The effect of slackline training on balance performance in healthy male children

Slackline has been proposed as a challenging and motivating tool for balance training. However, the transferability of balance performances among different balance tasks has been questioned. This study aimed to assess if slackline training affects dynamic and static balance performances on stable and unstable surfaces. Eighteen healthy males (8 to 14 years) were randomly assigned to an experimental or control group. For six weeks, both groups performed several supervised sports activities (2-hour sessions, 3 sessions per week). Additionally, the experimental group underwent a slackline-based balance training (1-hour sessions, 3 sessions per week). The dynamic and static balance were tested before and after the interventions using the Bass test (BASS) and the Stork stand test (SST), respectively. Landing (BASSlanding) and balance (BASSbalance) components of the dynamic balance were evaluated, while the static balance was assessed with eyes open (SSTopen) and closed (SSTclosed) on a stable surface, and with eyes open on an air cushion (SSTac). Two-way mixed-design ANOVAs revealed no interaction effect between time and group allocation in BASSlanding (p=0.791), BASSbalance (p=0.641), and right leg SSTopen (p=0.177), SSTclosed (p=0.076) and SSTac (p=0.039), and left leg SSTopen (p=0.100) and SSTclosed (p=0.032). There was a significant interaction on left leg SSTac (p=0.004), showing higher improvements over time in the experimental (mean improvement=4.5 seconds, p<0.001) compared to the control group (mean improvement=0.9 seconds, p=0.236). In conclusion, slackline balance training yielded no or negligible improvements on dynamic balance performances, whereas the improvements seemed higher on static balance, especially when measured on an unstable surface.