Chaotic activity during electrical stimulation of paralyzed muscle

In this paper, the authors consider the evoked EMG (EEMG) signal that is obtained using surface electrodes when the quadriceps muscles in paraplegic subjects are stimulated via percutaneous intramuscular electrodes. In this work, the authors explore the chaotic behavior of electrically stimulated muscle. It is found that the state space of the muscle exhibits a strange attractor which has a noninteger correlation dimension. In addition, the correlation dimension increases as the muscle becomes more fatigued.