The Impact of Utilizing a Balancing Blindfold During Training on the Backward Running Technique in Experienced and Novice Male Handball Players.

Backward running is common in handball defense and relies heavily on proprioceptive control when visual information is limited. Twenty-eight male handball players were allocated to three groups: experimental novice group with blindfold training (n = 7), control novice group with the same training without blindfold (n = 7), and target professional group (n = 14). Both novice groups completed a 6-week balance program (3 × 20 min/week). Lower-limb kinematics during backward running were captured with a 6-camera motion analysis system, and inter-joint coordination was quantified by Mean Absolute Relative Phase (MARP) and Deviation Phase (DP) for ankle-knee and knee-pelvic couplings. At baseline, professionals showed greater ankle-knee MARP than novices (ANOVA F(2,25) = 9.42, p < 0.001). Representative means (mean ± SD): ankle-knee MARP novices 1.62-1.79 vs. professionals 3.83. After training, ankle-knee MARP increased in both novice groups (experimental: t(6) = 4.72, p < 0.001; control: t(6) = 5.02, p < 0.001), approaching professional values (post-training novices ≈ 3.22-3.26). Post-training between-group differences were non-significant for ankle-knee MARP (ANOVA F(2,25) = 1.24, p = 0.30), while ankle-knee DP showed a group effect (F(2,25) = 5.12, p = 0.01; experimental vs. professional t(19) = 3.12, p = 0.01). A short-term balance program improved ankle-knee coordination during backward running in novice male players; additional blindfolding did not yield extra benefit over 6 weeks. These findings can inform short-term training and rehabilitation planning for handball, while long-term effects require future study.