Study On Postural Control Characteristics In Subtypes Of Chronic Ankle Instability Associated With Perceived Instability

Objective: Hiller’s model of chronic ankle instability can be divided into 7subgroups including perceived instability,mechanical instability,recurrent sprain,perceived instability with mechanical instability,perceived instability with recurrent sprain,mechanical instability with recurrent sprain,perceived instability with mechanical instability with recurrent sprain,the purpose of this paper is to investigate the characteristics of postural control impairments in different subtypes of chronic ankle instability associated with perceived instability,and provide theoretical basis for clinical prevention and treatment of chronic ankle instability.Methods: 109 chronic ankle instability patients were screened out and classified into different groups based on Hiller classification.26 participants without ankle sprain history were recruited as healthy control group.All participants took the same test(dynamic and static balance testing,foot-lifts test,star balance testing,lateral hop test).All parameters were analyzed by the ANOVA and nonparametric test to testify different posture control characteristics between different groups.Results: Male subjects 1)in the static stability test of Prokin,there was a significant difference in the length of movement of pressure center between the perceived instability with recurrent sprain group and the healthy control group when eyes closed(P<0.05);2)in the foot-lifts test,there was a significant difference in the number of foot lifting off the ground between the perceived instability group and the healthy control group(P<0.05).Female subjects 1)in the foot-lifts test,there were significant differences in the number of foot lifting off the ground among the perceived instability group,the perceived instability with mechanical instability group,the perceived instability with recurrent sprain group and the perceived instability with mechanical instability with recurrent sprain group and the healthy control group(P<0.01).There was a significant difference in the number of foot lifting off the ground between the perceived instability with mechanical instability group,the perceived instability with recurrent sprain group and the perceived instability with mechanical instability with recurrent group(P<0.01);2)in the multi-axis proprioception test of Prokin,the average trajectory error in the perceived instability with mechanical instability group,sensory instability with recurrent sprain group was significantly different from that in the healthy control group(P<0.05).The healthy control group was significantly different from the perceived instability group,the perceived instability with mechanical instability with recurrent sprain group(P<0.01).3)in the star excursion test,there were significant differences(P<0.05)and very significant differences(P<0.01)in the standardized distance in the anterior direction between the perceived instability group and the perceived instability with mechanical instability with repeated sprains and the healthy control group,respectively.Conclusions: patients with chronic ankle instability associated with perceived instability generally have static or dynamic postural control impairments,and there are different characteristics of postural control impairments among different subtypes.1)Both static and dynamic postural control impairments existed in the perceived instability group,indicating serious proprioception and neuromuscular control defects;2)the perceived instability with mechanical instability group only tended to show dynamic postural control impairment,indicating severe neuromuscular control defects;3)the patients with perceived instability and recurrent spain showed a large body center of gravity swing in the posture control with closed eyes and single leg support,indicating a serious proprioception defect;4)the patients with perceived instability with mechanical instability with recurrent spain group showed more serious static and dynamic posture control impairments than other subtypes,indicating very serious proprioception and neuromuscular control defects.Whether the conclusions of this study conforms to the general rule needto be verified by larger sample size and repeated experiments.