KU Leuven Musculoskeletal Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Belgium.
J Biomech. 2013 Sep 3;46(13):2213-9. doi: 10.1016/j.jbiomech.2013.06.026. Epub 2013 Jul 19.
Time to stabilization (TTS) has been introduced as a method to analyze dynamic postural stability during jump and landing tasks, but has also been applied during the transition task from double-leg stance (DLS) to single-leg stance (SLS). However, the application of the originally described TTS technique during the latter task has some important limitations. The first goal of this study was to present an adapted version of the TTS technique to provide an effective alternative method to better analyze postural stability during the transition from DLS to SLS. The second goal was to study the influence of pathology and different speeds on postural stability outcomes. Fifteen healthy control subjects and 15 subjects with chronic ankle instability (CAI) performed the transition task on their preferred speed and as fast as possible, with eyes open and with eyes closed. Subjects with CAI performed the transition significantly slower when moving at their preferred speed with eyes closed. The time subjects needed to reach a new stability point was not discriminative between groups and largely dependent on movement speed. However, the amount of sway after this new stability point was significantly increased in the CAI group and when eyes were closed. The results of this study suggest that subjects with CAI have a decreased ability to overcome the postural perturbation created by the voluntary movement from DLS to SLS. Focusing only on TTS during the transition from DLS to SLS may lead at least in some cases to misinterpretations when assessing postural stability.
稳定时间(TTS)已被引入作为分析跳跃和着陆任务中动态姿势稳定性的一种方法,但也已应用于从双腿支撑(DLS)到单腿支撑(SLS)的过渡任务中。然而,在后者任务中应用最初描述的 TTS 技术存在一些重要的局限性。本研究的第一个目标是提出 TTS 技术的改编版本,以提供一种有效的替代方法,更好地分析从 DLS 到 SLS 的过渡期间的姿势稳定性。第二个目标是研究病理和不同速度对姿势稳定性结果的影响。15 名健康对照组和 15 名慢性踝关节不稳定(CAI)患者以其偏好的速度和最快速度进行过渡任务,睁眼和闭眼。闭眼时以其偏好的速度移动时,CAI 患者的过渡速度明显较慢。受试者达到新稳定点所需的时间在组间没有差异,并且在很大程度上取决于运动速度。然而,在这个新的稳定点之后的摆动量在 CAI 组和闭眼时显著增加。这项研究的结果表明,CAI 患者在从 DLS 到 SLS 的自愿运动引起的姿势扰动中,克服能力降低。在从 DLS 到 SLS 的过渡期间仅关注 TTS,至少在某些情况下,在评估姿势稳定性时可能会导致误解。