Intensive unilateral core training improves trunk stability without preference for trunk left or right rotation

BACKGROUND AND OBJECTIVES: It is possible to increase multi-directional trunk stability using co-activation. However, it is unclear whether there is a preference for left or right trunk rotation after intensive unilateral stability training. The aim of this study was to examine the directional preference in trunk rotational stability after unilateral core training. MATERIAL AND METHOD: This study was conducted on 16 female basketball players. For eight weeks, eight participants performed unilateral core training that focused on one side of the trunk. The remaining eight participants were not provided any additional training. To determine rotational trunk stability, all participants were requested to maintain an upright sitting posture against sudden, external, left or right rotational perturbations of the trunk. Angular displacement of the trunk was measured using a motion analyzer. RESULTS: At the end of the training period, the angular displacement in response to the perturbation was reduced for both rotational directions (left: -26%, right: -24%) in the trained group (p < 0.05). CONCLUSION: This study showed that trunk stability improved without particular directional preference in response to unilateral core training. This result adds to our understanding of the nature of trunk stability and multi-directional improvement. LEVEL OF EVIDENCE: Intervention study, Level 1b.