title: Robot-assisted training of the kinesthetic sense: enhancing proprioception after stroke.
abstract: Proprioception has a crucial role in promoting or hindering motor learning. In particular, an intact position sense strongly correlates with the chances of recovery after stroke. A great majority of neurological patients present both motor dysfunctions and impairments in kinesthesia, but traditional robot and virtual reality training techniques focus either in recovering motor functions or in assessing proprioceptive deficits. An open challenge is to implement effective and reliable tests and training protocols for proprioception that go beyond the mere position sense evaluation and exploit the intrinsic bidirectionality of the kinesthetic sense, which refers to both sense of position and sense of movement. Modulated haptic interaction has a leading role in promoting sensorimotor integration, and it is a natural way to enhance volitional effort. Therefore, we designed a preliminary clinical study to test a new proprioception-based motor training technique for augmenting kinesthetic awareness via haptic feedback. The feedback was provided by a robotic manipulandum and the test involved seven chronic hemiparetic subjects over 3 weeks. The protocol included evaluation sessions that consisted of a psychometric estimate of the subject's kinesthetic sensation, and training sessions, in which the subject executed planar reaching movements in the absence of vision and under a minimally assistive haptic guidance made by sequences of graded force pulses. The bidirectional haptic interaction between the subject and the robot was optimally adapted to each participant in order to achieve a uniform task difficulty over the workspace. All the subjects consistently improved in the perceptual scores as a consequence of training. Moreover, they could minimize the level of haptic guidance in time. Results suggest that the proposed method is effective in enhancing kinesthetic acuity, but the level of impairment may affect the ability of subjects to retain their improvement in time.
authors.affiliation: Motor Learning and Robotic Rehabilitation Laboratory, Department of Robotics, Brain and Cognitive Sciences (RBCS), Istituto Italiano di Tecnologia , Genova , Italy.
authors.forename: Dalia
authors.initials: D
authors.lastname: De Santis
authors.affiliation: Motor Learning and Robotic Rehabilitation Laboratory, Department of Robotics, Brain and Cognitive Sciences (RBCS), Istituto Italiano di Tecnologia , Genova , Italy.
authors.forename: Jacopo
authors.initials: J
authors.lastname: Zenzeri
authors.affiliation: Motor Learning and Robotic Rehabilitation Laboratory, Department of Robotics, Brain and Cognitive Sciences (RBCS), Istituto Italiano di Tecnologia , Genova , Italy ; NeuroLab, Department of Informatics, Bioengineering, Robotics and Systems (DIBRIS), University of Genova , Genova , Italy.
authors.forename: Maura
authors.initials: M
authors.lastname: Casadio
authors.affiliation: Motor Learning and Robotic Rehabilitation Laboratory, Department of Robotics, Brain and Cognitive Sciences (RBCS), Istituto Italiano di Tecnologia , Genova , Italy ; Assistive Robotics and Interactive Ergonomic Systems Laboratory, Division of Mechatronics and Design, Robotic Research Center, School of Mechanical and Aerospace Engineering (MAE), Nanyang Technological University (NTU) , Singapore.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Masia
authors.affiliation: SI4LIFE - Innovation Hub for Elderly and Disabled People , Genova , Italy.
authors.forename: Assunta
authors.initials: A
authors.lastname: Riva
authors.affiliation: Motor Learning and Robotic Rehabilitation Laboratory, Department of Robotics, Brain and Cognitive Sciences (RBCS), Istituto Italiano di Tecnologia , Genova , Italy ; NeuroLab, Department of Informatics, Bioengineering, Robotics and Systems (DIBRIS), University of Genova , Genova , Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Morasso
authors.affiliation: Motor Learning and Robotic Rehabilitation Laboratory, Department of Robotics, Brain and Cognitive Sciences (RBCS), Istituto Italiano di Tecnologia , Genova , Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Squeri
keywords: force perception; haptic interaction; kinesthetic acuity; proprioception; pulsed assistance; robot assistance; robot therapy; stroke survivors