功能性踝关节不稳者斜面着地动作的生物力学特征

Biomechanical characteristics of the patients with functional ankle instability when landing on the slope

背景:跳跃动作通过闭环(着地后的神经控制)与开环(着地前的神经控制)机制维持正确关节排列与稳定冲击关节的力量。功能性踝关节不稳患者在着地前后的踝回馈稳定机制较差,目前对于功能性踝关节不稳患者的神经反应特征目前仍不清楚。目的:通过观察功能性踝关节不稳者于斜板上着地时踝部运动学及相关肌群的肌电活化表现,揭示功能性踝关节不稳患者无法通过踝关节周边肌肉来回复适当姿势的神经反应机制。方法:共招募到11例单侧功能性踝关节不稳者及同等样本数量且年龄相仿的健康女性参与者。以运动图像拍摄与表面肌电测试系统同步,并利用两大测试配套的分析软件收集2组受试者完成斜板着地测验前、后各200 ms的运动学及肌电参数,运用SPSS 17.0对相关指数进行统计处理。结果与结论:(1)着地前,功能性踝关节不稳组伤侧与健侧的神经肌肉活化差异比较发现,伤侧腓肠肌活化程度显著高于健侧(P<0.05),而胫骨前肌、腓骨长肌与比目鱼肌两侧比较差异均无显著性意义(P>0.05);伤侧平均矢状面跖屈程度显著高于健侧(P<0.05),而其余各方面角度两侧比较差异均无显著性意义(P>0.05);(2)着地后,功能性踝关节不稳组伤侧的腓骨长肌活化程度显著低于健侧(P<0.05),而胫骨前肌、腓肠肌、比目鱼肌两侧比较差异均无显著性意义(P>0.05);着地后,运动学参数显示伤侧与健侧差异均无显著性意义(P>0.05);(3)着地前,功能性踝关节不稳组伤侧的腓骨长肌活化程度显著高于健康对照组的两侧(P<0.05),而胫骨前肌、腓肠肌、比目鱼肌功能性踝关节不稳组伤侧与健康对照组两侧比较则差异均无显著性意义(P>0.05);着地后,四块肌伤侧与健侧差异均无显著性意义(P>0.05);(4)着地前、后功能性踝关节不稳组与健康对照组两侧的关节角度差异均无显著性意义(P>0.05);(5)结果提示,不论是开环还是闭环机制均不利于功能性踝关节不稳者患侧在斜板上着地,但这种差异在功能性踝关节不稳者与健康者之间差异不大,很难区分,故根据功能性踝关节不稳者的开环神经机制功能设计动作控制干扰的评估方法还需要后续学者进一步开发研究。

BACKGROUND： Leaping maintains the correct arrangement and stability of joint by closed-loop （neural control after landing） and open loop control （neural control before landing）. The stabilization mechanism of the ankle feedback is poor in functional ankle instability （FAI） patients. However, the characteristics of the nerve reaction in FAI patients are still unclear. OBJECTIVE： To explore the ankle joint kinematics of the FAI patients landing on the slope and the electromyographic activation of the relevant muscle, so as to reveal the nerve response mechanism of the FAI patients who cannot recover the proper posture through the muscles surrounding ankle joint. METHODS： Eleven unilateral FAI patients and 11 healthy female participants with similar age were recruited. The motion capture and surface electromyography test system were conducted synchronously. The kinematics and myoelectric parameters at 200 ms before and after landing on the slope were collected using relevant software, and statistical analysis was performed on SPSS 17.0 software. RESULTS AND CONCLUSION： （1） The activation of gastrocnemius of the affected side in the FAI patients before landing was significantly higher than that of the healthy side （P 〈 0.05）, and there was no significant difference in the anterior tibial muscle, peroneus longus and soleus muscles between sides （P 〉 0.05）. The average sagittal plane plantar flexion of the affected side was significantly higher than that of the healthy side （P 〈 0.05）, and other angles were insigificantly different between sides （P 〉 0.05）. （2） The activation of peroneus longus of the affected side in the FAI patients after landing was significantly lower than that of the healthy side （P 〈 0.05）, and there was no significant difference in the anterior tibial muscle, gastrocnemius and soleus muscles between sides （P 〉 0.05）. The kinematics parameters after landing showed no significant differences between sides （P 〉 0.05）. （3） The activation of peroneus longus of the affected side in the FAI patients before landing was significantly higher than that of the two sides in healthy controls （P 〈 0.05）, and there was no significant difference in the anterior tibial muscle, gastrocnemius and soleus muscles between groups （P 〉 0.05）. The activation of the four muscles after landing showed no significant difference between two groups （P 〉 0.05）. （4） The angles of the bilateral joints before and after landing did not differ significantly between two groups （P 〉 0.05）. （5） In summary, neither open nor closed loop mechanism is conducive to the landing on the slope, and the difference is insignificant between FAI and healthy people. Therefore, the assessment protocol on motion control based on open-loop neural mechanism needs to be further studied and developed.