Assessment and Enhancement of Proprioceptive Performance

In daily living activities, proprioception – information about limbs’ position and movement and the force that they applied - is fundamental to respond to the environment and rapidly react to changing circumstances. For example, it allows us to maneuver and find our way around obstacles in the dark and manipulate objects out of view, preventing their slippage. Many neurological conditions and traumatic events affect motor and somatosensory functions. Reliable methods to quantify proprioceptive deficits are crucial for better understanding the pathophysiology of disability, enhancing the detection of early symptoms, and developing novel neuro-rehabilitative approaches to improve upper-limb functions and quality of life. However, in the current formulation of neurological assessment protocols proprioceptive functions are commonly subjectively assessed by clinicians referring to qualitative clinical scales. Furthermore, after stroke the main focus of assessment is on the hemi-body contralateral to the brain lesion side. Less attention is dedicated to the ipsilateral side and to the bimanual coordination. To this end, I will present a new tool to assess after stroke the reciprocal interaction between position sense and force control in bimanual tasks and to compare position sense between the two upper limbs. Supplementary somatosensory feedback is a promising solution to enhance sensorimotor ability and proprioception in unimpaired participants as well as in people with sensorimotor deficits. It is well known that this type of feedback is an effective modulator of plasticity, enhances motor (re-)learning and control, and can also temporally reduce position sense disorders. However, how to encode it and the importance of its informational content are not well investigated. To this end, I will present some projects where I evaluated those features in the vibrotactile feedback to enhance position sense and the related motor outcomes in both unimpaired individuals and people with sensorimotor deficits.