Background Musculoskeletal assessment is very important for injuries prevention and should be made in different moments of sports season. Dynamic lower limb stability is an essential parameter for a good performance, and it can be assessed by Y-Test.

Objective To compare Y-Test performance during 3 different moments of an entire season in young futsal, volleyball and basketball athletes of a Brazilian sports club.

Design Observation (prospective).

Setting One club facility in Brazil.

Patients (or Participants) 90 male athletes divided in: jumpers (volleyball and basketball, 64 subjects); runners (futsal, 26 subjects).

Interventions (or Assessment of Risk Factors) All subjects performed Y-Test, which involves reaches with contralateral leg the furthest distance while maintaining single-leg stance in three directions (anterior, posteromedial, and posterolateral) in three different moments of the year.

Main Outcome Measurements Asymmetry between legs in each direction and composite scores (average between normalized distances in each direction divided by leg length).

Results ANOVA repeated measures were used in statistical analysis (p<0,05). Regarding asymmetry, the results showed significant difference only in the posteromedial direction of jumpers group (p=0,003), indicating an improvement throughout the season. Runners did not present any difference. In relation to composite scores, it was found a statistically significant difference in the non-dominant leg in runners’ group (p = 0,016), suggesting a decline of performance on Y-Test during the season. Moreover, the results found the dominant leg were bordering p value (p=0,06 in jumpers and p=0,0502 in runners), implying a decreased efficacy in jumpers and increased in runners.

Conclusions Throughout season neuromuscular adaptations occurred accordingly with sports gestures and this might explain the different results found between groups. Fatigue can be an important factor to explain the decrease of performance of runners. Sports with consecutive jumps maybe are related with the reduction of asymmetry, what does not happen between runners.