanced bone mineral density. The purpose of this study was to evaluate bone strength, as reflected by quantitative ultrasound (QUS, Sunlight Omniscence), of child (10-12 yrs old) and adolescent (14-16 yrs old) male soccer and hockey players in comparison with age-matched controls. The groups included 30 child (CH) and 31 adolescent (AH) hockey players, 26 child (CS) and 30 adolescent (AS) soccer players, as well as 34 child (CC) and 31 adolescent (AC) healthy, non-athletic, age-matched controls. All athletes trained at an elite level year-round, with no difference in training volume between groups. Ultrasound speed of sound (SOS) was measured at the distal-radius and mid-tibia. In both age groups, hockey players were the heaviest and had the highest fat-free mass. No differences were found among groups in total energy intake, calcium or vitamin D intake. Radial and tibial SOS increased with age. Hockey players had higher radial SOS in both age groups (children: CH:3763+/-74, CS:3736+/-77, CC:3721+/-88 m/s; adolescents: AH:3809+/-105, AS:3767+/-85, AC:3760+/-94 m/s). Tibial SOS was higher in soccer players compared with controls. In spite of the higher body mass and fat-free mass in hockey players, their tibial SOS was similar to the non-athletes in both age groups. These findings support previous suggestions of sport-specific effects on bone strength. However, they need to be corroborated with longitudinal or prospective intervention studies.

  11. Broadened population-level frequency tuning in human auditory cortex of portable music player users.

    Directory of Open Access Journals (Sweden)

    Hidehiko Okamoto

    Full Text Available Nowadays, many people use portable players to enrich their daily life with enjoyable music. However, in noisy environments, the player volume is often set to extremely high levels in order to drown out the intense ambient noise and satisfy the appetite for music. Extensive and inappropriate usage of portable music players might cause subtle damages in the auditory system, which are not behaviorally detectable in an early stage of the hearing impairment progress. Here, by means of magnetoencephalography, we objectively examined detrimental effects of portable music player misusage on the population-level frequency tuning in the human auditory cortex. We compared two groups of young people: one group had listened to music with portable music players intensively for a long period of time, while the other group had not. Both groups performed equally and normally in standard audiological examinations (pure tone audiogram, speech test, and hearing-in-noise test. However, the objective magnetoencephalographic data demonstrated that the population-level frequency tuning in the auditory cortex of the portable music player users was significantly broadened compared to the non-users, when attention was distracted from the auditory modality; this group difference vanished when attention was directed to the auditory modality. Our conclusion is that extensive and inadequate usage of portable music players could cause subtle damages, which standard behavioral audiometric measures fail to detect in an early stage. However, these damages could lead to future irreversible hearing disorders, which would have a huge negative impact on the quality of life of those affected, and the society as a whole.

  12. The Impact Of Oral Vitamin E In Preventing Mucositis (Bucal Mucous Inflammation Resulting From The Radiotherapy In Tumors Of Head And Neck

    Directory of Open Access Journals (Sweden)

    Bahador M

    2004-07-01

    Full Text Available Background: Mucositis [bucal Mucous inflamation] is the most common complication resulting from the radiotherapy in tumors of head and neck. These malignancies are often curable through radiotherapy. This complication, however, may impair the treatment process and cause malnutrition. So far no medicine has been Known to prevent this complication. Vitamin E is a stabilizer of cell membrane and is also used in mucositis treatment. The survey of oral vitamin E effect on mucositis prophylaxis in radiotherapy of head and neck malignancies. Materials and Methods: Seventy patients afflicted with head and neck malignancies referring to Imam Khomeini Hospital were randomly divided into 2groups, two of whom died during treatment process. The first group (The case group consisting of 34 patients Consumed oral vitamin E 200 mg daily for seven days. The second group (The control group did not use any medicine at all. The two group underwent radiotherapy. They were compared and contrasted as to mucositis severity and dysphagia during treatment. Results: In the first group, since the fourth week up to the end of the treatment, there was a lower frequency and grade of mucositis in contrast with the control group. In the fourth week, the grade two mucositis in the first group (Case group was 20.6% and 47.5% in the control group the difference was statistically significant (P=0.024. There was also a lower frequency and grade of dysphagia in the case group since the fourth week versus the control group. In the fourth week, moderate dysphagia was 29.4% in the case group and 55.9% in the control group. The difference was statistically significant (P=0.023. Conclusion: Oral vitamin E has Proved to be effective in the Prophylaxis of Moderate and severe mucositis and dysphagia resulting from radiotherapy. It is advisable to conduct more research with more cases, lengthier duration and heavier doses.

