单侧功能性踝关节不稳者单足站立的平衡控制策略研究

Single-leg Static Postural Balance in Individuals with or Without Unilateral Functional Ankle Instability

目的:通过比较单侧功能性踝关节不稳(functional ankle instability,FAI)者患侧和对照组的非优势侧静态平衡姿势中压力中心(centre of pressure,COP)的空间特征,以及慢成分(rambling)和快成分(trembling)轨迹控制特征,来探讨功能性踝关节不稳者的平衡控制策略。方法:12名FAI组和14名正常对照组受试者分别在测力台上进行睁眼和闭眼30 s单足站立测试,记录压力中心的轨迹并分析其空间特征,将压力中心信号分解为慢成分和快成分,并对快慢成分的轨迹进行时频特征分析。对于不同组别和视觉效应之间的比较采用混合多元方差分析。结果:在睁眼时,COP所形成曲线的95%置信椭圆面积(ar-ea)、COP在前后方向摆动的长度(length_x),COP在左右方向摆动的长度(length_y)、COP摆动的总轨迹长度(length_xy)在FAI组和对照组之间的差异无统计学意义(P>0.05);在闭眼时,area和length_x在FAI组和对照组之间的差异有统计学意义(P<0.05);对于单足站立时COP的慢成分和快成分的时域特征,除了平均摇晃幅度在两组之间以及睁、闭眼之间无统计学差异(P>0.05),摇晃幅度的均方根和标准差功能性踝关节不稳组均大于对照组(P<0.05);慢成分和快成分的摇晃频率在两组间也无统计学差异(P>0.05),但在睁眼和闭眼之间的差异有统计学意义(P<0.05)。结论:(1)单侧功能性踝关节不稳者静态平衡的中枢控制和外周控制能力均弱于对照组,因此不能仅仅将功能性踝关节不稳认为是外周的损伤,而要同时考虑中枢的损伤。(2)单侧功能性踝关节不稳者可以通过视觉来补偿平衡控制能力的缺失。

Objective To explore the static postural balance in individuals with or without functionalankle instability（FAI）by identifying and quantifying the spatial characteristics of center of pressure（COP）, as well as rambling and trembling trajectory properties. Methods Twelve FAI patients was se-lected into the FAI group, while another 14 healthy students were chosen into the control group. Thesingle-leg standing test with and without vision was conducted on the unstable side of the FAI groupand the non-dominant side of the control group 3 trials with each trial lasting 30 s. The displacementof COP and the time and frequency domain of rambling and trembling were analyzed and compared be-tween the two groups. Results There was no significant difference in the displacement of COP withopened eyes（P〉0.05）. The area and the anterior-posterior length of COP of the FAI group were larger than those of the control group with eyes closed（P〈0.05）. For the rambling and trembling trajectory,no significant differences were found in all the time domains between the two groups with eyes openor closed（P〉0.05）, except the mean sway amplitude（MSA）（P〈0.05）. Moreover, the mean square rootand standard deviation of MSA of the FAI group were significantly bigger than the control group（P〈0.05）. Significant differences were found in the MSA frequency between open and closed eyes（P〉0.05）,but not between the FAI and control groups（P〈0.05）. Conclusions The FAI patients are weaker thanhealthy people not only in the peripheral control, but also in the central control of the static posturalbalance. Therefore, injuries in the central neural system must also be considered when analyzing thereason for FAI. The imbalance of the FAI patients can be avoided by opening eyes.