A recent study suggested that something as simple as mental stress tests (math test) or eating or other sympathetic nervous system activators can activate the back muscles of people with fibromyalgia. That study suggested FM patients’ muscles could be in state of almost continual activation.
Electrical signals trigger the muscle contractions that people use to produce force but those signals should diminish in between the muscle contractions. Another FM study suggests that the electrical signals in the muscles of FM patients, under load, go into a hyper-active state; and do NOT relax, that the muscles in FM patients are constantly being prodded to contract.
Makes sense, right? WRONG!
If this was correct I should look like this
When I wake up, every one of my muscles feels like it has had a major work-out. When I’ve walked to the post office (less than a block), it feels like I have run a marathon. Just like all of you, my muscles always feel tight and contracted.
I would expect that we were supermen or women in disguise BUT the inability to turn our muscle activity off and allow them to rest suggests our muscles are chronically tensed, not strong.
This continued state of activation left the muscles in a state of something called ‘after-depolarization’. Depolarization simply refers to a change in the electrical status of a membrane. The membrane should switch from positive to negative regularly – allowing electrical currents (ions) to contract, relax, contract, relax, etc. the muscles. In a state of after-depolarization a state of confusion reigns, interrupting that regular pattern of ‘depolarization,’ leaving the membranes in a twitchy, unsettled state.
After-depolarization causes the muscle membrane to send the ‘contract’ message much more easily. Neither of the above studies tell us what is causing this but the ongoing electrical activity/muscle contraction in FM suggests chronically activated systems play a role in our pain.