Dynamic Systems Theory: Movement as Self-Organization
Quick Intro
Dynamic systems theory is an approach to motor control which holds that coordinated movement emerges from the interaction of many parts of the body, the task and the environment, instead of being run by a single motor program stored in the brain. It grew from the work of the Russian physiologist Nikolai Bernstein and developed through researchers such as Scott Kelso and Esther Thelen from the 1980s onward.
The Idea in Plain Terms
Bernstein posed a puzzle in the 1960s, known as the degrees of freedom problem. The human body has hundreds of muscles and many joints, which can combine in a vast number of ways. How does the nervous system pick one coordinated movement without computing every detail?
An older answer was that the brain stores a program for each movement and commands every muscle. Dynamic systems theory proposes a different answer. Patterns of coordination arise naturally from the interaction of the body’s parts, much as a flock of birds forms a pattern with no leader. The ingredients include muscles and tendons that behave like springs, the pull of gravity, the demands of the task and the surroundings.
Key concepts:
- Self-organization. Stable movement patterns emerge from interacting parts.
- Attractors. Preferred, stable patterns that the system settles into, like walking or running gaits.
- Phase transitions. When a control variable such as speed increases, the pattern suddenly shifts, as when a walker breaks into a run.
- Control parameters. The variable whose change triggers a shift, such as speed.
- Variability. Movement is never repeated exactly, and variability has a role in adaptation.
A well-known experiment by Haken, Kelso and Bunz in 1985 had people wag two index fingers in opposition at increasing speeds. At a critical speed, the pattern shifted spontaneously to a symmetric in-phase pattern. The shift behaved like a phase transition in physical systems.
A Worked Example
A coach applying the ideas teaches a child to run:
| Traditional approach | Dynamic systems approach |
|---|---|
| Teach arm position and foot strike by instruction | Change the task, such as running on a hill, over low barriers or at different speeds |
| Correct form with repeated drills | Let the child find stable patterns through varied tasks |
The coach manipulates conditions and lets the movement pattern emerge.
What the Research Shows
Studies of infants support the approach. Thelen’s work showed that stepping reflexes in infants disappeared and reappeared depending on leg weight, as when infants were placed in water, which suggested that body properties and not only brain maturation shaped the behavior. Studies of coordination in adults reveal phase transitions and preferred patterns.
Applied studies in sport are more limited. The theory leads to coaching ideas such as varied practice and manipulating task constraints, and trials comparing these with traditional instruction have mixed or small effects. Critics note that the theory is better at describing how coordination changes than at predicting it.
Dynamic systems thinking is influential in motor learning and rehabilitation, and its coaching recommendations are still being tested.
Who It Suits
This theory helps:
- Coaches who want to design practice conditions.
- Therapists working with movement problems.
- Students of motor control.
How to Use It
- Change the task or environment instead of only giving instructions.
- Allow variation across attempts.
- Look for stable patterns the learner finds.
- Change one constraint at a time.
- Expect sudden shifts in coordination.
- Combine with clear goals and feedback.
Common Misunderstandings
It is not that the brain does nothing.
It is not a rejection of coaching.
It is not fully tested in sport.
FAQ
What is the degrees of freedom problem? The challenge of choosing one movement among countless possibilities.
What is an attractor? A stable movement pattern.
How does it differ from motor program theory? It emphasizes emergence from interaction and not a stored command.
Is it used in practice? Yes, in constraints-based coaching.
Where This Comes From
Bernstein NA, 1967, The Co-ordination and Regulation of Movements (Pergamon Press). Haken H, Kelso JAS and Bunz H, 1985, a theoretical model of phase transitions in human hand movements (Biological Cybernetics, 51, 347 to 356). Kelso JAS, 1995, Dynamic Patterns (MIT Press). Thelen E and Ulrich BD, 1991, hidden skills (Monographs of the Society for Research in Child Development).
Related to: ecological dynamics, Fitts and Posner stages, the contextual interference effect and motor learning progressions.