  13. Impact of intraocular pressure on changes of blood flow in the retina, choroid, and optic nerve head in rats investigated by optical microangiography

    OpenAIRE

    Zhi, Zhongwei; Cepurna, William O.; Johnson, Elaine C.; Morrison, John C.; Wang, Ruikang K.

    2012-01-01

    In this paper, we demonstrate the use of optical coherence tomography/optical microangiography (OCT/OMAG) to image and measure the effects of acute intraocular pressure (IOP) elevation on retinal, choroidal and optic nerve head (ONH) perfusion in the rat eye. In the experiments, IOP was elevated from 10 to 100 mmHg in 10 mmHg increments. At each IOP level, three-dimensional data volumes were captured using an ultrahigh sensitive (UHS) OMAG scanning protocol for 3D volumetric perfusion imaging...

  14. Mechanisms for triceps surae injury in high performance front row rugby union players: a kinematic analysis of scrummaging drills.

    Science.gov (United States)

    Flavell, Carol A; Sayers, Mark G L; Gordon, Susan J; Lee, James B

    2013-01-01

    The front row of a rugby union scrum consists of three players. The loose head prop, hooker and tight head prop. The objective of this study was to determine if known biomechanical risk factors for triceps surae muscle injury are exhibited in the lower limb of front row players during contested scrummaging. Eleven high performance front row rugby union players were landmarked bilaterally at the posterior superior iliac spine (PSIS), greater trochanter, lateral femoral epicondyle, midline of the calcaneus above the plantar aspect of the heel, midline lower leg 5cm and 20cm proximal to the lateral malleolus, at the axis of subtalar joint, lateral malleolus, and head of the fifth metatarsal. Players were video recorded during a series of 2 on 1 live scrummaging drills. Biomechanical three dimensional analysis identified large angular displacements, and increased peak velocities and accelerations at the ankle joint during attacking scrummaging drill techniques when in the stance phase of gait. This places the triceps surae as increased risk of injury and provides valuable information for training staff regarding injury prevention and scrum training practices for front row players. Key pointsFront rowers exhibited patterns of single leg weight bearing, in a position of greater ankle plantar flexion and knee extension at toe off during scrummaging, which is a risk position for TS injury.Front rowers also exhibited greater acceleration at the ankle, knee, and hip joints, and greater changes in ankle ROM from toe strike to toe off during attacking scrum drills.These reported accelerations and joint displacements may be risk factors for TS injury, as the ankle is accelerating into plantar flexion at final push off and the muscle is shortening from an elongated state.

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  16. Do media players cause interference with pacemakers?

    Science.gov (United States)

    Thaker, Jay P; Patel, Mehul B; Shah, Ashok J; Liepa, Valdis V; Brunett, Joseph D; Jongnarangsin, Krit; Gardiner, Joseph C; Thakur, Ranjan

    2009-11-01

    Electrical devices generate electromagnetic fields that may interfere with pacemakers. Media players cause telemetry interference with pacemakers, but it is not known whether they cause direct interference with pacemakers. The purpose of this study was to examine the interaction between pacemakers and 3 different media players. In this prospective, randomized study, 54 patients with dual chamber pacemakers who were in sinus rhythm underwent baseline observation, followed by observation under telemetry communication. These patients were then randomly evaluated with 3 media players (iPod 3G, iPod Photo, and iPod Touch Apple, Cupertino, CA) with and without telemetry communication for 1 minute each. Patients were monitored for pacemaker malfunction using a single-channel ECG during exposure to media players. The pacemaker was interrogated after each exposure and an interrogation report was printed for evaluation. Pacemaker interference was categorized as type I, II, or III. Types I and II interference described telemetry interference and type III interference was defined as any direct interference with pacemaker function or programmed parameters. A total of 54 patients (29 men and 25 women; mean age 77.2 +/- 9.3 y) were evaluated. In total, of the 162 tests (for telemetry interference) 36.4% were positive (Type I and II). Type III interference was also evaluated in 162 tests and none showed any evidence of direct interference. Media players cause telemetry interference with pacemakers, but they do not directly interfere with pacemaker function.

