Auto-regressive Backpropagation Complex nonlinear system Joints (anatomy) Mean square error Muscle Neural networks Nonlinear systems Back propagation neural networks Backpropagation algorithms Logical modeling Muscle modeling Neural network model Non-linear model artificial neural network backpropagation nonlinear autoregressive quadriceps muscle Deep neural networks E-learning Hybrid Particle Swarm Optimization Information set Neural systems Non-linear modelling Non-linear relationships Nonlinear auto-regressive moving averages Optimization Particle swarm optimization (PSO) Planning data Statistical tests