The Effect Of Ankle Brace On The Dynamic Stability During The Jump Down

Objective:This paper mainly studies the influence of the type of ankle brace on the dynamic stability of the enthusiast by using different biomechanics parameters.This paper provides theoretical reference for the selection of ankle joint for healthy people and provides theoretical basis for preventing ankle sprain,and provides basic experimental data for improving the design of ankle braces.Methods: In this study,24 healthy male subjects were selected and the average age is 23 years.All participants and a half years without any history of head and the onset of damage,there is no related muscle,bone,nerve damage,formal experiment before to give participants the experimental steps in detail,and fill out basic information and signed informed consent.The subjects performed the test of forward jump,diagonal jump and lateral jump,respectively,wearing no brace,wearing lace-up brace and semi-rigid brace.The stability index of the landing process was collected by using kistler's force platform.Medial/lateral stability index(MLSI),anterior/posterior stability index(APSI),vertical stability index(VSI)and the Dynamic Postural Stability Index(DPSI)were calculated.Twenty-four male subjects were one group,all the collected data were compared by double-factor repeated measurement variance analysis.Results:(1)when the direction is certain,the effect of the type of ankle protector on the dynamic stability is as follows:The differences between APSI,VSI and DPSI of wearing no brace,wearing lace-up brace and semi-rigid brace were statistically significant(P<0.05).Forward jump,the stability index of wearing lace-up brace was significantly higher than that of wearing no brace and semi-rigid brace(P<0.05).The vertical stability index(VSI)and the Dynamic Postural Stability Index(DPSI)were were significantly higher than that of wearing no brace(P<0.05).When the diagonal jump,semi-rigid brace was a significant difference in MLSI compared with wearing nobrace(P < 0.05).In the lateral jump,the brace type had no significant effect on the dynamic stability index(APSI,MLSI,VSI and DPSI)(P >0.05).(2)When the brace type was certain,the difference of the jump direction in the MLSI and APSI indexes was significant difference(P<0.05)and there was no significant difference between VSI and DPSI indexes(P>0.05).After comparing two found in about MLSI)and APSI in three directions were significantly differences,minimum value MLSI in forward jump,the lateral jump biggest influence on MLSI.APSI index,the APSI value of the lateral jump is the smallest,while in the forward jump,APSI value is the largest.(3)The interaction effect of protective equipment and direction had significant difference on MLSI,APSI,VSI and DPSI(P < 0.05).(4)When wearing different ankle brace,the influence of the dynamic results is as follows: when the jump direction is the same,the brace type has significant influence on PVGRF,TTP and LR(P < 0.05).Two or two comparisons,wearing lace-up brace and semi-rigid brace landing of the vertical ground reaction force is significantly higher than wearing no brace(P < 0.01,P < 0.01),two brace TTP significantly less than wearing no brace(P < 0.05),wearing lace-up brace and semi-rigid brace LR value significantly greater than wearing no brace(P < 0.01).There was no significant difference in LR between wearing lace-up brace and semi-rigid brace(P > 0.05).(5)the jump direction has significant influence on TTP and LR values(P <0.01).(6)Ankle brace and direction had statistical significance for the interaction between TTP and LR(P < 0.05).Conclusions:(1)when wearing semi-rigid brace,the MLSI of semi-rigid protective gear is better than that of no brace.But the stability of vertical dropped significantly.Therefore,the effect of wearing semi-rigid brace on the overall dynamic stability of healthy population is not obvious.(2)Wearing lace-up brace jump down,APSI?VPSI and DPSI are increases significantly and the dynamic stability decreases,and the stability of the left and right change is not obvious,thus the wearing lace-up brace has a negative effect on the stability of jump down.Therefore,it is advisable to wearing lace-up brace during exercise.(3)Wearing lace-up brace,semi-rigid brace significantly increased the peak and load rate of the vertical ground reaction force when the enthusiast were falling,and reduced the peak of arrival time,increasing the risk ofjoint injury of lower limbs.(4)Wearing lace-up brace and semi-rigid brace on dynamic stability has obvious direction.It is not recommended to wearing lace-up brace in sports with a large range of sagittal motion of the ankle.A semi-rigid brace can be used to improve the dynamic stability of the left and right sides of the ankle joint.,it is suggested that sports fans should choose ankle brace with specific sports characteristics in practice.