In this paper, we propose to use the minimum jerk principle for representing on-line signatures. We briefly describe the minimum jerk model and the automatic procedure we propose for its implementation with signatures. Results on the MCYT-100 signature database are analysed regarding reconstruction error, residual analysis and stability. These results show that, despite its simplicity, the proposed model agrees with previous works on signature modelling and entropy-based signature categorization. Finally, possible applications and future works are suggested.