A novel device for proprioceptive acuity measurement: Validity and reliability analysis in young and older adults

Age, neurodegenerative diseases, diabetes, and sports injuries can all impair proprioception, i.e. a crucial sensory feedback system for balance control and gait. The purpose of this study was to assess the validity and reliability of a recently constructed device for measuring proprioceptive function. Forty-seven participants, comprising 26 younger healthy adults (20–40 years) and 21 older adults (> 65 years), were evaluated. The ankle’s sense of motion (SoM) sensitivity and sense of position (SoP, active/passive) acuity were measured by the device. The Intraclass Correlation Coefficient (ICC) and the Area Under the Receiver Operating Characteristic Curve (AUC-ROC) were used as indicators of reliability and validity. The results showed excellent reliability for SoM sensitivity in dorsiflexion (ICC = 0.985 for younger, 0.98 for older) and plantarflexion (ICC = 0.972 for younger, 0.982 for older). High reliability was also observed in passive SoP acuity (ICC = 0.825 – 0.989). However, the reliability of the active SoP acuity method was poor to moderate. Strong discriminative validity was demonstrated by the AUC-ROC values, with SoM sensitivity distinguishing between younger and older participants with an accuracy of over 91 %. Bland-Altman analysis revealed tighter agreement for SoM sensitivity (18 to 40 % of the device precision) than passive SoP acuity (70 to 90 % of the device precision), as well as minimal systematic bias (−0.03 to −0.01 degrees) to show interday test–retest reliability. According to these results, the device is valid for evaluating proprioceptive function, particularly SoM sensitivity, and it may be useful in clinical and research settings.