Digital Theses Archive


Tesi etd-03182020-151658

Type of thesis
The effects on proprioception of the vibration induced illusion of movements
Scientific disciplinary sector
Istituto di Biorobotica
Istituto di Biorobotica - BIOROBOTICS
  • Proprioception
  • Kinaesthetic Feedback
Exam session start date
Close your eyes and touch your nose with your finger. The ability to perform such a simple action is due to our internal sense called proprioception. Proprioception is a self-perception of the body that unconsciously provides information to the central nervous system about positions and movements of our body parts. This internal sense is of primary importance in the sensory-motor control to continuously estimate, compare and adjust the ongoing movements. Although the development of technologies such as microneurography and magnetic resonance imaging brings new scientific insights, the complexity and processing of proprioceptive sensory feedback is still unknown. A useful tool to investigate proprioception are vibrations induced illusion of movements. The non-invasive vibrations applied over muscle or tendon can elicit movement sensations directly activating the receptor of the stimulated muscle without promoting any actual movement. Since its first implementation, the use of vibrations induced illusion of movement was largely adopted to understand the neural mechanisms of proprioception and evaluate its impact in able bodied and people affected by motor deficits. <br>Starting from these considerations, three studies were conducted to characterize the vibration-induced illusion of movements using three different perspectives. The first study focused on a technical aspect of the vibration to better understand how the induced sensation is affected by vibration features. In particular the effects on perception caused by preload force and point of application of the vibrator were investigated. The second work concentrated on the effects on the embodiment of a robotic hand when vibration induced illusion of movements substitute or interfere with the natural proprioception. Using a modified version of the well-known ‘Rubber Hand Illusion’, the multisensory system composed of proprioceptive and visual feedbacks were tested while the hand fingers performed a voluntary tapping movement or when they were simply maintained in position. Finally, in the last study the vibrations induced illusion of movements were evaluated from a functional point of view. A reaching task was conducted on able bodied and people who had suffered a stroke to understand whether vibrations applied over the biceps brachii or triceps brachii might improve motor performance.<br>