Study On Standing Balance Ability Of Patients With History Of Ankle Injury

Objective:This study collects the plantar pressure in patients with history of ankle spain,then argues the balance function characteristics and influences in different standing conditions.Research method:The experiment consists of 3 steps:it first tests 34 male subjects and 15 female ones with sprained ankle history in four standing postures(Stand with feet apart and eyes closed/opened,stand with feet together and eyes closed/opened)then collects the plantar pressure parameters with the Zebris FDM-System gait analysis system.Finally,it makes comparisons in different standing positions with mathematical statistics.Results:(1)There is no statistically significance in the parameters between male and female in four standing positions(p>0.05).(2)The differences between percentage of the left hind foot pressure and the right one in the four standing posture are significant(p<0.01)with complete negative correlation;while the ipsilateral backfoot average forces(%)differences are not significant(p>0.05)but with strong correlation when standing with feet together or apart.(3)There are significant differences in the COP path length,COP average velocity and the angle between Y and major axis between standing with feet apart and eyes opened group and standing with feet apart and eyes closed group(p<0.01),while the differences between the deviation X,deviation Y,the 95% confidence ellipse area,the length of minor axis and the length of major axis parameter is not significant.The deviation X and the deviation Y are not significantly different between the standing with feet apart and eyes opened group and standing with feet together and eyes opened group,between the standing with feet apart and eyes closed group and standing with feet together and eyes closed group,and between the standing with feet together and open eyes group and standing with feet together and eyes closed group.The COP average velocity,95% confidence ellipse area,COP path length,length of minor axis,length of major axis,and the angle between Y and major axis are significantly different(p<0.01).Conclusions:(1)In the same standing position,the standing balance ability of patients with sprained ankle history has nothing to do with gender.(2)Percentage of the hind foot pressure in patients are left-right asymmetry,which could increases the risk of recurrent injuries.At the same time,the input of visual information has less influence on the percentage in the four standing positions.(3)From 95% confidence ellipse area,the patients can not be distinguished from the balance between eyes closed position or eyes open when legs are apart.And we also cannot measure the balance ability from parameters such as moving distance of X-axis and the Y-axis;(4)The standing stability of patients is better in standing with feet together and eyes open than eyes closed,which is reflected in the positive effect input of visual information have on 95% confidence ellipse area,cop path length,cop average velocity,length of minor axis,length of major axis,and the angle between Y and major axis;the input of visual information is also postive enough to evaluate the characteristics of the angle between the Y-axis and the main axis when the subject is standing.(5)There is a reason that the standing stability is higher with feet apart than that of standing with feet together: the expansion of the support area has a negative impact on95% confidence ellipse area,cop path length,cop average velocity,length of minor axis,length of major axis,and positive influence on the angle between Y and major axis.(6)The sway of patients in the four standing positions appears more often in the front-rear direction than the left-right direction.