Design of a new electromechanical platform for ankle sprain simulation and measurement of the muscle reaction time through electromyography

摘要

This work presents the design of a electromechanical platform that simulates an ankle sprain movement in order to measure the electromyographic time response of the ankle muscles. A new technique was employed to measure the initial time of the ankle movement, when the platform starts to fall. This technique uses a precision potentiometer to measure the angular position of the falling platform, so that all mechanical errors which are inherent to the conventional platforms are eliminated. Two data-acquisition boards were designed and implemented. The first board measures the reaction of the ankle muscles, and is basically an electromyograph. The second board measures both the weight on each feet of the patient, and the angular position of the falling platform as a function of the time. Both signal processing boards communicate with a computer through USB ports. A software especially created for the system, developed in Lab VIEW, receives and calculates several parameters from the data acquired from sensors. The system was tested in subjects without ankle sprain history, presenting excellent results. The electromyograph, developed as a part of the platform, can be used in stand-alone mode, in any application where electromyographic measurements are necessary.