[Purpose] The purpose of this study was to examine physical factors associated with falls by the elderly. We hypothesized that elderly people who had experienced at least one fall in the past 12 months would show a delayed response in the probe reaction time (P-RT) during rhythmic stabilization (RS) compared with elderly people with no history of falls. [Subjects] The subjects were 81 elderly people (37 males, 44 females) , and the subjects were divided into two groups: a Fall group and a No-fall group. [Methods] The simple reaction time (SRT), the P-RT during RS, the maximal resistance force of RS (Max. RF) , the resistance force of RS during P-RT (RF during P-RT) , the trail marking test part-A (TMT-A), and the timed up and go test (TUG) were evaluated. [Results] The Fall group showed longer SRT and P-RT times than the No-fall group and its RF during P-RT was decreased. In logistic regression analysis with fall as the dependent variable, the P-RT was identified as a significant factor, and the cut-off value of the P-RT was 639 ms as evaluated by the Receiver-Operating-Characteristic (ROC) curve. [Conclusion] We found that P-RT is both reliable and useful for the evaluation of the fall risk of the elderly.