  17. Game Performance Evaluation in Male Goalball Players

    Directory of Open Access Journals (Sweden)

    Molik Bartosz

    2015-12-01

    Full Text Available Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg, body height (cm, the arm span (cm and length of the body in the defensive position (cm. The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03 and the sum of good defense (p = 0.04. The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04, the sum of penalty defenses (p = 0.01, and fouls (p = 0.01. The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level.

  18. Practice effects reveal visuomotor vulnerability in school and university rugby players.

    Science.gov (United States)

    Shuttleworth-Edwards, Ann B; Radloff, Sarah E; Whitefield-Alexander, Victoria J; Smith, Ian P; Horsman, Mark

    2014-02-01

    This article reports on three pre- versus post-season prospective studies in which male university and high school contact sport players predominantly of Rugby Union (hereafter rugby) were compared with age, education, and IQ equivalent non-contact sport controls on the ImPACT (Immediate Postconcussion Assessment and Cognitive Testing) test. All analyses revealed a relative absence of practice effects on the Visual Motor Speed (VMS) composite for contact sport groups compared with controls. The VMS data for rugby players from each study were pooled and subjected to additional analysis (Rugby, n = 145; Controls, n = 106). Controls revealed significant improvement over the season (p rugby players whose performance remained the same (interaction effect, p = .028). It is apparent that practice effects have diagnostic potential in this context, implicating vulnerability on speeded visuomotor processing in association with participation in rugby. Pointers for further research and concussion management in the individual case are explored.

  19. Reverse breech extraction versus the standard approach of pushing the impacted fetal head up through the vagina in caesarean section for obstructed labour: A randomised controlled trial.

    Science.gov (United States)

    Nooh, Ahmed Mohamed; Abdeldayem, Hussein Mohammed; Ben-Affan, Othman

    2017-01-31

    The objective of this study was to assess effectiveness and safety of the reverse breech extraction approach in Caesarean section for obstructed labour, and compare it with the standard approach of pushing the fetal head up through the vagina. This randomised controlled trial included 192 women. In 96, the baby was delivered by the 'reverse breech extraction approach', and in the remaining 96, by the 'standard approach'. Extension of uterine incision occurred in 18 participants (18.8%) in the reverse breech extraction approach group, and 46 (47.9%) in the standard approach group (p = .0003). Two women (2.1%) in the reverse breech extraction approach group needed blood transfusion and 11 (11.5%) in the standard approach group (p = .012). Pyrexia developed in 3 participants (3.1%) in the reverse breech extraction approach group, and 19 (19.8%) in the standard approach group (p = .0006). Wound infection occurred in 2 women (2.1%) in the reverse breech extraction approach group, and 12 (12.5%) in the standard approach group (p = .007). Apgar score extraction approach group, and 21 (21.9%) in the standard approach group (p = .015). In conclusion, reverse breech extraction in Caesarean section for obstructed labour is an effective and safe alternative to the standard approach of pushing the fetal head up through the vagina.

