Knowledge of what occurs in the nerves and muscles during a voluntary muscular contraction is still meager, since it is not known even to what extent such a contraction is dependent on reflex mechanisms.1 Extensive work has been done on isolated neuromuscular preparations, but from such experiments alone one cannot hope to understand the activity in the nerves and muscles of the intact body. The chief method available at present for this purpose is that of recording the action currents which may be led off from the contracting muscle, and it is probable that this will prove to be the most satisfactory procedure. The only other method tried thus far, that of recording the muscle sounds, seems to be filled with so many uncontrolled factors that it is practically useless.
Gasser and Newcomer,2 in records taken simultaneously from the efferent nerve and from the contracting muscle itself (phrenic
RICHTER CP, FORD FR. ELECTROMYOGRAPHIC STUDIES IN DIFFERENT TYPES OF NEUROMUSCULAR DISTURBANCES. Arch NeurPsych. 1928;19(4):660-676. doi:10.1001/archneurpsyc.1928.02210100089008