The relation of frequency and extent of action currents to intensity of muscular contraction.

An action current study of handedness in relation to stuttering.

“…Regardless of the handedness of the subjects records were taken from the right forearm first. As determined by our previous study (12) our present procedure eliminated fatigue as a factor in influencing our results.…”

“…Results.-In a previous study (12) we determined that up to a certain amount of contraction there was an increase in action current frequency with an increase in intensity of mus- cular contraction. Beyond a certain amount of contraction the frequency of the action currents decreased (Fig.…”

“…Why is the critical point greater in the preferred than in the non-preferred arm of normal speakers? In regard to the first question Richter (27) and Travis and Lindsley (12) found that as contraction approaches a certain intensity the action current waves become more regular and the small projections on the sides or in the troughs of the waves (Nebenzachen) disappear. This would result naturally in an apparent reduction in the number or frequency of the action currents.…”

Measurement of Kinesthetic Perception of Muscular Force with Muscle Potential Changes

“…Since numerous investigations (3,4,7,10) indicate that muscle potentials increase as a function of the force over a fairly wide range of muscular exertion, it should be possible to substitute the potential changes for the customary scales and dynamometers. With a modern electronic amplification system for the study of muscle potentials, it would only be necessary to provide some sort of calibrated meter to register the muscle potential voltages.…”

An electromyographic study with respect to speed of movement and latency, disparate and reciprocal innervation, attention and relaxation.

“…Speed and latency. Adrian (2), Richter (19) and Travis and Lindsley (25) have found that there is an increase in frequency of action currents with increase in intensity of muscular contraction. Speed of contraction was not measured by any of these workers.…”