Data is not the beginning of change. Replication is.
  • Data is important to understand the movement, it can be added to experience, wisdom and science, and turned into Insight.
  • This Insight may drive an action or decision - if and how to change a motor pattern.
  • Either way, the coach still needs to communicate that action or decision to the athlete. The athlete still needs to understand,  execute, and more importantly,  Replicate the new pattern.
  • There are many data collection  systems that are used to understand sport movement, so it can be learned more efficiently. Many systems use Video or Motion Capture  of an athletes’ performance for later review or further analysis, AFTER the movement has Already happened. However...
Seeing a Mistake Afterwards is not the same as Feeling a Correction in Real-time.

Replication is the beginning of change and remember that widely known saying, Practice Makes Perfect? Well hold on...
 The saying may still need tweaking…
  • Human movement contains tiny variable differences in supposedly repetitive motions. Seemingly identical movements may not be identical, after examination of tiny micro-variations in motions of sport skills.
  • There may be a correlation in elite motor performance and the ability to adapt to this inherent movement variability.
  • Current pedagogy techniques like occlusion training, compensation and basic cross-training already encourage neural adaptations in movement. The concept movement of variability provides support for the mechanisms behind the effectiveness of these techniques.
  • Research suggests the ability to adapt (movement adaptation strategies) can be taught, to help an athlete adjust to the inherent movement variability for better performance.
  • Purposely training the ability to adapt,  i.e. training kinesthetic awareness, instead of training to perfect,  will improve motor performance.
The KAT system Captures the Desired Motion, and then helps the wearer Correct the Motion, with instructive vibrations FELT through the sensors DURING the movement.

The Brain's Model

Skill Progression & Proprioceptive Occlusion

by Dr. Jo Shattuck


Dynamical Systems Perspective

The dynamical systems perspective (DSP) suggests that human movement contains inherently varying patterns, even when the individual intends to repeat the same movement. Rhythmic movements like walking/running and trained discreet movements like a golf swing or racquet swing have subtle variations in the degrees of movement. The DSP in regard to human performance suggests that those with a wide range of movement variability have increased capacity to adapt during a movement than those who have a smaller range of movement variability. Consistent performance outcomes that repeatedly occur with variable patterns of movement suggest that motor control strategies are in place to adapt to these variations.


Small low cost sensors in motion capture technology have resulted in a surge in data collection of biomechanical movement variability. Analysis of the data suggests that seemingly repetitive motion (identical movements as those used in running, biking, pitching) have inherent subtle variations in the relative positions, angles, speeds and muscle tension of body parts, without a change in result.

For example, a golfer may appear to have the ‘same’ swing from the naked eye, but when examined on a micro scale, very small biomechanical changes are taking place within each swing, without a change the club's head speed, arc of the ball or, result of the effort.  How is this possible?*

What is Movement Variability?

This theory of human movement implies that the human body is always compensating for the random variations in its movement, (movement variability) due to many different factors- fatigue for example (a pitcher is not the same physiologically in the first inning as he is by the 5th inning.)  These tiny movement compensations are the body’s way of adapting to the inherent movement variability. During a swing, if a golfer's hips are not ‘loaded’ enough, she may speed up the rotation of her upper body.  If her elbow is too stiff, she may loosen her wrist. These minute changes are detectable only with high-speed sensors.

What is External and Internal Cueing?

External and Internal Cueing are verbal commands used by movement educators that help an athlete direct their focus of attention.  An external locus of attention is a point in the environment by which  an athlete can visually reference or compare their body - in relation to their actions.  A movement educator can offer external cues with language, by asking a learner to focus their attention on something, an object, or target that is outside their body, during a movement, whereas an internal cue is usually a part of the body or process of moving a body part.

Examples of Internal
and External Cues

In basketball  free throws, an external cue command could be "focus on the back of the rim", which is an external cue, as opposed to "focus on the wrist motion" - which is an internal cue, in this case - a part of the body.  External cues depend heavily on the visual system, which is the most dominant of the sensory inputs. However the body does not need visual input to know where it is in time and space.  See Visual occlusion training. It is used in training to augment/encourage other sensory inputs -  to help an athlete become more aware of other sensations.

What is Kinesthetic Awareness?

Kinesthetic awareness is also called body awareness. It is a person's knowledge of the location  and movement (in space and time)  in relation to the world around them.  This process to create this continual awareness occurs primarily in the subconscious. The brain creates a model -much like a 3d map - of the body in the world by constantly comparing incoming external and internal information. (See phasic and phasi-tonic receptors)

Adaptability and Neuroplasticity

Neuroplasticity and compensation to change are the benchmarks of motor learning that are revealed in elite performance. A highly skilled quarterback can throw an accurate pass while the ‘usual’ mechanics are not available to him, for example while he is being tackled, or having his arm grabbed. And an elite tennis player can perform very well while playing with a frying pan instead of a racquet. High performance in these examples are demonstrations of advanced motor control strategies-aka adaptability.

Why Does Movement Variability Exist?

It could be related to Entropy: the scientific principle that all organized systems eventually become disorganized. But the better question perhaps?  Is movement variability beneficial to human performance?  Some researchers think it helps to avoid repetitive use injury, aids in conservation of resources (muscle fuel), or helps distribute the physical demands of the tasks across body parts in changing environments.

What is Occlusion Training?

Many pedagogical techniques, especially in sport specificity training, occlude necessary sensory input during the execution a skill. This technique trains the athlete to ‘find a different way’ to get the outcome they want. Researchers sometimes call these ‘task constraints’.  Trainers and coaches sometimes call it compensation training, in accordance with the constraint led approach to motor skill instruction.

Movement Variability in Specific Skills

There are different physical and temporal (time-related) demands for closed/discreet skills, those with a beginning and end (pitching, basketball, free throws, American football field goal kicks) when compared to open/fluid skills (running route to tackle an opponent in rugby, or a crossover-dribble-head-fake- jump-shot in basketball. These more complex skills are often multiple discreet skills sequenced together in a longer movement. 

Sport Context and Movement Variability

Additionally, different situations in all sports demand alternating attention between internal and external cues. Both offense and defense require predicting, and then reacting to external cues. While other continuous repetitive skills (cycling, running, rowing) require sensing more internal movement cues from one’s own body. In general, the role of movement variability for different types of sports, positions, and unique skills is still being explored.  The most useful studies in a human performance would reveal an optimal level of movement variability and adaptation strategies correlated with performance measures and injury rates.

Yes but…

The most robust experiment is the real-world environment  including real world competition, which generally is comprised of practice-then-performance. Instead of training an athlete to achieve automaticity, I suggest training for ‘elite automaticity’  - train to achieve a wider bandwidth in which elite performance occurs, to adapt to environmental changes both internal factors and external factors by training kinesthetic awareness AND adaptation strategies:

- Dr. Jo Shattuck
Link to Reference Page

*Bernstein's Degrees of Freedom

The question is an example of Bernstein’s degrees of freedom problem in biomechanics.  A metaphor: In short, there are multiple available routes to drive to the store, but it is impossible determine which route a person drove, if the only information available is their final destination.


Principles of Athletics and Neuroscience Towards Human ExpeRtise