Robotic Exoskeletons: A Perspective for the Rehabilitation of Arm Coordination in Stroke Patients

Abstract

Upper-limb impairment after stroke is caused by weakness, loss of individual joint control, spasticity, and abnormal synergies. Upper-limb movement frequently involves abnormal, stereotyped, and fixed synergies, likely related to the increased use of sub-cortical networks following the stroke. The flexible coordination of the shoulder and elbow joints is also disrupted. New methods for motor learning, based on the stimulation of activity-dependent neural plasticity have been developed. These include robots that can adaptively assist active movements and generate many movement repetitions. However, most of these robots only control the movement of the hand in space. The aim of the present text is to analyze the potential of robotic exoskeletons to specifically rehabilitate joint motion and particularly inter-joint coordination. First, a review of studies on upper-limb coordination in stroke patients is presented and the potential for recovery of coordination is examined. Second, issues relating to the mechanical design of exoskeletons and the transmission of constraints between the robotic and human limbs are discussed. The third section considers the development of different methods to control exoskeletons: existing rehabilitation devices and approaches to the control and rehabilitation of joint coordinations are then reviewed, along with preliminary clinical results available. Finally, perspectives and future strategies for the design of control mechanisms for rehabilitation exoskeletons are discussed.

The spasticity in the motor and functional disability in adults with post-stroke hemiparetic

“…The lower limb presented FM mean score corresponding to 54.56% of motor recovery. Movement disorders following stroke may also be due to loss of strength and motor ability, because of disconnected interarticular coordination or pathological synergies (21).…”

A Brief Review on Robotic Exoskeletons for Upper Extremity Rehabilitation to Find the Gap between Research Porotype and Commercial Type

“…Despite development of many exoskeletons, there are a few exoskeletons available in the market for post-stroke patient's upper limb rehabilitation hitherto though. The first commercial upper limb exoskeleton for rehabilitation i.e., Armin was introduced at 2011 [22,113]. By the way, the ground floor hardware issues that needs to be solved to make exoskeletons nobler would be discussed in this section.…”

Design and evaluation of a new exoskeleton for gait rehabilitation

“…This principle according to which the exoskeleton replicates the desired joint trajectory corresponding to an experimental data set acquired from a healthy person is implemented to exoskeletons like HAL, Rewalk and Mindwalker (Wang et al, 2015a). Exoskeletons for industrial application are presented in de Looze et al (2016), powered exoskeletons in post -stroke rehabilitation are studied in Louie et al (2016) and for arm rehabilitation in Schorsch et al (2014); Jarrassé et al (2014). The aspect of control systems of active exoskeletons is studied in Anama et al (2012), while aspects of exoskeleton design, path planning, modeling and simulation, experimental tests are studied by Carbone et al (2007); Ashkani et al (2016); Wang et al (2015b); Ceccarelli et al (2009).…”