Abstract
Purpose :
Para Alpine skiing requires athletes to move quickly through an environment that rapidly changes during and between runs, and is a highly challenging sport for skiers with vision impairments. The current International Paralympic Committee (IPC) classification criteria for athletes with vision impairment competing in Para sport are based on static visual acuity and visual field radius of the better eye, but do not account for the dynamic vision demands of sports like skiing. To help develop an evidence based, sport-specific classification system for Para Alpine skiing, a prospective observational study was conducted to examine the relationships of vision functions and skiing performance. Static and dynamic VA, contrast sensitivity, and glare sensitivity were hypothesized to be predictive of skiing performance.
Methods :
Elite Para Alpine skiers (n=15) were recruited at the 2017 Para Alpine Skiing World Championships. Static visual acuity (SVA), light sensitivity, glare sensitivity, glare recovery, dynamic visual acuity (DVA), contrast sensitivity, translational and radial motion perception, and visual field were assessed binocularly in all skiers. Skiing performance was assessed with a modified IPC Alpine Skiing (IPCAS) points system based on athlete’s raw times. Performance on the vision function tests was compared with skiing performance in each discipline (downhill (DH), super G (SG), giant slalom (GS), slalom (SL)) using Kendall’s correlations and bootstrapped linear multiple regressions (p<0.05 considered significant).
Results :
DVA and DH performance were significantly correlated (ρ= 0.593, p=0.04; better DVA associated with better performance), however, in the regression models no variables were significantly predictive of DH performance after bootstrapping. SVA was found to be a significant predictor for GS [(F(3,11)=24.71, p<0.001), with an R2of 0.87], SG [(F(3,9)=17.34, p=0.002), with an R2of 0.85], and SL [(F(3,11)=11.8, p=0.002), with an R2of 0.80] performance in the regression models. Better SVA was also correlated with better skiing performance in SG and GS disciplines (ρ>0.50, p<0.01).
Conclusions :
Consistent with our hypotheses, SVA was predictive of GS, SG, and SL performance, which require more technical skill and less speed than DH. Dynamic visual acuity was not predictive of skiing performances, but it was significantly associated with DH performance.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.