Understanding Primitive Reflexes in 5 Minutes

Primitive reflexes – or archaic – are currently the subject of many discussions, whether they praise their merits or highlight the lack of articles proving their usefulness in adults. In the following lines, I will explain what a primitive reflex is in under 5 minutes so you can form your own opinion!

5 minutes, let's go!

How do we move?

Let's start by... not talking about reflexes! To understand how we move, it's essential to go back to the source. Have you ever wondered how our movements occur?It is precisely this reflection that led me to ask questions and find answers that I will share with you.

No need to take a break to search on the Internet; I will reveal the key to you. We move by contracting muscles! Revolutionary, isn't it? But how do we contract our muscles? The answer is simple: "voluntary movements of the body are controlled by the brain".This means that to move, it is necessary to understand how the brain works and, by extension, the nervous system as a whole.

The nervous system operates according to the sensorimotor loop. As its name suggests: sensori- refers to the sensory system, and -motor refers to the motor system. The sensory and motor systems are thus intimately linked.

The question to ask is: who has truly taken an interest in the sensory system when examining movement?

And what about primitive reflexes? We'll get to that a bit later.

First, let's explain how this loop works.

Primitive reflexes – or archaic – are currently the subject of many discussions, whether they praise their merits or highlight the lack of articles proving their usefulness in adults. In the following lines, I will explain what a primitive reflex is in under 5 minutes so you can form your own opinion!

5 minutes, let's go!

How do we move?

Let's start by... not talking about reflexes! To understand how we move, it's essential to go back to the source. Have you ever wondered how our movements occur?It is precisely this reflection that led me to ask questions and find answers that I will share with you.

No need to take a break to search on the Internet; I will reveal the key to you. We move by contracting muscles! Revolutionary, isn't it? But how do we contract our muscles? The answer is simple: "voluntary movements of the body are controlled by the brain".This means that to move, it is necessary to understand how the brain works and, by extension, the nervous system as a whole.

The nervous system operates according to the sensorimotor loop. As its name suggests: sensori- refers to the sensory system, and -motor refers to the motor system. The sensory and motor systems are thus intimately linked.

The question to ask is: who has truly taken an interest in the sensory system when examining movement?

And what about primitive reflexes? We'll get to that a bit later.

First, let's explain how this loop works.

The sensorimotor loop is not limited to the sensory and motor systems; it includes other steps. In simplified terms, we can distinguish 4 steps:

1. The intake of sensory information through various receptors, such as the vestibular system, proprioception (skin, muscles, tendons, etc.), the visual, olfactory, gustatory, and auditory systems, grouped under the terms proprioception, exteroception, and interoception.
2. The processing of this information by the central nervous system.
3. The decision-making for an effective and efficient voluntary movement.
4. The execution of the voluntary motor command to perform the movement.

This may seem complex, but in practice, it boils down to:

1. My eyes see my cup of coffee (my nose smells it;))
2. The brain processes this visual information to assess the distance and exact location of the cup.
3. The brain decides on the precise movement to make to grasp the cup.
4. Activation of the necessary muscles to take the cup of coffee.

The takeaway is that the quality of movement (step 4) depends on the quality of the previous steps.

Definition: a reflex – primitive –

But what about primitive reflexes? We will talk about that a bit later, because to understand a primitive reflex, one must first understand what a reflex is.

A reflex is an involuntary reaction of the nervous system to stimulation of proprioceptive, exteroceptive, or interoceptive receptors. It is an involuntary reflex arc, where certain steps of the sensorimotor loop are not involved. Step 4, the voluntary motor command, is excluded, making the reflex involuntary.

In the context of primitive reflexes, these automatic responses are present from the intrauterine life to ensure the baby’s survival. At this stage, the sensorimotor loop is immature. We will not go into detail about all the reflexes, but if you're interested, feel free to comment to indicate which reflex you would like to explore in a future article.

For example, take the palmar grasp reflex which is developed in our training – the foundations.As its name suggests, it manifests as a closure of the hand upon tactile stimulation. This reflex is adorable in a baby who grips your finger when you place it in their hand.However, in adults, its persistence can lead to involuntary responses when holding an object, such as excessive tension in the hand, forearm, elbow, etc.These involuntary reactions can result in a lack of coordination and precision when using the hand, for example, difficulties in throwing a ball or writing.

Throughout its development, if the baby and child do not sufficiently stimulate the tactile sense of the hand to inhibit this reflex, the nervous system does not have the opportunity to wire and mature. The involuntary character will remain predominant over voluntary action.

The inhibition of reflexes aims to eliminate these movement parasites, to wire the nervous system, and to make each step of the sensorimotor loop more efficient.

Are we required to inhibit and work on these primitive reflexes?

Yes and No.

No, if we work on all sensory information (step 1 of the sensorimotor loop) as well as the following steps..

Yes, to save time. Indeed, these reflexes act like highways of information to quickly calibrate the nervous system. Working on reflexes is like using a "cheat code" in the game of movement. It's a bit like starting a video game with unlimited lives and all the weapons!

The final word

Here we are at 5 minutes!

In summary, a primitive reflex is nothing more than a primitive version of the sensorimotor loop. It is a tool in optimizing movement, a powerful "cheat code" to fully exploit your potential.

P.S.: There is not functional neurology on one side and primitive reflexes on the other; they are the same thing.

That's all from me!

Seb