A Novel Approach to Neuromotor Rehabilitation for People with Spinal Cord Injury: from Objective Functional Assessment to Personalized Dyadic Training

Cervical spinal cord injury (cSCI) is a severe health condition that significantly impairs neuromotor functions below the lesion site, often resulting in partial or complete tetraplegia. Rehabilitation focusing on arm function is a high priority for these individuals, as even small improvements can significantly enhance quality of life and independence. While the incorporation of robotic devices into conventional therapy has shown potential in improving rehabilitation outcomes for cSCI, these systems have several shortcomings. They are often costly, lack customization based on individual neuromotor deficits, and are usually deployed by clinicians without thorough objective assessments. Furthermore, these devices don’t fully address the challenges faced by healthcare facilities, particularly the strain due to increasing patient-physiotherapist ratios. Recognizing these limitations, the aim of this project is to introduce a comprehensive approach to neuromotor rehabilitation for people with cSCI. This approach incorporates two key elements: (i) objective functional assessments to accurately and quantitatively characterize the upper limb neuromotor impairments of cSCI individuals; (ii) a rehabilitation treatment that considers individual rehabilitation goals and healthcare facility needs by targeting personal recovery using interactive dyadic therapy. Standard clinical assessments typically rely on qualitative or discrete measures, which may inadequately capture the nuanced motor impairments specific to cSCI individuals. Instrumental systems like motion capture and electromyography offer the potential for a more objective evaluation. However, these systems are not often incorporated into daily clinical practice due to the absence of standardized guidelines. This project aims to bridge this gap by introducing a new evaluation approach designed to supplement clinical tests with instrumented-based assessments, employing both optoelectronic and electromyographic systems. As for the adoption of personalized yet feasible rehabilitation treatments, in recent years, there has been a growing interest in including joint therapy sessions, leveraging enhanced motivation and time-cost efficiency. However, these therapies usually lack innovation and personal focus compared to one-on-one settings, rendering them unsuitable for people with cSCI who commonly present a spectrum of heterogeneous impairments, making it impractical for them to engage in identical activities. Body-Machine Interfaces (BoMIs), low-cost systems proven to be effective in providing tailored rehabilitation for cSCI individuals in individualized settings, could offer a viable solution to this issue. This project aims to optimize these systems by developing a novel BoMI that offers individualized treatment plans while also featuring an adaptive design for interactive dyadic practice sessions. This design allows for two patients to train simultaneously, thereby optimizing resources and potentially improving rehabilitation outcomes. By utilizing selected body motions to control a common external object, such as a computer cursor, the system allows the concurrent involvement of two participants, all while personalizing their engagement according to their distinctive abilities. The BoMI was validated on unimpaired individuals and preliminary tested on cSCI individuals. Both tests examined a dyadic synergic reaching task, an activity that is underexplored in literature and less likely to induce stress or anxiety, and an individual reaching task. The former test was conducted to investigate how the interaction would influence the learning process in unimpaired individuals. The latter was conducted to evaluate the potential of the BoMI as a motor training tool for cSCI individuals. The results obtained for the two key elements of this project demonstrated the promising impact of the proposed multi-facet approach. The functional assessments offered a comprehensive understanding of the different neuromotor alterations induced by cSCI. The setup, protocol and analysis selected were able to unveil the neuromuscular mechanisms and compensatory strategies employed by cSCI to complete tasks of diverse nature and complexity, including unilateral and bilateral coordinated arm movements. Moreover, the investigation of the effects of the BoMI on unimpaired individuals provided valuable insights both into motor learning theory and the optimization of the system for cSCI rehabilitation. When performing the shared dyadic task using an interface map built by concatenating the map used by each participant during the individual task, each pair of unimpaired participants displayed divergent behaviors, with one individual contributing less to the task solution and exhibiting changes in the adopted internal model. Leveraging on these findings, the BoMI protocol was adapted and tested on cSCI individuals. The outcomes of this study confirmed the feasibility and potential effectiveness of the BoMI as a tool for incorporating interactive motor training into the treatment of such a heterogeneous population. Cervical SCI participants, that used the BoMI with a personalized interface map and underwent multisession training with the interface, were able to learn how to proficiently use the system and overall reacted positively to the dyadic interaction. These results are promising for the inclusion of the proposed approach in the clinical setting, enabling cSCI individuals to undergo highly personalized individual and interactive therapy sessions.