Lower baseline neurocognitive ability could be a risk factor for anterior cruciate ligament (ACL) injuries. We investigated the effects of high-intensity exercise (HIE) on neurocognitive function in athletes, and if any changes in neurocognitive function after HIE had effects on an unanticipated cutting motion. Fourteen collegiate female athletes performed a bicycle ergometer HIE exercise at 80% of their heart rate reserve. Neurocognitive function was evaluated by the Stroop interference test (SIT) pre- and post-HIE. Biomechanical variables were captured using a motion analysis system while participants performed side-step cutting tasks in anticipated and unanticipated conditions. Participants were divided into two groups according to the changes in SIT scores after HIE: increased performers (IP; n = 7) and decreased performers (DP; n = 7). The average SIT score of the IP group significantly increased, while that of the DP group significantly decreased after HIE (Paired t-test, p < 0.001). The main effect of HIE using repeated-measures ANOVA, was a significant decrease in peak knee valgus moment (pre: anticipated 0.1 ± 0.1Nm/kg, unanticipated 0.0 ± 0.2Nm/kg; post: anticipated 0.0 ± 0.1Nm/kg, unanticipated 0.1 ± 0.2Nm/kg, p = 0.024) and peak ground reaction force (pre: anticipated 3.3 ± 0.2%BW, unanticipated 3.8 ± 0.2%BW; post: anticipated 3.1 ± 0.3%BW, unanticipated 3.6 ± 0.4%BW, p = 0.035) only in the IP group. Athletes with improved neurocognitive function had decreased the biomechanical ACL injury risk factors during side-step cutting. Improving neurocognitive function may contribute to ACL injury prevention.

This study assessed the effects of a rugby-specific concussion awareness program on improving the recognition of relevant symptoms and knowledge of concussion in male collegiate rugby union players. Thirty-one collegiate rugby union players from Japan were offered a concussion awareness program; they responded to a questionnaire assessing symptom recognition and knowledge of concussion three times (before, immediately after, and four weeks after the implementation of the program). Immediately after the program, the recognition score of suspected concussion symptoms was higher compared to before and four weeks later, when it was still higher than before the program, but not statistically significant. In addition, more players selected the correct answers about rugby-specific concussion topics after the program. Our findings suggest that while concussion awareness is expected to improve immediately, this effect was not maintained after four weeks. Therefore, concussion awareness opportunities should be scheduled regularly, such as at the start of each season, before the beginning of competition season, and when new players join the team.

This study aimed to investigate the differences in exercise load due to variations in lower limb weight during stair ascent and descent. The study involved 10 healthy adult men and women without respiratory or circulatory disease (five men and five women). Using a respiratory gas analysis device, the participants performed stair climbing under three conditions: 1) full weight-bearing, 2) half (partial) weight-bearing, and 3) non-weight-bearing. The maximum oxygen uptake during stair climbing was defined as the peak oxygen uptake. Additionally, the time required for ascent and descent was measured using a stopwatch, and heart rate and perceived fatigue at the end were assessed using the Borg scale. Peak oxygen uptake and Borg scale scores significantly increased during ascent and descent under the non-weight-bearing condition compared to those under the full weight-bearing and half-weight-bearing conditions. The required time was significantly extended under the half-weight-bearing and non-weight-bearing conditions compared to under the full-weight-bearing condition. Therefore, when stair ascent and descent are necessary during a period requiring the use of crutches, it is considered desirable to perform the task only after at least half-weight-bearing condition or more is permitted, as this approach results in a considerable reduction in load.