Shoulder Joint Position Sense Can Be Reduced by Sensory Reference Frame Transformations

Joint position sense (JPS) is commonly evaluated using an angle replication protocol with vision occluded. However, multiple sources of sensory information are integrated when moving limbs accurately, not just proprioception. The purpose of this study was to examine different availability of vision during an active JPS protocol at the shoulder. Specifically, the effects of four conditions of vision availability were examined for three target shoulder elevation angles (50°, 70° & 90°): vision occluded continuously (P-P); vision available continuously (VP-VP); vision occluded only during target memorization (P-VP); and vision occluded only during target position replication (VP-P). There were 18 participants ( M age = 21, SD = 1 years). We used separate repeated ANOVAs to examine the effect of condition and target angle on participants’ absolute error (AE, a measure of accuracy) and constant error (CE, a measure of directional bias). We found a significant main effect for condition and angle for both dependent variables ( p