Psychophysical thresholds are more precise measures of proprioceptive sensitivity than matching error values at the elbow joint.

Abstract

To assess proprioceptive function, clinicians employ joint position matching tasks. However, the reliability and validity of matching tasks are infrequently considered. Laboratory tests of proprioceptive sensitivity include more controlled matching methods that yield position error measures or psychophysical methods that yield a perceptual threshold. Psychophysical methods have been shown to be both valid and reliable. In this study, proprioceptive sensitivity of the elbow joint was assessed in 24 healthy adult volunteers using an ipsilateral matching method and a psychophysical method. The aims of the study were: 1) to determine if threshold measures obtained by psychophysical testing yield more precise measures of position sense than error measures obtained by an ipsilateral joint position matching method and 2) to determine if the two methods are linearly correlated with each other. The results indicated that the psychophysical method provided more precise measurements than the ipsilateral matching method. Despite both assessments measuring position sense sensitivity of the elbow, they were poorly linearly correlated with each other. Based on the findings, the study demonstrated that the psychophysical method provided a more precise measure of proprioceptive sensitivity at the elbow than the ipsilateral matching method.