The Reliability,Validity And Application Study Of Ankle Inversion Discrimination Apparatus During Stair Descent

Objects:Individuals with chronic ankle instability（CAI）may experience recurrent ankle sprains and symptoms during daily activities such as stair descent,where the associated proprioceptive deficit is largely unevaluated.In addition,riser height is emphasized as a critical element in stairway safety that can help reduce stair injuries.Therefore,this study aimed to develop a novel ankle proprioceptive assessment,the ankle inversion discrimination apparatus for stair descent（AIDASD）,to assess an individual’s ability to distinguish between different angles of ankle inversion in the process of stair descent,and to evaluate its test-retest reliability and discriminative validity.Then,the current study investigates the effect of varying riser heights on ankle inversion proprioceptive and kinematic performances in individuals with and without CAI and tries to establish the association between them to give insight into the mechanism underlying sensorimotor deficits among individuals with CAI.Methods:Trail one is to evaluate the test-retest reliability of AIDASD.24 volunteers（12CAI and 12 non-CAI）were recruited.Before AIDASD testing,all participants’demographic information was obtained.Then,they conducted 2 tests on AIDASD with the same test leg.The second test took place between 7 days from the original test date.By generating Receiver Operating Curves（ROCs）,the area under the curve（AUC）was calculated as the participant’s ankle proprioceptive discrimination score.To assess test-retest reliability,the intraclass correlation coefficient ICC（3,1）was calculated for the CAI,non-CAI and the entire group.The minimal detectable change with 90%(MDC₉₀)was calculated for both CAI and non-CAI groups to allow clinicians to assess the significance of changes in individual AIDASD scores.Trail two is to determine whether AIDASD can distinguish individuals with and without CAI.Sample T-test was used to assess differences in ankle proprioception scores between CAI and non-CAI groups.To determine the cutoff points for the AIDASD and assess sensitivity and specificity,a receiver operating characteristic（ROC）curve was created.Spearman’s correlation was used to assess the association between proprioceptive and CAIT scores.Trail three is to determine whether riser height can affect ankle proprioception in individuals with and without CAI during stair descent.40 participants（21 CAI and 19non-CAI）volunteered.The Ankle Inversion Discrimination Apparatus for Stair Descent（AIDASD）was used to measure ankle proprioception during stair descent.All participants were tested under 3 different riser heights:15cm,17.5cm and 20cm in random order.A 2-way repeated analysis of variance（ANOVA）was conducted using the factors of the group（CAI and non-CAI group）and the riser height（15cm,17.5cm,20cm）.After discovering a significant main effect,post hoc pairwise comparisons were carried out,with LSD adjustments used to account for multiple comparisons.Effect sizes using partial eta squared（η_p²）for measures were included.Results:In trial one,test-retest reliability ICC_（3,1）for CAI.was 0.701（95%CI=0.242-0.904）,with 0.728 for the non-CAI group（95%CI=0.293-0.913）and 0.785 for the whole group（95%CI=0.565-0.901）.The MDC₉₀score for both groups was 0.042.As for trial two,the CAI group performed at a significantly lower level than the non-CAI on the AIDASD assessment（0.769±0.034 VS 0.837±0.034,p<0.001）,which showed the AIDASD can differentiate individuals with and without CAI.The AIDASD cutoff score was 0.797（sensitivity=0.864,specificity=0.800）,associated with an AUC of 0.894,meaning that clinicians could correctly distinguish CAI 89.4%of the time.CAIT scores were strongly and significantly correlated with AIDASD scores（Spearman’s rho=0.730,p<0.001）.In trial three:repeated measures ANOVA indicated that compared to those without CAI,individuals with CAI performed significantly worse across the 3 different riser heights（F=44.066,p（27）0.001η_p²=0.537）.There was a significant riser height main effect（F=13.288,p（27）0.001η_p²=0.259）.Post hoc pair-wise comparisons revealed that AUC scores in 15cm were significantly higher compared to 17.5cm（p（27）0.001,95%CI=0.018,0.045）and 20cm（p（27）0.001,95%CI=0.021,0.049）,but no significant pairwise comparisons were detected between 17.5cm and 20cm（p=0.675,95%CI=-0.014,0.021）.However,there was no significant interaction between group and riser height effects on ankle proprioceptive discrimination scores（F=0.745,p=0.478,η_p²=0.019）.Conclusion:（1）The AIDASD is reliable and valid for assessing ankle proprioceptive ankle impairments in CAI.（2）The strong and significant relationship found between ankle proprioception during stair descent and the severity of chronic ankle instability suggests that rehabilitation programs focusing on deficits in ankle inversion proprioception during stair descent may improve self-reported instability in CAI.（3）The riser height had a significant effect on ankle proprioceptive performance.