In order to develop expression of the skill, the athlete first needs the physiological capacity necessary for specific skill expression. Because of this, these constraints set the ground floor for the attractor landscape.
Environmental Constraints
These are external factors, such as weather, terrain, lighting, and social or cultural contexts, that shape the affordance perspectives that guide action selection. One of the interesting insights I’ve had while working in training environments around the world is that motor pattern preferences often seem to be regional. High level Japanese and American pitchers have a clear divide in their movement strategies, likely driven by their learning environment.
Environmental constraints are much more modifiable than most people think they would be. One of my favorite forms of environmental change is playing dance or house music (typically 4/4 or 3/4 tempo, around 128 bpm) that encourages global rhythmic movement in the skill.
Task Specific Constraints
These are constraints that are by definition specific to the task at hand. Implement mass and weight, starting positions, and reward or point systems that define objective success or failure at the task. This blog will primarily focus on task specific constraints.
Between anatomical, environmental, and task specific constraints, there are almost infinite ways a constraint led motor learning approach can be applied. Because of this, it can be extremely to group these possible strategies into clusters, ensuring decision making in the face of infinite options is a practical and systemizable task.
Task Specific Constraint Heuristics for Throwers
There are four specific buckets that task specific constraints can be grouped into. All four of these approaches can be blended to train the desired skill adaptation,
1. Changing the mass of the implement
The classic. Play the hits. Although the use of overload and underload throwing implements has become common place, it’s incredibly important to understand exactly why changing the mass has such a large effect on movement outcomes.
One of the foundational principles of variably loaded ballistic work is that heavier and lighter implements have different effects on motor learning due to the difference in the implements inertia (the tendency of an object to resist a change in its motion).
Overloads and Underloads bias very different force-time shapes, changing the strategy necessary to produce the necessary impulse (area under the force time curve) necessary to change the implements velocity. Overloads will have more total force over a longer period, and a lower peak force. Underload implements will have significantly higher peak forces, and rates of force development, resulting in a much sharper, shorter force curve.
