Upper Extremity Paresis

Stroke survivors included in this research [n = 17] participated in the clinical trial E-BRAiN and completed the 2-week course of humanoid robot-led therapy. They received ten arm rehabilitation sessions (one introductory session with a human therapist and nine sessions with the humanoid robot) as either the arm basis training (ABT) for moderate-to-severe arm paresis [n = 9] or arm ability training (AAT) for mild arm paresis [n = 8] using the digital therapy system E-BRAiN with a humanoid robot as the therapeutic agent.
Stroke survivors with a residual arm and hand paresis who could move their arm well against gravity (shoulder abduction and elbow flexion strength ≥4 out of 5 strength grades) have no more than moderate paresis of their fingers (index and thumb strength ≥3 out of 5 strength grades), preserved selective movements of their fingers, and were capable of grasping small objects qualified for the category “mild arm paresis”, and hence, in AAT, those with more severe arm paresis (not fulfilling ≥1 criterion for mild arm paresis) fell into the category “moderate-to-severe arm paresis” and received ABT.
The AAT trains the sensorimotor efficiency by repetitive training. Eight tasks address different sensorimotor abilities such as aiming, steadiness, speed of finger movements, and finger and gross manual dexterity. During each therapeutic session, each of the eight tasks is repetitively practiced at the performance limit over four runs, each lasting approximately 1 min, while feedback as a summary of the knowledge of the results is provided intermittently. The trainee aims at improving her/his sensorimotor performance constantly. The ABT trains the selective movement capacity for individual joints of the arm and hand by repetitive movement attempts across the full range of passive movements in various directions for the shoulder, elbow, forearm, wrist, and fingers, addressed individually in a sequential way and physically assisted as needed. The graded exercises start with a single degree of freedom of the movements for all segments of the affected limb; each movement (selective active movement across the full range of a passive movement) is performed repetitively each day with assistance (e.g., weight support and completion of a movement) by a healthy subject (in the conventional setting a trained therapist) as needed (Platz, 2004 (link); Platz et al., 2009 (link)).
During the first introductory session, the participants learnt how to perform the standardised training (AAT or ABT), while the human therapist in addition noted and decided on the individualisations indicated that were then used as prescriptions for the digital therapy system E-BRAiN.
During the nine consecutive sessions, the therapeutic training was led by the humanoid robot (“robot”) providing therapeutic interaction as implemented in the digital system based on both training standards and individualisation algorithms. For safety reasons and to step in if needed, all humanoid robot-led sessions were accompanied by a supervising staff (“therapist”). The participants with moderate-to-severe arm paresis receiving the arm basis training could not necessarily perform all training movements by themselves and could perform them only to a variable degree, e.g., only with a limb weight support or over a limited range. Since the robot could not provide physical assistance and served as a social agent only (therapeutic interaction), these participants received physical assistance as needed provided by a “helper.” The helper was not a trained therapist, but was also using the instructions provided by the robot. In this research, the helper was a non-therapeutic staff member (e.g., a person with administrative or scientific duties).