List of my favourite resources on YouTube to learn anatomy

[vdm]

@Isaiah_40_31

It’s the “plastic” vs “elastic” response of muscles to stretching. When we stretch muscles, we’re using the “elastic” aspect of them but when they return to their usual length its the “plastic” or learned response. It’s thought that the plastic response can be changed through stretching & even through the shortening/lengthening exercise, but it takes persistence & can take a while for this to happen.

I’d guess the “stretch reflex” might be the one that in some cases prevents some chronically tight muscles from being stretched out, i.e. prevents from effectively using the “elastic” capability of the muscle tissue. That’s just a pure observation of bodies under anesthesia and other type of heavy influence, or when someone lost their consciousness - there is not much resistance from the muscles, as opposed to the times when the person is fully conscious.

I.e. like I wrote in one of the posts, Facial palsy with ES? - #11 by vdm

@vdm

Perhaps it’s something simple, like muscles constantly sending intense electrochemical signal to the brain demanding immediate action/reaction to keep the body in balance, eventually overloading the brain and putting the whole body into some sort of fight-or-flight state without any real need.

Perhaps that could possibly explain various effects, like chronically spasmed muscles being unable to properly relax because they (incorrectly) keep receiving signal to “react” (contract) as if there was stretching stimulus present, when it’s not… I don’t really know

It just seems this “stretch reflex” is exactly about which I speculated without knowing its name, as per the article

The stretch reflex and the contributions of C David Marsden

If the brain wished to contract a muscle to a certain length, it commanded the small sense organs in the muscles to react as if they had been already stretched to the intended position. The result would be reflex contraction of the muscle in question, and this meant that the nervous system only needed to specify the end position of any movement. This was the first attempt to explain how the nervous system might achieve accurate control of movements.