1. Dynamics of walking to music Leon van Noorden & Frederik Styns IPEM-Dept. of Musicology Ghent University, Belgium leonvannoorden@mac.com

2. introduction Van Noorden and Moelants (1999) have shown that many phenomena in rhythm perception/production can be explained by a resonance phenomenon with a peak close to 2 Hz. Recently MacDougall and Moore (2005) also found a peak at 2 Hz after measuring the body movements of people during a whole day. They found that this peak was due to the locomotion system and they linked this to the study of Van Noorden and Moelants (1999). Studying the relation between music and walking might lead to a scientifically based choice of music for fitness and sports training.

3. Experiment 1: walking on music of different tempi 20 subjects IPOD: 68 music + 13 metronome fragments, 1 minute, 50-190 BPM Measuring walking speed: Garmin GPS watch Measuring heart Rhythm: Garmin GPS watch Measuring step frequency: audio-recording of foot fall with mp3 recorder

4. Relation between walking tempo (bpm) and walking speed (km/h). These results show a clear discontinuity at 2 Hz.

5. There is a strong resemblance with the data of Bertram (2005): the red lines are the predicted loci of the lowest energy in human walking, the black lines are the measurements of the walking speed under frequency constraints

6. Experiment 2: walking on music of the same tempo, various styles In experiment 1 subjects walked faster on the music fragments than on the metronome fragments of the same tempo. In experiment 2 we studied whether we could also find a difference between musical fragments of the same tempo. 18 subjects IPOD: 52 music + 6 metronome fragments, 30 sec all 130 BPM measuring walking kinematics with Xsens

7. Preliminary results: Not all subjects show an equal impact of the music on their walking distance (see figure below). There is music that makes the ‘sensitive’ subjects walk faster and other music that makes them walk slower in comparison with the more neutral metronome fragments. The subjects agree upon what are ‘fast’ music fragments and ‘slow’ music fragments. The impact for the ‘sensitive’ subjects of the ‘slow’ music tends to be bigger than the ‘fast’ music in comparison with the subjects who don’t show any impact.

9. Cyclograms: angle thigh-shank (y) vs angle thigh (x) for 6 subjects and 6 musical fragments

10. References Bertram, J. E. A. (2005). Constrained optimization in human walking: Cost minimization and gait plasticity. Journal of Experimental Biology, 208, 979–991. McDougal l, HG., & Moore, ST(2005). Marching to the beat of the same drummer. Journal of applied physiology, 99, 1164- 1173. Styns, F., Van Noorden, L., Moelants, D., Leman, M. (2007). Walking on music. Human movement science, 26, 769-785. Van Noorden, L., & Moelants, D. (1999). Resonance in the perception of musical pulse. Journal of new music research, 28, 43-66.