Wrist proprioceptive acuity: A comprehensive robot-aided assessment

Proprioception is the sense of the body awareness. Proprioceptive deficits represent frequent consequences of several neurological conditions like stroke, Parkinson's disease and others. The assessment of such somatosensory function is crucial, although the available clinical tests are not sensitive enough. The human wrist is a crucial joint for many activities of daily living and to address the lack of its characterization in terms of proprioceptive acuity the authors in previous studies proposed a novel method that combined the use of a 3-DoF robot and a threshold haunting paradigm. Further experiments were performed to characterize the proprioceptive acuity of the dominant wrist for adduction, extension, pronation and supination by using a 2-alternative-forced-choice test. The acuity thresholds obtained from six subjects (mean values ± standard deviation of 1.65±0.39 for extension, 1.13±0.34 for adduction, 1.90±0.58 for pronation and 1.70±0.30 for supination) were finally combined with the ones harvested in the previous studies for flexion and abduction in order to build the first comprehensive database of human wrist proprioceptive acuity.