The relationship between the initiation timing of fast forearm movement and respiratory rhythm

A case of spontaneous initiation of movement

Abstract

Respiratory rhythms were analyzed in relation to spontaneous initiation of fast flexion and extension of the forearm around the elbow joint. Forty-one right-handed healthy adults (twenty-seven males, 19-35 years old and fourteen females, 20-33 years old) were adopted as the subjects. Main findings are: 1) the duration of the inspiratory and/or expiratory phases varies in a subject-specific direction up to the movement onset, 2) conspicuous shortening of the expiratory phase duration occurs just before the movement onset in many subjects starting their movement in the inspiratory phase, 3) each subject has his particular pattern of distribution of initiation timings over a respiratory cycle, and 4) there is no respiratory phase in which the fast forearm movement is spontaneously initiated more frequently than in the other phase.