My 29 year old son recently complained of being sore all over, as though he had had a strenuous workout. The soreness is now gone but his forearms are very weak. He can't grip and his handwriting is very shaky and looks like an elderly person's writing.
He is a truck driver and has always been in perfect health, never taken drugs, never smoked and only drinks a beer on occasion.
It could be several things, but a couple of them might be the following.
When someone complains of being sore all over, it is usually something to do with the muscles. Which could also explain the continued weakness in the forearm muscles.
Certain medications can cause a myelopathy. The most common ones are the statin drugs taken for high cholesterol. If a patient is on one of these medications, and complains of wide spread muscle pain, or their urine looking like ice tea, the medicine should be stopped immediately. As this is an early sign of rhamdomyelitis, a disorder where the muscle fibers break down. That is not the only problem though, because the proteins from the muscle can damage the kidneys.
Another cause of muscle problems is a viral illness. The patient does not have to be ill, like with the flu, to have this problem. Some viruses can attack the muscles, first causing wide spread muscle pain (soreness). If the attack is severe, it can disable certain muscles, causing paralysis or weakness. There is even one type of virus that attacks the muscle of the heart, causing a cardiomyopathy.
So, if the weakness does not resolve within a few days, he should see his physician. Sometimes, the virus's effects only last of few days. But, again, if he doesn't start showing improvement shortly, he should really see his physician.