  20. Predictors of perceptions of mental illness and averseness to help: a survey of elite football players.

    Science.gov (United States)

    Jones, Tiffanie-Victoria

    2016-10-01

    Hypermasculinity may impact elite football players' willingness to seek help for mental health problems. This quantitative study sought to identify what set of characteristics, including hypermasculinity, best predicts elite football players' mental health attitudes. The Attitude Scale for Mental Illness, Inventory of Attitudes toward Seeking Mental Health Services, and Athlete's Perception of Masculinity Scale were self-administered to 112 football players from the NFLPA and the Washington, DC metro area. Canonical correlation analysis was used to develop a regression model that best predicts elite football players' mental health attitudes. This study found that though the athletes have high levels of hypermasculinity (x = 19.66, SD = 7.43), other factors, including marital status and sport level lessen the effects of hypermasculinity and facilitate positive perceptions of mental illness and receptivity to help. Predictors suggest that therapeutic efforts targeted toward family and support networks, as well as intervention strategies for decreasing mental illness stigma are essential to encourage positive mental health attitudes in elite football players.

  1. Everyday music listening and affect regulation: The role of MP3 players

    Directory of Open Access Journals (Sweden)

    Marie Strand Skånland

    2013-08-01

    Full Text Available The use of digital portable music devices such as MP3 players has rapidly increased during the last decade, and the sheer availability of music offered by such players raises questions about their impact on listeners’ mental and physical health and well-being. This article explores MP3 player use as an everyday tactic for affect regulation, here understood as an individual's efforts to maintain or change the intensity or duration of a given affect. The ability to understand and regulate affects has significant health implications, and among the tactics relevant to such regulation, engagement with music has proven to be particularly successful. The material presented in this article is based on a qualitative interview study focused on MP3 player use as a medium for musical self-care. Because MP3 users can listen to whatever they want, whenever they want, and target their music in the interests of managing and regulating moods and emotions, the MP3 player represents a valuable and convenient technology of affect regulation.

  2. Nutrient Intake and Food Habits of Soccer Players: Analyzing the Correlates of Eating Practice

    Directory of Open Access Journals (Sweden)

    Pablo M. García-Rovés

    2014-07-01

    Full Text Available Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player’s career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.

  3. Pilot study of female high school basketball players' anterior cruciate ligament injury knowledge, attitudes, and practices.

    Science.gov (United States)

    Iversen, M D; Friden, C

    2009-08-01

    An anterior cruciate ligament (ACL) injury prevention program was evaluated. One hundred and thirteen female high school varsity and junior varsity basketball players and 12 coaches participated in an 8-week educational and skills program. Demographic and injury history data were collected. At pre-intervention and at the end of season, knowledge, attitudes, and practices about ACL risk and injury prevention were assessed via questionnaires, and frequency of two-footed landings were videotaped during games. Univariate statistics described the sample. Paired t-tests evaluated the program's impact. Cronbach's alpha, correlations, and kappa statistics assessed the validity and reliability of questionnaires and video analysis. Of the 113 players, 74 completed the study. The players' mean age was 16.25 years (SD=1.07; range=14.2-18.8). Baseline knowledge score was 57.2%, practice 58.4%, and attitude 73.5%. The mean baseline knowledge score of the 12 coaches (mean age=40.8 years; SD=10.3; range=26.9-56.3) was 68.7%. Players' knowledge about ACL injury prevention improved (t=2.57; Pinjury prevention were found (t(diff)=1.88; PACL injury risk and improved player's landing skills.

  4. An Analysis of Creative Process Learning in Computer Game Activities Through Player Experiences

    Directory of Open Access Journals (Sweden)

    Wilawan Inchamnan

    2016-09-01

    Full Text Available This research investigates the extent to which creative processes can be fostered through computer gaming. It focuses on creative components in games that have been specifically designed for educational purposes: Digital Game Based Learning (DGBL. A behavior analysis for measuring the creative potential of computer game activities and learning outcomes is described. Creative components were measured by examining task motivation and domain-relevant and creativity-relevant skill factors. The research approach applied heuristic checklists in the field of gameplay to analyze the stage of player activities involved in the performance of the task and to examine player experiences with the Player Experience of Need Satisfaction (PENS survey. Player experiences were influenced by competency, autonomy, intuitive controls, relatedness and presence. This study examines the impact of these activities on the player experience for evaluating learning outcomes through school records. The study is designed to better understand the creative potential of people who are engaged in learning knowledge and skills during the course while playing video games. The findings show the creative potential that occurred to yield levels of creative performance within game play activities to support learning. The anticipated outcome is knowledge on how video games foster creative thinking as an overview of the Creative Potential of Learning Model (CPLN. CPLN clearly describes the interrelationships between principles of learning and creative potential, the interpretation of the results is indispensable.

