Lower Extremity Biomechanical Characteristics Of Skateboard Disturbance During Sit-to-stand In People With Functional Ankle Instability

Objective: Functional ankle instability(FAI)is a common lower limb dysfunction after the lateral ankle sprains,FAI to cause a decline in function of patients' gait instability,and dynamic posture control ability,the problem such as pain,it seriously affected the daily life of patients and athletic performance.In view of the present dynamic posture of lack of control in patients with FAI,in response to this study posture instability of emergency,reduce the risk of ankle sprains repeatedly and improve the ability of patients with FAI dynamic posture control may provide theoretic basis.Methods: This study recruited 12 functional ankle instability for the right of the subjects(FAI),according to the FAI group features such as age,height,body mass index recruiting 12 no functional ankle instability in healthy subjects(control group).This study to simulate the FAI patients sit to stand forward sliding supporting surface experimental conditions in the process of movement,make the participants have slipped back the trend of losing stability,using Qulisys 3 d motion capture system,Delsys electrical system,synchronous acquisition from the two groups sat station by sliding the skateboard disturbance in the process of movement of myoelectricity index and kinematics index.The data collected in the independent sample T test.Results:(1)In the curve of lower limb joint angle change before and after sliding,the hip joint angle of FAI patients appeared asymmetry in the sagittal plane before sliding;FAI in patients with stage of knee joint after sliding in the coronal appears asymmetric,which left knee adduction Angle decreases,the right knee adduction Angle is increased gradually.(2)In terms of muscle activity,the peak amplitude of affected side erector spinae muscle of experimental group was greater than that of control group when sitting up(P < 0.05);while in experimental group when sitting up,the peak amplitude of affected side erector spinae muscle of experimental group was higher than that of control group(P < 0.05)The amplitude peak of the lateral femoral muscle of the healthy side was greater than that of the affected side(P < 0.05);the amplitude peak of the medial head of gastrocnemius muscle of the affected side was greater than that of the healthy side(P < 0.05);The amplitude peak of biceps femoris muscle of the affected side of the experimental group was greater than that of the control group(P < 0.05);(3)The activation time of the lateral head of gastrocnemius muscle of the left side of the experimental group was faster than that of the control group(P < 0.05);and The time from activation to peak of rectus femoris muscle in the affected side of lower limb muscle was faster than that in the control group(P < 0.05);(4)The amplitude of right erector spinae muscle activity in the experimental group was greater than that in the control group(P < 0.05);the amplitude of left rectus femoris muscle activity in the experimental group was less than that in the control group(P < 0.05);the amplitude of left tibialis anterior muscle activity in the experimental group was less than that in the control group(P < 0.05);the amplitude of right erector spinae muscle activity in the recovery stage was significantly lower The amplitude of left gastrocnemius activity in the experimental group was weaker than that in the control group(P < 0.05);(5)The co contraction index of left rectus femoris and biceps femoris in the experimental group was greater or less than that in the control group after sliding(P < 0.05)Conclusion:(1)Patients with functional ankle instability in the STS when sudden sliding bearing surface of the position control in the left and right sides of the knee joint Angle change appears asymmetric,which left knee adduction Angle decreases,the right knee adduction Angle is increased gradually.Stage before sliding hip Angle in the coronal appears asymmetric,this tip functional ankle instability in addition to the sagittal plane kinematics changes,coronal kinematics changes;(2)in patients with functional ankle instability in the STS when sudden sliding bearing surface of the position control in the left and right side of the kinematics and muscle activation patterns of asymmetry,the contralateral compensation was found in the peak amplitude of lateral femoris and the contraction of rectus femoris and biceps femoris.