Results

1. Stimulator Movement analysis with a new robotic device – the MotionMaker™: a case report F. Reynard, F. Gerber, C. Favre, A. Al-Khodairy Clinique romande de réadaptationSuvaCare, Sion, Switzerland • Introduction • The MotionMaker™ is a stationary robotic system providing rehabilitation possibilities for patients with neurological disorders. • It allows to carry out lower limb mobilisation with an active participation of the paretic/paralysed limbs through residual lower extremity activity and/or electromyostimulation. • It is designed to assess and train the muscle strength and endurance. In this way it prepares the patient for gait activities. • This device consists of : • two motorised orthoses which include hip, knee and ankle joints, • force sensors, • position sensors, • closed loop electrical muscle stimulation. • A central control unit coordinates the electrical stimulation of the muscles and the motors of the orthoses and allows to perform guided and controlled movement. • In this work, moments and forces values were measured during an isokineticleg press movement in extension and analysed in order to identify objectively the performance of the subject and its evolution. • Results • The mean horizontal force produced with the residual strength was initially of 10N for the left leg and of 27N for the right leg. With time, the increase was of 270% (38N) and 460% (148N), respectively. • Hip moment was the greatest on the left side and knee moment on the right side; this remained over time. Interestingly, a left knee flexor moment, instead of an extensor moment, was found when the movement was performed with residual strength or with residual strength + electromyostimulation. That could be the consequence of somatosensoryimpairment that modifies the sensorimotor circuits. • When manual muscle testing (Kendall test) was used to grade the force, improvements were found only on the right quadriceps and triceps surae. • Mean forces and moments were the highest when the movement was performed with electromyostimulation + residual strength: gain of 55% compared to residual strength and of 235% compared to electromyostimulation alone. • Methods • One 37 years-old paraplegic subject (neurological level T12, ASIA impairment scale B) was assessed with the MotionMaker™ 10 and 28 weeks after his injury. • He performed three repetitive leg press movements in extension in three different conditions: - with his residual strength,- with electrical stimulation of the glutei, quadriceps and triceps suraemuscles, - with a combination of residual strength and electromyostimulation. • The leg press movement consists of concentric contraction of the extensor muscles, followed by an eccentric then concentric contraction of the calf muscles and finally eccentric contraction of the extensor muscles. • For each condition, horizontal forces developed at the foot as well as hip, knee and ankle moments were recorded and averaged across the three trials. • The data were compared over time, between the different types of contraction’s conditions, with manual muscle testing and with data of healthy subjects. • When compared to healthy subjects, amplitude values of the paraplegic subject were smaller but the shape of the curves showed strong similarities. • Note that the amplitude scale is different between the paraplegic and healthy subjects to be able to compare the shape of the curves. • Summary & Conclusion • Robotic rehabilitation device such as the MotionMaker™ can measure objectively and precisely the lower extremity force developed during specific movements and can evaluate the relative participation of the different muscles groups. • Problems of force, motor control, coordination and muscle tone can be highlighted. • Consequently, this device can be used to monitor and control the effects of training programs. ESMAC LONDON 2009 17-19 september 2009 Contact : Fabienne.Reynard@crr-suva.ch