功能性踝关节不稳者动态平衡能力及等速肌力特征研究

Examination of dynamic balance ability and isokinetic strength in participants with functional ankle instability

目的分析功能性踝关节不稳者动态平衡能力和不同速度、不同收缩模式下跖屈、背屈等速肌力特征。方法应用Biodex Balance System测试系统对FAI组(19例)和对照组(19例)分别进行姿势稳定性测试和60°/s、180°/s跖屈肌群、背屈肌群等速向心、离心肌力测试分析。结果 FAI组健侧、患侧的稳定指数和前后方向稳定指数大于对照组,而左右方向稳定指数无差异;双脚站立姿势稳定性测试结果 FAI组和对照组无差异;FAI组跖屈肌群低速离心肌力和高速向心、离心肌力不足;FAI组跖屈肌群的向心、离心峰值力矩差值比在不同速度下均大于10%,背屈肌群均小于10%。结论功能性踝关节不稳者单脚站立时健侧和患侧都存在动态平衡能力下降,双脚站立时动态平衡能力与常人无异;功能性踝关节不稳者跖屈肌群高速工作能力较差;功能性踝关节不稳者随角速度增加离心力量增加越小者,其跖屈肌群的弹性组织损伤的可能性越大。

Objective To investigate dynamic balance ability and isokinetic strength of plantar flexion or dorsiflexion under different velocity and contraction modes in the participants with the functional ankle instability（FAI）.Methods The participants（including 19 participants with a history of unilateral FAI and 19 participants with stable ankles） were tested in both postural stability（PS） and plantar-flexion-dorsiflexion movements at the speed of 60°/s and 180°/s using Biodex Balance System.The injured ankle of the FAI group was matched by side and limb dominance to an ankle in the control group.The order of the test side and movement was counterbalanced for all participants.Results Significant differences were noted for the anterior/posterior stability between FAI group and control group,but medial/lateral stability difference was not significant;two leg standing PS test result showed no significant difference between FAI group and control group;FAI group had eccentric plantar-flexor torque deficits in low speed test environment.Moreover,the concentric and eccentric plantar-flexor torque deficits in high speed test environment;under the two contraction modes and two velocities,plantar-flexor′s peak torque differences between the uninjured side and FAI side were bigger than 10%,and dorsiflexor′s peak torque differences were smaller than 10%.Conclusion Regardless of the FAI side or the uninjured side,FAI dynamic balance ability might reduce standing on one foot compared with the control group.While standing on two feet,FAI dynamic balance ability is not significant compared with the normal people.A deficit in plantar flexion torque is identified in the FAI,especially in high speed test environment.The less plantar-flexor′s eccentric strength increasing with the growing of angular speed,the higher risk factor elastic tissue is caused damaged in the FAI.