Fingering technique that maximizes the power of the little finger [Things guitarists should know about their body]

Hello!
My name is Takuto Fujioka, guitarist in an acoustic unit called BABY BABY and an occupational therapist.

This time again is about fingering.
Have you ever been concerned that your little finger is difficult to move when you play a chord or a guitar solo?
What kind of practice do you do in such a case? Do you practice repeatedly until you can play the phrase? Or do you practice chromatically?
Certainly, I think that the movement of the fingers will become smoother little by little through repeated practice and motor learning. Of course, repetitive practice is also important.
Would you like to know if there is a way to maximize the power of your little finger on top of that? Today I would like to talk about how to maximize the ability of your little finger!

From the start, I will write the most important points this time. It is the positional relationship between the thumb and little finger.

First, let's check the position of the thumb when you feel that your little finger is difficult to move. In my case, I used to take a form where my thumb opened outward.
This form supports the back of the neck on the surface, so it can handle phrases that move sideways, but it was difficult to apply force to the little finger and it was difficult to move quickly.

This is a structural problem of the hand, and with this positional relationship between the thumb and little finger, the innate power of the little finger cannot be exerted. So how can you bring out the innate power of your little finger?

I will tell you the conclusion first.
Bring your thumb to the middle finger and inside your hand. Then, try pressing the strings by imagining that the tips of your thumb and little finger are aligned.

It may be difficult to understand in words, but please see the photo as an example. What do you think? Has the force applied or the accuracy of the movement changed?

From here, I will briefly explain why the little finger becomes easier to move when the position of the thumb changes. If you are interested, please read this to the end.

The point is the action of aligning the tips of the thumb and little finger. In kinematics it is called a confrontational movement.
In the very first image, the thumb position is on the outside of the palm. If you move your little finger in this state, the flexor digiti minimi muscle, which bends the little finger, works and causes the little finger to bend.

In the form shown in the second photo, the thumb moves to the inside of the hand and supports the neck. The movement of the thumb inward in this way is called the confrontational movement of the thumb.
Also, if you move the little finger in this state, the little finger's confrontational movement will occur instead of the flexion movement. The confrontational movement of the thumb and little finger causes a pinching motion. This is called a fingertip knob in kinematics.
In other words, the confrontational movement (fingertip knob) performed at the same time as the thumb is superior in power and delicacy to the flexion movement of the little finger alone.

Like this time, knowing the structure of the body and how to move it kinematically makes sense, so you may find it easier to play phrases that you couldn't play before! On the contrary, it may be difficult for some people to play, so please use it for your own playing as a reference only!

If you have any questions or concerns, "How is my playing?", Please contact me from my official LINE account (https://lin.ee/6AGJ9JX)! I will answer your questions to the best of my ability (^ ω ^)
See you next time!