phasic muscles pilates and movement

What are tonic and phasic muscles (and why should I care)?

Understanding tonic and phasic muscles Tonic and phasic muscle theory originated in the late 1960s with Dr. Vladimir Janda, a Czech neurologist and physiotherapist.  Using electromyography (EMG), Dr. Janda found that some muscles are practically always active and seemingly resistant to fatigue, while others fatigue easily and are only active when deliberately called upon. Dr.…