181 Can Movement Modelling Software, in a Digital Preclinical Trial, Help Understand the Optimal Sit to Stand Motion Using Commercially Available Peripheral Nerve Stimulators?

Abstract Aim Ethical approval is difficult to acquire for functional electrical stimulation trials, simulation may bridge the gap between FES concept and clinical trial approval. Using OpenSim modelling tool, this project aims identify minimum number of muscles, their strength order stimulation, that can produce safest standing motion, using commercially available peripheral nerve stimulators. Method Modelling was executed version 4.1 OpenSim, utilising a previously validated, extensively referred to, lower limb model (Gait2354_Simbody) as base model. Starting excitation values emulated previous literature optimal sit stand motion. EMG were inputted function forward dynamics used predict motion given defined neurological values. Muscle groups altered iteratively achieve objective. Once performed required function, within normal joint forces, stopped. Results For movement, muscles included, Gluteus Maximus, Rectus Femoris, Sartorius, Soleus, Tibialis Anterior, Vastus Intermedialis. This exceeded 5-muscle objective, however shared nervous supply could utilise single port. Joint reaction forces remained estimates, knee on tibia in vertical plane achieved 2500N bilaterally, represents force equating 3.64 times body weight. Conclusions Movement software become fundamental tool acquiring ethical studies through full requires iterative improvements by user, therefore which generates automated efficient movements would be more accurate faster.