  5. Everyday music listening and affect regulation: the role of MP3 players.

    Science.gov (United States)

    Skånland, Marie Strand

    2013-08-07

    The use of digital portable music devices such as MP3 players has rapidly increased during the last decade, and the sheer availability of music offered by such players raises questions about their impact on listeners' mental and physical health and well-being. This article explores MP3 player use as an everyday tactic for affect regulation, here understood as an individual's efforts to maintain or change the intensity or duration of a given affect. The ability to understand and regulate affects has significant health implications, and among the tactics relevant to such regulation, engagement with music has proven to be particularly successful. The material presented in this article is based on a qualitative interview study focused on MP3 player use as a medium for musical self-care. Because MP3 users can listen to whatever they want, whenever they want, and target their music in the interests of managing and regulating moods and emotions, the MP3 player represents a valuable and convenient technology of affect regulation.

  6. Motivation and Sport Injuries in Handball Players

    Directory of Open Access Journals (Sweden)

    Laguna, María

    2010-12-01

    Full Text Available The aim of the study was to test whether different levels of motivation are related to the injuries suffered by elite athletes. The sample consists of 80 professional handball players of ASOBAL League, with a mean age of 24.83 years (+ 5.21. Motivation was assessed through the CPRD scale (Gimeno, Buceta & Pérez-Llantada; 1999 and a self-report questionnaire was used to register sports injuries. The results indicate that there is a relationship between motivational levels and the risk for injury. Specifically, players with high motivated players had a greater number of moderate injuries. Although it may seem paradoxical, it is possible that an excessively high motivation leads to overachievement and risk behaviors, which in turn facilitate the appearance of lesions.

  7. Cricket club looking for new players

    CERN Multimedia

    Cricket Club

    2016-01-01

    The CERN Cricket Club, having lost several key players, has had a very difficult season so far and is desperately in need of new players. Having qualified for the Cricket Switzerland semi-finals for the last two years (unfortunately losing both), this year we are bottom of the Western Pool, having played the last two league matches with only 10 players. If you are interested in playing cricket please join us at net practice, which takes place on the Prevessin site each Thursday evening from 18:00 to around 20:00 (weather permitting) or send me an e-mail (see below). Please have a look at the Cricket Club web site for more information: http://cern.ch/Club-Cricket/ Chris Onions, President of the CERN Cricket Club   (christopher.onions@gmail.com)

  8. Big Data for Business Ecosystem Players

    Directory of Open Access Journals (Sweden)

    Perko Igor

    2016-06-01

    Full Text Available In the provided research, some of the Big Data most prospective usage domains connect with distinguished player groups found in the business ecosystem. Literature analysis is used to identify the state of the art of Big Data related research in the major domains of its use-namely, individual marketing, health treatment, work opportunities, financial services, and security enforcement. System theory was used to identify business ecosystem major player types disrupted by Big Data: individuals, small and mid-sized enterprises, large organizations, information providers, and regulators. Relationships between the domains and players were explained through new Big Data opportunities and threats and by players’ responsive strategies. System dynamics was used to visualize relationships in the provided model.

  9. Adapting virtual camera behaviour through player modelling

    DEFF Research Database (Denmark)

    Burelli, Paolo; Yannakakis, Georgios N.

    2015-01-01

    Research in virtual camera control has focused primarily on finding methods to allow designers to place cameras effectively and efficiently in dynamic and unpredictable environments, and to generate complex and dynamic plans for cinematography in virtual environments. In this article, we propose...... a novel approach to virtual camera control, which builds upon camera control and player modelling to provide the user with an adaptive point-of-view. To achieve this goal, we propose a methodology to model the player’s preferences on virtual camera movements and we employ the resulting models to tailor...... the viewpoint movements to the player type and her game-play style. Ultimately, the methodology is applied to a 3D platform game and is evaluated through a controlled experiment; the results suggest that the resulting adaptive cinematographic experience is favoured by some player types and it can generate...

