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The science behind motor control: What kind of ability is rhythm?

Akito Miura
Assistant Professor, Faculty of Sport Sciences, Waseda University

Having rhythm is essential in sports. It is not uncommon for top athletes to incorporate dance into their routine practice. For example, speed skater Miho Takagi is famous for having practiced hip hop dancing. What kind of ability is rhythmic coordination skills, and how does it affect athletic competency? Athletes and trainers can instinctively and empirically identify players who have rhythm, and they admit that good rhythmic coordination is crucial for athletic performance. Rhythmic coordination, however, is not a scientifically proven ability; it is based on multiple factors, such as sensory, cognitive, and motor skills. Therefore, studying rhythm becomes difficult.

Scientific exploration of rhythmic coordination first requires quantifying its phenomena. Hence, we face the challenging task of converting rhythm into numerical values. Some people have a good sense of rhythm while others do not. Figuring out how to measure and quantitatively express rhythm would be the first step. For this purpose, I have asked individuals with good and “not-so-great” rhythmic coordination skills to engage in rhythmic motions in the laboratory to investigate the difference between the two groups.

Studying street dancers

Street dancers are rhythmic experts 123. We all know very well that street dancers who display free and fluid movements to music have acquired rhythmic coordination skills to extreme heights. Components of street dance include two basic moves: down-on-the-beat and up-on-the-beat. On down-on-the-beat, dancers bend their knees to the beat (Figure 1A), and on up-on-the-beat, they straighten their knees (Figure 1B). Novices usually show difficulty in performing up-on-the-beat coordination. In my study, participants performed these two moves using a metronome at variable rates. I found that all participants were able to stably and accurately perform the down-on-the-beat at any metronome rate (Figure 2A). They were also able to perform the up-on-the-beat as long as it was slow. When the tempo became faster, however, their up-on-the-beat shifted to down-on-the-beat without realization (Figure 2B). This unintentional change of coordination patterns is called phase transition, which is seen in a wide variety of human motions. For instance, try rhythmically moving your fingers like windshield wipers in the opposite phase (Figure 3 left). The faster you move your fingers, you will find them moving symmetrically in the same phase (Figure 3 right) (4. Interestingly, the phase transition observed in the finger coordination above and street dance can both be expressed by the same differential equation(5. This means that human rhythmic coordination obeys the same rule.

Figure 1: Task movement in the street dancer experiment (cited and modified from Miura et al., 2011(2

Figure 2: Phase transition from the up-on-the-beat to down-on-the-beat. A cycle of the knee-bending motion is expressed in 360 degrees (1–179 degrees: straight knees, 181–359 degrees: bent knees), and the beat (phase angle) is expressed as a histogram. In the down-on-the-beat, the knees flex on the beat (A). In the up-on-the-beat, the knees extend on the beat (proper up-on-the-beat) for a slow beat but flex when the tempo becomes fasters (B) (cited and modified from Miura et al., 2013 (1

Figure 3 Phase transition of the fingers (created based on Kelso, 1984(4

Overcoming phase transition and entrainment

The previous section described phase transition, a phenomenon in which rhythmic motions unintentionally became coordinated into a stereotyped pattern. Something similar also occur in other cases, such as walking in step with someone beside you. This happens due to a function of our nervous system called entrainment. Some zoologists insist this entrainment has evolutionary significance(. According to their theory, humans travelling in small groups would not have been able to hear approaching predators if they had walked in different step with others. They synchronized their footsteps to create silent moments so that they could distinguish noise made by predators. In other words, walking in step with neighboring humans increased their chances of survival.

Regardless, phase transition and entrainment of rhythmic movements can be problematic for coordination in sports and dance. For example, entrainment observed among 100m sprint runners caused them to run unintentionally in step with sprinters running besides them (, which can affect athletic performance. Another example is dance. When movement patterns of dancers dancing to music undergo a phase transition, they lose creativity and freedom in their choreography. In one of my studies of street dancers, I saw that dance experts with years of experience had overcome phase transition from the up-on-the-beat to down-on-the-beat. Mastering rhythmic movements entails conquering phase transition and entrainment ()

Based on the studies to date, this article explained that skillful, rhythmically coordinated performance is free from restrictions such as phase transitions and entrainment caused by nervous system functions. Although we have not yet ascertained the entire picture of this ability called rhythm, we can at least conclude that people without such restrictions are people with good sense of rhythm.


^ 1) Miura, A. et al., Action-perception coordination dynamics of whole-body rhythmic movement in stance: A comparison study of street dancers and non-dancers. Neuroscience Letters. Vol.544, pp. 157-162 (2013)
^ 2) Miura, A. et al., Coordination modes in sensorimotor synchronization of whole-body movement: A study of street dancers and non-dancers. Human Movement Science. Vol.30, pp. 1260-1271 (2011)
^ 3) Miura, A. et al., Finger-to-beat coordination skill of non-dancers, street dancers, and the world champion of a street-dance competition. Frontiers in Psychology. Vol.7, pp. 542 (2016)
^ 4) Kelso, J.A.S., Phase-transitions and critical-behavior in human bimanual coordination. American Journal of Physiology. Vol.246, pp. 1000-1004 (1984)
^ 5) Kelso, J.A.S., Dynamic patterns: The self-organization of brain and behavior. 1995, Cambridge, MA The MIT Press.
^ 6) Larsson, M., Self-generated sounds of locomotion and ventilation and the evolution of human rhythmic abilities. Animal cognition. Vol.17, pp. 1-14 (2014)
^ 7) Varlet, M. and Richardson, M.J., What would be Usain Bolt’s 100-meter sprint world record without Tyson Gay? Unintentional interpersonal synchronization between the two sprinters. Vol.41, pp. 36-41 (2015)
^ 8) Miura, A. et al., Motor Control of Rhythmic Dance from a Dynamical Systems Perspective: A Review. Journal of Dance Medicine & Science. Vol.19, pp. 11-21 (2015)

Akito Miura
Assistant Professor, Faculty of Sport Sciences, Waseda University

Akito Miura graduated from the Department of Medicine and Science in Sport, School of Sport Sciences, Waseda University in 2007 and received his Ph.D. from the Graduate School of Arts and Sciences, Tokyo University in 2012. After his positions as Research Fellow (Post-Doc) at the Japan Society for the Promotion of Science and Visiting Research Fellow at Université Montpellier 1 in France, he became Assistant Professor at the Faculty of Sport Sciences, Waseda University in September 2015. His expertise are sport psychology and neuroscience.