Longitudinal Study of Individual Exercises in Elite Rhythmic Gymnastics

The performance evolution in rhythmic gymnastics depends on changes in code of points. At the beginning of each Olympic cycle the code of points changes and therefore, the content of the competition exercises, as well. This study aimed to analyze - for each apparatus - the evolution of number of technical elements and final score over the last two decades (last 13 world championships), how they have been affected by changed code of points, and how the final score relates to the number of technical elements performed. The sample consisted of 416 exercises in five apparatus: ball (96), rope (40), hoop (96), ribbon (88), and clubs (96). The following variables were gathered: code of points, apparatus, technical group, total number of elements, final classification, and final score. Linear mixed-effects models were used to examine the effects on the number of elements and final score in each apparatus. The number of technical elements increased in all apparatus, between 7.4 and 20% over a 10-year period. There were mixed evolutions of final score between the different apparatus, between -6.3 and 14% over a 10-year period. There is small increase in number of elements in hoop and a small decrease in rope after a code change. There was a small decrease in final score in championships after a code change in hoop, moderate in clubs and ribbon, and large in rope. There was a negative relationship between number of elements performed and final score in clubs. In conclusion, the code change generally effects the final score negatively, but there were apparatus specific effects of code change on number of elements and relationship between number of elements and final score.

Effect of Penalty Minute Rule Change on Injuries and Game Disqualification Penalties in High School Ice Hockey

BACKGROUND

Recent efforts have focused on eliminating dangerous hits in ice hockey. Fair play rule changes have successfully reduced injury risk but have not been widely implemented.

PURPOSE

To determine the effect of a penalty infraction minutes (PIM) rule change in high school boys' ice hockey on injuries and game disqualification penalties.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Injury data were collected from 2 Rhode Island hospital systems and game/penalty data through the Rhode Island Hockey Coaches Association website. Participants included high school boys' hockey varsity players aged 13 to 19 years presenting to 5 emergency departments for hockey injuries during 6 seasons (December 2012-April 2018). Rule change for the 2015-2016 season implemented varying suspensions for players accumulating ≥50 PIM and ≥70 PIM during regular season and playoffs. Injuries were classified as body checking or non-body checking related, and injury rates pre- versus post-rule change were compared via the Cochran-Mantel-Haenszel chi-square test with the odds ratio (OR) to measure risk reduction.

RESULTS

During the study period, 1762 boys' high school varsity hockey games were played. Of 134 game-related injuries, 82 (61.2%) were attributable to body checking. The PIM rule change was associated with a significant reduction in all injuries (OR, 0.55; 95% CI, 0.35-0.86; P = .008), concussion/closed head injury (OR, 0.44; 95% CI, 0.23-0.85; P = .012), and combined subgroups of concussion/closed head injury and upper body injury (OR, 0.50; 95% CI, 0.31-0.80; P = .003). Game disqualification penalties per season were not significantly reduced following the rule change, occurring in 5.2% of games before the rule change and 4.4% of games after (OR, 0.84; 95% CI, 0.54-1.31; P = .440).

CONCLUSION

Implementation of a statewide PIM restriction rule change effectively reduced the mean number of game-related injuries per season among high school boys' hockey varsity players.

Increasing Lower Extremity Injury Rates Across the 2009-2010 to 2014-2015 Seasons of National Collegiate Athletic Association Football: An Unintended Consequence of the "Targeting" Rule Used to Prevent Concussions?

BACKGROUND

Sports-related concussions (SRCs) have gained increased societal interest in the past decade. The National Collegiate Athletic Association (NCAA) has implemented legislation and rule changes to decrease the incidence and risk of head injury impacts. The "targeting" rule forbids initiating contact with the crown of a helmet and targeting defenseless players in the head and neck area; however, there are concerns that this rule change has unintentionally led to an increased incidence of lower extremity injuries.

PURPOSE/HYPOTHESIS

The purpose of this study was to evaluate the change in lower extremity injury rates in NCAA football during the 2009-2010 to 2014-2015 seasons. We hypothesized that the lower extremity injury rate has increased across the time period.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Sixty-eight NCAA football programs provided 153 team-seasons of data to the NCAA Injury Surveillance Program. Lower extremity injuries (ie, hip/groin, upper leg/thigh, knee, lower leg/Achilles, foot/toes) and SRCs sustained during NCAA football games were examined. We calculated injury rates per 1000 athlete-exposures (AEs) for lower extremity injuries and SRCs. Rate ratios (RRs) compared injury rates between the 2009-2010 to 2011-2012 and 2012-2013 to 2014-2015 seasons.

RESULTS

Overall, 2400 lower extremity injuries were reported during the 2009-2010 to 2014-2015 seasons; most were to the knee (33.6%) and ankle (28.5%) and caused by player contact (59.2%). The lower extremity injury rate increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (23.55 vs 20.45/1000 AEs, respectively; RR, 1.15; 95% CI, 1.06-1.25). This finding was retained when restricted to injuries due to player contact (RR, 1.19; 95% CI, 1.07-1.32) but not for injuries due to noncontact/overuse (RR, 0.96; 95% CI, 0.80-1.14). When examining player contact injury rates by anatomic site, only ankle injuries had an increase (RR, 1.36; 95% CI, 1.13-1.64). The SRC rate also increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (3.52 vs 2.63/1000 AEs, respectively; RR, 1.34; 95% CI, 1.08-1.66).

CONCLUSION

The lower extremity injury rate has increased in NCAA football athletes. Similarly, SRC rates have increased, although this may be caused by concurrent policies related to better education, identification, and management. Targeting rule changes may be contributing to increased rates of player contact-related ankle injuries. Alongside continued surveillance research to examine longitudinal time trends, more in-depth individual-level examinations of how targeting rule changes influence coaching and player behaviors are warranted.

Structural Analysis of Women's Heptathlon

The heptathlon comprises the results of seven single disciplines, assuming an equal influence from each discipline, depending on the measured performance. Data analysis was based on the data recorded for the individual performances of the 10 winning heptathletes in the World Athletics Championships from 1987 to 2013 and the Olympic Games from 1988 to 2012. In addition to descriptive analysis methods, correlations, bivariate and multivariate linear regressions, and panel data regressions were used. The transformation of the performances from seconds, centimeters, and meters into points showed that the individual disciplines do not equally affect the overall competition result. The currently valid conversion formula for the run, jump, and throw disciplines prefers the sprint and jump disciplines but penalizes the athletes performing in the 800 m run, javelin throw, and shotput disciplines. Furthermore, 21% to 48% of the variance of the sum of points can be attributed to the performances in the disciplines of long jump, 200 m sprint, 100 m hurdles, and high jump. To balance the effects of the single disciplines in the heptathlon, the formula to calculate points should be reevaluated.