  10. Mean Field Games with a Dominating Player

    Energy Technology Data Exchange (ETDEWEB)

    Bensoussan, A., E-mail: axb046100@utdallas.edu [The University of Texas at Dallas, International Center for Decision and Risk Analysis, Jindal School of Management (United States); Chau, M. H. M., E-mail: michaelchaumanho@gmail.com; Yam, S. C. P., E-mail: scpyam@sta.cuhk.edu.hk [The Chinese University of Hong Kong, Department of Statistics (Hong Kong, People’s Republic of China) (China)

    2016-08-15

    In this article, we consider mean field games between a dominating player and a group of representative agents, each of which acts similarly and also interacts with each other through a mean field term being substantially influenced by the dominating player. We first provide the general theory and discuss the necessary condition for the optimal controls and equilibrium condition by adopting adjoint equation approach. We then present a special case in the context of linear-quadratic framework, in which a necessary and sufficient condition can be asserted by stochastic maximum principle; we finally establish the sufficient condition that guarantees the unique existence of the equilibrium control. The proof of the convergence result of finite player game to mean field counterpart is provided in Appendix.

  11. There is no game without a player

    DEFF Research Database (Denmark)

    Larsen, Lasse Juel

    on the subject matter from the catalogue of game theory. All four suggestions exclude the player from the relationship. This paper introduces a phenomenological point of view and includes the player in order to understand the relationship between structure and dressing. It argues that players constitute a bridge......This paper is a search for meaning or to be more precise a study of how meaning is produced between ontology and fiction in computer games. It sets out to investigate the relationship between formal abstract game structures and game representation (dressing) by presenting four suggestions...... or the center which establishes, upholds and renegotiate the relationship between formal game structure and game dressing. It also argues that players’ interaction with both structure and dressing produce meaning and the production of meaning is the relationship between formal abstract game structures and game...

  12. Modelling Virtual Camera Behaviour Through Player Gaze

    DEFF Research Database (Denmark)

    Picardi, Andrea; Burelli, Paolo; Yannakakis, Georgios N.

    2012-01-01

    In a three-dimensional virtual environment, aspects such as narrative and interaction largely depend on the placement and animation of the virtual camera. Therefore, virtual camera control plays a critical role in player experience and, thereby, in the overall quality of a computer game. Both game...... industry and game AI research focus on the devel- opment of increasingly sophisticated systems to automate the control of the virtual camera integrating artificial intel- ligence algorithms within physical simulations. However, in both industry and academia little research has been carried out...... on the relationship between virtual camera, game-play and player behaviour. We run a game user experiment to shed some light on this relationship and identify relevant dif- ferences between camera behaviours through different game sessions, playing behaviours and player gaze patterns. Re- sults show that users can...

  13. Individual recovery profiles in basketball players.

    Science.gov (United States)

    Moreno, Jordi; Ramos-Castro, Juan; Rodas, Gil; Tarragó, Joan R; Capdevila, Lluís

    2015-01-01

    In the sport context, recovery has been characterized as a multifactor process (physiological, psychological, behavioral, social, etc.). This study takes a multidisciplinary approach to find psychophysiological markers of the stress-recovery process. It aims to determine how athletes' specific recovery actions relate to their perceptions of recovery, and Heart Rate Variability (HRV). A total of 196 assessments were analyzed from 6 players on a men's professional basketball team within the Liga LEB Oro basketball federation (2012/2013 season). Perceptions of recovery, recovery strategies, and HRV were recorded. The results show a pattern of individual differences in behavior related to athletes' recovery actions and HRV profiles throughout the season (p < .05). Moreover, we observed that each player had different recovery needs. In light of these results, we suggest an individualistic approach to evaluating and monitoring recovery to attend more accurately to each player's recovery needs.

