So what's the relationship between muscles and nerves?
One of the most obvious connection between muscles and nerves is when muscles grow so large (usually because of repeated muscle actions) that they press on a particular nerve.
So for example, painters & decorator or plasterers commonly find that the constant rotation of their arm upwards means that they have a super-sized teres minor muscle on the arm that they use for their job. This gets so big that it presses against the nerve that lies underneath it; that pressure can cause a feeling like pins & needles or even "electric" pains down into the fingers.
Similarly, cyclists with bike's that aren't fitted perfectly can find that there's a slight outward rotation of the hip when they pedal - this can lead to the piriformis muscle at the side of the hip becoming much larger than the space allocated to it - so it impinges on the sciatic nerve and can cause those "electric shock" type pains down into the leg.
Treating this relationship between the muscle and the nerve is relatively straightforward: traditional deep tissue massage on the affected muscle, aggressive assisted stretching and, if possible, removal of the offending repeated movement if possible (pretty tough if it's your job, and pretty expensive it's your bike!).
This relationship between nerves and muscles is, clinically at least, more interesting.
It's the job of nerves to innervate muscles. That is, so send the little electrical impulses to the muscle to tell it to move.
More specifically, around 60% of the nerve ending within muscle fibre is motor fibre: these are the fibres that connect the muscle to the spinal chord and ultimately the brain. When you want to make a movement (like a bicep curl or a step in walking) your brain instructs the nervous system to send a signal along the motor fibres into the relevant muscles, to make the movement happen.
The other 40% of the cells in the nerve endings in muscle are called sensory fibres. The job of these sensory fibres is to send messages back to the brain about the current position of the muscle - it's how the brain knows when to stop sending "move" signals. The sensory fibres also communicate, via the nervous system, when a particular muscle is relaxed.
It's a pretty neat system, but sometimes it can go astray.
In certain situations the "reset" state can become confused - what I mean by that is that if a muscle is kept tight for way too long, then the nervous system will assume that that is the new "relaxed" state. So when the brain instructs the nervous system to stop and return to the relaxed stated, it in turn tells the motor fibres in the muscle to return to the new (faulty) "relaxed" state rather than the genuine relaxed state.
A great example would be the person who's lived with chronic stress. Pretty much all of us show our stress in our body - keeping our shoulders hunched would be a prime example of this (remember the fight-or-flight response). With persistent high levels of stress, this position of shoulders hunched becomes the new "normal." So even when we try to relax, what we relax back to is the new faulty default!
Treating muscles that have become incorrectly set is a bit of an art form - but the emphasis is actually on a range of different techniques. So much so, that I'll save that for next week.
As ever, if you think I can help, give me a call or book yourself in for an appointment online.