Publications by Year: 2012

2012
Vagenas, G., & Vlachokyriakou, E. (2012). Olympic Medals and Demo-Economic Factors: Novel predictors, the ex-host effect, the exact role of team size, and the "Population-GDP" model revisited. Sport Management Review, (15), 211-217. Publisher's VersionAbstract
The present study revisited the problem of estimating Olympic success by critical demo-economic indicators. The sample consisted of the 75 winner countries at the Athens 2004 Olympic Games (not previously analyzed). Medal totals were log-linearly regressed on land, population, GDP, urban population, inflation, growth rate, unemployment, labor force, health expenditures, ex-host, and team size. Multiple regression assumptions were tested with proper diagnostics including collinearity. Olympic team size was the best single predictors of Olympic medals (R2 = 0.690, p < 0.001), and as an alternative criterion variable was significantly regressed on population, growth rate, health expenditure, and unemployment (R2 = 0.563, p < 0.001). Medal totals were significantly regressed on population, ex-host, health expenditure, growth rate, and unemployment (R2 = 0.541, p < 0.001). The classical population-GDP model extracted only 28% of the variance in total medals (R2 = 0.277, p < 0.001), and this was slightly improved when combined with unemployment (R2 = 0.365, p < 0.001). It appears that the size of the Olympic team plays the role of transmitting the composite impact of a country's size and economy to the end-phase of Olympic success. Winning Olympic medals depends on the combined potential of population, wealth, growth rate, unemployment, ex-host, and social-sport expenditures. Larger and wealthier countries win more medals by “producing” larger Olympic teams as a result of possessing more athletic talents and better support for social and sport related activities.
vagenas_vlachokyriakou_2012_smr.pdf
Fousekis, K., Tsepis, E., & Vagenas, G. (2012). Intrinsic risk factors of non-contact ankle sprains in soccer - A prospective study on 100 professional players. American Journal of Sports Medicine, 40(8), 1842-1850. Publisher's VersionAbstract
Background: Ankle sprain is an extremely common injury in soccer players. Despite extensive research, the intrinsic cause of this injury under noncontact conditions remains unclear. Purpose: To identify intrinsic risk factors for noncontact ankle sprains in professional soccer players. Study Design: Cohort study; Level of evidence, 2. Methods: One hundred professional soccer players were assessed in the preseason for potential risk factors of noncontact ankle. sprains. The assessment included (A) ankle joint asymmetries (right-left) in isokinetic muscle strength, flexibility, proprioception. and stability; (B) somatometric asymmetries; (C) previous injuries; and (D) lateral dominance traits. Noncontact ankle sprains were prospectively recorded and diagnosed for a full competition period (10 months). Results: Seventeen of the players sustained at least 1 noncontact ankle sprain. Logistic regression revealed that players with (A) eccentric isokinetic ankle flexion strength asymmetries (odds ratio [OR] = 8.88; 95% confidence interval [CI], 1.95-40.36, P = .005), (B) increased body mass index (OR = 8.16; 95% CI, 1.42-46.63, P = .018), and (C) increased body weight (OR = 5.72; 95% CI, 1.37-23.95, P = .017 ) each had a significantly higher risk of a noncontact ankle sprain. A trend for younger players(OR = 0.28; 95% CI, 0.061-1.24, P = .092) and for players with ankle laxity asymmetries (OR = 3.38; 95% CI, 0.82-14.00, P = .093) to be at greater risk for ankle sprain was also apparent to the limit of statistical significance (.05<P<.10). Conclusion: Functional strength asymmetries of the ankle flexors and increased body mass index and body weight raise the propensity for ankle sprains in professional soccer players. Age and asymmetries in ankle laxity are potential factors worth revisiting, as there was an indication for younger players and players with ankle instability to be at higher risk for ankle injury. Proper preseason evaluation may improve prevention strategies for this type of injury in soccer.
fousekis_tsepis_vagenas_2012_ajsm.pdf