  14. BODY POSTURES AND ASYMMETRIES IN FRONTAL AND TRANSVERSE PLANES IN THE TRUNK AREA IN TABLE TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Katarzyna Barczyk-Pawelec

    2012-04-01

    Full Text Available The aim of this research was to assess the body posture within the trunk area in table tennis players and to estimate the correlations between the specific body posture types, their asymmetries and table tennis practice (training experience. To evaluate body posture the photogrammetric method based on the Moiré phenomenon with equipment by CQ Electronic was applied. Tests of significance of difference and correlation were used to estimate the correlation of the observed asymmetries with the training experience. 40 table tennis players and 43 subjects not practising sports participated in the research. The analysis of the results revealed that table tennis players, unlike non-players, are characterized by kyphotic body posture. It probably results from a specific trunk, head and limb position during table tennis matches. Thus, many asymmetries in frontal and transverse planes were observed in the examined table tennis players. Perhaps table tennis, which is characterized by intensive and one-sided trunk muscle work during its performance, is in favour of creating asymmetries. The majority of subjects did not reveal any statistically significant correlations between the observed body posture types, their asymmetries and training experience. However, it was observed that training experience is significantly related to the considerable asymmetry of the inclination angle of shoulder line (KLB. It may result from the negative influence of very intensive, one-sided work and constant work of the shoulder girdle muscles of the playing limb with negligence of exercises of the second limb.

  15. Making a Difference in the Lives of Infants and Toddlers and Their Families: The Impacts of Early Head Start. Volumes I-III: Final Technical Report [and] Appendixes [and] Local Contributions to Understanding the Programs and Their Impacts.

    Science.gov (United States)

    Love, John M.; Kisker, Ellen Eliason; Ross, Christine M.; Schochet, Peter Z.; Brooks-Gunn, Jeanne; Paulsell, Diane; Boller, Kimberly; Constantine, Jill; Vogel, Cheri; Fuligni, Alison Sidle; Brady-Smith, Christy

    Early Head Start was designed in 1994 as a 2-generation program to enhance children's development and health, strengthen family and community partnerships, and support the staff delivering new services to low-income families with pregnant women, infants, or toddlers. This document contains the final technical report, appendixes, and local…

  16. Sleep Hygiene and Recovery Strategies in Elite Soccer Players.

    Science.gov (United States)

    Nédélec, Mathieu; Halson, Shona; Delecroix, Barthélémy; Abaidia, Abd-Elbasset; Ahmaidi, Said; Dupont, Gregory

    2015-11-01

    In elite soccer, players are frequently exposed to various situations and conditions that can interfere with sleep (e.g., playing night matches interspersed with 3 days; performing activities demanding high levels of concentration close to bedtime; use of products containing caffeine or alcohol in the period preceding bedtime; regular daytime napping throughout the week; variable wake-up times or bedtime), potentially leading to sleep deprivation. We outline simple, practical, and pharmaceutical-free sleep strategies that are coordinated to the constraints of elite soccer in order to promote sleep. Sleep deprivation is best alleviated by sleep extension; however, sleep hygiene strategies (i.e., consistent sleep pattern, appropriate napping, and active daytime behaviors) can be utilized to promote restorative sleep. Light has a profound impact on sleep, and sleep hygiene strategies that support the natural environmental light-dark cycle (i.e., red-light treatment prior to sleep, dawn-simulation therapy prior to waking) and prevent cycle disruption (i.e., filtering short wavelengths prior to sleep) may be beneficial to elite soccer players. Under conditions of inordinate stress, techniques such as brainwave entrainment and meditation are promising sleep-promoting strategies, but future studies are required to ascertain the applicability of these techniques to elite soccer players. Consuming high-electrolyte fluids such as milk, high-glycemic index carbohydrates, some forms of protein immediately prior to sleep, as well as tart cherry juice concentrate and tryptophan may promote rehydration, substrate stores replenishment, muscle-damage repair and/or restorative sleep. The influence of cold water immersion performed close to bedtime on subsequent sleep is still debated. Conversely, the potential detrimental effects of sleeping medication must be recognized. Sleep initiation is influenced by numerous factors, reinforcing the need for future research to identify such