Acute Effects of Brock String-Based Visuo-Oculomotor Training on Postural Stability and Reactive Motor Performance in Athletes: A Pilot Study.

BACKGROUND: Balance and reactive performance in ball sports rely on effective visuomotor and sensorimotor integration. Although Hemsball places considerable demands on visual processing, eye-hand coordination, and postural control, the acute effects of visual-oculomotor training on sport-related performance remain unclear. This pilot study investigated the immediate effects of a Brock string-based visual-oculomotor training program on postural stability, eye-hand coordination, and reactive visuomotor performance in Hemsball athletes. METHODS: Twenty-seven Hemsball athletes (mean age: 10.22 ± 0.57 years) participated in a single-group pre-post intervention study. Participants completed a single session of a Brock string-based visual-oculomotor training that combined progressive vergence exercises with balance and lower-extremity motor tasks. Static balance (Flamingo Balance Test), eye-hand coordination (Alternative Hand Wall Toss Test), and reactive visuomotor performance (Reactive 90/90 Wall Toss Test) were assessed before and immediately after the intervention. Pre-post comparisons were performed using paired-sample t-tests or Wilcoxon signed-rank tests, and effect sizes were reported as Cohen's dz or r, as appropriate. RESULTS: Following the intervention, significant improvements were observed in static balance (p = 0.023, r = 0.436), eye-hand coordination (p = 0.004, r = 0.556), the number of correct responses (p < 0.001, r = 0.661), and a reduction in the number of errors (p = 0.006, r = 0.524) during the Reactive 90/90 Wall Toss Test. Mean reaction time also decreased significantly (p = 0.049, Cohen's dz = 0.415). The largest effect was observed for response accuracy, whereas the improvement in reaction time was comparatively smaller. CONCLUSION: Acute Brock string-based visual-oculomotor training was associated with improvements in postural stability, eye-hand coordination, response accuracy, error rate, and reaction time in Hemsball athletes. However, given the single-group design and the absence of a control group, these findings should be interpreted with caution. Randomized controlled studies are needed to determine whether these preliminary improvements represent true intervention effects beyond practice-related and other non-specific influences.