This book is a science book on dexterity written by the Russian physiologist, Nikolai A Bernstein for the general public. And this book is very unique since the author wrote this book in the 1940s, but wasn’t published until the 1990s.

I think this book is very impressive and I learn so many things about how to exercise the skill of movement.

What is the Dexterity?

Dexterity is the ability to solve athletic tasks correctly, quickly, reasonably using resources.

When Dexterity is needed?

If the movement is simple and not disturbed by anyone/anything, and an unexpected thing has not happened, we don’t need dexterity. We need dexterity when we need to adjust our skills to adapt to changing environments including the precise switching of ongoing movements.

Extended definition of Dexterity 

Dexterity is the ability to find a movement that can be solved in any external situation, that is, the ability to sufficiently solve the problem of the movement that has occurred by satisfying the following conditions.

Right: Appropriately and accurately

Quick: In decision making and in achieving results

Reasonable: Appropriately and economically

Utilizing resources: with wit and foresight

The skillful movement is beautiful as a result. So beauty is not the condition of dexterity.

Dexterity is accumulated with exercise experience. Whenever you exercise, it is certainly desirable or even necessary to emphasize each key feature contained in the definition of dexterity.

Key features of Dexterity 

Right: Appropriately and accurately

The appropriateness and accuracy of movement need to be developed from the beginning. In the early stages, we can pay conscious attention to the detail of the movement. It’s the worst mistake not to pay attention to the quality of the movement in the first stage, as the details of the action will disappear into the automation.

If we are not accurate, we learn the wrong move and will not be able to get rid of bad habits. Therefore it is more effective to exercise for 10 minutes with concentration and intention than to exercise without consideration for 2-3 hours. Even when the skill is close to perfect, we still need attention and intention to focus on the quality of the action result.

Quick: In decision making and in achieving results

Quickness is worth the time to practice, which significantly improves performance. The fastest runner in the world is not the most skillful player in the world.

How to get the Dexterity

Firstly what I learn is why motor control is difficult and how we overcome it.

Why motor control is difficult?

Motor control is difficult when there are so many degrees of freedom of each movement.

There are more than 100 degrees of freedom moving parts on our body and head. And in order to walk, run, and throw, those many moving parts have to perform different movements at the same time. If we pay attention to each element of complicated movements such as muscles and joints and control them individually, we have to allocate a huge amount of attention. The movement we want is very simple like run, walk or throw, and we don’t like to spend our effort on controlling each moving element. So we need to overcome redundant degrees of freedom to simplify those movements.

I can’t imagine how much effort is needed just to walk. We may get exhausted after walking a step or two if we pay attention to each muscle and joint. But in reality, we can walk without paying attention. The one-step or two-step movement has no problem and we don’t get tired.

How about motor control for a machine?

On the other hand, different from the human body, a machine has only 1 degree of freedom, so the movement of the machine is fixed and the exact same route should be used every time. Even if there is a very big and complicated machine, the degree of freedom is “1” then we can combine the movement of each part to build a complicated operation without an error.

How we can overcome a redundant degree of freedom?

We can overcome a redundant degree of freedom by ignoring the middle part of the movement by automation which is described later.

If we think about the movement such as picking up a box, eventually, we will pick up the box, but the path to picking up the box will be different each time. We care about picking up the box but don’t care about the intermediate path.

Sensory correction is the process of coordinating the movement continuously based on the sensing information. And it is necessary for motor coordination.

Building the Motor skills

Building motor skills is a meaningful chain reaction, and the steps cannot be omitted or swapped.

When the brain sends a command to a muscle, the brain can’t know in advance how the body actually moves, because it has a huge number of redundant degrees of freedom. Therefore, the brain has to carefully monitor body movement based on the report from body sensors and keep coordinating the control of body movements.

Repeated movements and actions are necessary to solve motor tasks to find the best way so motor skills take time to develop. 

By the way, motor skills can sometimes be acquired instantly. And once we learn it, we will never forget it.

Automation

is a part of the process of building Motor skills. Automation of motor control is background adjustment, which controls the movement but does not have an independent meaning and does not help another movement. Automation may take up most of the time required to acquire motor skills.

By the way, the automation acquired for skill X can be used for another new skill Y. It’s called skill transfer or training transfer. For example, despite training with only the left hand, the effect appears in the right hand in addition to the left hand.

Coordinating background

is also a part of the process and is needed when old automation interferes with newly acquiring automation. If it happens, we may face the delay of learning a skill or temporary performance down.

There is no need to concern the temporary performance down. Because this is a necessary step to upgrade our skill to a higher performance level. We can take a break from training, reduce the amount of training, or do something different to refresh your mind. If we continue to exercise patiently, we will always have a leap forward in automation.

An example of interferences is adjustments for accuracy and quick movements. It means adjustments for increasing speed cannot achieve a high level of accuracy. So it needs coordination between accuracy control and quick control.

Standardization

is the process that starts with finding a feasible pattern. And then stabilizing the pattern need the help of sensory correction to protect our body from the destructive effects of external force. Once a stable pattern is identified, the role of sensory correction becomes smaller.

Stabilization

is the final process to develop the ability to find immediate solutions in an unexpected situation without confusion. We should focus on the desire to solve athletic tasks as accurately and appropriately as possible. This desire provides a basic and meaningful adjustment to the overall movement.

For example, there is a piano student who mastered passages well in terms of speed and accuracy. What if the piano teacher encourages the student to learn artistic impressions and meaningful sounds rather than learning proper finger movement? The teacher expresses this more concisely and says “listen to the melody you are playing”. Students try to do a higher level of move than their skill level but they can’t do that. The solution is to re-learn everything. Re-learning is more difficult than learning from scratch.

How to maximize exercise

The essence and purpose of the exercise are to improve the movement, that is, to change the movement. Therefore, the correct exercise is repetition without repetition. Instead of repeating one method of solving a certain motor task, the solution process is changed every time and is improved by repeating the solution process.

Thank you for reading this long post! I hope you will find something important.