Slacklines, wobble boards or BOSU balls are widely used by athletes and patients to enhance their balance. They assume that an enhanced balance leads to an improved sport performance and a reduction in the number of injuries.
However, a recent meta-analysis found that balance training only improves balance in the trained task and not in other balance tasks (all trivial effect sizes), which suggests a general balance ability does not exist! Since most daily activities do not involve keeping balance at unstable surfaces such as a wobble board or a BOSU ball it can therefore also be questioned wether we should train this.
Similarly, sport performance usually also doesn’t involve such unstable surfaces, which suggests balance training using unstable surfaces may be a waste of time. Moreover, while there is usually plenty of time to correct a loss of balance in traditional balance training, there is limited time to correct a loss of balance in most sports situations due to the short time for force application (for example, the ground contact during running, see Figure 1). Therefore, traditional balance training may have even more limited transfer to high-intensity sports.
Conclusion and practical applications
Instead of using unstable surfaces during which there is plenty of time to correct possible losses of balance, balance training for sport performance should primarily focus on fast movements that replicate the actual sport. Unstable loads and time pressure may be used to force the athlete to co-activate all muscles. The preflex effect resulting from co-activation muscles may:
1) Reduce the amount of perturbations and hence protect against injuries;
2) Reduce the amount of muscle slack and hence improve sport performance.
More information related to this topic can be found in our free-to-read article, accessible at this link: https://www.frontiersin.org/articles/10.3389/fphys.2018.01934/full
Bosch, F. (2015). Strength training and coordination: An integrative approach. Ten Brink, The Netherlands: 2010 Publishers.
DeMers, M. S., Hicks, J. L., & Delp, S. L. (2016). Preparatory co-activation of the ankle muscles may prevent ankle inversion injuries. Journal of Biomechanics, Epub ahead of print. doi:10.1016/j.jbiomech.2016.11.002
Kummel, J., Kramer, A., Giboin, L. S., & Gruber, M. (2016). Specificity of Balance Training in Healthy Individuals: A Systematic Review and Meta-Analysis. Sports medicine, 46(9), 1261-1271. doi:10.1007/s40279-016-0515-z
Van Hooren, B., & Bosch, F. (2016). Influence of Muscle Slack on High-Intensity Sport Performance. Strength and Conditioning Journal, 38(5), 75-87. doi:10.1519/ssc.0000000000000251
Van Hooren, B., Meijer, K., & McCrum, C. (2018). Attractive Gait Training: Applying Dynamical Systems Theory to the Improvement of Locomotor Performance Across the Lifespan. Frontiers in Physiology, 9(1934), 1934. doi:10.3389/fphys.2018.01934