Piri Makan, Malmir Kazem, Otadi Khadijeh, Shadmehr Azadeh
Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Science, Enghelab St, Pich-e-Shemiran, Tehran, Iran.
BMC Sports Sci Med Rehabil. 2025 Jan 30;17(1):16. doi: 10.1186/s13102-025-01064-y.
Chronic ankle instability (CAI) is characterized by recurrent sprains and persistent symptoms, which impair postural control. This study evaluates the diagnostic utility of various linear and nonlinear postural stability measures in distinguishing individuals with CAI from healthy controls.
Postural stability was assessed in 24 participants (12 with CAI and 12 healthy controls) using a force platform under four conditions: hard surface with eyes open, hard surface with eyes closed, soft surface with eyes open, and soft surface with eyes closed. Linear measures of center of pressure (COP) included range in the anteroposterior (Rfa) and mediolateral (Rsw) directions, mean velocity (MV), and sway area. Nonlinear measures included approximate entropy (ApEn), the largest Lyapunov exponent, and correlation dimension (CD) with its standard deviation. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) analysis to determine cutoff scores, allowing effective differentiation between CAI and healthy participants.
AI individuals exhibited increased mediolateral COP sway and higher mean velocity on hard surfaces with both eyes open and closed. On soft surfaces with eyes closed, they showed significant deficits in sway area and mean velocity, reflecting challenges in postural control. ROC analysis revealed that certain linear and nonlinear measures showed strong diagnostic accuracy in distinguishing individuals with CAI from healthy controls. Nonlinear analysis revealed elevated ApEn and reduced CD in CAI participants, indicating greater postural irregularity and reduced dynamic stability. On a hard surface with eyes open both Rsw (cutoff: 1.18 cm, OR: 4.55) and ApEn (cutoff: 0.07, OR: 4.0) were particularly strong diagnostic indicators.
Linear and nonlinear postural stability measures effectively differentiate individuals with CAI from healthy controls. Key metrics, including Rsw, MV, ApEn, and CD, offer strong diagnostic value for early detection and personalized rehabilitation. Incorporating these measures into clinical practice may improve CAI management and patient outcomes.
IR.TUMS.FNM.REC.1400.236. March 14, 2022.
慢性踝关节不稳（CAI）的特征是反复扭伤和持续症状，这会损害姿势控制。本研究评估了各种线性和非线性姿势稳定性测量方法在区分CAI患者与健康对照者方面的诊断效用。
使用测力平台在四种条件下对24名参与者（12名CAI患者和12名健康对照者）的姿势稳定性进行评估：睁眼硬表面、闭眼硬表面、睁眼软表面和闭眼软表面。压力中心（COP）的线性测量包括前后方向范围（Rfa）和内外侧方向范围（Rsw）、平均速度（MV）和摆动面积。非线性测量包括近似熵（ApEn）、最大Lyapunov指数和相关维数（CD）及其标准差。使用受试者工作特征（ROC）分析评估诊断准确性，以确定临界值，从而有效区分CAI患者和健康参与者。
CAI患者在睁眼和闭眼的硬表面上表现出更大的内外侧COP摆动和更高的平均速度。在闭眼软表面上，他们在摆动面积和平均速度方面存在显著缺陷，反映出姿势控制方面的挑战。ROC分析显示，某些线性和非线性测量方法在区分CAI患者与健康对照者方面具有很强的诊断准确性。非线性分析显示，CAI参与者的ApEn升高，CD降低，表明姿势不规则性增加，动态稳定性降低。在睁眼硬表面上，Rsw（临界值：1.18厘米，比值比：4.55）和ApEn（临界值：0.07，比值比：4.0）都是特别强的诊断指标。
线性和非线性姿势稳定性测量方法能有效区分CAI患者与健康对照者。包括Rsw、MV、ApEn和CD在内的关键指标对早期检测和个性化康复具有很强的诊断价值。将这些测量方法纳入临床实践可能会改善CAI的管理和患者预后。
IR.TUMS.FNM.REC.1400.236。2022年3月14日。
