Reliability of the MMAAS in patients with multiple sclerosis

Abstract

In the management of multiple sclerosis (MS) moderate exercise has been shown to improve the patients’ physical fitness, walking as well as quality of life, particularly through a combination of resistance and endurance training . Alternative forms of exercise training both for upper and lower limbs include the use of robot-mediated therapy, which has gained support, mainly in stroke rehabilitation, as an established method to provide treatment of the same quality as that provided by a trained therapist for the improvement of motor function. However in the management of MS there is still limited evidence on the benefits of this treatment. MS patients who used a robot-controlled manipulandum have been shown to adapt to haptic force fields, and additional evidence indicates that upper limb motor coordination also improved mainly in patients with ataxia who performed reaching tasks using, again, a robotic manipulandum. Several research groups have begun to investigate the effect of upper limb training in MS using virtual reality and robot-based exercise programmes for wheelchair-bound patients who presented muscle weakness. In the course of the Interreg IV project we developed a robot-mediated virtual learning environment, named ITRAVLE (Individualized Technology and Robot-Assisted Virtual Learning Environment) that can provide upper limb therapy to subjects recovering from neurological conditions. However in order to assess the effect of robot therapy on the quality of a patient’s arm movements, clinically interpretable outcome measures should become available. In addition to the dynamic measurements recorded by the robot, kinematic measurements of compensation, muscle and joint activity provide the most objective methods to monitor and quantify clinical progresses. In order to obtain more objective measurements a portable motion capture system (Motion and Muscle Ambulatory Activity System or MMAAS) was developed to enable wireless monitoring of upper limb function in clinical settings. A system’s reliability is one of the pre-requisites in the clinic. In this study we present a reliability analysis on the measurements carried out using the MMAAS on a group of MS patients who received upper limb robot therapy. The aim of this study is to evaluate whether the test-retest reliability of the MMAAS is sufficient to use it as a clinical assessment tool. We discuss the significance of the results and their implication for remote monitoring of MS subjects receiving therapeutic treatment.