107 1-4244-1525-X/07/$25.00 © 2007 IEEE  Abstract—An interactive software assistant (SimScript) has been developed to help in the design of neuromuscular tests and in the analysis of data gathered from these tests. The tool is based on the Kinematic Theory of rapid human movements and its Sigma-Lognormal ( Λ Σ G ) model. It allows the manipulation of the movement kinematics using analytical expressions. Although the project is still exploratory, current work focuses on three long term objectives: improvement of clinical rehabilitation results from stroke-impaired patients, lowering medical cost by helping in the development of at-home rehabilitation exercises and the development of a deeper understanding of the human neuromuscular kinematics properties. This paper briefly summarizes the Λ Σ G model, presents the properties and possibilities of SimScript and presents an example of practical application. Index Terms— movement kinematics, rehabilitation, lognormal, neuromuscular test. I. INTRODUCTION ith the developments of modern medicine and the increasing aging population in occident, medical health care systems are becoming more and more expensive. A key solution to avoid medical care costs from becoming prohibitive resides in the development of new strategies in the diagnostic and treatment of diseases, schemes that are cheaper without compromising the human quality of the service offered to the patients. To alleviate the pressure on medical staff dealing with the increasing number of patient needing time-consuming rehabilitation therapy, some research teams have oriented their work around robot-assisted therapy ([1], [2]). In an complementary way, other teams preferred to work on cheaper software solution. Virtual reality framework used for rehabilitation [3] is an example of such an approach. With similar goals in mind, we have developed a software tool that aims at planning and analyzing clinical tests designed to study neuromuscular systems under a Λ Σ G paradigm. The following sections present the mathematical model used in this study, the software tool developed from its representation scheme and finally an example of its potential application.  II. KINEMATICS THEORY OF RAPID HUMAN MOVEMENT A. Generalities The Kinematics Theory of rapid human movements ([4], [5], [6] and [7]) represents a neuromuscular system as a lognormal actuator moving a structure around a rotating point. The synergy emerging from the interaction and coupling of many of these neuromuscular systems results in the sequential generation of complex movements. This representation scheme has been mathematically supported from a theoretical point of view [4]. Furthermore, the analytical formulation of movement kinematics provides the opportunity to go far beyond simple experimental curve fitting. It allows the prediction as well as the analysis of the kinematics associated with a given neuromuscular task [8], offering opportunities for practical applications in many fields [9], particularly in biomedical engineering. B. The action of a neuromuscular system As previously stated, the magnitude of the velocity of a simple rapid movement is lognormal and is scaled by a command issued at a given time t 0 , as shown in (1). [ ]           - - - - = 2 2 0 0 2 ) ln( exp 2 ) ( ) ( σ μ π σ t t t t D t v G (1) From the hypothesis of movement acting along a rotating point – real or virtual – the angular position (3) can be calculated from angular velocity (2). ) ( ) ( t v D t v s e G G θ θ - = ∠ (2) ∫ - + = t s e s d v D t 0 ) ( ) ( τ τ θ θ θ φ G (3) Table I describes the meaning of parameters used with their corresponding units in the S.I. system. W A software assistant for the design and analysis of neuromuscular tests Christian O’Reilly & Réjean Plamondon École Polytechnique de Montréal, Laboratoire Scribens, Département de Génie Électrique, C.P. 6079, Succursale Centre-Ville, Montréal QC, H3C 3A7, Canada { christian.oreilly, rejean.plamondon}@polymtl.ca