Condition to produce oscillation after twitch shortening in the bullfrog geniohyoid muscle

Two different types of elastic behaviors could be distinguished in the twitch contraction curve of the isolated frog geniohyoid muscle under changing of chemical conditions; one was negative oscillation that occurred after completion of the relaxation phase which was sequential to a typical cyclic pattern demonstrated in the contraction and relaxation period, and the other was oscillation which occurred in the phase of plateau formation during relaxation. The former will relate to the parallel elastic component (the effect of caffeine combined with a low Ca++ condition) and the latter will to the series one (collagenase and dantrolene). The causal or genetic relationship is not yet clarified.