Organism
Anatomy, physiology, perception, intention, experience, current resources, impairments, and action capabilities.
Scientific foundations
Dynamic systems, constraints, and dynamic resources.
A foundation for investigating how movement patterns emerge from changing organismic, task, and environmental constraints, and how coordination and available mechanical and physiological resources contribute to those patterns.
An observed movement pattern is a temporary resolution of interacting constraints, not a direct readout of one structure or impairment.
Holt, Wagenaar, and Saltzman use this position to connect body structure and function with activity and participation while asking what resources and relationships make a particular movement solution possible.
Constraint domains
Constraints restrict possibilities without prescribing one pathway.
Movement changes as the person, task, and environment change. These domains constrain one another, so none provides a sufficient explanation in isolation.
Task
The goal, rules, workload, timing, accuracy, sequence, and success criteria that make some solutions more useful than others.
Environment
Physical forces, surfaces, objects, information, social conditions, and opportunities or restrictions for action.
Two complementary tools
Characterizing organization is not the same as explaining production.
Holt and colleagues distinguish tools for describing how movement is organized from models of the resources and mechanics contributing to the observed pattern.
How is the movement organized?
Coordination patterns, coupling, relative phase, stability, control parameters, and transitions characterize relationships among changing components.
These constructs can describe and predict pattern changes, but they do not alone identify the forces, energy exchanges, or physiological processes producing them.
How can the movement be produced?
Mechanical and physiological models investigate how anatomy, force, timing, energy storage, energy loss, and energy supply contribute to a movement solution.
A resource matters only when it can be recruited in the amount and at the time the task and environment require.
Dynamic resources
Movement depends on more than force capacity.
Available resources can be combined in different proportions for different tasks. Their effective use depends on coordination and environmental context.
- Active forcing
- Appropriately timed muscular force that adds energy to the movement.
- Elastic storage and return
- Muscle, tendon, and other soft tissues acting as springs.
- Pendular exchange
- Segment mass and length supporting exchanges of kinetic and gravitational potential energy.
- Inertia
- Mass distribution and moments of inertia shaping how segments move and couple.
- Damping and braking
- Passive and active processes that dissipate energy, absorb shock, or stop motion.
- Energy supply
- Cardiopulmonary and metabolic processes supporting continued mechanical work.
Rehabilitation consequence
A nonstandard pattern may be an adaptation to available resources.
The question is not only whether a pattern differs from a reference pattern. It is also what the pattern accomplishes, which constraints and resources contribute to it, and what short- and long-term consequences follow.
- 01What functional goal does the movement solution accomplish?
- 02Which organismic, task, and environmental constraints are most influential?
- 03Which resources are available, and are they available at the required time and amount?
- 04What changes when a constraint or resource is manipulated?
- 05Would changing the visible pattern improve the outcome or remove a useful adaptation?
Principal source and limits
Use the framework to generate testable explanations.
Holt, Wagenaar, and Saltzman (2010)
The principal source connects constraints, coordination dynamics, biomechanical models, dynamic resources, locomotor adaptation, and rehabilitation.
Read the published articleInterpretive boundary
Naming constraints does not establish causation. Competing explanations require measurement, manipulation, model comparison, and attention to consequences across tasks and timescales.
Connect explanation to measurement