Effects Of Hip Strength Train In Individuals With Chronic Ankle Instability

Background:The CAI population not only showed ankle abnormalities,but also at the proximal abnormalities,such as lower hip muscle strength,abnormal gluteal muscle activation and lower limb kinematics.Furthermore,the lower hip isometric abductor strength was a risk factor for lateral ankle sprain in male soccer players,and kinematics abnormalities of the hip joint may be a risk factor for primary lateral ankle sprain to develop CAI.In addition,the study found that ankle sprains were more likely to occur during walking,running,and jumping.Objective:Examine the effects of hip strength training on abnormal gluteus muscle activation level and lower limb kinematics characteristics of CAI subjects during landing task.Methods:thirty-four participants with CAI were randomly assigned to control(12 males and 4 females,age=22.25±2.44 years,height=173.56±8.40cm,weight=68.81 ± 15.42kg)or training groups(13 males and 5 females,age=20.78±2.05 years,height=174.00±11.63cm,weight=69.50±13.47kg).The participants completed either four week of supervised hip strength training program that consisted of 12 training sessions or no intervention.Participants were assessed on hip isometric strength(hip abduction strength,hip extension strength,hip external rotation strength),Star Excursion Balance Test(SEBT)in anterior,posteromedial and posterolateral directions,a patient reported measure(Cumberland Ankle Instability Tool,CAIT)and Gluteal muscle electromyographic activation(gluteus maximus,gluteus medius),Lower extremity kinematics during two landing tasks before and after the four week training period.Results:(1)post-test,the training group displayed significantly improved post-test for hip isometric strength(hip extension strength;hip abduction strength;hip external rotation,P<0.01),SEBT reach in the posteromedial(P=0.04)and posterolateral(p=0.03)directions;CAIT score(P<0.01).(2)during hop landing task,the training group displayed greater gluteus medius activation(P<0.01)during initial contact to 200ms post-initial contact,reduced hip flexion(P<0.05),hip adduction(P<0.05),hip internal rotation(P<0.05),Knee flexion(P<0.05),varus(P<0.05),external rotation(P<0.05)and ankle varus(P<0.05)angle at initial contact and 200ms post-initial contact,greater ankle plantarflexion(P<0.05)at initial contact;。(3)during Single-leg drop landing task,the training group displayed greater gluteus maximus activation(P<0.01)during initial contact to 200 ms post-initial contact,reduced hip flexion(P<0.05),Knee flexion(P<0.05)angle at initial contact and 200ms post-initial contact.(4)In addition,compared with the control group,the training group displayed greater hip extension strength(P=0.03),hip abduction strength(P=0.03),hip external rotation strength(P=0.04);higher CAIT score(P<0.01);And,during hop landing task,greater gluteus medius activation(P=0.02)during initial contact to 200ms post-initial contact,Less knee flexion(P=0.04)and varus(P=0.04)at the initial touch,and less hip adduction(P=0.03)and internal rotation(P=0.01)at 200ms post-initial contact;during Single-leg drop landing task,gluteus maximus activation(P<0.01)during initial contact to 200ms post-initial contact.Conclusion:The 4-week hip strength training program can enhance hip isometric strength,Dynamic stability,patient-reported function,improved gluteus medius activation during hop landing and gluteus maximus activation during single-leg drop landing,improve abnormal lower extremity kinematics during landing task.