May the best-sighted win? The relationship between visual function and performance in Para judo.

This study aimed to establish the optimal cut-off point(s) between classes in a new, evidence-based classification system for VI judo. We collected results from international VI judo competitions held between 2012 and 2018. Data on visual acuity (VA) and visual field (VF) measured during classification were obtained. Performance was determined by calculating a win ratio for each athlete. VA was significantly associated with judo performance (r = -.33, p <.001), VF was not (r =.30, p =.15). Decision tree analysis suggested to split the data into two groups with a VA cut-off of 2.5 logMAR units. Stability assessment using bootstrap sampling suggested a split into two groups, but showed considerable variability in the cut-off point between 2.0 and 3.5 logMAR. We conclude that to minimise the impact of impairment on the outcome of competition, VI judo should be split into two sport classes to separate partially sighted from functionally blind athletes. To establish an exact cut-off point and to decide if other measures of visual function need to be included, we argue for continued research efforts together with careful evaluation of research results from a multidisciplinary perspective.

Degree of vision impairment influence the fight outcomes in the Paralympic judo: a 10-year retrospective analysis.

BACKGROUND: In the International Blind Sports Federation (IBSA) judo Sports Classes B1, B2, and B3 compete against each other within weight- and gender-specific categories. B1 athletes are totally blind, whereas B2 and B3 are partially sighted. The aim of this study was to examine the impact of the degree of vision impairment on fight outcomes. METHODS: We analyzed 1936 fights from official competitions and compare win ratio in fights between discordant Sports Classes. RESULTS: B1 won B2 ratio was 34.8%, B1 won B3 ratio was 36.5%, B2 won B3 ratio = 50.6%. The B1 percent of IBSA judo athletes decreased from 25.9% in 2007 to 19.4% in 2016, while the total number of participants increased over this period. CONCLUSIONS: These findings confirm that blind athletes have fewer chances to win a fight in IBSA Judo and become a member of National Team. Loss of vision functions affects movement coordination, balance, and emotional state, which are important for martial arts and may explain why B1 athletes are more likely to lose competitions against either B2 or B3. Creation of the evidence-based and sport-specific classification system and/or improvement of the technical rules are necessary for fair IBSA Judo competitions.