You’ve probably noticed that you can tense your muscles and when you are done tensing they relax, but they do not fall into a mush, but into resting tone. I draw on the rev counter of a car engine to illustrate resting tone of muscle. When we return to idle our muscles are said to be in resting tone.
In generalised anxiety or big life change muscle tone can be illustrative of the rev counter of the brain. When you have more going on in life there is more tension held in your body. Increased physical tension doesn’t mean you aren’t coping you may just have a lot on. The opposite is also true. Altered muscular tone can lead to unhelpful movement patterns meaning muscular imbalance is a learned condition just as muscle balance is a learned condition. Not through a conscious intentional memory. More a creep up on you through repetition memory.
When a muscle is in a higher tone or spasm, the movement of body nutrients is affected meaning muscles can’t get food in nor waste out. A physiological cause of muscular aches and joint pains.